IMPACTED THIRD MOLARS Colgate Dental Education Programs Special Topic No. 16

arcpoh.adelaide.edu.au/dperu IMPACTED THIRD MOLARS

DECISION MAKING ON EXTRACTING Risks associated with third surgery IMPACTED THIRD MOLARS: INFORMATION In general, TME is accompanied with intra- operative and post-operative complications FOR DENTAL PRACTITIONERS which negatively impact on patients’ quality of life7. Although most of these complications are transient, some of them might persist for Third molar surgery is the longer periods or even become permanent. Current evidence for retention Most patients experience post-operative pain, most commonly performed oral versus prophylactic extraction swelling, , tenderness and tiredness. surgical procedure with most of -free Moreover, many patients (48%) experience a of the young adults having one periodontal defect distal to the second molar. impacted third molars Other complications might include alveolar 1 or more impacted third molars . A Cochrane review published in 2016 osteitis (2.7-26%), infection (0.7-4.2%) or When impacted third molars are investigated the impact of retention versus secondary bleeding (up to 5%). associated with pathology or prophylactic extraction of asymptomatic disease-free impacted third molars on The incidence of recurrent symptoms, there is a several outcomes5. The review identified injury varies from 0.35 to 8.4% however, consensus among clinicians about only two studies: a prospective cohort and most patients recover within 6-months post- 8 the need for extraction2. However, a randomized control trial (RCT), with operatively . Permanent inferior alveolar a follow-up period of more than 5-years. nerve injury, the most common cause of there is a debate regarding This review shows that there is no increase litigation in , is observed in 0.9% the need for prophylactically in the prevalence of dental caries among of patients undergoing TME9. To reduce removing asymptomatic disease- patients who retained versus removed, their the risk of inferior alveolar nerve injury, it is asymptomatic impacted third molar (soft recommended that a Cone Beam CT (CBCT) free impacted third molars. tissue or bony impacted), in the cohort scan be used when the Orthopantomogram study. Very low-quality evidence (obtained (OPG) shows that the third molar is close to from the same cohort study) indicates that the inferior alveolar nerve. The CBCT has a better risk prediction for inferior alveolar Unlike other countries including New retention versus prophylactic TME influences nerve injury than the OPG10. In situations Zealand3, Australia does not have guidelines for periodontitis of the second molar. However, where there is high risk of inferior alveolar third molar extraction (TME). Australia shows periodontitis is not considered as an indication nerve injury, coronectomy might be a safer high rates of TME under general anaesthesia for prophylactic TME as periodontitis is 6 option without increasing the risk of post- and most of these (85%) are prophylactic. treatable . Additionally, there was a minimal operative infection11. Moreover, lingual The estimated annual direct cost of TME is decrease in arch length (1.03mm) in those nerve injury risk varies based on the surgical $350 million4 in addition to other indirect who retained their asymptomatic impacted approach used with less risk associated with costs such as days absent from work/school third molars compared with those who had avoidance of lingual flap retraction during the and post-operative morbidities. Accordingly, them removed. A jaw dimension difference was surgery (2.6%) 12. Although most patients it is recommended that clinicians discuss reported in the RCT. However, the observed recover, 0.4% suffer permanent lingual nerve with their patients the current evidence on difference in arch length is believed to be damage12. the necessity for TME and explain risks and clinically insignificant as a cause of late teen 2 benefits of TME. Additionally, clinicians need crowding . No randomized clinical trials have Unusual complications can include to explore patients’ concerns and values and reported adverse events, risk of developing (0.0049-0.2%) which the best timing for TME. Also, patients need cysts, tumours, or inflammation/infection in is associated with patients’ age. There are to be aware that there are some indications retention versus prophylactic TME. Therefore, some case reports of severe infection, for prophylactic TME to facilitate orthodontic the current evidence does not support or displacement, aspiration of tooth fragments treatment, such as, gaining more arch length, refute the practice of prophylactic extraction and even death. There is a reported variability or in preparing for jaw correction surgeries. of asymptomatic disease-free impacted third in providing patients with information Discussing all aspects related to TME with the molars. regarding the risks associated with TME patient is important not only medico-legally among the oral and maxillofacial surgeons but also in improving the decision’s quality. consulted when gaining informed consent This pamphlet highlights the best available from patients for the TME procedure13. evidence for TME. The information provided here might help clinicians in better informing their patients about risks associated with TME. IMPACTED THIRD MOLARS

Orthodontic treatment and the Shared decision-making versus noting that patients who are privately insured decision on prophylactic third informed consent in third molar are more likely to adhere to their dentist’s recommendation for prophylactic TME than molar extraction extraction those who are not insured22. When a decision The current evidence does not justify The current clinical practice in informing is made to retain an asymptomatic impacted the practice of prophylactic extraction of patients about TME is via verbal consultation third molar, patients need to be aware that asymptomatic impacted mandibular third and information leaflets. The receipt of active surveillance is recommended every molars to prevent lower anterior teeth this information is then confirmed by the 2-years which includes thorough clinical and crowding after orthodontic treatment14. signing of the informed consent document. radiographic examinations5. Active monitoring Prophylactic TME might be performed Considering that clinics are often over- of the asymptomatic disease-free third molars to facilitate orthodontic treatment or jaw booked18, third molar patients might be every two years is argued to be a cost-effective correction surgery (orthognathic surgery). hindered in receiving adequate information19. alternative to prophylactic TME4. Figure 1 This includes moving the first/second molar As informed consent is medico-legally shows the decision tree for the management of distally to correct Class II or Class III molar important, patients and clinicians need to impacted third molars. relationship or gaining space to correct share the decision on TME. The uncertainty crowding without extracting functional about the evidence to recommend the removal premolars. The procedure of moving molars of asymptomatic disease-free impacted third distally is called molar distalization. Molar molars needs to be communicated clearly distalization is becoming popular, facilitated to patients as well as risks and benefits of by the availability of temporary skeletal receiving the surgery. Evidence suggests anchorage devices2. However, the decision that knowledge of third molar patients is should be based on the need for space gain positively associated with participation in of 3mm or less per quadrant, availability third molar extraction decision-making20. of distal bony support using Cone-Beam Therefore, patients should be encouraged CT scan and good anchorage2. If more to express their concerns and values and to space is needed, extraction of premolars is take an active role in third molar extraction recommended. If the decision is made to carry decision-making. When dental patients out prophylactic TME for molar distalization, are involved in dental treatment decision- it is recommended that this happens at making, it is associated with a better oral the age of 17-24 years for more treatment health-related quality of life21. It is worth compliance such as periodic device activation and immediately before distalization to reduce treatment time2. Decision Tree

Orthognathic surgeries might need prophylactic TME to prevent the potential Impacted of a bad bony split although there is a lack of TMs consistency in the published research data2. Repositioning the using a specific cut bilaterally on the ramus and body of the Recurrent symptoms or mandible is called Bilateral Sagittal Split Asymptomatic Osteotomy (BSSO)15. If the clinician and pathology TMs the patient agree on prophylactic TME in preparation for the BSSO, TME should be Orthodontic No TME recommended 6-months before the BSSO. Extraction This period will allow for a complete bone indications for TME indications remodelling. On the other hand, repositioning the mandible using a vertical cut in the ramus (Vertical Ramus Osteotomy) does not need Explain the uncertainity prophylactic TME as the operation is distant Extraction about prophylactic TME from third molars. Repositioning the maxilla before shared decision-making using a horizontal cut at the lateral maxillary buttress is called Le Fort I osteotomy16. The presence of maxillary impacted third molars might facilitate Le Fort I osteotomy17. Prophylactic TME Figure 1: Decision tree for the management of impacted third molars TM = Third Molar Active monitoring TME = Third Molar Extraction every 2-years Summary • Impacted third molars that are associated • Shared decision-making on third molar with recurrent symptoms or pathology are extraction might be an opportunity to recommended to be surgically extracted. improve the decision quality and thus, oral health-related quality of life. • For the asymptomatic disease-free impacted third molars, the current • If a patient, under the guidance of his/her evidence does not support or refute the experienced dentist/oral surgeon, decides practice of prophylactic extraction. to retain his/her asymptomatic disease-free impacted third molars, active surveillance • The uncertainty regarding retention versus every 2-years is recommended to eliminate prophylactic extraction of asymptomatic any potential adverse effects. disease-free impacted third molars should be clearly communicated to patients. • Further studies including well-designed randomized controlled trials or high • Patients need to be adequately informed quality long-term prospective cohort about the risks and benefits associated studies are required to improve decision- with third molar extraction. making on asymptomatic disease-free • There are considerations in performing impacted third molars. prophylactic third molar extraction for orthodontic treatment and/or preparation for orthognathic surgery that should be taken into account.

References 1. Dodson T, Susarla S. Impacted wisdom teeth. Clin Evid. 13. Badenoch-Jones EK, Lynham AJ, Loessner D. Consent for 2010;2010PMID: 21729337 third molar tooth extractions in Australia and New Zealand: a review of current practice. Aust Dent J. 2016;61(2):203- 2. Kim S-J, Hwang C-J, Park J-H, Kim H-J, Yu H-S. 207. PMID: 26031850. Surgical removal of asymptomatic impacted third molars: Considerations for orthodontists and oral surgeons. Seminars 14. Zawawi KH, Melis M. The Role of Mandibular Third in Orthodontics. 2016;22(1):75-83. Molars on Lower Anterior Teeth Crowding and Relapse after Orthodontic Treatment: A Systematic Review. The Scientific 3. NZ Ministry of Health. Operational guidlines: For the World Journal. 2014;2014:615429. PMID: 24883415. Combined Dental Agreement (CDA). In: Health Mo, ed. Wellington, New Zealand.20107. 15. Monson L. Bilateral Sagittal Split Osteotomy. Seminars in Plastic Surgery. 2013;27(3):145-148. PMID: 24872760. 4. Anjrini A, Kruger E, Tennant M. Cost effectiveness modelling of a ‘watchful monitoring strategy’ for impacted third molars 16. Buchanan E, Hyman CH. LeFort I Osteotomy. Seminars in vs prophylactic removal under GA: an Australian perspective. Plastic Surgery. 2013;27(3):149-154. PMID: 24872761. Br Dent J. 2015;219(1):19-23. PMID: 26159980. 17. Balaji SM. Influence of third molars in Le Fort 1 osteotomy. 5. Ghaeminia H, Perry J, Nienhuijs M, et al. Surgical removal Annals of Maxillofacial Surgery. 2011;1(2):136-144. PMID: versus retention for the management of asymptomatic 23482647. disease-free impacted wisdom teeth. Cochrane Database of Systematic Reviews. 2016;8. 18. Levinson W, Hudak P, Tricco A. A systematic review of surgeon-patient communication: strengths and opportunities FOR FURTHER ENQUIRIES 6. Friedman J. The prophylactic extraction of third molars: a for improvement. Patient Educ Couns. 2013;93(1):3-17. public health hazard. Am J Public Health. 2007;97(9):1554- PMID: 23867446. Dental Practice Education Research Unit 1559. PMID: 17666691 19. Ferrús-Torres E, Valmaseda-Castellón E, Berini-Aytés L, ARCPOH, Adelaide Dental School 7. Hanna K, Sambrook P, Armfield J, Brennan D. Exploring Gay-Escoda C. Informed consent in oral surgery: The The University of Adelaide, SA 5005 and modelling impacts of third molar experience on quality value of written information. J Oral Maxillofac Surg. of life: A real-time qualitative study using Twitter. Int Dent J. 2011;69(1):54-58. PMID: 21050650. 2017;67(5):272-280. PMID: 28338226 A joint program by 20. Hanna K, Sambrook P, Armfield J, Brennan D. Online Colgate Oral Care and The University of Adelaide 8. Sarikov R, Juodzbalys G. Inferior Alveolar Nerve Injury after resources provision and wisdom teeth extractions: A pilot Mandibular Third Molar Extraction: a Literature Review. randomized controlled trial. 57th Annual Scientific Meeting Journal of Oral & Maxillofacial Research. 2014;5(4):e1. of the International Association for Dental Research ANZ ENQUIRIES [email protected] PMCID: PMC4306319. Division. Adelaide: IADR-ANZ; 2017.

9. Brauer HU. Unusual complications associated with 21. Hanna K, Sambrook P, Armfield JM, Brennan D. Preferences TELEPHONE +61 8 8313 3291 third molar surgery: a systematic review. Quintessence for dental decisional control and associations with quality international. 2009;40(7):565-572. PMID: 19626231. of life among third molar patients attending public dental WEB adelaide.edu.au/arcpoh/dperu services. Community Dent Health. 2017;34(3):163-168. 10. Korkmaz YT, Kayipmaz S, Senel FC, Atasoy KT, Gumrukcu PMID: 28872811. © The University of Adelaide. Published December 2018. Z. Does additional cone beam computed tomography CRICOS 00123M decrease the risk of inferior alveolar nerve injury in high- 22. Cunha-Cruz J, Rothen M, Spiekerman C, Drangsholt M, risk cases undergoing third molar surgery?Does CBCT McClellan L, Huang GJ. Recommendations for third molar decrease the risk of IAN injury? Int J Oral Maxillofac Surg. removal: a practice-based cohort study. Am J Public Health. DISCLAIMER The information in this publication is current as 2017;46(5):628-635. PMID: 28174060 2014;104(4):735-743. PMC: 4025689. at the date of printing and is subject to change. You can find updated information on our website at or 11. Long H, Zhou Y, Liao L, Pyakurel U, Wang Y, Lai W. adelaide.edu.au contact us on 1800 061 459. The University of Adelaide assumes Coronectomy vs. total removal for third molar extraction: a Kamal Hanna, Australian Research Centre for Population Oral no responsibility for the accuracy of information provided by systematic review. J Dent Res. 2012;91(7):659-665. PMID: Health (ARCPOH), Adelaide Dental School, The University of third parties. 22622663. Adelaide.

12. Shad S, Shah SM, Alamgir, Abbasi MM. Frequency of lingual nerve injury in mandibular third molar extraction: A comparison of two surgical techniques. J Ayub Med Coll Abbottabad. 2015;27(3):580-583. PMID: 26721012