Branching patterns of the inferior alveolar canal in a Thai population: a novel classification using cone beam computed tomography

Objective: This aim of this study was to determine the prevalence and branching patterns of the inferior alveolar canal (IAC) in premolar and molar areas using cone beam computed tomography (CBCT). Method and materials: CBCT volumes from partially or fully edentulous premolar and molar areas were investigated retrospectively. The presence of such branches with their patterns, sides, and areas, as well as the sex of the patient, were recorded by two observers and analyzed statistically. The branching patterns were initially classified into three types: A, superior type; B, forward type; and C, plexus type. During the investigation, an additional type was found in the premolar area and was classified as type D, an anterior extension type. Results: In total, 243 mandibular sites in 176 subjects were included. Among them, 106 sites displayed branches (43.62%). In the premolar area, most branches were of the anterior extension type (D, 33%), followed by the superior and plexus types (A and C, respectively, 29%), and the forward type (B, 9%). In the molar area, the plexus type was the most common finding (C, 39%), followed by the superior type (A, 32%) and the forward type (B, 29%). Branches in the molar area were significantly more frequent in men than in women (P = .011). Conclusion: IAC branches with four branching patterns in the premolar and molar areas are not rare and could be detected by CBCT. Clinicians should be aware of these branches during surgical procedures concerning the posterior mandible. Keywords: bifid mandibular canal, branching pattern of inferior alveolar canal, cone beam CT, inferior alveolar canal, trifid mandibular canal