Bifid Mandibular Canal: A Case Review and Retrospective Review of CBCTs

This case presentation and retrospective review of cone-beam computed tomograms is to evaluate prevalence, classification, and demographics of bifid mandibular canals (BMC) to inform practitioners on this variation and avoid untoward complications due to failure to diagnose.

Two thousand one hundred thirty scans were evaluated by 2 oral and maxillofacial radiologists. BMCs were noted and classified according to Naitoh. Demographic data were also collected and analyzed.

Twenty-eight patients were noted to have bifid mandibular canal, with an average age of 39 years (± 19.5), with no strong sex predilection. Patients (1.31%) were noted to have bifid canals. A greater percentage of patients were shown to have bilateral bifid canals (42.9%) versus either unilateral side (25% left, 32.1% right), but is statistically insignificant. Prevalence was greatest in types 1 and 3 (35.9% and 51.3%, respectively, P = 0.000011). Types 2 and 4 were much less common.

BMCs are an important anatomic variation that has implications on any mandibular surgery, including implant surgery. Just more than 1% of patients have this variation, but failure to recognize this in a patient can result in poor outcome, as illustrated in the case presented.