目的 了解北京地区正常(牙合)青少年下颌骨对称性随生长发育变化.方法 筛选正常(牙合)青少年样本36人(初始测量年龄为9～11岁).每年进行一次锥体束CT扫描.结果 下颌骨的22项距离测量项目和10项角度测量项目在连续三年的观察中,均无显著性差异.结论 正常(牙合)青少年的面部对称性在生长发育期,有些测量值的对称性在某一年有显著性差异,下颌骨结构呈对称性生长.“,”Objective To evaluate the change of the mandibular symmetry with growth in adolescents with normal occlusion in Beijing area.Methods 36 adolescents with normal occlusion (9-11 years were collected and observed for three years.The CBCT was taken every year for each subject.The mandibular symmetry was evaluated three-dimensionally.Results No significant difference was found in 22 linear and 10 angular measurements in the three consecutive years of observation.Conclusions Normal facial symmetry in a period of growth and development,some measurements about asymmetry in a given year had significant difference,but with the growth of the age,the growth of the mandible was symmetrical structure.