Annals Vol 21 (2012)

MICHAEL BURROW 99 TABLE 1 Treatment alternatives based on tooth condition where enough tooth remains for placement of an adhesive restoration. Onlay materials can be either aesthetic (composite or ceramic) or gold. Region Tooth condition Treatment Alternative treatment Posterior teeth No caries or restoration Direct resin composite Onlay Small caries lesion, small –moderate Direct resin composite Onlay Anterior teeth sized restoration Large caries lesion, large restoration, Onlay or overlay – either gold Complete crown non-vital tooth or tooth coloured No caries or restoration Direct composite Ceramic/Composite veneer with resin composite No caries lesion, no restoration but Veneer and direct composite Complete crown labial enamel lost/damaged Small caries lesion, small –moderate Direct composite Ceramic/Composite veneer with sized restoration resin composite Large caries lesion, large restoration, Veneer and direct resin Complete crown non-vital tooth and discoloured composite The table has been modified from Dietschi and Argente, 2011.22 teeth that have been severely worn. One of the common stated it may take 18-24 months in some cases. Occasionally methods, particularly for anterior teeth that have undergone the teeth do not completely erupt into occlusion. However, severe wear is to use the concept originally published by these teeth can easily be modified with the addition of resin Dahl.15,16 His work used cemented cast restorations on the composite. When undertaking such treatment, patients must anterior teeth or a bite-plane type removable appliance to be fully informed and cognizant that there will be a period create an ‘open bite’ in the posterior region. The aim of such when mastication may be difficult until the posterior teeth treatment was to slightly intrude the anterior teeth as well as to erupt back into occlusion. allow the posterior to erupt into occlusion. This then ‘gained’ space in the anterior segments allowing7the placement of The papers by Dietschi and Argente11,22 provides a an aesthetic restoration of some type. With adhesive resin comprehensive overview for the treatment of tooth wear composite materials having been developed to the point of caused by abrasion and erosion. Table 1 outlines their being relatively wear resistant and also having good strength,17 recommendations for restoration based on the amount of they have now superseded the use of metal restorations in tooth loss. Where possible a conservative approach should many cases. A ten-year survival analysis using ‘Dahl’ type be the first option as it would seem this form of treatment can resin composite restorations to treat anterior tooth wear was be quite successful, at least in the short to medium term. It conducted on 26 patients with 283 restorations.18 The median is reversible; restorations can be easily repaired and thus can survival of the restorations was 5.8 years and 4.75 years reduce the cost for patients. Most of the authors reporting for those restorations that required replacement. The study on the restoration of worn teeth also advise the use of a showed that material, incisor relationship and the opposing night guard to assist in prevention of restoration fracture and dentition had a significant effect on survival. Another study reduction of wear. treating the same form of tooth wear with resin composite build-ups in 31 patients with 225 restorations showed that When treating posterior teeth, the use of resin composite major failure requiring replacement was “uncommon within is more likely to be an intermediate step prior to a more the first five years”.19 The median survival of restorations in permanent restoration. Although resin composites have this study was 4 years 9 months, which is little different from improved with respect to wear and fracture resistance, it is the other study. The latter study did show that those patients still an issue for long lasting restorations when considering with a Class II Division 2 occlusion exhibited a higher this patient group.9 Thus it is prudent to consider the failure rate of restorations, whereas Class II Division 1 had placement of metal crowns or an aesthetic material such a higher survival rate. No doubt this relates to the amount of as ceramic or ceramo-metal crowns at some later stage. stress placed on the restorations during function. A further Adhesive and self-adhesive resin cements such as Super recent paper also concluded that hybrid resin composite Bond C & B† or Panavia‡ have now made it much easier to restorations on posterior teeth performed well in cases with prepare very conservative preparations on molars to modify increased OVD in severely worn teeth over time.20 OVD and give the patient a retentive restoration leaving a lot of sound tooth structure. The metal crowns can be either One of the concerns is what occurs when the anterior teeth a gold-based alloy or nickel-chrome. Metal restorations can are built up leaving the posterior out of occlusion. Several be made in thin section, so in the case where OVD may only papers have shown that the posterior teeth can take from 4-6 months to erupt into occlusion whereas the Poyser et al.,21 † Sun Medical, Japan ‡ Kuraray Medical, Japan

100 ATTRITION AND EROSION: RESTORATIVE PLANNING AND PERFORMANCE need a slight increase or the patient is unable to tolerate a 9. Mehta SB, Banerji S, Millar BJ, Suarez-Feito J-M. Current concepts larger change, then these materials are ideal. Where patients on management of tooth wear: Part 4. AN overview of the restorative also have a bruxing component in the wear, then metal techniques and dental materials commonly applied for the management of restorations are excellent due to their wear resistance but tooth wear. Brit Dent J 2012;212:169-77. also they will not wear the opposing dentition.9 Ceramic 10. Freitas AC Jr, Silva AM, Verde MARL, Jorge de Aguiar RP. Oral restorations can be another alternative. However, ceramic rehabilitation of severely worn dentition using an overlay for immediate restorations need bulk and adequate thickness to prevent re-establishment of occlusal vertical dimension. Gerodontol 2012;29:75-80. fracture, can more easily abrade the opposing dentition, and 11. Dietschi D, Argente A. A comprehensive and conservative approach are difficult to repair simply. for the restoration of abrasion and erosion. PArft 1: Concepts and clinical rationale for early intervention using adhesive techniques. Euro J Esthetic This patient group seems to be increasing, hence it Dent 2011;6:20-32. is likely the treatment of the warn dentition will become 12. Kelleher MGD, Bomfim DI, Austin RS. Biologically based restorative more common. It is essential to accurately diagnose the management of tooth wear. Int J Dent 2012;742509, Epub Jan 18. problem and determine the underlying causative factors. A good knowledge of occlusion is essential. Where possible a 13. Zimmerli B, De Munck JD, Lussi A, Lambrechts P, Van Meerbeek B. conservative approach to rehabilitation should be undertaken Long-term bonding to eroded dentin requires superficial bur preparation. by the use of adhesive resin-based materials to ‘rebuild’ Clin Oral Invest 2011, Dec 8 epub. teeth. The use of the traditional type of restoration such as crowns increases loss of tooth structure through prearation, 14. Burrow MF, Tyas MJ. Comparison of two all-in-one adhesives bonded may compromise pulp vitality and is often more difficult to on-carious cervical lesions at 3 years. Clin Oral Invest 2011, July 26, to adjust and repair. It is also essential to maintain constant epub. monitoring of patients after treatment is undertaken to 15. Dahl BL, Krogstad O.The effect of a partial bite raising splint on the circumvent further problems from eventuating. occlusal face height. An x-ray cephalometric study in human adults. Acta Odont Scand 1982; 40:17-24. References 16. Poyser NJ, Porter RW, Briggs PF, Chana HS, Kelleher MG. The Dahl concept: past, present and future. Br Dent J 2005;198:669-76. 1. Bartlett DW, The role of erosion in tooth wear: aetiology, prevention 17. Ferrcane JL. Resin composite- state of the art. Dent Mater 2011;27:29-38. and management. Int Dent J 2005;55:277-84. 18. Gulamali AB, Hemmings KW, Tredwin CJ, Petrie A. Survival analysis of composite Dahl restorations provided to manage localised anterior tooth 2. Arnadottir IB, Holbrook WP, Eggertsson H, Gudmundsdottir H, wear (ten year follow-up). Br Dent J 2011;E9:1-8. Jonsson SH, Gudlaugsson JO, Saemundsson SR, Eliasson ST, Agustsdottir 19. Redman CDJ, Hemmings KW, Good JA. The survival and clinical H. Prevalence of dental erosion in children: a national survey. Community performance of resin-based composite restorations used to treat localised Dent Oral Epidemiol 2010;38:521-6. anterior tooth wear. Br Dent J 2003;194:566-72. 20. Hamburger JT, Opdam NJM, Bronkhorst EM, Kreulen CM, Roeters JJM. 3. Abrahamson TC. The worn dentition – pathognomonic patterns of Huysmans M-CDNJM. Clinical performance of direct composite restorations abrasion and erosion. Int Dent J 2005;55:268-75. for treatment of severe tooth wear. J Adhes Dent 2011;13:585-93. 21. Poyser NJ, Briggs PFA, Chana HS, Kelleher MGD, Porter RWJ, 4. Barlett DW. Retrospective long term monitoring of tooth wear using Patel MM. The evaluation of direct composite restorations for the worn study models. Brit Dent J 2003;194:21103. mandibular anterior dentition – clinical performance and patient satisfaction. J Oral Rehabil 2007;34:361-76. 5. Mehta SB, Banerji S, Millar BJ, Suarez-Feito J-M. Current concepts 22. Dietschi D, Argente A. A comprehensive and conservative approach for on management of tooth wear: Part 1. Assessment, treatment planning and the restoration of abrasion and erosion. Part II: Clinical procedures and case strategies for the prevention and the passive management of tooth wear. Brit report. Euro J Esthet Dent 2011;6:14259. Dent J 2012;212:17-27. Address for correspondence: 6. Van’t Spijker A, Rodriguez JM, Kreulen CM, Bronkhurst EM, Bartlett Prince Philip Dental Hospital DW, Creugers NH. Prevalence of tooth wear in adults. Int J Prosthodont 34 Hospital Road 2009;22:35-42. Sai Ying Pun Hong Kong SAR 7. Mehta SB, Banerji S, Millar BJ, Suarez-Feito J-M. Current concepts [email protected] on management of tooth wear: Part 2. Acctive restorative care 1: the management of localised tooth wear. Brit Dent J 2012;212:73-82. 8. Mehta SB, Banerji S, Millar BJ, Suarez-Feito J-M. Current concepts on management of tooth wear: Part 3. Active restorative care 2: the management of generalised tooth wear. Brit Dent J 2012;212:121-127.

Ann Roy Australas Coll Dent Surg 2012;21:101-102 ENDODONTIC ASSESSMENT: PULPS, PAIN AND PROGNOSIS Paul V. Abbott, BDSc(WA), MDS(Adel), FRACDS(Endo), FPFA, FADI, FICD, FACD* Paul Abbott is Winthrop Professor of Clinical Dentistry and Director of Postgraduate Studies and Research at the School of Dentistry/Oral Health Centre of Western Australia (OHCWA). Pulp, root canal and periapical conditions are the provided they have been taken with appropriate techniques, most common reasons for patients to present to dentists angulations and processing. However, in some cases, other for emergency or urgent management. These conditions imaging techniques may be required - such as computed will be either inflammatory in nature or due to infections, tomography or cone beam volumetric tomography. These can with infections also causing inflamed tissues. In order to be used to assist diagnosis as well as to provide information accurately diagnose such conditions and to then manage them to assess the feasibility of treatment, and at times the tooth’s appropriately, it is essential that dentists have a thorough prognosis. However, the potential benefits and disadvantages knowledge and understanding of the various conditions that (especially radiation levels and costs) must be carefully affect the pulp, the root canal system and the periapical tissues. considered before ordering such images. The popularity Traditionally, many dentists have used vague and misleading or excitement of using new technology should not be the terms to indicate pulp diseases – such as ‘vital’ and ‘non- determining factor; rather the patient’s welfare and whether vital’ pulps. However, these terms are very inaccurate and the imaging is likely to be of benefit should be paramount. meaningless as they do not accurately indicate the state of In many (especially routine) cases, these imaging techniques the pulp (only the presence or absence of blood supply) and do not change the diagnosis or the management required and they do not indicate the management options. For example, therefore they will not be beneficial to the patient. the pulp of a tooth that responds to pulp sensibility tests and is therefore designated as ‘vital’ could have any one of 12 Prior to commencing root canal treatment, it is essential different conditions if a more comprehensive diagnostic that dentists consider the prognosis of the tooth. Most classification is used.1 These 12 conditions require different endodontists, dentists and research studies have focussed management – such as no treatment (e.g., for a clinically on either the technical aspects of treatment or whether normal pulp), caries removal or restoration replacement the periapical tissues heal following treatment. There is (e.g., for acute reversible pulpitis), root canal treatment ample evidence to show that the presence of a periapical (e.g., for acute irreversible pulpitis) or extraction (where radiolucency is a significant factor associated with post- the tooth is not suitable for further restoration). Similarly, operative healing when assessed radiographically.3 It is also a tooth that does not respond to pulp sensibility testing and well-accepted that periapical radiolucencies indicate that was previously designated as ‘non-vital’ could have any one the root canal system is infected and if the bacteria can be of 10 different pulp or root canal conditions which require eliminated from the root canal system, then healing is very different management. In addition to considering the pulp likely to occur.4 The small number of cases that do not heal and root canal conditions, the diagnosis must also include are usually due to persistent intra-radicular infection, a assessment of the periapical tissues, ideally also using a periapical scar, an extra-radicular infection, a periapical true comprehensive diagnostic classification2 that includes all cyst or a foreign body reaction.4 The latter three conditions of the possible tissue changes that can occur throughout require surgical management whilst the first requires re- the life of a tooth. Overall, there are 17 different pulp/root treatment of the root canal system and possibly surgery if canal conditions and 14 different periapical conditions in still no healing. Periapical scars do not require any treatment these two classifications. When diagnosing any tooth, both but they should be regularly reviewed since they usually have tissues must be considered (because the state of the pulp/ the same radiographic appearance as the other conditions and canal determines the periapical condition) and therefore cannot be accurately diagnosed clinically. Notwithstanding there are many permutations and combinations that must be these periapical conditions that can occur in a small number considered. of cases, most teeth will demonstrate healing if adequate anti-bacterial measures are incorporated into the root canal The diagnostic process is extremely important and treatment protocol. Many cases will even heal without the must be followed for every case. It begins with obtaining a root canal treatment being completed – that is, following thorough history which should enable the dentist to formulate an emergency appointment where some initial root canal a provisional diagnosis. Then the clinical examination, pulp treatment is performed along with removing the cause of tests and radiographs should lead to a definitive diagnosis the disease (e.g., caries, cracks, defective restorations) and which should also include an assessment of the cause(s) of the placement of an adequate interim restoration.5 Hence, the disease(s).1,2 Periapical radiographs are usually sufficient root canal treatment is reasonably predictable if scientific to diagnose pulp, root canal and periapical conditions principles are followed. * Presented at the Twenty-first Convocation of the Royal Australasian College The above consideration of prognosis is only concerned of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012 with healing. This is obviously a very important aspect, but a key factor that has been missing in assessing prognosis is

102 ENDODONTIC ASSESSMENT: PULPS, PAIN AND PROGNOSIS the longevity of the tooth. In other words, how long will the involved, an accurate diagnosis and good case selection. tooth remain in the mouth in a stable, healthy and functional The latter can only be predictably achieved following state following root canal treatment and restoration? investigation of the tooth to determine its suitability for root canal treatment and further restoration by removing the This will depend on how long the restoration can prevent existing restorations, caries, cracks and any other cause of the bacteria entering the tooth, whether any other problems diseases. Good case selection will lead to more predictable develop (e.g., caries, cracks, etc.) that allow bacterial treatment outcomes and only teeth with predictable longevity entry into the tooth, and the periodontal status. The latter will be chosen for treatment. is important and can be assessed pre-operatively6 whereas the former two factors cannot be assessed prior to root canal References treatment. The key determinant for these will be the amount and quality of the remaining tooth structure as this will 1. Abbott PV, Yu C. A clinical classification of the status of the pulp and dictate firstly whether the tooth should be restored, secondly the root canal system. Aust Dent J 2007; 52(Suppl 1):S17-31. whether it can be restored, and thirdly what restoration(s) 2. Abbott PV. Classification, Diagnosis and clinical manifestations of can be provided. apical periodontitis. Endo Topics 2004;8:36-54. 3. Ng Y-L, Mann V, Gulabivala K. A prospective study of the factors In order to assess the amount and quality of the tooth affecting outcomes of nonsurgical root canal treatment: part 1: periapical structure, operators need to visualize the tooth itself and not health. Int Endo J 2011;44:583-609. the tooth with a restoration.5,7,8 Hence, all existing restorations 4. Nair PN. On the causes of persistent apical periodontitis: a review. Int need to be removed prior to commencing root canal treatment Endo J 2006;39:249-81. along with all caries, cracks and any other entry point for 5. Jensen AL, Abbott PV, Castro Salgado J. Interim and temporary bacteria.9 Furthermore, it is impossible to determine by restoration of teeth during endodontic treatment. Aust Dent J 2007;52(Suppl clinical and radiographic examination whether an existing 1):S83-99. restoration has marginal breakdown allowing bacterial 6. Setzer FC, Boyer KR, Jeppson JR, Karabucak B, Kim S. Long-term entry. It is also impossible to accurately determine whether prognosis of endodontically-treated teeth: A retrospective analysis of pre- there are cracks and/or caries in a restored tooth without operative factors in molars. J Endod 2011;37:21-5. first removing the restoration.9 Hence, complete removal 7. McDonald A, Setchell D. developing a tooth restorability index. Dent of all possible pathways for bacterial penetration not only Update 2005;32:343-8. removes the possibility of further bacterial contamination during treatment, but it also allows the operator to assess 8. Saunders W. Restoration of the root filled tooth. In: Ørstavik D, Pitt the prognosis and longevity of the tooth far more accurately. Ford T, eds. Essential Endodontology – Prevention and Treatment of This phase of treatment has been called “investigation” of Apical Periodontitis. Oxford: Blackwell Science Ltd, 1998:331-66. the tooth and it should form an integral part of all root canal treatment.5,9 Tooth investigation leads to better case selection 9. Abbott PV. Assessing restored teeth with pulp and periapical diseases since only teeth that are suitable for further restoration will be for the presence of cracks, caries and marginal breakdown. Aust Dent J treated. If the tooth is not suitable for further restoration then 2004;49:33-9. it should be extracted and a prosthesis can be considered. Address for correspondence: In summary, the outcome of root canal treatment can be School of Dentistry, greatly enhanced by understanding the disease processes The University of Western Australia 17 Monash Avenue NEDLANDS WA 6009 Australia [email protected]

Ann Roy Australas Coll Dent Surg 2012;21:103-105 PERSISTENT ENDODONTIC INFECTION - RE-TREATMENT OR SURGERY? Robert M. Love, BDS, MDS, PhD, FRACDS* Robert Love is Professor and Head of Endodontics at the University of Otago School of Dentistry, Dunedin, New Zealand. Abstract Management of a tooth with persistent periradicular disease primarily involves management of persistent intraradicular infection. Conventional endodontic re-treatment is the main modality that will manage this condition although endodontic surgery with or without retreatment is a viable option in cases. Case selection involves an appreciation of the disease aetiology and expected outcomes and consideration of patient, tooth and clinician factors. Both conventional endodontic re-treatment and surgery have high long-term success and survival rates and it has been shown that an endodontically treated tooth with persistent periradicular pathology that can be managed by conventional endodontic re-treatment or surgery and restoration has comparable, and potentially more beneficial, outcomes to treatment options involving tooth loss and rehabilitation, such as an implant supported crown. As such endodontic re- treatment should be the prime treatment modality unless a tooth has reached a stage where these techniques cannot manage ongoing disease and/or structural integrity. Introduction within two years. Importantly Ørstavik also showed that radiographic signs of definite, but incomplete, healing were Persistent endodontic infection is a biofilm disease apparent at one year post-treatment in the majority (89%) usually located within the root canal system that induces an of lesions that subsequently fully healed indicating that inflammatory response in the periradicular tissues leading observation of healing on a radiograph is a strong predictor to the development of the two most common inflammatory of total healing.3 This information may allow a clinician to lesions of the jaws – periapical granuloma and radicular accurately determine the status of a periradicular radiolucent cyst.1 When treatment planning the management of persistent lesion and the ultimate success of the endodontic treatment. endodontic disease a clinician should take into consideration a number of factors. These will be briefly considered. It should be noted that these data are related to the analysis of periapical radiographs. It is likely that new Criteria for Evaluation of Endodontic Outcome technology, such as Cone Beam Computed Tomography will detect the presence of periradicular lesions sooner in a When evaluating endodontic treatment outcome there disease process and for longer in the healing phase due to its are three general criteria that a clinician should consider: higher specificity. As such clinicians will have to be wary in adequate clinical function, histological evaluation, and diagnosing “non-healing” lesions from CBCT imaging. radiographic evaluation. Adequate clinical function relates to the absence of clinical signs of infection for example, Biological Reasons for Persistent Periradicular absence of pain, swelling, draining sinus, and the retention and function of a tooth. These criteria must be met and could Pathology of Endodontic Origin be considered as survival for an endodontically treated tooth. Histological assessment of healing of periradicular Periradicular pathology of endodontic origin is a bacterial tissues is the most demanding criterion and in practical and biofilm disease modulated by the host inflammatory response ethical terms is unable to be determined. However, previous that results in the most common types of lesions of endodontic studies have shown us that a radiographic assessment using origin – periapical granuloma and radicular cyst.1,4 Generally standardized technique and assessment criteria based on the there are three main reasons why periradicular disease normal width and contour of the periodontal ligament space2 persists after endodontic treatment. can accurately determine healing of the radicular tissues,3 and as such radiography is an important tool in assessing Intraradicular Infection outcome. This is characterized by infection within the treated Time-course for Radiographic Evidence of Healing root canal system (root canal space and radicular dentinal tubules) and is the most common cause of persistent disease. It is important to have an understanding of how long It may be associated with a number of factors such as re- healing of periradicular pathology may take in order to infection via coronal microleakage or the presence of determine successful outcome. In general, complete healing residual bacteria that were not eradicated during chemo- of periradicular pathology of endodontic origin may take mechanical instrumentation e.g., due to missed canals, four to five years.2,3 However, Ørstavik3 has shown that inadequate technique, root canal morphology, or therapy approximately half of these lesions may completely heal in resistant bacteria. As such the treatment of choice to remove one year post-treatment and the majority (86%) will heal the cause(s) is conventional endodontic re-treatment. * Presented at the Twenty-first Convocation of the Royal Australasian College Extraradicular Infection of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012 In a small number of cases endodontic bacteria, primarily Propionibacterium spp. and Actinomyces spp, can colonize

104 PERSISTENT ENDODONTIC INFECTION - RE-TREATMENT OR SURGERY? the external surface of an endodontically well-treated root debris). Conventional re-treatment should be considered (usually within areas of cementum/dentine resorption) and in the first instance. However, endodontic surgery alone can sustain an infection.5 Endodontic surgery is required to or in combination with conventional re-treatment may eradicate the cause. However, clinically it is impossible to be the best option particularly if the apical portion detect if this has occurred. of the root canal cannot be gained by conventional re-treatment. As with all treatment modalities, a clinician’s Radicular cyst skill and experience and the use of contemporary materials and techniques must be considered. There are a number of types of lesions that can mimic a periradicular lesion of endodontic origin.1 However, the most Treatment Options common persistent lesions caused by endodontic biofilm are the inflammatory lesions of periapical granuloma and Although conventional endodontic treatment and radicular cyst. Traditionally it has been assumed that a true endodontic surgery are technically possible treatment options radicular cyst will not resolve after conventional endodontic to manage persistent periradicular pathology, clinicians treatment, compared with a bay/apical pocket cyst5 due to the should be confident that they can provide good outcomes cyst “being under its own growth control” and endodontic to a patient. Similarly, if a clinician considers an alternative surgery is required to remove the lesion. However, recently option of extraction and rehabilitation (e.g., removable this has been questioned as it has been shown that radicular partial denture, fixed partial denture, implant supported cysts from teeth with persistent periradicular lesions express crown) rather than retaining a tooth by endodontic means, Toll-Like-Receptor 2 that indicates the presence of a Gram- he/she must be confident that it provides a clear long-term positive bacterial antigen and a host inflammatory response benefit to the patient. to the antigen.6 This suggests that the true radicular cyst may resolve when bacterial stimulation is removed i.e., by It has been shown in rigorous systematic reviews that conventional root canal re-treatment. Further research in this conventional endodontic treatment and restoration of a area is warranted. tooth results in high (> 90%) long-term success and survival rates.7,8 In comparison, tooth extraction and replacement The presence of extraradicular foreign material e.g., with an implant supported crown provides no better survival non-surgical endodontic materials,4 food particles has been rates,7,8 while a fixed partial denture (bridge) offers poorer identified as another cause of persistent periradicular disease5 success and survival rates.7 Clinicians should also take and highlights the concept of maintaining instrumentation into account other considerations on treatment type when within the root canal with no violation of the periradicular treatment planning e.g., single implant supported crowns tissues and providing a coronal seal from exogenous material. require approximately five times more post-treatment interventions compared with endodontically treated teeth.9 Case Selection Similarly, systematic reviews report high long-term In treating persistent endodontic disease the guiding success and survival rates for teeth treated by conventional principle is that conventional re-treatment is the treatment endodontic re-treatment (87%)10 or endodontic surgery of choice as it can provide the best ability to eliminate the (94%)11 similar to fixed partial denture (89%)12 and single primary aetiology of persistent infection i.e., intraradicular implant supported crown (94.5%).13 Additionally, Kim infection. However, other patient, tooth, and clinical factors and Solomon14 undertook a cost-effectiveness analysis of should be considered when choosing the best treatment treatment options and showed that endodontic surgery and option. conventional re-treatment undertaken by either a general dental practitioner or specialist were the most cost-effective Patient considerations (Table 1) also include medical, options (Table 2) i.e., lowest cost treatment with similar anatomical, and aesthetic considerations. Tooth considerations outcome to other options. are primarily focussed on determining whether a clinician can gain access to the whole root canal system and adequately These results indicate that a tooth compromised by any manage the infected root canal system. Management structural or pathological disorder that can be endodontically of the biofilm may be hampered by canal anatomy treated and restored should be the prime treatment option (e.g., intercanal communications, canal location), as it will provide long-term benefits to a patient. Tooth procedural errors (ledge, zip, perforation), or obstructions extraction and replacement e.g., by a fixed partial denture (un-negotiable ledge, posts, canal blockage by materials/ or implant supported crown should only be considered when a tooth has reached “end-stage tooth failure” where a tooth TABLE 1. with a pathological state or structural deficiency continues to exhibit progressive pathological changes and clinical Some patient considerations when treatment planning management dysfunction that cannot be managed by endodontic and of persistent periradicular pathology of endodontic origin. restorative treatment. Consideration No Yes Conclusion extraction re-treatment or Motivation to retain tooth surgery Management of a tooth with persistent periradicular surgery pathology of endodontic origin should follow the principle Motivation to pursue best long- re-treatment re-treatment of optimal elimination of disease aetiology with minimal term outcome re-treatment biological cost. A tooth that can be re-treated by conventional Critical time concerns surgery Critical financial concerns surgery

ROBERT LOVE 105 TABLE 2. Cost-effectiveness of treatment options.14 Ranking General practitioner Specialist 1 Endodontic surgery 2 Endodontic surgery Conventional re-treatment + crown 3 Conventional re-treatment + Conventional re-treatment + crown crown + post/core 4 Conventional re-treatment + Conventional re-treatment + crown crown + post/core + crown lengthening 5 Conventional re-treatment + Conventional re-treatment + crown 6 crown+ crown lengthening + post/core + crown lengthening 7 Conventional re-treatment + Extraction + fixed partial denture crown + post/core + crown lengthening Extraction + fixed partial denture Extraction + single implant crown Extraction + single implant crown re-treatment and/or endodontic surgery offers high long-term 10. Ng YL, Mann V, Gulabivala K. Tooth survival following non-surgical success and is the primary treatment option. root canal treatment: a systematic review of the literature. Int Endod J 2010; 43:171–89. References 11. Setzer FC, Shah SB, Kohli MR et al. Outcome of endodontic surgery: a meta-analysis of the literature—part 1: comparison of traditional root-end 1. Becconsall-Ryan K, Tong D, Love RM. Radiolucent surgery and endodontic microsurgery. J Endod 2010; 36:1757–65. inflammatory jaw lesions-a twenty year analysis. Int Endod J 2010; 12. Tan K, Pjetursson BE, Lang NP et al. A systematic review of the survival 43:859-65. and complication rates of fixed partial dentures (FPDs) after an observation period of at least 5 years. Clin Oral Implants Res 2004; 15:654–66. 2. Strindberg LZ. The dependence of the results of pulp therapy on certain 13. Jung RE, Pjetursson BE, Glauser R et al. A systematic review of the factors. An analytical study based on radiographic and clinical follow-up 5-year survival and complication rates of implant-supported single crowns. examinations. Acta Odontol Scand 1956; 14 (Suppl 21):1-174. Dissertation. Clin Oral Implants Res 2008; 19: 119–30. 14. Kim SG, Solomon C. Cost-effectiveness of endodontic molar 3. Ørstavik D. Time-course and risk analyses of the development and healing retreatment compared with fixed partial dentures and single-tooth implant of chronic apical periodontitis in man. Int Endod J 1996; 29:150-55. alternatives. J Endod 2011; 37:321-5. 4. Love RM, Firth N. Histopathological profile of surgically removed Address for correspondence: persistent periapical radiolucent lesions of endodontic origin. Int Endod J Professor Robert M. Love 2009; 42:198-202. Department of Oral Diagnostic and Surgical Sciences PO Box 647 5. Nair PNR. On the causes of persistent apical periodontitis: a review. Int University of Otago Endod J 2006; 39:249-81. Dunedin New Zealand 6. Desai S, Love RM, Rich A, Seymour G. Toll-like receptor 2 expression [email protected] in refractory periapical lesions. Int Endod J 2011; 44: 907-16. 7. Torabinejad M, Anderson P, Bader J et al. Outcomes of root canal treatment and restoration, implant-supported single crowns, fixed partial dentures, and extraction without replacement: a systematic review. J Prosthet Dent 2007; 98:285-311. 8. Iqbal MK, Kim S. A review of factors influencing treatment planning decisions of single-tooth implants versus preserving natural teeth with nonsurgical endodontic therapy. J Endod 2008; 34:519-29. 9. Doyle SL, Hodges JS, Pesun IJ, Baisden MK, Bowles WR. Factors affecting outcomes for single-tooth implants and endodontic restorations. J Endod 2007;33:399–402.

Ann Roy Australas Coll Dent Surg 2010;20:106-108 TIMING OF IMPLANT PLACEMENT: PLANNING AND PROCEDURES FOR PREDICTABLE CLINICAL AND AESTHETIC OUTCOMES Michael Danesh-Meyer, BDS, MDS(Perio)* Dr Danesh-Meyer is a periodontist who established the Institute of Dental Implants and Periodondontics and the Auckland Clinical Training Centre in Auckland, New Zealand. Abstract The placement of dental implants is dependent on a number of factors relating to both the patient and the site in which implant placement is contemplated. Additionally, there has been a general trend towards immediacy in implant therapy. This paper considers case selection and clinical decision-making and treatment guidelines in cases where immediate implant placement is contemplated. Treatment alternatives, including site preservation, early and delayed implant placement are also discussed. The timing of dental implant placement relative to tooth • Strict patient compliance is required with immediate extraction is dependent on a number of factors relating to loading/ provisionalization both the patient and the site into which implant placement is contemplated. In recent years there has also been much • Can not be undertaken when Guided Bone Regeneration emphasis and a general trend toward immediacy in implant (GBR) is also required due to need for primary soft therapy. The challenge for the clinician is to determine what tissue closure. staging is appropriate for which case. The timing of implant placement relative to the removal of a tooth has been the • Implant site is required to have good bone support, subject of interest since the early 1990s.1-3 good bone density and sufficient bone height apically to allow primary fixation of the implant. Generally, the timing of implant placement can be divided into three main categories: immediate, early and • No significant periapical pathology or apical cyst. late. However, until recently it has been difficult to interpret the literature due to the variation in the definitions of what One of the more intriguing questions relating to constitutes “early” placement with some authors suggesting immediate implant placement in recent years, is whether or this indicates implant placement within weeks of tooth not the placement of a dental implant into a extraction socket extraction and others suggesting a number of months. In will help to preserve and maintain the bone of the socket, 2008, the ITI treatment guide published a comprehensive particularly the labial bone, which has a direct bearing on the overview of what constitutes immediate, early and late aesthetic outcome of the case. Studies involving both animal implant placement. Table 1 represents a modified form of models and clinical work have shown that the placement of the classification proposed for the time of implant placement dental implant into an extraction socket does not prevent loss after tooth extraction. of the bundle bone that constitutes the labial plate and that it will still undergo resorption as part of remodelling post Immediate implant placement extraction regardless of whether or not there is an implant present. This loss of buccal plate is manifest clinically This is where the implant is placed at the same time as through tissue shrinkage and apical settling of the marginal tooth extraction. Case selection is critical and immediate gingival (recession) which can be of concern aesthetically. implant placement should generally be avoided in cases More recent research suggests that if the space between the with a high aesthetic demand and thin gingival biotype labial plate of bone and the implant within the extraction (high aesthetic risk). The advantages of immediate implant socket is augmented with a slowly resorbable allograft, the placement are as follow: negative effects of labial plate bone loss on gingival recession and the subsequent aesthetic result can be minimized.4,5 • Reduced treatment time with fewer surgical appointments. Early Placement • No need for transitional removable/fixed prosthesis In cases where immediate implant placement is not where an immediate provisional crown in provided. indicated, post tooth extraction early placement may be indicated. Acute periapical infection, high aesthetic cases, • Immediate aesthetics and function (with immediate insufficient apical bone/poor bone density and proximity provisionalization) of anatomical structures (maxillary antrum, mental nerve, inferior alveolar nerve) may all preclude immediate implant The main disadvantages of immediate implant placement placement. Early placement refers to implant placement 4-8 include: weeks after tooth extraction. It allows for primary soft tissue healing over the extraction site. Early placement carries a • More clinically demanding (higher level of surgical lower aesthetic risk relative to immediate implant placement. and prosthetic skill). Early implant placement is often undertaken in conjunction with simultaneous GBR. The success of GBR in these cases • Higher aesthetic risk especially in thin Biotype cases. is greatly enhanced by the relative ease of primary soft * Presented at the Twenty-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012

MICHAEL DANESH-MEYER 107 TABLE 1 Classification Descriptive terminology Period after tooth Desired clinical situation extractions at implant placement TYPE 1 Immediate placement Immediate Nil Fresh intact extraction site TYPE 2 Early placement with soft Typically 4 to 8 weeks Post extraction with soft Early tissue healing tissue healing no bone healing Type 3 Early placement with partial Typically 3-4 months Post extraction with healed Early bone healing soft tissue & significant 6 months or longer after bony healing Type 4 Late placement extraction Complete osseous healing Late post extraction. Adapted from ITI treatment guide, Vol. 3.Quintesence Publishing, 2008. tissue closure. Early placement still allows for a reduced onlay grafting (autogenous or allograft) or GBR with bone treatment time relative to late placement and also provides particulate and GTR membranes may be used to reconstruct sufficient time to allow for resolution of any pre-existing the alveolar ridge prior to implant placement. Grafting the apical pathology infection following tooth extraction. maxillary antrum using a lateral wall approach has also Recent retrospective and prospective clinical studies suggest shown to be very effective and predictable at increasing favourable and predictable aesthetic outcomes following vertical bone height in the posterior maxilla, thereby assisting early placement protocols.6,7 in implant installation. In recent years, socket grafting has also led to the Summary development of site preservation and represents a form of early placement. Grafting the extraction socket has been show Each of the abovementioned treatment approaches are to maintain ridge height and width and reduced soft tissue valid options in clinical practice depending on the presenting collapse post extraction. Materials and techniques proposed condition of the case. A recent Cochrane systematic review in the literature vary widely, but the general consensus is that comparing the outcomes of these different treatments a slowly resorbing fine particulate xenograft or allograft is concluded that there was no strong evidence that one the most appropriate material to be used. Recent pre-clinical placement method was significantly better that another. This and clinical research suggest a real place for socket grafting study also pointed out the fact that it was difficult to draw in clinical practice and it is also very helpful in cases where any strong conclusions as most of the studies reviewed had implant placement may be deferred for a extended period of low power and exhibited bias. Despite the limitations, the time to help maintain ridge form.8,9 authors suggested that immediate implant placement may have a higher risk of failure and complications (including Late placement aesthetic) compared with later placement. But they also commented that overall aesthetic results may be enhanced Severe trauma, significant infection or pathology or by placing implants soon after tooth extraction.10 close proximity of the maxillary antrum can leave implants sites with so little residual bone that implant placement is References not possible unless site development is undertaken. GBR can be undertaken in conjunction with implant placement in 1. Wilson TG, Webber HP. Classification of and therapy for areas of some cases where there is still a reasonable amount of basal deficient boy housing prior to dental implant placement. 1993;IJPRD bone remaining to allow for good primary implant fixation. 13:451-8. However, in cases with severe underlying bone loss, GBR may be required prior to implant placement. This results in 2. Mayfield L. Immediate delayed and late submerged and transmucosal multiple surgical treatments and a protracted treatment time implants. In: Lang NP, Karring T, Lindhe J, eds. Proceeding of the Third in most cases. European Workshop on Periodontology Implant Dentistry. Berlin: Quintessence, 1999:520-34. A staged surgical approach also allows for more opportunity to correct complex hard and soft tissue defects, 3. Chen ST, et al. Immediate or early placement of dental implants through the possibility of multiple GBR procedures and following tooth extraction: review of biologic basis, clinical procedures and through the use of connective tissue grafting (CTG) to outcomes. Int J Oral Maxillofac Implants 2004;19:Suppl. 12-25. increase the quality and quantity of gingival tissue over an implant site. In cases with severe bony defects either block 4. Araujo MG, et al. BioOss collagen in the buccal gap at immediate implants: a 6 month study in dogs. COIR 2011;22:1-8. 5. Kan JY, et al. Facial gingival tissue stability following immediate implant placement and provisionalization:2-8 year follow-up. Int J Oral Maxillofacial Implants 2011;26:179-88.

108 THE TIMING OF IMPLANT PLACEMENT 6. Buser D, et al. Early implant placement with simultaneous GBR Address for correspondence: following single tooth extraction in the aesthetic zone. Retrospective study. Institute of Dental Implants and Periodontics J Periodontol 2008;79:1773-9. Level 4, 142 Broadway Newmarket 7. Buser D, et al. Early implant placement with simultaneous GBR Auckland 1023 following single tooth extraction in the aesthetic zone. Prospective study. J New Zealand Periodontol 2009;80:152-61. [email protected] 8. Araujo MG, Lindhe J. Ridge preservation with the use of BioOss collagen: a 6 month dog study. COIR 2009;20:433-40. 9. Darby I, et al. Ridge preservation techniques for implant therapy. Int J Oral Maxillofac Implants 2009;24(suppl):260-71. 10. Esposito M, et al. Timing of implant placement after tooth extraction: immediate, immediate-delayed or delayed implants. A Cochrane systematic review. Eur J Oral Implantol 2010;3:189-98.

Ann Roy Australas Coll Dent Surg 2012;21:109-110 IMPLANT COMPLICATIONS: RISK EVALUATION, DIAGNOSIS, MANAGEMENT AND OUTCOMES Gregory G. Peake MDSc, FRACDS* Dr Peake is a periodontist practising in the ACT. His practice is limited to implant surgery and associated procedures. Abstract Dental implants and their restorations have become an accepted and predictable modality of treatment. The literature reflects excellent long-term survival rates. However, survival of an implant does not necessarily translate to success, and in between these two outcomes lies the world of implant complications. Complications associated with dental implants occur with both the restorative and surgical components, with the restorative component complications being more frequent and to some extent, more easily managed. Surgical complications are difficult to manage, and can be the result of many aspects of the implant surgery. Potential complications can arise from poor planning, poor case selection, and poor execution. Complications can also occur where no technical or surgical errors are apparent, but where biology and the fundamental flaw of the trans-mucosal design of dental implant prostheses, adversely affects the outcome. This presentation outlines the nature of potential complications and looks at practical and pragmatic methods, first to try to prevent complications, through improved case selection and execution; secondly, it discusses the most effective methods to prevent complications in implants already installed, by adequate maintenance programmes. Lastly, it deals with those cases which require clinical management of the complications. This presentation provides the clinician with a greater understanding of the difficulties in managing implants that are not progressing as we, the clinicians, and the patients, had originally expected. Dental implants and their associated restorations more often than complications with the implants.5 This is have become a widely used treatment modality. A recent somewhat comforting. Managing restorative complications retrospective study1 of 511 titanium implants with a is often less invasive and clinically can give a good outcome. sandblasted and acid etched surface indicated a survival rate of 98.8% after 10 years. This patient cohort was partially In assessing implant complications in this presentation, edentulous and restoration consisted of single crowns and we will look at risk evaluation, diagnosis, management and fixed bridges. The reported success rate in this study, also outcomes. at 10 years was 97%. This reported success rate is high and, in contrast with a number of other studies.2,3 These other Risk evaluation studies show a gap between the survival rate and the success rate of dental implants. Success has been defined as ‘the For accurate assessment of risk, we can apply the 3P element (implant or reconstruction) is present at the follow- principle, to assess: up examinations and complications are absent’.4 Survival is defined as ‘the element (implant or reconstruction), is The Practitioner present at the follow-up examination, but its condition is not specified’.4 Surgical placement of dental implants can sometimes be quite straight-forward. Very often the surgery can be very The wide use of implant survival as a measure of a challenging. An escalation of difficulty can occur quickly, positive clinical outcome is misleading because no clinical if each stage of the surgical procedure is not performed factors are assessed in survival rates, apart from the absolute adequately. Disasters in dental implant surgery are rarely presence or absence of the implant. Whilst survival rates the result of one catastrophic incident, but usually the result accurately reflect implant attachment, they do not give us of smaller complications, not adequately assessed, and a true picture of the clinical situation of the implant or the addressed at the time. Similar outcomes are often noted complications which may have occurred or are occurring, or in general aviation. Accidents occur when multiple small the treatment that may have been necessary to deal with any errors go uncorrected and contribute to an adverse outcome. complications. The measure of implant success and details The importance of adequate surgical training and surgical of clinical complications is a more accurate reflection of the prudence cannot be over-emphasized. health of dental implants. The Procedure Implant complications seem to occur frequently. Complications with the restorations on implants will occur The use of the SAC treatment planning guide, developed by the ITI is a useful tool for classifying the degree of the * Presented at the Twenty-first Convocation of the Royal Australasian College difficulty of a surgical or restorative implant procedure. A of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012 clinician should progress from straight-forward to advanced and then to complex, when satisfactory outcomes of a number of implants at each level are performed successfully by the practitioner.

110 IMPLANT COMPLICATIONS: RISK EVALUATION, DIAGNOSIS, MANAGEMENT AND OUTCOMES The Patient implants for five years following surgery, debridement and antibiotic therapy. Seven of the 26 implants studied were Patient related risk factors need to be considered. lost due to peri-implantitis at or before the five year follow- Liddelow and Klineberg6 reviewed some of the relevant up, indicating ongoing progression of the disease, despite literature in their review paper and indicated that there was surgical intervention. good evidence for increased risk of failure of implants for smokers, patients with a history of radiotherapy and where Summary local bone quality and quantity was compromised. Weaker evidence exists for those with a history of periodontitis, and Dental implants provide a reliable modality of treatment, patients who had taken bisphosphonate medications. This but complications are frequent and biological complications, paper also suggested that there is a correlation between particularly peri-implantitis are poorly managed. Rocusso genetic traits and disruption of osseointegration. Mayfield et al.13 summarized our current dilemma as ‘the approach and Huynh Ba indicated increased risk of peri-implantitis in smokers and those suffering from chronic periodontitis.7 for multiple preventive dental extractions and implant Diagnosis placement, based on the assumption that implants perform The literature indicates that technical complications better than teeth, should be followed with extreme caution’.’ will occur more frequently than biological complications in implant supported restorations. A supportive programme, References involving regular scheduled examination should occur for every implant. A successful implant should be treated in the 1. Buser D, Janner S, Wittneben J-G, Brägger U, Ramseier CA, Salvi same was as a periodontally compromised tooth. Regular GE. 10 year survival and success rates of 511 titanium implants with a reviews of each implant should involve; sandblasted and acid-etched (SLA) surface: A retrospective study in 303 partially edentulous patients. Clin Implant Dent Relat Res. Accepted for [i] pocket depth recording publication 2012. [ii] radiographic assessment 2. Fransson C, Wennstrom J, Berglund T. Clinical characteristics of implants with a history of progressive bone loss. Clin Oral Implants Res [iii] bleeding on probing and suppuration assessment 2008;19:142-7. [iv] occlusal assessment of fixed restorations 3. Koldsland OC, Scheie AA and Aass Am. Prevalence of peri-implantitis related to severity of the disease with different degrees of bone loss. J Perio [v] implant-specific plaque control instruction. 2010;81: 231-8. Management 4. Taylor T, Buser D. Proceedings of the third ITI Consensus Conference. Int J Oral Maxillofac Implants 2004 19. Suppl. The management of complications is case-specific. Papaspyridakos et al.8 followed 281 implant-supported 5. Pjetursson B, Tan K, Lang N, Bragger U, Egger M, Zwahein M. A complete dental prosthesis. Their conclusions indicated that systemic review of the survival and complication rates of fixed partial large percentages of the restorations had complications, dentures (FPD’S) after an observation period of at least 6 years. Clin Oral with only 8.6% of restorations being complication-free at Implants Res 2004;15:625-42. 10 years post-placement. The most significant biological complication for dental implants in the longer term, is peri- 6. Liddelow G, Klineberg I. Patient related risk factors for implant therapy. implantitis, with high rates reported. Fransson et al.2 reported A critique of pertinent literature. Aust Dent J 2011;56:417-26. peri-implantitis rates at 28%. Koldsland et al.3 at 47% and Zitzmann and Berglundh9 had rates of greater than 56%. 7. Mayfield L, Huynh Ba G. History of treated periodontitis and smoking Buser1 in his recent study indicated a rate of peri-implantitis as risk factors for implant therapy. Int J Oral Maxillofac Implants 2009;24:7 at 10 years at 1.4%. The current controversy and variability Suppl. in reported rates does appear to be related to the definition of peri-implantitis, with Buser et al.1 requiring suppuration to be 8. Papaspyridakos P, Chen GJ, Chuang SK, Weber HP, Galluci C. A included as a defining characteristic, whereas other authors systemic review of biological and technical complications with fixed used only increased probing pocket depths and bleeding on implant rehabilitations for edentulous patients. Int J Oral Maxillofac probing. A useful tool in the management of peri-implantitis Implants 2012;27:102-10. was developed by Lang et al.10 and established as a formalized treatment protocol for the varying clinical health of the peri- 9. Zitzmann N, Berglundh T. Definition and prevalence of peri-implant implant tissues. The Cumulative Interceptive Supportive diseases. J Clin Perio 2008; 35: Suppl 286-91. Therapy model is easily applied to all implants. 10. Lang N, Berglundh T, Heitz-Mayfield L, Ptejursson B, Salvi G, Sanz Outcomes M. Consensus statements and recommended clinical procedures regarding implant survival and complications. Int J Oral Maxillofac Implants 2004;19: Outcome data for implants affected by peri-implantitis Suppl. are limited. Only two papers are noted, with differing outcomes. Heitz Mayfield et al.11 followed 36 implants in 24 11. Heitz-Mayfield L, Salvi G, Mombelli A, Faddy M, Lang N. Anti- patients. One hundred percent survival was recorded at 12 infective surgical therapy of peri-implantitis. A 12 month prospective months, following treatment which involved plaque control clinical study. Clin Oral Implants Res 2011; 23: 205-10. instruction, antibiotics, open flap debridement and regular reviews. Leonhardt et al.12 followed peri-implantitis affected 12. Leonhardt A, Dahlen G, Renvert S. Five year clinical, microbiological and radiological outcome following treatment of peri-implantitis in man. J Perio 2003;74:1415-22. 13. Rocozzo M, Bonino F, Marco A, Paolo D. Ten year results of a three arms prospective cohort study on implants in periodontally compromised patients. Part 2: Clinical results Clin Oral Implants Res 2012;23:389-95. Address for correspondence: Canberra Implant and Periodontal Centre 203 North Point Plaza 8 Chandler Street Belconnen ACT 2617 [email protected]

Ann Roy Australas Coll Dent Surg 2012;21:111-112 THE IMPACTED CANINE – AN ORTHODONTIC PERSPECTIVE David P. Madsen DP, BDS DClinDent MOrthRCS MRACDS* Dr Madsen received his Bachelor of Dental Surgery at the University of Sydney and received a Doctor of Clinical Dentistry (Orthodontics) from the University of Adelaide. He holds memberships with the Royal Australasian College of Dental Surgeons and the Royal College of Surgeons of Edinburgh in Orthodontics and is in private specialist practice. ABSTRACT The impacted canine is relatively common in incidence and can often lead to difficult treatment planning decisions. Cone Beam Computed Tomography (CBCT) imaging has improved diagnosis and treatment planning of impacted canines. In particular, this technology has allowed the clinician to accurately locate and visualize these teeth better than ever before, as well as greater appreciate the degree of damage to neighbouring teeth such as lateral incisors. Improved diagnosis and treatment planning with CBCT has therefore resulted in improved treatment outcomes. The objective of this presentation will be to cover the incidence, complications and management of impacted canines from an orthodontic perspective. Impacted canines are commonly cited as occurring in 1% of the population. Complications of impacted canines include root resorption and devitalization of the adjacent lateral incisor, ankylosis, cyst formation and prolonged retention of the deciduous canine. Interceptive management of impacted canines may include the removal of the deciduous canine. Management of impacted canines also include either their removal or orthodontic movement into their correct position. Introduction retention of the deciduous canine, absence of a canine bulge of palpation of the buccal alveolus, a palpable canine bulge Impacted teeth can be defined as those teeth that are ectopically such as palatally, and excessive distal tipping of delayed in eruption or that are assessed as unable to erupt the adjacent maxillary lateral incisor.6 spontaneously. Maxillary canines are the second most frequently impacted teeth in the dental arch after third Radiographic evaluation of an impacted canine usually is molars.1 The diagnosis and treatment of this problem is performed with a panoramic radiographic view. Localization often challenging, requiring a multi-disciplinary approach to of the canine can be determined with periapical radiographs treatment planning and management. with a tube shift technique or more recently with a CBCT. In addition to accurate localization, CBCTs allow for the clear Incidence, Aetiology and Complications assessment of external root resorption in neighbouring teeth. The maxillary impacted canine is reported to occur Treatment Options between 0.9% and 3% of the general population.1-3 They are twice as common in females compared with males4 and The decision to treat a developing impacted canine may the unilateral:bilateral occurrence is 5:1.2 In 61% of canine be based on a patient’s age, position of the impacted canine, impactions, the tooth is located palatally in the dental arch.5 condition of the retained deciduous canine, the presence of Mandibular canine impaction is less common occurring in pathology such as resorption and ultimately, the patient’s 0.35%.2 preference for treatment. If the decision is made to not treat, then periodic follow up is required to assess the presence of The most common causes of impacted canines relate developing complications. to local factors such as crowding, prolonged retention or early loss of the deciduous canine, ectopic position of the Interceptive treatment of a developing impacted canine tooth bud, presence of an alveolar cleft, ankylosis, cystic may improve its eruption path. It has been shown that or neoplastic formation, or dilacerations.6 Other possible interceptive removal of a retained deciduous canine could factors may involve the guided eruption of the canine by the improve the angulation and eruption path of an ectopic canine lateral incisor7 or genetic factors.8 in 78% of cases.11 The likelihood of improved angulation was correlated to age of the patient (≤ 11 years) and the degree A number of complications may arise from an impacted of overlap of the canine over the root of the lateral incisor in canine such as displacement of neighbouring teeth, internal radiographs. The rate of angulation improvement was 91% resorption, cyst formation, referred pain.9 The most for canines that overlapped less than half the lateral incisor significant complication is the external root resorption of the root, and 64% for those that overlapped more than this (Fig. adjacent teeth which is very common (48%) in ectopically 1). erupting maxillary canines.10 Surgical exposure of an impacted canine is a common Diagnosis treatment option most commonly performed in combination with orthodontic treatment to move the impacted tooth into The clinical features of an impacted canine may include the dental arch. This can be performed as an open or closed delayed eruption of the permanent canine, prolonged exposure with or without a bonded attachment placed at the time of surgery. Predictability of achieving the desired * Presented at the Twenty-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand, 31 March -4 April 2012

112 THE IMPACTED CANINE – AN ORTHODONTIC PERSPECTIVE Fig. 1. – Normalization rate after interceptive removal of deciduous delicate surgical removal and temporary placement in the canine.11 sulcus during bone healing. Subsequent site preparation, tooth insertion and fixation are performed. Anecdotally the treatment outcome is an important consideration when failure rate of this option is high, however some published selecting this treatment option. The advantage of surgical data are more promising finding an 83% survival rate and exposure and orthodontics is that the ideal occlusion, 38% success rate over a 14 year follow up.13 aesthetics and function can be achieved. The risks are that orthodontic treatment is often prolonged, iatrogenic root Conclusions resorption may occur (particularly to the adjacent teeth), gingival recession may occur on the impacted canine, and Impacted canines are a common dental anomaly with on rare occasions there may be ankylosis of the exposed the potential to cause a number of complications. Early canine.12 diagnosis is important in achieving improved outcomes through interceptive removal of deciduous canines. Clinical Surgical removal of an impacted canine can also examination including the palpation of canines will aid the be considered. Indications for removal may include diagnostic process. Radiographic examination including severe displacement of the canine (beyond the scope of CBCTs aid localization and treatment planning. The main orthodontic movement), root resorption or dilaceration treatment options for impacted canines are surgical exposure of the canine, anticipated poor patient compliance with and orthodontics or surgical removal. orthodontic treatment, acceptable position and prognosis of the adjacent first premolar or pathology associated with References the impacted canine. The advantage with surgical removal is that orthodontics may be avoided or treatment time may 1. Shah RM, Boyd MA, Vakil TF. Studies of permanent tooth anomalies be reduced. The disadvantages are that the adjacent teeth in 7886 Canadian individuals. J Can Dent Assoc 1978;44:262-4. may be damaged during removal, the first premolar may 2. Dachi SF, Howell FV. A survey of 3874 routine full mouth radiographs. not perform as an ideal replacement for the canine, or the Oral Surg Oral Med Oral Path 1961;14:1165-9. canine may need to be replaced with a prosthetic tooth. In 3. Zahrani AA. Impacted cuspids in a Saudi population. Egypt Dent J such circumstances, the deciduous canine may be kept if its 1993;39:367-74. prognosis is deemed adequate. 4. Ericson S, Kurol J. Radiographic assessment of maxillary canine eruption in children with clinical signs of eruption disturbances. Eur J Autotransplantation of the impacted canine is a less Orthod 1986; 8:133-40. common treatment option. This initially involves that 5. Stivaros N, Mandall NA. Radiographic factors affecting the management of impacted upper permanent canines. J Orthod 2000;27:169- 73. 6. Bishara SE. Impacted maxillary canines: a review. Am J Orthod Dentofacial Orthop 1992;101:159-71. 7. Becker A. In defence of the guidance theory of palatal canine displacement. Angle Orthod 1995;65:95-8. 8. Peck S, Peck L, Kataja M. The palatally displaced canine as a dental anomaly of genetic origin. Angle Orthod 1994;64:249-56. 9. Shafer WG, Hine MK, Levy BM. A textbook of oral pathology. 2nd ed. Philadelphia: WB Saunders, 1963:2-75. 10. Ericson S, Kurol J. Resorption of lateral incisors after ectopic eruption of maxillary canines: a CT study. Angle Orthod 2000;70:415-23. 11. Ericson S, Kurol J. Early treatment of palatally erupting maxillary canines by extracting of primary canines. Eur J Orthod. 1988;10:283-95. 12. Boyd RL. Clinical assessment of injuries in orthodontic movement of impacted teeth. Am J Orthod 1982;82:478-85. 13. Patel S, Fanshawe T, Bister D, Cobourne MT. Survival and success of maxillary canine autotransplantation: a retrospective investigation. Eur J Orthod 2011;33:298-304. Address for correspondance 1st Floor, 27 Bougainville Street Manuka ACT 2603 [email protected]

Ann Roy Australas Coll Dent Surg 2012;21:113-119 THE APPLICATION OF SKELETAL ANCHORAGE IN THE CORRECTION OF ANTERIOR OPEN BITE AND SKELETAL CLASS III MALOCCLUSION: A PARADIGM SHIFT Nour Eldin Tarraf, BDS(Hons), MDSc(Hons), MRACDS(Ortho), MOrth RCSEd* Dr Tarraf is an orthodontist in private practice in Sydney and is a PhD candidate at the University of Sydney in the Department of Orthodontics. Abstract In recent years orthodontic treatment has been revolutionized by the introduction of skeletal anchorage or temporary anchorage devices (TADs). Many malocclusions, which have been previously only treatable through orthognathic surgery, such as skeletal open-bites, can now be managed non-surgically with less biological cost to the patient. Furthermore the recent application of TADs in the treatment of growing skeletal Class III patients is not only minimizing the need for obtrusive appliances, such as head gear and face masks, but it is also proving to deliver better and superior results to conventional growth modification protocols with more patient acceptance and less need for compliance. This overview covers the applications of TADs in the treatment of skeletal open bites and skeletal Class III malocclusions with reference to current evidence and clinical case presentations. Introduction to Mizrahi.4 Skeletal open bites5 can be defined as a deviation from the normal vertical relationship of the maxillary and Temporary anchorage devices have steadily made their mandibular dental arches. The reason for the lack of contact way into mainstream orthodontics over the past decade. is a deviation in the orientation of the basal bones of the Although there have been sporadic reports in the literature maxilla and mandible in relation to each other,6 and it can previously1.2 it is only recently that the use of skeletal be present combined with a dual occlusal plane. In many anchorage has made its way into becoming an everyday cases it is associated with the facial features of the long face part of orthodontic practice. Cope in 20073 defined them: syndrome.7 “(TAD) or a temporary anchorage device is a device that Although the aetiology and features of open bite can be is temporarily fixed to bone for the purpose of enhancing variable, traditionally skeletal open bites have been corrected by restricting the vertical development of the molar segment, orthodontic anchorage by supporting the teeth of the usually in a growing child, or by attempting to intrude the molar segment. This usually employed obtrusive appliances reactive unit or by obviating the need for the reactive unit utilizing extra-oral anchorage such as high-pull headgear8 (Fig. 1a), vertical pull chin cups9 or the use of acrylic bite altogether and which is subsequently removed after use blocks.10,11 In many cases the results were limited by patient .” They can be divided into two main groups: anchorage compliance and the difficulty in continuous wear of such plates and miniscrews. Anchorage plates usually involve devices due to their interference with the patient’s daily the elevation of a flap and a surgical plate is secured to the activities and social interactions. In most adults surgical bone using two or more screws with an attachment point for impaction of the maxilla was the treatment of choice. The force application protruding through the mucosa into the treatment usually aimed to intrude the posterior maxillary oral cavity, whereas mini-screws are usually single titanium segment thus allowing mandibular auto-rotation resulting in screws placed transmucosally and in the majority of cases do anterior tooth contact and closure of the open bite. Full fixed not require any flaps or incisions. In both cases the TADs are appliances with intermaxillary elastics12 and/or extractions13 removed after treatment. have also been advocated although the treatment camouflaged the skeletal discrepancy through dental movements rather The indications for use of TADs in orthodontics are than addressing the skeletal aspect, which sometimes results numerous and it can be said they have introduced a paradigm in less than ideal facial aesthetics. shift in orthodontics greatly expanding the horizon of what is achievable through orthodontic treatment for both With the introduction of skeletal anchorage using adults and children. In many cases they may preclude the TADs as a point of force application, molar intrusion the need for orthognathic surgery. This can be seen in the can be achieved reliably using intraoral and compliance management of skeletal anterior open bite and skeletal Class free orthodontic mechanics. The molar intrusion allows III malocclusions. mandibular autorotation and closure of the open bite without the need for extra oral devices or surgical maxillary Anterior Open bite treatment with skeletal anchorage impaction. This can be done through maxillary molar intrusion, mandibular molar intrusion or a combination of Anterior Open bite malocclusion has always been both. The first published reports on molar intrusion used considered one of the more difficult ones to treat in anchorage plates, fixed to the buccal cortical bone around orthodontics. It is present “where the upper incisor crowns fail to overlap the incisal third of the lower incisor crowns when the mandible is brought into full occlusion” according * Presented at the Twentiy-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012

114 SKELETAL ANCHORAGE IN THE CORRECTION OF ANTERIOR OPEN BITE TABLE 1 Cephalometric analysis (Sydney-Geneva). Most of the vertical parameters highlighted in bold font indicate skeletal open bite patterns. Fig. 1. – Extra-oral anchorage a. High Pull Head Gear b. Face Mask or Parameter Norms Value Reverse Pull Head Gear (RPHG). SNA* 82 ± 4º 74.6º SNB† 79 ± 2º 69.9º the apical regions of the lower first and second molars on ANB‡ 2.6 º ± 2.4º (4.7º) both the right and left sides, to intrude mandibular molars for 64 % 57.9% open bite correction.14 This was followed by several reports S-Go’/ N-Me (J%)§ 45%, 55% 42.1%, 57.9% on maxillary molar intrusion using anchorage plates placed N-ANS / ANS-Me¶ 8 ± 2º 12.8º in the zygoma.15,16 In all cases the result was successful 23 ± 4º closure of the anterior open bites. With mini-screws gaining SN-PP** 31 ± 3º 35.7º popularity several studies successfully used them as TADs PP-MP†† 15 ± 3º for molar intrusion in open bite treatment17-19 with placement SN-MP‡‡ 122 ± 4º 48.4º locations varying from buccal, palatal and combinations SN-OP§§ 68 ± 4º of both. Mini-screws offer the advantage of being simpler Gonial angle 7.8 ± 2.4º 24.5º to insert and remove with less surgery involved compared Y axis¶¶ 130 ± 4º 129.7º with surgical plates. Overall the amount of molar intrusion SN-FH*** 0±2 79.5º reported varied between 3-5 mm in a treatment duration SN-Ba††† 103 ± 7º 13.6º of 4-10 months depending on the study.14-19 Almost all Witz ‡‡‡ 111 ± 6º 128.2º of the studies report successful closure of the open bites 1/-SN §§§ 92 ± 9º with various degrees of mandibular auto rotation of 1.7-4 134 ± 13º 3.4 degrees.14-18 1/-PP 1-3 mm 94.2º /1-MP¶¶¶ 1-3 mm 106.9º In a recent prospective clinical study at the University of 88.8º Sydney, Foot et al.20 treated 16 patients with anterior open 1/1 128.6º bites using mini-screws and a specially designed intrusion Overjet spring (the SIS Sydney Intrusion Spring). The SIS aims to Overbite 5.9 provide a specifically designed force application mechanism -2.5 that is both hygienic, easy to use and does not require frequent reactivation to minimize patient discomfort. The * SNA: SN for Sella –Nasion the line represents the anterior cranial base open bite was corrected in all subjects in a period of 4.9 and A for (A-point) the anterior limit of the maxillary base. The angle months on average with a mean molar intrusion of 2.9 ± denotes the relationship between the maxilla and the cranial base in the 0.8 mm resulting in a 1.2° ± 1.3° counterclockwise rotation antero-posterior plane. of the mandible. There was also an effect to elongate and † B is B-point for the anterior limit of the mandibular base and SNB is the upright the upper incisors with no significant extrusion of angle denoting the relationship between the mandible and the cranial base the lower molars. The authors concluded that the SIS used in the antero-posterior plane. in conjunction with TADs is an effective means of correcting ‡ ANB the angle denotes the relationship between the maxilla and mandible anterior open bites. in the antero-posterior plane. § S-Go’/N-Me (J%) ratio between Sella-Gonion, distance denoting posterior The long-term stability of open bite correction reported face height, and Nasion-Menton, the distance denoting the anterior face in the literature is very variable with some degree of relapse height. expected regardless of the treatment modality. With traditional ¶ N-ANS/ANS-Me ratio between upper anterior face height and lower orthodontic mechanics21 relapse was reported in up to 33% anterior face height where ANS is anterior nasal spine. of cases while others have reported negligible relapse.22 ** SN-PP angle between the cranial base line and PP palatal plane. Proffit et al.23 examined surgical treatment results up to 3 †† PP-MP angle between mandibular plane and palatal plane. years post treatment and reported a 10% chance a patient ‡‡ SN-MP angle between cranial base line and mandibular plane usually a will have 2-4 mm relapse in the overbite. They speculated it strong indicator of the vertical skeletal pattern. § §SN-OP angle between anterior cranial base line and occlusal plane. ¶¶ Y axis angle between Frankfurt Horizontal plane and Sella-Gnathion line is a good indicator on the vertical skeletal pattern. ***SN-FH angle between anterior cranial base and Frankfurt horizontal plane. ††† SN-Ba cranial base angle (between anterior and posterior cranial base). ‡‡‡ Witz appraisal denotes the antero posterior relationship between maxilla and mandible as evident on the occlusal plane. §§§ 1/-SN upper incisor angle to the cranial base. might be due to incomplete adaptation of the tongue posture to the correction. Molar intrusion with TADs as treatment for open bites is a relatively new treatment modality, therefore there is little published literature on the long-term stability of the correction. The most comprehensive follow up to date was by Baek et al.24 looking at nine adult patients three years post treatment. They found that molar intrusion relapsed

NOUR ELDIN TARRAF 115 Fig. 2. – Pretreatment photos: Extra oral views showing long a face with increased lower anterior face height and retrognathic profile. The smile line is canted with more gingival display on the right hand side on smiling. Intra oral views showing open bite from 13-23 of 2-3 mm with Class II buccal segments. by 0.45 mm after 2.39 mm of intrusion on average over the palatal mucosa was left in order to allow room for intrusion three-year period. Furthermore the overbite was increased without palatal impingement. In the lower arch a rigid lower in treatment by an average of 5.56 mm and relapsed by lingual bar connecting the mandibular first molars with rests only 1.2 mm over the retention period. They concluded that on the second molars was cemented (Fig. 4). Sectional fixed molar intrusion with TADs was a valid treatment modality appliances were also bonded on the premolars and second providing long-term stability comparable with conventional molars to unite the buccal segments. Five TADs were placed orthodontics and orthognathic surgery. Their results also in total. One mini-screw was placed on the buccal side indicate the need for over correction during treatment as well between the second premolars and first molars in all four as perhaps some form of active retention. Case reports Fig. 3. – Cephalometric tracing showing increase in most vertical parameters and a tendency towards a skeletal Class II pattern. Case 1: 19 year old female presented with Class II malocclusion with an anterior open bite (Fig. 2), an increased lower anterior face height and a long face, as evident from the increased mandibular plane angle and vertical skeletal parameters (Fig. 3) (Table 1). There was also a slight cant in her smile line with more gingival exposure on smiling on the right hand side (Fig. 2). When surgical maxillary impaction was declined by the patient, molar intrusion using mini- screws was planned in both maxilla and mandible followed by full fixed appliances with the extraction of all third molars. The objective was to intrude the molar segments thus allowing mandibular autorotation to achieve anterior tooth contact eliminating the open bite and improving the vertical facial proportions at the same time. In order to prevent molars from tipping buccally with the intrusive forces a rigid transpalatal bar was constructed between the maxillary first molars with rested on the second molars (Fig. 4). In addition a 4 mm clearance between the bar and the

116 SKELETAL ANCHORAGE IN THE CORRECTION OF ANTERIOR OPEN BITE Fig. 4. – Appliance placement with a rigid transpalatal bar and rigid lower lingual arch with rests on second molars. TADs (mini-screws) placed between the first molar and second premolar in all four quadrants and one mini-screw placed in the mid palate. Nickel titanium coil springs attached TADs to the molar teeth with 150 g of intrusive force and secured with flowable resin composite to minimize cheek irritation. quadrants and one mini-screw was placed in the midpalate placed in the maxillary and mandibular anterior segments (Fig. 4). The TADs were immediately loaded by connecting (Fig. 7) and the patient was also issued with clear vacuum NiTi coil springs with a force of 150g buccally and palatally formed retainers for night time wear. attached to the first molars. The intrusion period continued for a period of 10 months in which a positive overbite of 5 From the above it appears that TADs in open bite mm was achieved (Fig. 5b). Full fixed appliances were then treatment offer a predictable method for the correction of placed and the TADs were passively tied to the first molars open bites with limited need for patient compliance and with to maintain the molar intrusion. Superimposition of lateral completely intraoral mechanics. It also allows the correction cephalometric tracings after molar intrusion using Bjork’s of skeletal open bites without the midfacial changes stable structures25 shows successful maxillary and mandibular associated with maxillary impaction surgery, which are not molar intrusion with subsequent mandibular auto rotation always desirable. (Fig. 6). Profile photographs also demonstrated a significant profile improvement with improved chin projection and a However it must be emphasized that the application of more pronounced soft tissue chin appearance following the TADs does not provide a universal solution for open bite reduction of the lower anterior face height (Fig. 5). Treatment malocclusion problems and that diagnosis and assessment was continued with fixed appliances correcting the smile line of the aetiology behind the open bite is of paramount and finishing with a Class I molar and canine relationship importance for success and long-term stability of the with normal overjet and overbite. Fixed retainers were outcome but is beyond the scope of this manuscript. Factors such as thumb sucking habits and abnormal tongue posture must be addressed as a priority. Furthermore it needs to be Fig. 5. – Showing progression of treatment: A. Pretreatment B. After 10 months of intrusion overcorrection with 5 mm overbite and a posterior open bite. Improved profile with more pronounced chin projection. C. Treatment completed.

NOUR ELDIN TARRAF 117 Fig. 6. – Superimposition of lateral cephalometric tracings A. Stable is necessary for successful maxillary protraction. Maxillary structures of the cranial base showing mandibular autorotation with sutures become more complex with age making protraction increased forward projection of the chin. B. Maxillary regional super less effective.30 Therefore it has been advocated that treatment imposition showing maxillary molar intrusion and maxillary incisor using reverse pull head gear (RPHG) or a protraction face flaring. C. Mandibular regional superimpositon showing mandibular molar mask (Fig. 1b) should be employed early between ages 7-10 intrusion. years old to utilize the growth potential of the maxillary sutures. It is believed that simultaneous rapid maxillary remembered that facial balance and harmony are the main expansion aids in activation of the circummaxillary sutures aim of modern orthodontics and dentofacial orthopaedics or to somewhat “disarticulate” the maxilla, although the and should be the main guiding parameters behind decision- evidence in this regard is equivocal.31,32 In addition to the making. Particular attention must be paid to the smile line importance of treating early, success with RPHG is highly and incisal/gingival display at rest and on smiling in order dependent on patient compliance usually involving the use to decide whether molar intrusion will indeed provide the of the cumbersome extra-oral appliance for 14-16 hours per desired effect. TADs and molar intrusion present a new day for a period of 10-12 months.30 The protraction facemask treatment modality that should be used when indicated by therapy leads to both dental and skeletal effects including the facial and occlusal goals. desirable forward movement of the maxilla but also downward and backwards movement of the mandible with Class III correction with skeletal anchorage: proclination of the maxillary incisors and retroclination of the Correction of skeletal Class III malocclusion is among the mandibular incisors, which are considered undesirable dental more challenging malocclusions to treat in the orthodontic compensations that detract from the skeletal correction.30 office. Class III malocclusion according to Angle26 occurs The amount of forward movement of the maxilla (A-point) when the lower teeth occlude mesial to their normal and therefore skeletal correction is significantly higher if relationship with the maxillary teeth the width of one treatment is done early, before age 10, ranging around 2-3 premolar or more. Skeletal Class III maloccusion occurs mm, while the benefits of treatment is greatly reduced for when the mandibular base is more mesial than the normal older children dropping to 1-2 mm after the age of 10 years.31 in relation to the maxilla and this can be due to a deficient In recent years two treatment modalities have changed the maxilla, prognathic mandible or a combination of both.27 face of Class III growth modification treatment. The first It is generally believed that the majority of Class III was when Liou et al.33 introduced a protocol of alternating malocclusions will have an element of maxillary deficiency rapid maxillary expansion and contraction (ALT RAMEC) as a common feature.28 Treatment modalities in growing prior to maxillary protraction. The aim of the technique children have typically aimed to stimulate sutural growth of was to improve the efficiency of the treatment through the maxilla, restrain the growth of the mandible or attempt a disarticulation of the maxilla by repeated cycles of expansion combination of both. and contraction thus facilitating maxillary protraction. Treatment timing for Class III malocclusion in growing In addition he used an intra-oral compliance free spring children is considered paramount29 as patency of the sutures thereby eliminating the need for RPHG and the compliance issues associated. The results were very impressive, with a forward movement of the maxilla (A-point) of 5.8 mm over a period of 2-3 months. This amount of maxillary forward movement is almost 2-3 fold what the literature29-31,34 on RPHG demonstrates and in one third of the treatment time. In addition he treated patients who were considered late in terms maxillary protraction at 11.5 years old and the results were stable two years after treatment. DeClerk et al.35 introduced another treatment modality. The technique applies Class III intermaxillary elastics to titanium mini-plates placed in the zygoma and the anterior mandible to correct maxillary deficiency. The group36 compared the results of their treated patients with what is expected from Fig. 7. – Appliances at start of protraction. From Al-Mozany et al. (with permission).38

118 SKELETAL ANCHORAGE IN THE CORRECTION OF ANTERIOR OPEN BITE untreated Class III controls and found on average 4 mm more were worn 24 hours per day and protraction was ceased when of maxillary forward movement and 2 mm of restrained an overjet of 2 mm was achieved. The results were promising mandibular growth. This was almost double the amount with the 2 mm overjet achieved in all subjects after an average produced by RPHG treatment.29-31 In addition the results of 8.6 weeks. The maxilla moved forward by 3.3 mm on were achieved in a group of children who were 11 years old, average (Fig. 9), twice as much as what would be expected which would be considered past the ideal time for RPHG at this age with RPHG and in only a third of the treatment treatment.29-31 They37 then compared the mini-plate and time.29-31 The results are also comparable with those achieved Class III elastics protocol with a sample of cases treated with by the De Clerck35 protocol with less treatment duration. RPHG and found that the skeletal anchorage group showed However, there were dental compensations experienced on average 2-3 mm more maxillary advancement while the such as proclination of maxillary incisors and retroclination effects on mandibular growth were comparable with those of of mandibular incisors as well as backward rotation of the the RPHG. Furthermore the vertical control with the skeletal mandible. This can be attributed to the fact that the appliances anchorage group was better with no backwards rotation of the were tooth borne and indirectly supported by skeletal mandible and no lower incisor retroclination. The technique anchorage and the inherent flexibility of the wires used does not involve any tooth borne appliances. would have allowed some dental movement. Nevertherless, A recent prospective study38 at the University of Sydney the combination of Alt-RAMEC with TADs and Class III examined the effects of combining both Alt-RAMEC and elastics for the correction of Class III malocclusions appears skeletal anchorage with Class III elastics in the treatment of very promising. It offers an alternative to conventional skeletal Class III maxillary deficiency in growing children. RPHG that is completely intraoral with improved patient In order to eliminate the need for flap surgery and general acceptance. In addition to offering superior results in shorter anaesthesia the study used mini-screws instead of anchorage duration it also allows effective treatment for patients who plates. A group of 14 (7 male and 7 female) Class III patients previously would be considered too old to benefit fully from with maxillary deficiency aged 12.5 years on average were RPHG therapy. However long term stability of the changes treated with Alt-RAMEC and TADS with Class III elastics. still need to be evaluated. This study is part of an ongoing Two mini-screws were inserted on either side of the mid- project at the University of Sydney aiming to improve the palatine suture and two mini-screws were inserted into the efficiency and efficacy of Class III correction in growing anterior mandible between the canines and lateral incisors. individuals. The palatal TADs39 were attached to a modified bonded From the above it appears that the incorporation of TADs rapid palatal expander and the lower TADs were fixed to a in orthodontic treatment has significantly changed the way modified bonded lingual arch (Fig. 8). The maxilla was then modern orthodontic treatment is approached. TADs have expanded at 1 mm/day for a period of seven days followed widened the possibilities of what can be done with orthodontic by constriction of the maxilla at 1 mm/day for 7 days. This treatment alone. They have enabled the elimination of many protocol was repeated for nine weeks. Following this Alt- cumbersome and obtrusive appliances as well as reduced the RAMEC protocol intermaxillary Class III elastics (Fig. 8) need for patient compliance in many aspects of treatment, making treatment simpler and more predictable. It can also Fig. 8. – From Al-Mozany et al. (with permission).38A. Pretreatment B. post be said that the research so far has merely scratched the protraction. surface in the field of skeletal anchorage. Acknowledgments: The author would like to acknowledge Dr Stephen Bartley and Ms Naomi Cook for proofreading this manuscript. References: 1. Creekmore T, Eklund M. The Possibility of Skeletal Anchorage. J Clin Orthod 1983;18:266-69. 2. Jenner JD, Fitzpatrick BN. Skeletal anchorage utilizing bone plates. Australian Orthodontic Journal 1985;9:231-3. 3. Cope JB. Ortho TADs: The Clinical Guide and Atlas. Dallas,Texas: Under Dog Media, LP, 2007. 4. Mizrahi E. A review of anterior open bite. British Journal of Orthodontics 1978:21-27. 5. Subtelny J, Sakuda M. Open-bite: diagnosis and treatment. American Journal of Orthodontics 1964;50:337 –58. 6. Sassouni V. A classification of skeletal facial types. Am J Orthod 1969;55:109-23. 7. Schendel W, Bell W. The long face syndrome: Vertical maxillary excess. American Journal of Orthodontics 1976;70:398-408. 8. Barber RE, Sinclair P. A cephalometric evaluation of anterior open bite correction with the magnetic active vertical corrector. The Angle Orthodontist 1991;61:93-102. 9. Pearson L. Vertical control in treatment of patients having backward- rotational growth tendencies. The Angle Orthodontist 1978;48:132-40. 10. Darendeliler M, Darendeliler A, Mandurino M. Clinical application of magnets in orthodontics and biological implications. European Journal of Orthodontics 1997;19:431-42.

NOUR ELDIN TARRAF 119 11. Dellinger E. A clinical assessment of the Active Vertical Corrector - A 28. Ellis IE, McNamara JJ. Components of adult class III malocclusion. J nonsurgical alternative for skeletal open bite treatment. American Journal Oral Maxillofac Surg 1984;42:295-305. of Orthodontics 1986;89:428-36. 29. Kapust A, Sinclair P, Turley P. Cephalometric effects of face mask/ 12. Kim Y. Anterior openbite and its treatment with multiloop edgewise expansion therapy in Class III children: A comparison of three age groups. archwire Angle Orthod 1987;57:290-321. Am J Orthod Dentofac Orthoped 1998;113:204-12. 13. Janson G, Valarelli F, Targino R, Beltrao S, Freitas M, Henriqoesc J. 30. Ngan P. Early timely treatment of Class III malocclusion. Seminars in Stability of anterior open-bite extraction and nonextraction treatment in the Oethodontics 2005;11:140-45. permanent dentition. Am J Orthod Dentofac Orthop 2006;129:768-77. 31. Kim JH, Viana MA, Graber TM, Omerza FF, Begole EA. The 14. Umemori M, Sugawara J, Mitani H, Nagasaka H, Kawamura H. Skeletal effectiveness of protraction face mask therapy: a meta-analysis. Am J anchorage system for open bite correction. Am J Orthod Dentofacial Orthop Orthod Dentofac Orthoped 1999;115:675-85. 1998;115:166-74. 32. Vaughn G, Mason B, Moon HB, Turley PK. The effects of maxillary 15. Erverdi N, Tosun T, Keles A. A New Anchorage Site for the Treatment protraction therapy with or without rapid palatal expansion: a prospective, of Anterior Open Bite: Zygomatic Anchorage. Case Report. World J Orthod randomized clinical trial. Am J Orthod Dentofac Orthoped 2005;128:299-309. 2002;3:147-53. 33. Liou E-W. Effective maxillary orthopaedic protraction for growing 16. Sherwood K, Burch J, Thompson W. Closing anterior open bites Class III patients: a clinical application simulated distraction osteogenesis. by intruding molars with titanium miniplate anchorage. Am J Orthod Progress In Orthodontics 2005;6:154-71. Dentofacial Orthop 2002;122:593-600. 34. Baccetti T, McGill J, Franchi L, McNamara J, Tollaro I. Skeletal effects 17. Kuroda S, Sakai Y, Tamamura N, Deguchi T, Takano-Yamamoto T. of early treatment of Class III malocclusion with maxillary expansion and Treatment of severe anterior open bite with skeletal anchorage in adults: face-mask therapy. Am J Orthod Dentofac Orthoped 1998;113:333-43. Comparison with orthognathic surgery outcomes. Am J Orthod Dentofacial 35. De Clerck H, Cornelis MA, Cevidanes L, Heymann GC, Tulloch C. Orthop 2007;132(5):559-605. Orthopedic Traction of the Maxilla With Miniplates: A New Perspective 18. Paik C, Woo Y, Boyd R. Treatment of an Adult Patiet with Vertical for Treatment of Midface Deficiency. Journal of Oral and Maxillofacial Maxillary Excess Using Miniscrew Fixation. J Clin Orthod 2003;37:423- Surgery 2009;67(10):2123–29. 28. 36. De Clerck H, Cevidanes L, Baccetti T. Dentofacial effects of bone- 19. Yao C, Lee J, Chen H, Chang Z, Chang H, Chen Y. Maxillary Molar anchored maxillary protraction: A controlled study of consecutively treated Intrusion with Fixed Appliances and Mini-implant Anchorage Studied in Class III patients. American Journal of Orthodontics and Dentofacial Three Dimensions. Angle Orthod 2005;75:754-60. Orthopedics 2010;138(5):577–81. 20. Foot R, Tarraf N, Gonzales C, Darendeliler M. The Sydney Intrusion 37. Cevidanes L, Baccetti T, Franchi L, McNamara JA, De Clerck H. Spring (SIS): An appliance for the intrusion of posterior maxillary teeth. A Comparison of two protocols for maxillary protraction: bone anchors Prospective Clinical Study. University of Sydney, 2011. versus face mask with rapid maxillary expansion. The Angle Orthodontist 21. Lopez-Gavito G, Joondeph D. Anterior open bite malocclusion: 2010;80:799-806. longitudinal 10 year postretention evaluation of orthodontically treated 38. Al-Mozany S, Tarraf N, Dalci O, Gonzales C, Darendeliler M. Treatment patients. Am J Orthod 1985;87:175-86. of Class III malocclusions using Temporary Anchorage Devices (TADs) 22. Kim Y, Unae K, Diana D, Laarni P. Stability of anterior open bite and intermaxillary Class III elastics in the growing patient. University of correction with multiloop edgewise archwire therapy: A cephalometric Sydney, 2011. follow-up study. Am J Orthod Dentofac Orthop 2000;118. 39. Ludwig B, Glasl B, Bowman JS, Drescher D, Wilmes B. Miniscrew- 23. Proffit W, Bailey LTJ, Phillips C, Turvey TA. Long-Term Stability Supported Class III Treatment with the Hybrid RPE Advancer. J Clin of Surgical Open-Bite Correction by Le Fort I Osteotomy. The Angle Orthod 2010;XLIV(9):533-39. Orthodontist 2000;70:112–17. 24. Baek MS, Choi YJ, Yu HS, Lee KJ, Kwak J, Park YC. Long-term Address for Correspondence: stability of anterior open-bite treatment by intrusion of maxillary posterior 181/18-34 Waverly Street teeth. Am J Orthod Dentofacial Orthop 2010;138:396.e1-96.e9. Bondi Junction 25. Bjork A, Skieller V. Normal and abnormal growth of the mandible. A NSW 2022 synthesis of longitudinal cephalometric implant studies over a period of 25 [email protected] years. European Journal of Orthodontics 1983;5:1-46. 26. Angle E, editor. Treatment of malocclusion of teeth and fractures of the maxillae: Angle’s Systems. 6 ed. Philadelphia: SS White Dental Mfg, 1900. 27. Bishara S, editor. Textbook of orthodontics. Philadelphia: W.B. Saunders Company, 2001.

Ann Roy Australas Coll Dent Surg 2012;21;120-123 RESIN INFILTRATION- TAKING THE FIRST STEPS TO FILLING THE HOLES IN CHEESE MOLARS Harleen Kumar, BDSc, DCD* Joseph Palamara, PhD, Dip Ed Michael F. Burrow, BDS, MDS, PhD, MEd, MRACDS (Pros), FRACDS, FICD David J. Manton, BDSc, MDSc, PhD, FRACDS, FICD Harleen Kumar is a paediatric dentist in practice in Melbourne. Joseph Palamara is an Associate/Professor in the Melbourne Dental School responsible for teaching Dental Materials at the Melbourne Dental School. Michael Burrow is a Clinical Associate Professor in the Faculty of Dentistry at the University of Hong Kong, and an Honorary Professorial Fellow in the Melbourne Dental School at the University of Melbourne. David Manton holds the Elsdon Storey Chair in Child Dental Health at the Melbourne Dental School. Abstract Molar incisor hypomineralization (MIH) involves enamel hypomineralization of systemic origin affecting one or more first permanent molars (FPM) and is often associated with other teeth, particularly the incisors. A challenging condition for both the clinician and the patient, MIH affected teeth are often subjected to repeated treatments and frequently the decision to extract one or more FPM is made. At present, there are no clinical reports of available restorative materials that are able to provide consistently adequate restorations on hypomineralized teeth. The concept of resin infiltration, which involves occluding incipient enamel carious lesions with low viscosity resins to arrest or slow the development of caries has the potential to be applied to hypomineralized enamel. Successful penetration of resin infiltrant into MIH affected enamel may aid in improving its micromechanical properties. Introduction highlighted a lack of consensus on the restorative management of MIH teeth, with many practitioners reporting difficulty in In 2001, Weerheijm et al. first defined “molar incisor providing adequate and long-lasting restorations.3 hypomineralization” as enamel hypomineralization of systemic origin of one to four permanent first molars The probability of undergoing restorative treatment frequently associated with affected incisors.1 Typically, the amongst children with MIH affected molars has been permanent first molars are the most frequently affected teeth reported to be ten to eleven times more often than unaffected with possible involvement of the incisors, second primary children.7.9 High restorative failure rates may be explained molars, second permanent molars and the permanent by a decrease in mineral content of the affected enamel that canines.2 Individuals with MIH-affected teeth present with has a more porous prism structure and significantly higher white, yellow and/or brown demarcated opacities of the protein content and subsequently reduced strength and enamel, with normal enamel thickness and a confluent hardness of MIH affected teeth.10-15 The inherent weakness in surface at eruption. Numerous attempts have been made hypomineralized enamel may result in marginal breakdown to describe and classify enamel hypomineralization which of restorations, and adversely affect adhesive strengths of mainly affects the molars and incisors, leading to a plethora resin composite bonded to hypomineralized enamel.12,16 of names in the literature, including: “cheese molars”, “hypomineralized permanent first molars”, “idiopathic Children with affected teeth often complain of enamel hypomineralization”, “dysmineralization of first hypersensitivity to common oral and mechanical stimuli permanent molars”, “non-fluoride hypomineralization”, and such as heat, cold, sweet and tooth brushing.1 The “idiopathic molar hypomineralization”.3-5 increased sensitivity can cause children to avoid brushing hypomineralized teeth which leads to increased plaque The clinical relevance of molar incisor stagnation, demineralization and caries development.17 Often, during a dental examination, children respond hypomineralization intensely to air blowing, and plaque is visible around the FPM in a mouth with otherwise good oral hygiene. A The management of MIH can present several challenges histological study of hypomineralized enamel found that to both the clinician and patient, including problems even apparently intact enamel surfaces of some MIH teeth associated with post-eruptive enamel breakdown (PEB), the had bacterial presence in the dentinal tubules with a zone rapid development of caries, difficulty in achieving pulpal of reparative/reactive dentine formed at the pulpal surface.18 anaesthesia and the predisposition for marginal breakdown The pulp was free from bacteria, with one coronal pulp of restorations leading to frequent re-treatment.2,6 There containing inflammatory cells indicative of an inflammatory may also be aesthetic concerns, especially if the incisors reaction. This suggests that if bacterial penetration of the are involved.2,7,8 A survey of the Australian members of the dentinal tubules does occur in MIH teeth it is likely that an Australian and New Zealand Society of Paediatric Dentistry inflammatory reaction is initiated in the pulp and probably contributes to the hypersensitivity of the affected teeth. * Young Lecturer presentation at the Twenty-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand. 31 March - 4 April 2012

KUMAR, BURROWS, PALAMARA, MANTON 121 Practitioners often experience difficulty achieving phosphate (CPP-ACFP) solution for 14 days on molars adequate pulpal anaesthesia in children affected by MIH. affected by MIH.27 A selected sample of the test teeth were This may be due to chronic sub-clinical inflammation of the pre-treated with 0.95% m/v NaOCl irrigation prior to CPP- pulpal cells due to increased enamel porosity and subsequent ACFP application and all specimens were examined by bacterial penetration of the dentinal tubules leading transverse microradiography. The study found application of to inflammation and therefore hypersensitivity to oral CPP-ACFP increased the mineral content of hypomineralized stimuli.7,18,19 Preventive materials such as resin composite or enamel. NaOCl pre-treatment increased remineralization glass ionomer cement (GIC) fissure sealants, mineralizing prior to exposure to CPP-ACFP, however, not significantly agents, or resin infiltration of the enamel and possibly when compared with enamel not exposed to NaOCl.27 dentine, may be a treatment option to prevent ingress of bacteria and decrease hypersensitivity. A recent three year prospective in vivo trial of 30 children aged six to nine years was conducted to investigate Increased sensitivity to oral stimuli, poor anaesthesia the qualitative and quantitative effects of CPP-ACP (Tooth during restorative procedures, repeated treatment or extraction Mousse†) application for 20 minutes nightly on MIH of MIH teeth has the added disadvantage of often leading molars.28 Polyvinylsiloxane impressions and 15 cusp or to patient ‘burnout’, behaviour management problems and tooth side biopsies of the teeth were taken at the start and end increase in the risk of developing dental fear and anxiety in of the three year test period and were examined by scanning children.7 This creates substantial challenges to the clinician electron microscopy (SEM). The SEM images revealed and early detection, prevention, and development of an decreased porosity and homogenization of the enamel, and appropriate therapeutic approach may aid in minimizing a more geometric and mineralized rod structure of the Tooth repeated interventions. The stated detrimental outcomes may Mousse-treated enamel compared with defective crystal be avoided or reduced in severity by further investigations organization of the baseline MIH enamel. Limitations of into the removal of enamel proteins to enhance bonding this study include the limited number of controls and the and resin penetration, agents to increase mineralization, and request for the subjects to not brush or use toothpaste for the novel infiltration materials that reduce leakage of restorations three year test period presumably to eliminate confounding and improve the restorative micromechanical properties and variables such as fluoride. In addition, enamel biopsies of bond strengths of MIH teeth. some teeth were taken from areas adjacent to temporary restorations. The type of restoration used was not mentioned New research areas for molar incisor hypomineralization and if fluoride releasing materials were used these may have had an effect on the properties of the MIH enamel. However, Sodium hypochlorite (NaOCl) is an oxidizing agent the study is the first to provide in vivo results of the efficacy and degrades protein.20,21 In a case-report, improved of a remineralizing agent on MIH affected teeth. resin bonding of orthodontic brackets onto hypocalcified amelogenesis imperfecta affected enamel by pre-treating the Mildly affected MIH teeth without enamel breakdown tooth with 5% NaOCl was reported.22 The authors proposed may benefit from fissure sealants to help reduce or postpone NaOCl produced a more effective acid etch by exposing PEB, caries and subsequent treatment.6,11,24,29,30 Currently, the enamel mineral previously encased in acid-insoluble resin fissure sealants applied using the conventional etch proteins. Reduced microleakage levels in resin-based and seal technique on MIH molars exhibit low retention composite bonded to MIH enamel following pre-treatment rates and require re-treatment after a much shorter period of with 5% NaOCl have also been demonstrated.23 Whilst these time compared with application of a single-bottle adhesive results are encouraging, the evidence for this procedure is system prior to sealant placement.9,30 limited. Mathu-Muju and Wright suggested administration of remineralizing agents, or removal of intrinsic enamel Resin infiltration proteins by pre-treatment of the pits and fissures for 60 seconds with 5% NaOCl prior to fissure sealing MIH At present, there are no reports of restorative materials affected teeth in order to improve bond strength.24 There is in the market that are able to provide consistently adequate no clinical or scientific evidence at this time to support these restorations on hypomineralized teeth. The major problem in recommendations. restoring MIH affected teeth is determining the quality of the remaining enamel.3,16 Improving the mechanical properties From a clinical perspective, topical fluoride applications of the enamel in MIH teeth would be critical to their on hypomineralized teeth may help promote post- successful restoration. Occluding incipient enamel lesions eruptive maturation of the surface layer to improve the with low viscosity resins to arrest or slow the development micromechanical and bonding properties of affected enamel, of proximal and smooth surface caries is not a new concept however the amount of remineralization is limited by the and has been explored over the years.31,31 presence of bio-available calcium and phosphate in the saliva, unless an extraneous source is provided.11,25 Further, Icon‡ is a micro-invasive caries treatment that reportedly casein phosphopeptide-amorphous calcium phosphate (CPP- penetrates the inter-rod spaces of dental hard tissues with ACP) which remineralizes sub-surface carious lesions may a low viscosity light curable resin infiltrant. Icon has been aid in reducing sensitivity to oral stimuli and improving developed to treat white spot lesions on smooth surfaces and mineralization of the hypomineralized areas.26 early non-cavitated approximal carious lesions extending A pilot laboratory study investigated the effects of 1% † GC Corp, Tokyo, Japan m/v casein phosphopeptide amorphous calcium fluoride ‡ DMG, Hamburg, Germany

122 FILLING THE HOLES IN CHEESE MOLARS to a maximum radiological lesion progression into the where the surface layer is relatively thin.41 outer third of dentine.33 Its use aims to postpone or prevent invasive restorative procedures, especially interproximally, It is postulated that the advent of Icon® may aid in where the ratio of carious to healthy hard tissue removal altering the micromechanical properties of hypomineralized can be unfavourable.34 The process of infiltration involves enamel via resin infiltration. However, differences may exist occlusion of the enamel pores with a light polymerized between the infiltration of carious versus hypomineralized resin in order to block the diffusion of acids into the lesion enamel. Evidence suggests up to 21 times more protein body and ions out of the enamel, therefore inhibiting carious is present in MIH affected enamel compared with normal demineralization.34 Successful blocking of caries progression enamel which may not allow adequate etching and hamper via infiltration has been demonstrated in both artificial and the infiltration process similar to the caries model.5,42 It is natural carious lesions.35-38 This is different from fissure not known how the penetration depth of the light-cured resin sealing caries which creates a diffusion barrier only on the infiltrant will be affected by the retained proteins. lesion surface.34,39 In vitro infiltration of a fissure sealant and various adhesives Icon® has proved to be effective in almost complete into sub-surface bovine enamel lesions has been described as penetration of natural enamel caries in an in vitro study successfully improving the resistance of subsurface lesions with penetration depths of the infiltrant reaching values against cariogenic challenge.35,36 Based on these results, it is greater than 500μm.38 The efficacy of resin infiltration, postulated that infiltration of hypomineralized enamel may however, depends on the cavitation status of caries lesions. inhibit or reduce the progression rate of demineralization The above results were for non-cavitated enamel porosities. and ultimately reduce caries risk, improve sensitivity to oral Under in vitro conditions, cavitated aproximal lesions stimuli, and increase bond strength of composite resin to the are negligibly infiltrated irrespective of the International infiltrated surface. Caries Assessment and Detection System (ICDAS) codes and cavity sizes of the lesions.37 Paris et al. postulated this Final considerations may be due to weak capillary action in cavitated lesions as opposed to demineralized porous enamel that can readily The ideal restorative material for hypomineralized teeth allow infiltration of the resin due to strong capillary forces. would be one that could provide restorations with a good Other reasons for failure may include unintentional removal prognosis. However, the problem lies not with the restorative of the resin before light curing when the excess is cleaned material itself but with the affected enamel of MIH teeth. off, or air bubbles within the cavitation may have prevented Improving the mechanical properties of the enamel in MIH penetration of the liquid resin due to its resultant surface teeth seems critical to their successful restoration. This may tension.37 By inference from these findings, it is possible be by utilizing currently available products such as NaOCl, infiltration of MIH affected lesions may be limited to those CPP-ACP, resin and glass ionomer based fissure sealants, not associated with caries or PEB. resin infiltrants; or by developing new products more suited to the mechanical properties and microstructure of The development of a micro-invasive restorative hypomineralized enamel. material led researchers to study its applicability in areas other than blocking caries progression. White spot lesions Infiltrating hypomineralized hard tissue with a low as a result of dental caries, developmental defects of enamel viscosity light curing resin may pave the way for delaying (DDE) and post-orthodontic demineralization around or preventing restorative intervention, creating a less orthodontic brackets present problems associated with not destructive restorative procedure, increasing hardness of the only progression of demineralization but compromised lesion and preventing or reducing PEB. It may also allow aesthetics. An in vivo study investigating the effect of resin improved bond strength of a restoration on the infiltrant infiltration with Icon on white spot lesions after debonding surface and reduce its marginal breakdown risk. Clinically, fixed orthodontic brackets found a 65- 80% improvement in infiltrating hard tissue may reduce sensitivity to oral stimuli the masking of the lesions with a significant improvement and improve the appearance of demarcated opacities on in colour.40 Another in vivo study assessing the effect of affected incisors. A simplified restorative procedure, whereby Icon on white spot lesions of teeth with DDE and teeth with the patient experiences less sensitivity and the reduced need post-orthodontic decalcification found complete masking of for restorations may in turn improve patient behaviour and the lesions in 25% of the DDE teeth, and 61% of the post- compliance. orthodontic specimens.41 From the DDE and post-orthodontic groups, 40% and 6% of the teeth respectively did not show References any changes after resin infiltration. Failure of masking of a large proportion of lesions from the DDE was attributed to 1. Weerheijm KL, Jalevik B, Alaluusua S. Molar-incisor their depth which may be greater than the infiltration range, hypomineralisation. Caries Res 2001;35:390-1. and of the lesion activity where older/ inactive lesions may have had a thicker surface layer that was only partially 2. Weerheijm KL, Duggal M, Mejare I, Papagiannoulis L, Koch G, removed with etching and thus incompletely penetrated with Martens LC, et al. Judgement criteria for molar incisor hypomineralisation resin infiltrant. The authors commented resin infiltration may (MIH) in epidemiologic studies: a summary of the European meeting on be more suited for active, shallower and younger lesions MIH held in Athens, 2003. Eur J Paediatr Dent 2003;4:110-3. 3. Crombie FA, Manton DJ, Weerheijm KL, Kilpatrick NM. Molar incisor hypomineralization: a survey of members of the Australian and New Zealand Society of Paediatric Dentistry. Aust Dent J 2008;53:160-6. 4. Croll TP. Creating the appearance of white enamel dysmineralization with bonded resins. J Esthet Dent 1991;3:30-3.

KUMAR, BURROWS, PALAMARA, MANTON 123 5. Mangum JE, Crombie FA, Kilpatrick N, Manton DJ, Hubbard MJ. 26. Willmott NS, Bryan RA, Duggal MS. Molar-incisor-hypomineralisation: Surface integrity governs the proteome of hypomineralized enamel. J Dent a literature review. Eur Arch Paediatr Dent 2008;9:172-9. Res. 2010;89:1160-5. 27. Crombie FA, Manton DJ, Palamara J, Reynolds EC. The Effect of a Remineralising Agent on Developmentally Hypomineralised Enamel. 6. William V, Messer LB, Burrow MF. Molar incisor hypomineralization: Caries Res 2011;45:174-242. review and recommendations for clinical management. Pediatr Dent 28. Baroni C, Marchionni S. MIH supplementation strategies: prospective 2006;28:224-32. clinical and laboratory trial. J Dent Res 2011;90:371-6. 29. Fayle SA. Molar incisor hypomineralisation: restorative management. 7. Jalevik B, Klingberg GA. Dental treatment, dental fear and behaviour Eur J Paediatr Dent 2003;4:121-6. management problems in children with severe enamel hypomineralization 30. Lygidakis NA, Dimou G, Stamataki E. Retention of fissure sealants using of their permanent first molars. Int J Paediatr Dent 2002;12:24-32. two different methods of application in teeth with hypomineralised molars (MIH): a 4 year clinical study. Eur Arch Paediatr Dent 2009;10:223-6. 8. Weerheijm KL. Molar incisor hypomineralization (MIH): clinical 31. Davila JM, Buonocore MG, Greeley CB, Provenza DV. Adhesive presentation, aetiology and management. Dent Update 2004;31:9-12. penetration in human artificial and natural white spots. J Dent Res 1975;54:999-1008. 9. Kotsanos N, Kaklamanos EG, Arapostathis K. Treatment management 32. Robinson C, Hallsworth AS, Weatherell JA, Kunzel W. Arrest and of first permanent molars in children with Molar-Incisor Hypomineralisation. control of carious lesions: a study based on preliminary experiments with Eur J Paediatr Dent 2005;6:179-84. resorcinol-formaldehyde resin. J Dent Res 1976;55:812-8. 33. Paris S, Hopfenmuller W, Meyer-Lueckel H. Resin infiltration of caries 10. Suckling GW, Nelson DG, Patel MJ. Macroscopic and scanning lesions: an efficacy randomized trial. J Dent Res 2010;89:823-6. electron microscopic appearance and hardness values of developmental 34. Paris S, Bitter K, Renz H, Hopfenmuller W, Meyer-Lueckel H. defects in human permanent tooth enamel. Adv Dent Res 1989;3:219-33. Validation of two dual fluorescence techniques for confocal microscopic visualization of resin penetration into enamel caries lesions. Microsc Res 11. Fearne J, Anderson P, Davis GR. 3D X-ray microscopic study of Tech 2009;72:489-94. the extent of variations in enamel density in first permanent molars 35. Mueller J, Meyer-Lueckel H, Paris S, Hopfenmuller W, Kielbassa with idiopathic enamel hypomineralisation. Br Dent J 2004;196:634-8; AM. Inhibition of lesion progression by the penetration of resins in vitro: discussion 25. influence of the application procedure. Oper Dent 2006;31:338-45. 36. Paris S, Meyer-Lueckel H, Mueller J, Hummel M, Kielbassa AM. 12. Mahoney EK, Rohanizadeh R, Ismail FS, Kilpatrick NM, Swain MV. Progression of sealed initial bovine enamel lesions under demineralizing Mechanical properties and microstructure of hypomineralised enamel of conditions in vitro. Caries Res 2006;40:124-9. permanent teeth. Biomaterials 2004;25:5091-100. 37. Paris S, Bitter K, Naumann M, Dorfer CE, Meyer-Lueckel H. Resin infiltration of proximal caries lesions differing in ICDAS codes. Eur J Oral 13. Xie ZH, Mahoney EK, Kilpatrick NM, Swain MV, Hoffman M. On the Sci 2011;119:182-6. structure-property relationship of sound and hypomineralized enamel. Acta 38. Meyer-Lueckel H, Chatzidakis A, Naumann M, Dorfer CE, Paris S. Biomater 2007;3:865-72. Influence of application time on penetration of an infiltrant into natural enamel caries. J Dent 2011;39:465-9. 14. Farah RA, Drummond BK, Swain MV, Williams S. Relationship 39. Paris S, Meyer-Lueckel H, Kielbassa AM. Resin infiltration of natural between laser fluorescence and enamel hypomineralisation. J Dent caries lesions. J Dent Res 2007;86:662-6. 2008;36:915-21. 40. Mohsen MMA, Hammad, S.M., El Zayat, I.M.G, El Banna, M. . Effect of Resin Infiltration Material on White Spot Lesions after Brackets 15. Farah RA, Swain MV, Drummond BK, Cook R, Atieh M. Mineral Removal. Caries Res 2011;45:174–242. density of hypomineralised enamel. J Dent 2010;38:50-8. 41. Kim S, Kim EY, Jeong TS, Kim JW. The evaluation of resin infiltration for masking labial enamel white spot lesions. Int J Paediatr Dent 16. William V, Burrow MF, Palamara JE, Messer LB. Microshear bond 2011;21:241-8. strength of resin composite to teeth affected by molar hypomineralization 42. Farah RA, Monk BC, Swain MV, Drummond BK. Protein content of using 2 adhesive systems. Pediatr Dent 2006;28:233-41. molar-incisor hypomineralisation enamel. J Dent 2010;38:591-6.. 17. Weerheijm KL. Molar incisor hypomineralisation (MIH). Eur J Address for correspondence: Paediatr Dent 2003;4:114-20. Melbourne Dental School, Faculty of Medicine Dentistry and Health Sciences, 18. Fagrell TG, Lingstrom P, Olsson S, Steiniger F, Noren JG. Bacterial The University of Melbourne, invasion of dentinal tubules beneath apparently intact but hypomineralized 720 Swanston Street, Melbourne, enamel in molar teeth with molar incisor hypomineralization. Int J Paediatr Victoria, Australia 3010. Dent 2008;18:333-40. Email: [email protected] 19. Rodd HD, Morgan CR, Day PF, Boissonade FM. Pulpal expression of TRPV1 in molar incisor hypomineralisation. Eur Arch Paediatr Dent.2007;8:184-8. 20. Inaba D, Duschner H, Jongebloed W, Odelius H, Takagi O, Arends J. The effects of a sodium hypochlorite treatment on demineralized root dentin. Eur J Oral Sci 1995;103:368-74. 21. Perdigao J, Lopes M, Geraldeli S, Lopes GC, Garcia-Godoy F. Effect of a sodium hypochlorite gel on dentin bonding. Dent Mater 2000;16:311-23. 22. Venezie RD, Vadiakas G, Christensen JR, Wright JT. Enamel pretreatment with sodium hypochlorite to enhance bonding in hypocalcified amelogenesis imperfecta: case report and SEM analysis. Pediatr Dent 1994;16:433-6. 23. Sood S, Fleming GJ, O’Connell AC. An in vitro study on the microleakage of resin based composite and resin modified glass ionomer to MIH teeth. European Archives of Paediatric Dentistry, Abstracts of EAPD Congress,2008. 24. Mathu-Muju K, Wright JT. Diagnosis and treatment of molar incisor hypomineralization. Compend Contin Educ Dent 2006;27:604-10; quiz 11. 25. Shen P, Manton DJ, Cochrane NJ, Walker GD, Yuan Y, Reynolds C, et al. Effect of added calcium phosphate on enamel remineralization by fluoride in a randomized controlled in situ trial. J Dent 2011;39:518-25.

Ann Roy Australas Coll Dent Surg 2012;21;124 EVALUATION OF PULPOTOMY OUTCOMES IN PRIMARY MOLARS USING MINERAL TRIOXIDE AGGREGATE AS A PULP DRESSING AND BASE, RESTORED WITH STAINLESS STEEL CROWNS VERSUS AMALGAM – A pilot study Sonali Mistry, BDS, MDSc* Kim Seow, BDS, MDSc, PhD, DDSc, FRACDS, FICD, FADI Trevor Holcombe, BDSc, BCom, Grad Cert (Clin Dent), MDSc Dr Mistry is a Paediatric Dentist at the Kingston Oral Health Centre, Queensland Health and an Honorary Senior Lecturer at the University of Queensland. Professor Kim Seow is the Director of the Centre for Paediatric Dentistry Research and Training at the University of Queensland. Dr Holcombe is the Director of the Oral Health (Logan-Beaudesert Division), Metro South Health Service District, Queensland Health and an Honorary Senior Lecturer at the University of Queensland. Purpose internal root resorption showed calcific metamorphosis of the resorbed area at subsequent recall. At all recall periods, The objective of this study was to evaluate the outcomes there was no statistically significant difference in pulpotomy of mineral trioxide aggregate (MTA) as a pulp dressing and outcomes between the groups (p > 0.05). base in primary molars restored with stainless steel crowns (SSC) and compare them with those restored with amalgam. Conclusions Methods MTA is a clinically successful pulp dressing and base for primary teeth pulpotomy. SSC perform better than Fifty-eight carious primary molars in 33 children were amalgam for pulp treated teeth. A larger series of patients treated with the conventional pulpotomy technique. A and histological evaluations are recommended to establish minimum of 3 mm of MTA was placed against the remaining definitive success rates. pulp to serve as a pulp dressing and base. The pulpotomized teeth were assigned to either the SSC or amalgam group Acknowledgments for restoration. Clinical and radiographic follow-up ranged between 3-58 months. The authors would like to acknowledge the Australian Dental Research Foundation and Queensland Health for Results their support of this research project. The clinical success rate for teeth available at follow-up Address for correspondence: was 100% at 54 months and 98% at 58 months. Recurrent Paediatric Dentistry caries, tooth fractures and revisits to restorations were School of Dentistry more frequently encountered in the amalgam group. The The University of Queensland radiographic success rate was 100% at 18 months, 98% at 200 Turbot St 42 months and 96.5% at 54 months. Pulp canal obliteration Brisbane. QUEENSLAND 4000 and dentine bridging were the most common outcomes and were observed at all recalls. Some teeth presenting with [email protected] * Young Lecturer presentation at the Twenty-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand. 31 March - 4 April 2012

Ann Roy Australas Coll Dent Surg 2012;21:125-127 ABSTRACTS OF PRESENTED PAPERS* Editor’s note A number of presenters indicated that they were unable to provide manuscripts for this volume of the Annals. For the sake of completeness, the Abstracts from the Convocatiion booklet are included in this section. THE MUTILATED DENTITION – SURGICAL APPROACHES Jocelyn Shand, MBBS(Melb), MDSc(Melb), BDS(Otago), FDSRCS(Eng), FRACDS(OMS)* Dr Jocelyn Shand is a Consultant Oral and Maxillofacial Surgeon at The Royal Children’s Hospital of Melbourne and is in part-time private practice in Melbourne. The approach to the compromised dentition and occlusion assessment, treatment options and the factors that influence can be challenging and complex. The optimal management and impact upon planning are discussed along with the of these patients should involve assessment and planning treatment outcomes in the contemporary literature. within a multidisciplinary team. The management of the skeletal discrepancy with orthognathic surgery, bone grafting Address for correspondence: for augmentation and implant therapy can be undertaken as Level 12 required as part of the combined approach. With an ageing 63 Exhibition Street population the underlying medical condition of the patient Melbourne Victoria 3000 may also have significant implications on planning. The [email protected] ORAL HEALTH AS THE CANARY IN THE COALMINE Ritchie Poulton, PhD* Professor Richie Poulton is Director of the Dunedin Multidisciplinary Health and Development Research Unit and Co-director of the recently established National Centre for Lifecourse Research at the University of Otago, Dunedin, New Zealand. The Dunedin longitudinal study is one of the most A review of findings from this Dunedin Multidisciplinary detailed studies of human health and development ever Health and Development Study is followed by an in-depth undertaken. It is a multidisciplinary, longitudinal study of examination of oral health research from this cohort. 1,037 babies born in Dunedin during 1972/73. The study Links are made between oral health and a range of other members have been followed up since birth, at age three, health outcomes, including those related to cardiovascular then every two years to age 15, and at ages 18, 21, 26, and biomarkers, inflammation and early life risk factors including 32. The latest assessment phase, at age 38, is currently psychosocial exposures. The study asks and begins to answer underway (2010/2012). For each follow-up phase, the the question “is oral health an early warning sign for poor Study members are brought to the Dunedin Unit where they overall health and well-being?” undergo numerous assessments and measures of their health and development. Recent assessments have included a broad Address for correspondence: range of studies in the psychosocial, behavioural medicine Dunedin School of Medicine and biomedical research areas. The age 32 assessment phase University of Otago (2003/2005) was an outstanding success with 96% of the PO Box 913, Dunedin, New Zealand surviving Study members being assessed. [email protected] * Presented at the Twenty-first Convocation of the Royal Australasian College of Dental Surgeons, Queenstown, New Zealand, 31 March - 4 April 2012

126 ABSTRACTS OF PAPERS MUCO-GINGIVAL DEFECTS: RISK, EVALUATION, MANAGEMENT AND OUTCOMES Dr Helen English, BDS, MDS(Perio), FRACDS(Perio)* Dr English is a specialist periodontist. She established Nelson Periodontics, the only private specialist periodontal and dental implant surgery practice in the top of the South Island, New Zealand. As our society becomes increasingly more aware of the progression of muco-gingival defects, along with discussion health and function of their dentition and the aesthetics of of an evidence-based clinical assessment pathway to aid their smile, muco-gingival defects such as recession or lack treatment planning and determine which defects require of attached gingiva are of growing concern to patients. These intervention and why. The current techniques (including both defects may be congenital, developmental, or acquired, and conservative approaches and periodontal plastic surgical can occur around natural teeth, implants, or in edentulous procedures) utilized in the management of problematic ridges. Although frequently localized to soft tissues, they muco-gingival defects are examined. Finally, the expected are also often associated with defects in the underlying bone success outcomes of each interventive strategy and the long- and will show different degrees of severity depending on the term prognosis of muco-gingival defects following treatment individual biology and aetiology. As a result, muco-gingival are reviewed. defects form one of the challenges that both the general dentist and specialist practitioner face. Address for correspondence: 2 Brougham St Risk assessment and identification are critical components Nelson, New Zealand of the clinical decision-making process and are vital in [email protected] optimizing delivery of patient care. This paper examines the existing methods available to assess the likelihood of future FURCATION INVOLVEMENT: TOOTH ASSESSMENT, PROGNOSIS AND MANAGEMENT. WHEN IS IT TIME FOR IMPLANTS?* Andre Bendyk, BDS(Adel), FRACDS(Perio), DClinDent(Perio)* Dr Andre Bendyk maintains a full time specialist private practice limited to Periodontics and Implant Dentistry in Adelaide. He is a past president of the Australian Society of Periodontology (SA Branch) and lecturer in Periodontology at the University of Adelaide. The anatomy of the furcation favours retention of bacterial Long-term prognosis of furcation involved teeth depends deposits and makes both oral hygiene and periodontal de- on multiple factors but is largely influenced by the trajec- bridement difficult. Whilst furcation involvement is a risk tory of the disease process in each individual patient. Whilst factor for future tooth loss it has been shown conclusively each case must be considered individually evidence does not that with appropriate treatment and then thorough ongo- currently support the principle of early removal of furcation ing periodontal maintenance most furcation involved teeth involved molars for implant replacement. can be maintained in the longer term. This presentation dis- cusses furcation anatomy and local factors which predispose Address for correspondence: to periodontal furcation involvement. Clinically applicable Adelaide Periodontal and Implant Professionals treatment options are presented in detail along with their lim- Ground Floor, 186 Pulteney Street itations. Periodontal regeneration techniques currently have Adelaide, South Australia 5000 a narrow range of usefulness in furcation defects, limited [email protected] predominantly to isolated Grade II furcation involvement.

ABSTRACTS OF PAPERS 127 A CASE STUDY OF INTERDISCIPLINARY TREATMENT INVOLVING SURGERY, ORTHODONTICS, PROSTHODONTICS OVER 18 YEARS Susan Needham, BDSc, MDSc, FRACDS* Susan Needham has been a consultant orthodontist to the Royal Children’s Hospital, Melbourne since 1996. Her areas of interest are hypodontia, cleft care and naso-alveolar moulding, a type of infant pre-surgical orthopaedics. She also maintains a private specialist orthodontic practice in Brighton, Melbourne. A case report of an interdisciplinary management Address for correspondence: spanning over 20 years is presented. The case follows 313 New Street the patient with complex medical and dental conditions Brighton from birth to adulthood. It highlights the need for careful Victoria 3186 planning, constant review and a preparedness to change [email protected] treatment plans as outcomes evolve and the patient needs alter. Above all, it emphasizes the role of a team approach and good communication between all disciplines involved and the patient and the family..

Ann Roy Australas Coll Dent Surg 2012;21:128 ANNALS OF THE ROYAL AUSTRALASIAN COLLEGE OF DENTAL SURGEONS VOLUME 21 APRIL 2012 SCIENTIFIC PROGRAMME - PAPERS AND ABSTRACTS CONTRIBUTORS’ INDEX Abbott PV ........................................................... 101 Madsen D ............................................................ 111 Banerjee A ............................................................. 43 Mahoney E ............................................................ 56 Bendyk A ............................................................. 126 Manton DJ ........................................................... 120 Borromeo GL ........................................................ 77 Meyers IA .............................................................. 94 Burrow MF ..................................................... 97,120 Mistry S ............................................................... 124 Cullinan M ............................................................ 85 Naish T .................................................................. 23 Danesh-Meyer M ................................................ 106 Needham S .......................................................... 127 De Silva HL .......................................................... 60 Neill A ................................................................... 63 English H ............................................................ 126 Nolan A ................................................................. 58 Foster Page LA ...................................................... 53 Palamara J ........................................................... 120 Gillingham W ........................................................ 64 Papapanou P N ...................................................... 33 Hanlin SM ............................................................. 49 Peake GG ............................................................ 109 Harding W ............................................................. 51 Poulton G ............................................................ 125 Holcombe T ......................................................... 124 Punshon K ............................................................. 70 Ivanovski S ............................................................ 81 Schifter M ............................................................. 91 Kim Seow W ....................................................... 124 Shand J ................................................................ 125 Kingon A ............................................................... 88 Shnider W ............................................................. 66 Kumar H .............................................................. 120 Tarraf N ............................................................... 113 Love RM ............................................................. 103 Ting G ................................................................... 72 All rights reserved. No part of this publication may be reproduced in any material form or by any means (graphic, electronic, or mechanical including photocopying, recording, taping, or information and retrieval systems) without the written permission of the Royal Australasian College of Dental Surgeons. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the College. Photographs taken at the opening ceremony are copyright to Stephen D Barnby, Steve’s Photography, Perth The publication of statements, opinions or other material in this work carries no representation by or on behalf of the Royal Australasian College of Dental Surgeons express or implied of any belief in their truth or otherwise, in whole or in part, unless an express statement to that effect accompanies the item in question. Printed and published by the Proprietors, the Royal Australasian College of Dental Surgeons ROYAL AUSTRALASIAN COLLEGE OF DENTAL SURGEONS Incorporated Level 13/37 York Street, Sydney, New South Wales 2000 Australia Telephone: (02) 9262 6044 Facsimile: (02) 9262 1974 Email: [email protected] Website: http://www.racds.org