Comparative Evaluation of Buccal Cortical Bone Thickness in the Posterior Mandible Across Skeletal Patterns: A CBCT Study in a Sample of Iranians.

Purpose: This study aimed to evaluate buccal cortical bone thickness in the posterior mandible across different sagittal and vertical skeletal patterns using cone-beam computed tomography (CBCT).

Materials and methods: In this retrospective observational study, cortical buccal bone thickness between posterior teeth was assessed at 4 and 7 mm distances from the alveolar crest using CBCT images of 112 Iranian participants aged 18-60 years. Participants were classified into six groups: Class I normal angle, Class I low angle, Class I high angle, Class II normal angle, Class II low angle, and Class II high angle. Statistical analyses included the Shapiro-Wilk test, Levene's test, multivariate analysis of variance (MANOVA), paired-sample t-test, and intraclass correlation coefficient (ICC), with a significance level set at α = 0.05.

Results: Cortical bone thickness generally increased from anterior to posterior regions and from the alveolar crest toward the basal jaw in Class II and both high- and low-angle groups, with exceptions observed in Class I and normal-angle individuals. Statistically significant differences in cortical bone thickness were observed between Class I and Class II skeletal patterns at specific posterior sites, with Class I individuals consistently exhibiting greater thickness. Differences related to vertical skeletal pattern were limited, observed only at the distal canine (4-mm level). Sex, age, and side-to-side differences influenced cortical thickness in certain regions, with slightly greater thickness on the left side at some measurement sites.

Conclusions: Buccal cortical bone thickness in the posterior mandible varies significantly with the sagittal skeletal pattern, whereas the vertical skeletal pattern has minimal influence.