Inferior alveolar nerve injury in impacted mandibular third molar: Prevalence and associations
DOI:
https://doi.org/10.30442/Keywords:
Impacted mandibular third molar, Inferior alveolar canal, Inferior alveolar nerve injury, Radiographic prediction sign, Risk factorAbstract
Background: Injury to the inferior alveolar nerve can occur as a result of proximity of the root of the impacted mandibular third molar to the canal.
Objectives: This study aims to prospectively assess injury to the inferior alveolar nerve due to its proximity to the root of the impacted mandibular third molar as well as associated risk factors.
Methods: This was a double-blind observational study to assess injury to the inferior alveolar nerve after the surgical removal of the impacted mandibular third molar. Subjects who met the inclusion criteria were evaluated for lower lip numbness before and after the surgery. Data were analysed using IBM SPSS Statistics for Windows, Version 25.0. The level of significance was set at p<0.05.
Results: 123 impacted mandibular third molars were extracted. There were 39 (31.7%) males and 84 (68.3%) females, with ages ranging from 18 to 66 years and a mean (±SD) age of 24.82 (±9.18). The most common radiographic prediction sign was darkening of the root apex, observed in 72 (58.5%) cases. The 2 (1.6%) subjects who experienced inferior alveolar nerve injury, had diversion of the inferior alveolar canal as their radiographic prediction sign, and this was statistical significance (p=0.001).
Conclusion: Injury to the inferior alveolar nerve is a nuisance to both the surgeon and patient. It is important for the surgeon to be familiar with the risk factors associated with developing injury and inform patient accordingly
References
1. Sarikov R, Juodzbalys G. Inferior alveolar nerve injury after mandibular third molar extraction: a literature review. J Oral Maxillofac Res. 2014;5(4):1-15. doi:10.5037/jomr.2014.5401.
2. Kuang S, Liu Y, Zhuang W, Li K, Yang W, Tian Y. The effect of root orientation on inferior alveolar nerve injury after extraction of impacted mandibular third molars based on propensity score-matched analysis: a retrospective cohort study. BMC Oral Health. 2023;23:929-938. doi.org/10.1186/s12903-023-03661-0.
3. Kim HJ, Jo YJ, Choi JS, Kim HJ, Kim J, Moon SY. Anatomical risk factors of inferior alveolar nerve injury associated with surgical extraction of mandibular third molars. Appl Sci. 2021;11(2):816-831. doi:10.3390/app11020816.
4. Meshram VS, Meshram PV, Lambade P. Assessment of nerve injuries after surgical removal of mandibular third molar: a prospective study. Asian J Neurosci. 2013;1-6. doi.org/10.1155/2013/291926.
5. Apaydın BK, Icoz D, Uzun E, Orhan K. Investigation of the relationship between the mandibular third molar teeth and the inferior alveolar nerve using posteroanterior radiographs: a pilot study. BMC Oral Health. 2024;24:371-379. doi: 10.1186/s12903-024-04123-x.
6. Costa FWG, Fontenele EHL, Bezerra TP, Ribeiro TR, Carneiro BGDS, Soares ECS. Correlation between radiographic signs of third molar proximity with inferior alveolar nerve and postoperative occurrence of neurosensory disorders: a prospective double-blind study. Acta Cir Bras. 2013;28(3):221-227. doi: 10.1590/s0102-86502013000300011.
7. Rood JP, Shehab BAA. The radiological prediction of inferior alveolar nerve injury during
third molar surgery. Br J Oral Maxillofac Surg. 1990;28(1):20-25. doi:10.1016/0266-4356(90)90005-6.
8. Szalma J, Lempel E, Jeges S, Szabó G, Olasz L. The prognostic value of panoramic radiography of inferior alveolar nerve damage after mandibular third molar removal: a retrospective study of 400 cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;109(2):294-302. doi: 10.1016/j.tripleo.2009.09.023.
9. Blaeser BF, August MA, Donoff RB, Kaban LB, Dodson TB. Panoramic radiographic risk factors for inferior alveolar nerve injury after third molar extraction. J Oral Maxillofac Surg. 2003;61(4):417-421. doi:10.1053/joms.2003.50088.
10. Leung YY, Cheung LK. Risk factors of neurosensory deficits in lower third molar surgery: a literature review of prospective studies. Int J Oral Maxillofac Surg. 2011;40(1):1-10. doi: 10.1016/j.ijom.2010.09.005.
11. Kim JW, Cha IH, Kim SJ, Kim MR. Which risk factors are associated with neurosensory deficits of inferior alveolar nerve after mandibular third molar extraction? J Oral Maxillofac Surg. 2012;70(11):2508-2514. doi: 10.1016/j.joms.2012.06.004.
12. He H, Ruan N. Factors influencing inferior alveolar nerve injury after extraction of mandibular third molar. Med Oral Patol Oral Cir Bucal. 2024;29(5):e613-e619. doi: 10.4317/medoral.26576.
13. Israr M, Sattar N, Irfan M, Khan M, Rehman S. Inferior alveolar nerve deficit after removal of lower third molars: frequency and factors affecting nerve damage in a prospective clinical study of 1487 extractions in 1185 patients. J Khyber Coll Dent. 2021;11(2):59-65.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Annals of Health Research (The Journal of the Medical and Dental Consultants Association of Nigeria, OOUTH, Sagamu, Nigeria)
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
The articles and other materials published in the Annals of Health Research are protected by the Nigerian Copyright laws. The journal owns the copyright over every article, scientific and intellectual materials published in it. However, the journal grants all authors, users and researchers access to the materials published in the journal with the permission to copy, use and distribute the materials contained therein only for academic, scientific and non-commercial purposes.
