Effects of orthodontics on dental alveolar bone density in patients with periodontitis: a cone beam computed tomography study

Objective To analyze the phenomenon that tooth mobility remarkable increased under a prerequisite for tooth movement in a non-active condition of periodontal disease, alveolar bone density was preliminarily investigated. Methods 20 patients with periodontal disease (group 1) and 21 patients with healthy periodontal tissue (group 2) were selected. CBCT (cone beam computed tomography) scanning were taken before and after the first stage of orthodontic treatment. The data were analyzed by SPSS16. 0 software package for paired t test and independent-samples t test, and Pearson correlation coefficient was used to study the relationships between alveolar bone density and clinical parameters. Results There were no significant differences in alveolar bone density between two groups before treatment (P＞0. 05); After treatment, bone density showed a statistically significant decrease in two groups, and the reduction was greater in group 1 than that in group 2 (P＜0. 05 ). Tooth mobility in group 1 showed a remarkable increase after treatment (P＜0. 05 ).Conclusions The alveolar bone density decreased through tooth movement in a non-active periodontal condition, and density reduction had a significant positive correlation with the increase of tooth mobility. The increase of tooth mobility may result from the reduction of alveolar density, which needs further study. Key words: CBCT;  Periodontal disease;  Dental alveolar bone density;  Tooth mobility;  Tooth movement