Assessment of mandibular canal proximity to molar root apices in a Turkish subpopulation: A cone-beam computed tomography study.

BACKGROUND The close anatomical relationship between root apices and the mandibular canal (MC) may be of clinical importance in preventing inferior alveolar nerve (IAN) injury during the root canal treatment (RCT) of mandibular molars.

OBJECTIVES The aim of the present study was to evaluate the impact of the mean distance between MC and the root apices of mandibular first and second molars on the risk of IAN injury during RCT in a Turkish subpopulation.

MATERIAL AND METHODS Cone-beam computed tomography (CBCT) images of 934 patients were evaluated. Mandibular molars were examined, and parasagittal sections were used to measure the shortest linear distance between the root apex and the superior cortical border of MC.

RESULTS The mesial and distal roots were closer to MC in the 18-25-year age group and in females (p < 0.05). Overall, 284 (10.5%) mesial roots were in intimate contact with or invading MC, and 80 (3.0%) were located very close to MC (<1.00 mm). Among distal roots, 328 (12.2%) were in intimate contact with or invading MC, 76 (2.8%) were very close to MC, and 2,288 (85.0%) were distant from MC.

CONCLUSIONS The risk of IAN injury during RCT was higher for the distal roots of second molar teeth, especially in the age group of 18-25 years and in female patients.