Morphological assessment of the mandibular canal trajectory in dentate subjects

The mandibular canal is the most important vital structure within the mandibular body. The aim of the present study was to determine the course of mandibular canal in relation to external surfaces of the mandible (buccal, lingual) and to root apices of the lateral teeth, in order to minimize the risk of its content being injured during either conservative or radical treatment of the mandibular lateral teeth.

Morphometric evaluations were performed on 11 dried dentate human mandibles and on cone-beam computed tomography (CBCT) cross-sectional images of the mandible, from 18 dentate patients. By means of both methods, the following parameters were assessed: (i) the distance between the mandibular canal and the buccal (lateral) surface of the mandible (MC-BS distance); (ii) the distance between the mandibular canal and the lingual (medial) surface of the mandible (MC-LS distance); (iii) the distance between the mandibular canal and the root apices of the second premolar, the first and second molars (MC-T distance). The results were statistically processed in Stata MP÷13 software package using analysis of variance (ANOVA).

With respect to buccal-lingual location, the mandibular canal passed horizontally through the mandibular trabecular bone, from posterior to anterior, and from lingual to lateral (buccal), and so at premolar level it approached the lateral (buccal) cortical bone plate, main topographic pattern found in 26 (89.65%) of the cases. The mandibular canal had a descending trajectory from the second molar to the first molar, after which it ascended slightly towards the second premolar, main topographic pattern found in 24 (82.75%) of the cases.

According to the results, the second mandibular molar is the most common tooth involved in the accidental damaging of the content of the mandibular canal, during various therapeutic procedures. Overlooking the location of the mandibular canal can lead to complications in endodontic therapy and in dentoalveolar surgical procedures in the posterior region of the mandible.