Predictive Value of Panoramic Referral Signs for Inferior Alveolar Canal Contact in Impacted Mandibular Third Molars

Abstract

Background: To assess whether cone-beam computed tomography (CBCT) referrals for impacted mandibular third molars (IMTMs) are justified based on radiographic indications and to evaluate the diagnostic value of referral criteria in predicting inferior alveolar canal (IAC) contact.

Methods: This retrospective study analyzed 1200 IMTMs that underwent both panoramic radiography and CBCT between 2016 and 2025. Cone-beam computed tomography referral reasons were retrospectively categorized into 5 radiographic indicators: canal interruption, canal contraction, dark area, canal variation, and superposition. Winter and Pell & Gregory classifications were recorded from panoramic images. The presence of IAC contact was determined by CBCT and served as the reference standard. The association between panoramic indicators and CBCTconfirmed IAC contact was evaluated using chi-square analysis.

Results: Of the 1200 IMTMs evaluated, 86% demonstrated IAC contact on CBCT. Superimposition was the most frequent referral reason (77.4%) and accounted for the largest proportion of cases without confirmed contact. In contrast, canal interruption and canal contraction were associated with higher rates of confirmed contact. Winter and Pell & Gregory classifications showed limited value in discriminating cases with and without IAC contact. Overall, 14% of referred cases showed no contact on CBCT.

Conclusion: Panoramic indicators such as canal interruption and contraction are reliable predictors of IAC contact, while superposition alone often leads to unnecessary CBCT use. Classification systems offer limited diagnostic utility in imaging decisions. Objective, guideline-driven criteria and artificial intelligence–assisted triage tools may enhance referral accuracy and reduce radiation exposure in third molar assessment.

Cite this article as: Taşyapan SA, Kentkuran M, Çeki A, et al. Predictive value of panoramic referral signs for inferior alveolar canal contact in impacted mandibular third molars. Essent Dent. 2026, 5, 0002, doi: 10.5152/EssentDent.2026.26002.