Use of CBCT to evaluate the relationship between the mandibular canal and the roots of third molars

Abstract

Surgical procedures performed on the mandible require a detailed understanding of the position and course of the inferior alveolar canal (IAC). Third molar odontectomy is one of the most common procedures in oral surgery, yet it presents high variability in complications due to its close relationship with the inferior alveolar nerve (IAN). Cone-beam computed tomography (CBCT) has become a valuable diagnostic tool, allowing three-dimensional analysis of the proximity between third molar roots and the mandibular canal, overcoming the limitations of panoramic radiography. Objective: To determine the association between the mandibular canal and third molar roots using CBCT. Materials and Methods: An observational, cross-sectional, retrospective, descriptive, and correlational study was conducted. Thirty-two CBCT scans were selected from a database of 1,155 examinations obtained from the Department of Dentistry at Centro Médico Docente La Trinidad 2024. Each case was evaluated according to Nolla’s root development stage, Pell and Gregory’s classification, and nerve-to-root distance on axial, coronal, and sagittal planes. Results: Nolla stage 10 was the most frequent finding. Class III, Position C showed the greatest contact with the IAC, with an average distance of 0 mm (direct contact), while Class II, Position B showed a lower incidence of contact. Conclusions: CBCT is an essential diagnostic method for assessing the relationship between the roots of mandibular third molars and the IAC. In cases of direct contact, coronectomy represents a safe approach that significantly reduces the risk of neurosensory complications.