Alveolar bone mapping in subjects with different vertical facial dimensions.

OBJECTIVE The purpose of this study was to investigate differences in alveolar and skeletal dimensions among subjects with different vertical facial dimensions using cone beam computed tomography (CBCT). To date, this is the first study that investigates the relationship between facial type and posterior alveolar thickness in both maxilla and mandible, using CBCT data. MATERIALS AND METHODS From a sample of 152 CBCT scans, 45 scans were selected to be included in the study. CBCT-synthesized lateral cephalograms were used to categorize subjects into three groups based on their vertical skeletal pattern. Using iCATVision™ software, measurements of alveolar height and thickness were carried out in the entire tooth-bearing region. In addition, AutoCAD™ software was used to carry out measurements for the anatomical limitation to labio-lingual incisor movement. Kruskal-Wallis and Mann-Whitney U-tests with the Bonferroni adjustment were done for statistical analyses. RESULTS Compared to the other two groups, high-angle group had larger anterior dentoalveolar height with no significant differences in alveolar height posteriorly, in both the maxilla and mandible. Furthermore, high-angle group presented thinner alveolus anteriorly in the maxilla and at almost all sites in the mandible. Low-angle group had higher mean values for some measurements of the anatomical limitation to labio-lingual incisor movement for all upper and lower incisors. LIMITATIONS Inherent limitations of CBCT scanning as related to physical spatial resolution of the image and limitations posed by the study sample size should be considered. CONCLUSIONS There is a statistically significant relationship between facial type and alveolar height and thickness. High-angle subjects can be at increased risk of moving incisors beyond alveolar bone support when subjected to marked antero-posterior incisor movement.