Abstract:

Objective: To investigate the effect of the scissors bite and crossbite occlusion on the symmetric development of the mandible. Methods: The mandibular asymmetry was measured by the panoramic X-ray images of 87 orthodontic patients. The patients were divided into control group(n=28), crossbite group(n=23) and scissors bite group(n=36). The data of ascending ramus, condylar process, and asymmetric index of mandibular height were analyzed statistically. Results: It showed that age had nothing to do with the symmetry of mandible, but the gender was significantly different in the symmetry index of condylar process in the scissors bite group（P<0.05）. There was no statistical difference in mandibular ramus and asymmetric index of mandibular height between the control group, the scissors bite group and the crossbite group, while there was a statistical difference in the asymmetry of condylar process between the control group and the scissors bite group. Conclusion: Patients with unilateral scissors bite can cause the asymmetry of the condyle which needs to be paid more attention in clinical practice.

Key words: scissors bite, crossbite, temporomandibular joint, condyle, symmetry

摘要：

目的：通过对正锁𬌗、反𬌗患者与磨牙中性关系者进行比较，探究其是否对下颌骨对称性发育有影响。方法：选取87例正畸患者的全景X线片资料，进行下颌不对称性测量。将患者分为对照组（28例）、反𬌗组（23例）及正锁𬌗组（36例），对各组男性与女性下颌升支、髁突及下颌高度不对称指数进行统计学分析。结果：患者年龄与下颌骨对称性无关；正锁𬌗组男性与女性髁突对称性指数差异存在统计学意义（P<0.05）。3组间的下颌升支、下颌高度不对称指数差异无统计学意义（P>0.05），而对照组与正锁𬌗组髁突不对称指数的差异存在统计学意义。结论：单侧正锁𬌗可引起患者髁突的不对称，临床上需引起重视。

关键词: 正锁牙合, 反牙合, 颞下颌关节, 髁突, 对称性