Vestibular bone thickness of the mandible in relation to the mandibular canal—a retrospective CBCT-based study

BACKGROUND: The aim of this study was to assess vestibular bone thickness of the mandible in relation to the mandibular canal and position of the mental foramen in relation to the neighbouring teeth. Measurements were performed on radiographic cone-beam computed tomography (CBCT) images. METHODS: This retrospective study analysed 314 CBCTs, having been taken at the Clinic of Cranio-Maxillofacial and Oral Surgery, University of Zurich, Switzerland. RESULTS: CBCTs from 168 female and 146 male patients (median age 40.2 years) were analysed. Median bone thickness lateral to the nerve canal to the buccal mandibular cortical plate was ~ 4 mm immediately posterior to the mental foramen, increased to ≤ 6 mm over the next 30 mm, then decreased to ~ 3 mm at the level of the mandibular foramen. In two thirds of cases, both mental foramina were located near the second premolar (66.2% right, 67.7% left). Bone thickness and the position of the mental foramen showed marked intra- and interindividual variance. CONCLUSIONS: A preoperative CBCT is recommended for detailed planning of surgical interventions that may reach the mandibular canal (e.g. wisdom teeth removal, root resection, implant placement, bone block harvesting).