Detecting direct inferior alveolar nerve – Third molar contact and canal decorticalization by cone-beam computed tomography to predict postoperative sensory impairment

Abstract

BackgroundInjury to the inferior alveolar nerve (IAN) is a severe complication of third molar (M3) surgeries that may interfere with speech, chewing, and social interactions, all of which affect quality of life. Factors such as direct IAN-M3 contact and interruption of the mandibular canal border (decorticalization) diagnosed from cone-beam computed tomography (CBCT) images have been reported as risk factors, although their relation to postoperative sensory impairment is controversial. The purpose of this study was to assess the association between postoperative nerve injury and direct contact between IAN and M3 or canal decorticalization defined with CBCT. Materials and methodsSeventy-five patients with at least one M3 tooth (total of 126 teeth) in direct contact with the IAN were included in the study. All associations were confirmed with CBCT. Nerve injuries after surgery were confirmed and follow-ups were made with information given by patients, light touch, and pinprick tests. The relationship between sensory impairment and direct contact between IAN and M3 or canal decorticalization on CBCT images was statistically assessed. ResultsOne M3 extraction (0.8%) presented with postoperative permanent sensory impairment. No correlation between nerve injury and direct contact with the IAN or canal decorticalization on CBCT could be established. ConclusionThere is no association between nerve injury and direct IAN-M3 contact or canal decorticalization. Although orthopantomography is commonly used to plan M3 surgeries, consideration of CBCT as a viable alternative is warranted.