The Buccolingual Course of the Mandibular Canal at Posterior Mandible

Objectives: Invasive surgical procedures may result in complications to the inferior alveolar nerve (IAN). This study quantified the buccolingual positions of the mandibular canal which contains the IAN, as it transverses the body of the mandible.
Methods: This study was conducted on 57 cone-beam computed tomography (CBCT) images. Measurements were done on cross-sectional mandibular images at positions inferior to the apices of all mandibular roots, with the mandibular canal being the reference landmark. At each location, four separate measurements were recorded: the buccal width, the diameter of mandibular canal, the lingual width, and the shortest distance from tooth apex to the mandibular canal. The width of the mandible was calculated, and a buccolingual ratio was derived using the buccal distance as the numerator over the mandible width.
Results: CBCTs of 19 females and 38 males were studied. There were no left and right side differences; the average buccolingual ratios of the mandibular canal were 0.40 for the second premolar, 0.45 for the mesial root of the first molar (M1M), 0.51 for the distal root of the first molar (M1D), 0.55 for the mesial root of the second molar (M2M), 0.54 for the distal root of the second molar (M2D), 0.48 for mesial root of the third molar (M3M) and 0.43 for the distal root of the third molar (M3D). The diameter of the mandibular canal ranged from 3.2mm (at M1) to 3.8mm (at M3).
Conclusions: The direction of the mandibular canal gradually changes from buccal to lingual and then back to buccal antero-posteriorly.