牙周病患者正畸前后牙槽骨密度变化的CBCT研究

目的 牙周病正畸治疗中,在严格控制炎症和正畸力的情况下,牙齿松动度仍然增加,本研究旨在从牙槽骨骨密度变化方面对其机制进行初步探讨.方法 选择牙周病正畸治疗者20例,牙周健康正畸者为对照组21例,应用锥束CT（cone beam computed tomography,CBCT）,在正畸治疗的第一期排齐阶段前后拍摄,使用头影测量方法原理,在CBCT图像的选定截面定点,对上下颌前牙区牙槽间隔骨密度进行测量,同时记录相关的临床牙周指标,采用SPSSl6.0软件包分析,以配对t检验和独立样本t检验比较两组内和组间的牙槽骨密度的差异,Pearson相关分析评价骨密度与临床指标间的相关性.结果 治疗前牙周病组和对照组骨密度无明显差别（P＞0.05）,治疗后牙槽骨密度降低量为牙周病组（-18.94±30.81）显著大于对照组（-11.35±31.55）（P＜0.05）,牙周病组牙松动度有明显增加（P＜0.05）.结论 静止期牙周病牙槽骨在正畸力刺激下,牙槽骨密度明显降低.牙槽骨密度降低与牙齿松动度增加有显著相关,推测松动度增加可能由于骨密度降低引起,这方面值得进一步研究.

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.