Is cone beam computed tomography accurate in predicting inferior alveolar nerve exposure during third molar extraction?

Abstract

Abstract Objectives This study aims to evaluate the accuracy of cone beam computed tomography (CBCT) in predicting the exposure of inferior alveolar nerve (IAN) during complicated mandibular third molars (M3M) extraction. Methods 115 M3Ms with canal cortical defect (CCD) signs on CBCT were extracted. Candidate variables included basic information and CCD size. Primary outcome were IAN exposure and exposed IAN size measured under endoscope. Multivariate logistic and linear regression analyses were performed to identify the association between outcome and candidate variables. Results 85/115 M3Ms had intraoperative IAN exposure. The average length and width of exposed IAN were significantly smaller than those of CCD. Logistic regression showed that IAN exposure was significantly associated with the length of CCD on CBCT (P = 0.001). Linear regression analyses showed that the size of exposed IAN were significantly associated with the CCD length (P = 0.013) and width (P＜0.001). Conclusions The size of CCD on CBCT is larger than that of intraoperative exposed IAN. IAN exposure can be predicted by the length of CCD on preoperative CBCT. IAN exposure is prone to occur in cases with a length of CCD ≥ 3.4 mm on CBCT. Clinical Relevance: Endoscope provides the possibility to observe and record the IAN exposure directly. IAN exposure can be predicted by the length of CCD on preoperative CBCT. IAN exposure is prone to occur in cases with a length of CCD ≥ 3.4 mm on CBCT.