Proximity of the mandibular canal to the tooth apex

Introduction: Knowledge of the inferior alveolar nerve (IAN) position is important in avoiding nerve damage during invasive dental procedures. Because the exact position of the nerve bundle can vary in patients, this study evaluated the distance from the apices of mandibular premolar and molar teeth to the superior border of the mandibular canal. Methods: Cone-beam computed tomography (CBCT) scans from 139 patients were analyzed to evaluate the proximity of the mandibular canal to the root apices of 743 mandibular second premolar and first and second molar teeth. Subjects were subgrouped by age and sex. A random intercept model was used to account for multiple measurements within a patient. Results: In all groups, root apices of the mandibular second molars were closer to the mandibular canal than other teeth. The mesial root of the second molar was closer to the nerve in female patients compared with male patients. Root apices in younger patients (<18 years) were generally closer to the mandibular canal than in older patients. Conclusions: The CBCT scan is an accurate, noninvasive method to evaluate the position of the mandibular canal. The variable position of this structure between patients suggests the need for CBCT to determine the proximity of the nerve bundle before attempting invasive treatment in this area. Dental practitioners should consider potential differences of mandibular canal position as a result of age and gender when performing these procedures in this area.