• Regina LandesbergEmail author


Coronectomy (partial odontectomy, intentional root retention) was developed primarily as an alternative to complete surgical removal of mandibular third molars that decreases the incidence of temporary/permanent paresthesia/anesthesia in cases where there is significant risk of damage to the inferior alveolar nerve (IAN). Originally described in the English literature in 1989 by Knutsson et al. (Swed Dent J 13:15–221, 1989), the technique still has not achieved wide acceptance likely due to the minimal number of randomized controlled trials (RCT). This chapter will review the strengths/weaknesses of the available RCT and available case control trials (CCT) and summarize the indications, contraindications, complications, and outcomes as well the variations in techniques that have been reported for this procedure.


Coronectomy Partial odontectomy Intentional root retention Inferior alveolar nerve Third molar 


  1. 1.
    Queral-Godoy E, Valmaseda-Castellón E, Berini-Aytés L, Gay-Escoda C. Incidence and evolution of inferior alveolar nerve lesions following lower third molar extraction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005;99(3):259–64.CrossRefGoogle Scholar
  2. 2.
    Leung YY, Cheung LK. Risk factors of neurosensory deficits in lower third molar surgery: an literature review of prospective studies. Int J Oral Maxillofac Surg. 2011;40(1):1–10.CrossRefGoogle Scholar
  3. 3.
    Cheung LK, Leung YY, Chow LK, Wong MC, Chan EK, Fok YH. Incidence of neurosensory deficits and recovery after lower third molar surgery: a prospective clinical study of 4338 cases. Int J Oral Maxillofac Surg. 2010;39(4):320–6.CrossRefGoogle Scholar
  4. 4.
    Knutsson K, Lysell L, Rohlin M. Postoperative status after partial removal of the mandibular third molar. Swed Dent J. 1989;13(1-2):15–22.PubMedGoogle Scholar
  5. 5.
    Dalle Carbonare M, Zavattini A, Duncan M, Williams M, Moody A. Injury to the inferior alveolar and lingual nerves in successful and failed coronectomies: systematic review. Br J Oral Maxillofac Surg. 2017;55(9):892–8.CrossRefGoogle Scholar
  6. 6.
    Long H, Zhou Y, Liao L, Pyakurel U, Wang Y, Lai W. Coronectomy vs. total removal for third molar extraction: a systematic review. J Dent Res. 2012;91(7):659–65.CrossRefGoogle Scholar
  7. 7.
    Leung YY, Cheung LK. Safety of coronectomy versus excision of wisdom teeth: a randomized controlled trial. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;108(6):21–7.CrossRefGoogle Scholar
  8. 8.
    Renton T, Hankins M, Sproate C, McGurk M. A randomised controlled clinical trial to compare the incidence of injury to the inferior alveolar nerve as a result of coronectomy and removal of mandibular third molars. Br J Oral Maxillofac Surg. 2005;43(1):7–12.CrossRefGoogle Scholar
  9. 9.
    Leung YY, Cheung KY. Root migration pattern after third molar coronectomy: a long-term analysis. Int J Oral Maxillofac Surg. 2018;47(6):802–8.CrossRefGoogle Scholar
  10. 10.
    Rood JP, Shehab BA. The radiological prediction of inferior alveolar nerve injury during third molar surgery. Br J Oral Maxillofac Surg. 1990;28(1):20–5.CrossRefGoogle Scholar
  11. 11.
    Sedaghatfar M, August MA, Dodson TB. Panoramic radiographic findings as predictors of inferior alveolar nerve exposure following third molar extraction. J Oral Maxillofac Surg. 2005;63(1):3–7.CrossRefGoogle Scholar
  12. 12.
    Matzen LH, Christensen J, Hintze H, Schou S, Wenzel A. Influence of cone beam CT on treatment plan before surgical intervention of mandibular third molars and impact of radiographic factors on deciding on coronectomy vs surgical removal. Dentomaxillofac Radiol. 2013;42(1):98870341.CrossRefGoogle Scholar
  13. 13.
    Monaco G, Vignudelli E, Diazzi M, Marchetti C, Corinaldesi G. Coronectomy of mandibular third molars: a clinical protocol to avoid inferior alveolar nerve injury. J Craniomaxillofac Surg. 2015;43(8):1694–9.CrossRefGoogle Scholar
  14. 14.
    Patel V, Gleeson CF, Kwok J, Sproat C. Coronectomy practice. Paper 2: complications and long term management. Br J Oral Maxillofac Surg. 2013;51(4):347–52.CrossRefGoogle Scholar
  15. 15.
    Gady J, Fletcher MC. Coronectomy: indications, outcomes, and description of techniqueAtlas Oral Maxillofac Surg Clin North Am. 2013;21(2):221–6.CrossRefGoogle Scholar
  16. 16.
    Pogrel MA. Coronectomy: partial odontectomy or intentional root retention. Oral Maxillofac Surg Clin North Am. 2015;27(3):373–82.CrossRefGoogle Scholar
  17. 17.
    Pogrel MA. Partial odontectomy. Oral Maxillofac Surg Clin North Am. 2007;19(1):85–91.CrossRefGoogle Scholar
  18. 18.
    Gleeson CF, Patel V, Kwok J, Sproat C. Coronectomy practice. Paper 1. Technique and trouble-shooting. Br J Oral Maxillofac Surg. 2012;50(8):739–44.CrossRefGoogle Scholar
  19. 19.
    Patel V, Sproat C, Kwok J, Beneng K, Thavaraj S, McGurk M. Histological evaluation of mandibular third molar roots retrieved after coronectomy. J Oral Maxillofac Surg. 2014;52(5):415–9.CrossRefGoogle Scholar
  20. 20.
    Vignudelli E, Monaco G, Mazzoni A, Marchetti C. Root fragment vitality after coronectomy: histological evidence in a case. J Oral Maxillofac Surg. 2015;73(11):2093.CrossRefGoogle Scholar
  21. 21.
    O’Riordan BC. Coronectomy (intentional partial odontectomy of lower third molars). Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;98(3):274–80.CrossRefGoogle Scholar
  22. 22.
    Pederson MH, Bak J, Matzen LH, Hartlev J, Bindslev J, Schou S, Nørholt SE. Coronectomy of mandibular third molars: a clinical and radiological study of 231 cases with a mean follow-up period of 5.7 years. Int J Oral Maxillofac Surg. 2018;47(12):1596–603.CrossRefGoogle Scholar
  23. 23.
    Yeung AWK, Wong NSM, Bornstein MM, Leung YY. Three-dimensional radiographic evaluation of root migration patterns 4-8.5 years after lower third molar coronectomy: a cone beam computed tomography study. Int J Oral Maxillofac Surg. 2018;47(9):1145–52.CrossRefGoogle Scholar
  24. 24.
    Cervera-Espert J, Pérez-Martínez S, Cervera-Ballester J, Peñarrocha-Oltra D, Peñarrocha-Diago M. Coronectomy of impacted mandibular third molars: a meta-analysis and systematic review of the literature. Med Oral Patol Oral Cir Bucal. 2016;21(4):e505–13.PubMedPubMedCentralGoogle Scholar
  25. 25.
    Hatano Y, Kurita K, Kuroiwa Y, Yuasa H, Ariji E. Clinical evaluations of coronectomy (intentional partial odontectomy) for mandibular third molars using dental computed tomography: a case-control study. J Oral Maxillofac Surg. 2009;67(9):1806–14.CrossRefGoogle Scholar
  26. 26.
    Cilasun U, Yildirim T, Guzeldemir E, Pektas ZO. Coronectomy in patients with high risk of inferior alveolar nerve injury diagnosed by computed tomography. J Oral Maxillofac Surg. 2011;69(6):1557–61.CrossRefGoogle Scholar
  27. 27.
    Kouwenberg AJ, Stroy LP, Rijt ED, Mensink G, Gooris PJ. Coronectomy of the mandibular third molar: respect for the inferior alveolar nerve. J Craniomaxillofac Surg. 2016;44(5):616–21.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Oral/Maxillofacial SurgerySimsburyUSA

Personalised recommendations