Assessment of the inferior mandibular canal's position by Cone-Beam Computed Tomography

The knowledge of anatomic landmarks’ positions, including inferior alveolar nerve’s canal, is crucial for dentist, who has to master it. It is important to know the exact location and anatomic variety of this canal for different procedures of mandibular surgeries. The aim of the present study was to evaluate inferior mandibular canal’s anatomic position by Cone-beam Computed Tomography (CBCT).
In a cross sectional study, CBCT were taken and assessed from 130 patients (260 semi-arch) aged more than 18 years old referring to the radiologic department of Shahid Beheshti Dental Faculty. Three points including 1cm before mental foramen (point A), under second molar’s furcation (point B) and 1cm after mandibular foramen on the inferior alveolar canal (point C) were chosen, where the canal diameter and the distance between the canal and inferior border of mandible were measured. Canal length was also measured. SPSS version 19 software was used for data analysis and the role of variables including age, gender, canal length and jaw side were evaluated by t-test and variance analysis.
Patients’ age mean was 43.73±13.25. Patients’ mandibular canal length’s mean in this study was 61.71± 4.95. The mandibular canal’s mean diameter was 2.94 mm ± 0.58, and the mean value of the distance between the canal and the inferior border of mandible was 9.47 ± 2.23 mm. There was a significant difference between men and women for all parameters, and particularly concerning the mandibular canal length and the distance between the canal and the inferior border of mandible in C point, both sides; this significant difference was also clinically important. Regarding the distance between the inferior border of mandible and mandibular canal in A, B and C points, there was a significant difference between different groups of age. The distance between the canal and the inferior border in C point and at mental foramen in cases with short canal length and those with long canal length showed a significant difference. And finally, in data analysis of each side separately, none of the variables showed significant difference between right and left sides.