Spatial relationship between the root apices of mandibular teeth and the mandibular canal on CBCT reconstructions

Abstract Introduction: Close relationship between root apices of mandibular teeth and the mandibular canal is related to the risk of complications involving the inferior alveolar nerve. The objective of this study was to determine the spatial relationship of the root apices of mandibular teeth in relation to the mandibular canal. Materials and methods: On the frontal plane of 300 cone beam computed tomography (CBCT) scans, the spatial mutual position and measurements of the vertical and horizontal distance between the tooth root apices and the mandibular canal were determined. Results: For 23 root types out of 26, the roots of the mandibular teeth were found to exhibit a buccal orientation. The exceptions were the mesial roots of the 1st molars and the mesio-buccal roots of the 2nd molars on the right side, which showed a lingual orientation. The distances were measured for 2053 roots. For the teeth on the left side, the mean measurements ranged 0.23–3.77 mm for buccal roots, and the measurement was 0.21 mm for roots located lingually. For the teeth on the right side, the mean measurements ranged 0.38–2.93 mm for buccal rootsand 0.11–0.32 mm for lingual roots. Conclusions: The predominantly buccal orientation of the root apices of the mandibular teeth in relation to the mandibular canal was demonstrated.