中文摘要：

目的 比较常规固定正畸治疗与舌侧正畸治疗对牙周状况的影响.方法 采取随机对照实验,将试验对象分成常规固定正畸治疗组和舌侧正畸治疗组,收集并比较两组患者治疗前后牙周指数的变化.结果 正畸治疗后牙周指数略高于治疗前,但差异无统计学意义（P〉0.05）.治疗后两组患者牙周状况差异无统计学意义（P〉0.05）.结论 固定正畸治疗对牙周状况无显著影响,常规固定正畸治疗与舌侧正畸治疗对牙周状况影响无明显区别.

英文摘要：

Objective To compare the effect of conventional fixed orthodontic treatment and lingual orthodontic treatment on periodontal status. Methods A randomized controlled trial was carried out,in which the subjects were divided into conventional orthodontic treatment group and lingual orthodontic treatment group and the changes of periodontal index were compared between the two groups before and after treatment. Results Orthodontic treatment of periodontal index was slightly higher than that before treatment（ P 〉 0.05 ）. There was no significant difference between the two groups after treatment （ P 〉 0.05 ）. Conclusion Fixed orthodontic treatment made no difference to periodontal status. There was no significant difference between conventional orthodontic treatment and lingual orthodontic treatment.