Prevalence and topography of bifid and trifid mandibular canal in Turkish Western Anatolia Population: Evaluation of the inferior alveolar canal with CBCT

Abstract Purpose Various anatomical variations of the inferior alveolar canal increase the incidence of surgical complications; Therefore, this study aimed to evaluate the frequency and configuration of bifid and trifid mandibular canals using cone beam computed tomography (CBCT) in the Turkish subpopulation.Methods The inferior alveolar canal was evaluated on 1014 hemi-mandibles in the CBCT (I-CAT 3D Imaging System) images of 513 patients. The frequency and configuration of the bifid and trifid mandibular canal (MC) were examined. The relationship between bifid MC configuration and dental status and age groups was analyzed. The distance of the accessory canal to the buccal and lingual walls and to the alveolar crest was measured. The diameter of the main canal and accessory canal was measured and its relationship with dental status and age groups was evaluated.Results Bifid mandibular canal was found in 266 hemi-mandibles (24.7%) and 212 (41.3%) of 513 patients. The most common type of bifid MC was the retromolar canal (87 sides), followed by the forward canal without confluence (41; 4%) and the dental canal (34; 3.4%). 10 of the dental canals were opening to the 1st molar, 14 of the 2nd molars, and 10 of the 3rd molars. The number of retromolar foramina was 1 on 56 sides, 2 on 15 sides, and 3 on 4 sides. Forward canal without confluence was more common in edentulous patients than in dentulous patients, while the dental canal was more common in dentulous patients. The main canal diameter was 3.53 ± 0.97 mm and bifid MC diameter was 1.82 ± 0.70 mm. Distance of the bifid MC to the lingual wall was higher in > 64 years group than in 18–39 years group (p = 0.022). Distance of the bifid MC to the alveolar crest was lower in the > 64 years group compared to 18–39 years group and 40–64 years group (p = 0.015). The main canal diameter was higher in 40–64 years group than in 18–39 years group (p = 0.012).Conclusion Bifid Mandibular canal has a high prevalence, occurring in almost one in two patients. Dental and retromolar types, which are close to the teeth, are more common, and this increases the possibility of complications. CBCT is the most accurate imaging technique used to detect and define these variations.