Configuration and Corticalization of the Mandibular Bifid Canal in a Taiwanese Adult Population: A Computed Tomography Study

Purpose: The configuration and degree of corticalization of bifid mandibular canals were examined using medical computed tomography (CT) images from 170 hemimandibles obtained from 308 Taiwanese adults. Materials and Methods: The configurations of the bifid canals were assessed according to their anatomical position in relation to the ramus, molars, premolars, and mental foramen; their course (anterior/posterior or superior/inferior); the presence or absence of confluence with the main mandibular canal; and the presence or absence of penetration through the mandible to form an accessory foramen. The percentage of the canal length that was corticalized was measured. Two different classifications of bifid canals were also briefly summarized and compared. Results: When bifid canals are present (41.2% of patients; 27.6% of hemimandibles), the bifid canals were primarily located in the ramus and retromolar regions (67.7%) running anteriorly (95.9%) and superiorly (95.9%) without confluence with the main mandibular canal (91.1%). Up to 16.5% of bifid canals form accessory foramina on the cortical surface of the mandible. Approximately 78% of the bifid canals have varied degrees of corticalization around the bifid canals. Conclusion: The configuration and course of 170 mandibular bifid canals were evaluated with CT images. The bifid canals were primarily located in the ramus and retromolar regions; however, 32.4% of the bifid canals were located in potential positions for dental implant placement. Most of the bifid canals ran anteriorly superior to the main mandibular canal, did not rejoin with the main mandibular canal, and diminished within the mandibular body. Approximately half of the bifid canals (45%) were completely corticated. Keywords: configuration, corticalization, mandibular bifid canal