It is difficult to correlate the direction of mandibular canal branches (MCBs) with altered sensation in dental treatments. In contrast, calcitonin gene–related peptide (CGRP) is related to vasodilation, bone formation, and the interaction with the peripheral nervous system. Therefore, we investigated the detailed morphological characteristics of MCBs using cone-beam computed tomography (CBCT) and observation of the CGRP distribution around the MCB. The MCB measurements were evaluated using principal component analysis (PCA) to identify morphological correlations. A total of 168 sides of mandibles from 84 cadavers were analyzed in this study. Most of the MCBs were primarily in the direction of the clock model from X to XI in sagittal sections and XII to I in coronal sections of the mandible. The structure of the MCB was divided into the fine canal branch (60.4%, 223/369), partial branch (24.4%, 90/369), and no canal branch (15.2%, 56/369). PCA indicated that the measurement element with the MCB and its structures were correlated in contrast to tooth factors. Positive CGRP reactions were clearly observed in the no-canal branch group compared to other groups. These data provide useful suggestions for MCB dynamics and information for clinical dental treatment.
Morphological Observations of the Bony Canal Structure of the Eustachian Tube in Elderly Human Cadavers With Cone-Beam Computed Tomography and Principal Component Analysis
