BACKGROUND AND OBJECTIVE: Iatrogenic injury to the inferior alveolar nerve is one of the possible complications in surgical procedures such as implant placement. Considering the anatomic variety in nerve placement, the present study aims to assess the exact position of mandibular canal in the posterior mandibular body using cone beam computed tomography (CBCT).

METHODS: CBCT mandible images of 150 patients with mean age of 45 years were used in this cross-sectional study. The cross-sectional profiles of each patient were measured at intervals of 5 mm, starting from 1 mm before mental foramen to the anterior border of the ramus in two age groups, below 50 and above 50. In each profile, the distances from the walls of the mandibular canal to the cranial nerve (CN), inferior nerve (IN), buccal nerve (BN) and lingual nerve (LN) were measured.

FINDINGS: 70 men with mean age of 48.91±13.46 years and 80 women with mean age of 41.56±14.41 years participated in this study. The mean distances (mm) on the right and the left were respectively as follows: CN: 10.67±3.83, 10.38±3.73, BN: 4.44±1.42, 4.31±1.37, LN: 2.23±1.15, 2.42±1.23, and IN: 5.75±1.86, 5.63±1.86. According to the separate analysis of the profiles, the mandibular canal in men was more inclined to lingual nerve in buccolingual dimension and was more inclined to the top of the alveolar ridge in the inferior alveolar dimension. In terms of age, the bone in the cranial nerve (CN) in patients under 50 years in all profiles was significantly more than patients above 50 years (p<0.001).

CONCLUSION: According to the results of this study, age and sex may have significant effect on the position of inferior alveolar nerve and the use of 3D radiographies such as cone beam computed tomography is essential