关键词: 下颌骨偏斜, 颏孔, 颏管, 颏成形术, 锥体束CT（CBCT）

Abstract:

Objective    To observe and measure the mandibular alveolar bone morphology at the area of mental foramen in the patients with mandibular deviation by CBCT to provide reference for genioplasty in orthognathic surgery，so as to reduce the complications such as the injury to nerves and blood vessels. Methods    In this study，84 adults with mandible deviation were selected，CBCT scans were conducted and InVivo 5 software was used to reconstruct the mandible；locate the markers；observe and measure and analyze the position of the mental foramen and the morphology of the mental canal. All the measurements were analyzed with SSPS 17.0 package. Results    The mental foramen was mostly below the second premolar at the mandibular（39.29%），and below the first premolar is the least（11.90%）. There was no significant difference between the oblique side and the contralateral side on all measurement values，in addition to the angle of the mental canal，the gender difference is significant，and it's much greater in males. Conclusion    There are some differences in the position of the mental foramen between the individuals of mandibular deviation deformity and the normal，and also are somewhat different between males and females. The CBCT imaging can clearly display the three-dimensional structure，the trend and the relationship with adjacent structures of the mental canal，which can effectively reduce or avoid the surgical complications.

Key words: mandibular deviation；mental foramen；mental canal；genioplasty；cone-beam computed tomography, CBCT