High- Risk Factors Associated with Inferior Alveolar Nerve Injury Following Removal of the Third Molars: A Preliminary Study

Year 2023, Volume: 50 Issue: Suppl 1, 6 - 9, 06.12.2023

Nezaket Ezgi Özer , Meltem Özden Yüce , Hayal Boyacıoğlu , Betül Karaca , Pelin Güneri

https://doi.org/10.52037/eads.2023.0012

Abstract

PURPOSE: This study aims to determine the incidence of inferior alveolar nerve (IAN) injury following the extraction of the lower third molars (LTMs) and to identify the demographic, radiographic, and intra-operative risk factors associated with this complication.
MATERIALS & METHODS: Fifty LTMs from 47 patients were included in this prospective clinical study. Demographic data and intra-operative parameters including operation time, bone removal and duration, excessive bleeding and IAN exposure were recorded. Bone retention, anatomical position of LTMs (Pell&Gregory and Winter classification) and 5 radiographic criteria proposed by Rood and Shehab were evaluated on panoramic images, whereas the distance between roots and the inferior alveolar canal (IAC), the cortication status of IAC, and the buccolingual position of IAC were examined on CBCT images. Chi-square test was used to compare the presence of IAN injury with variables. A p-value < 0.05 was considered as statistically significant.
RESULTS: The incidence of temporary IAN injury was 6% among study population. No permanent IAN injury was observed. Excessive bleeding (p=0.007), IAN exposure (p=0.007), the lingual position of IAC (p=0.035) and dumbbell-shaped IAC (p=0.002) were found to be associated with increased risk of temporary IAN injury.
CONCLUSION: Identification of high-risk factors is essential for predicting the risk of IAN injury, and determining the most convenient treatment plan for each case. Further studies with larger study samples are needed both to confirm the risk factors that are proposed in the present study and to identify the other potential ones.

Keywords

third molars, inferior alveolar nerve injury, paresthesia

References

• 1. 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):320‐326.
• 2. Kang F, Sah MK, Fei G. Determining the risk relationship associated with inferior alveolar nerve injury following removal of mandibular third molar teeth: A systematic review. J Stomatol Oral Maxillofac Surg. 2020 Feb;121(1):63-69.
• 3. Matzen LH, Petersen LB, Schropp L, Wenzel A. Mandibular canal-related parameters interpreted in panoramic images and CBCT of mandibular third molars as risk factors to predict sensory disturbances of the inferior alveolar nerve. Int J Oral Maxillofac Surg. 2019;48(8):1094‐1101.
• 4. Tachinami H, Tomihara K, Fujiwara K, Nakamori K, Noguchi M. Combined preoperative measurement of three inferior alveolar canal factors using computed tomography predicts the risk of inferior alveolar nerve injury during lower third molar extraction. Int J Oral Maxillofac Surg. 2017 Nov;46(11):1479-1483.
• 5.Ramesh A. Panoramic Imagining. In: Mallya S, Lam E, editors. White and Pharoah’s Oral Radiology Principles and Interpretation , 2018. p.136-137.
• 6. Hasegawa T, Ri S, Shigeta T, Akashi M, Imai Y, Kakei Y, et al. Risk factors associated with inferior alveolar nerve injury after extraction of the mandibular third molar--a comparative study of preoperative images by panoramic radiography and computed tomography. Int J Oral Maxillofac Surg. 2013 Jul;42(7):843-51.
• 7. Rood JP, Shehab BA. The radiological prediction of inferior alveolar nerve injury during third molar surgery. Br J Oral Maxillofac Surg 1990; 28:20–25.
• 8. Ueda M, Nakamori K, Shiratori K, et al: Clinical significance of computed tomographic assessment and anatomic features of the inferior alveolar canal as risk factors for injury of the inferior alveolar nerve at third molar surgery. J Oral Maxillofac Surg 70:514, 2012.