关键词: 不同年龄偏颌；正畸治疗；面部对称性, jaw deviation of different ages；orthdontic treatment；facial symmetry

Abstract: Objective This study was to designed to detect the changes on facial symmetry of patients with mandible deviation in different age groups who have received orthodontic treatment. PA cephalometic radiographs and facial photograms were compared before and after orthdontic treatment. Methods 40 patients with mandible deviation were included and divided equally into two groups by age: adolescent group and adult group (male and female were equal in each group). Every patient’s asymmetry ratio of the facial hard and soft tissue was calculated and analyzed with SPSS 13.0 software package with paried t test. Results Before orthdontic treatment, the asymmetry ratios of Mas and Max of patients in adolescent group were in the normal range ,while asymmetry ratios of Go and Ag were much higher than 5%, and the Me deviation was over 3.0mm. After the treatment, the abnormal ratios were obviously lowered. The data of facial photogram was in accordance with those of PA cephalometic radiograph. In the adult group, the asymmetry ratios of Mas, Max, Go and Ag were abnormal with the Me deviation over 3.0mm before orthdontic treatment. After the treatment, the abnormal ratios were lowered slightly. The data of facial photogram was in agreement with those of PA cephalometic radiograph while the ratios of soft tissue was slightly lower than those of hard tissue .Conclusions The facial asymmetry ratios of all patients with mandible deviation was lower amd lower from middle 1/3 to lower 1/3 of the face .The asymmetry ratios of the soft tissue in both groups were consistant with the hard tissue in each group, while soft tissue asymmetry ratio slightly lowered than hard tissue in adult group. The facial symmetry of adolescent patients was highly improved after orthdontic treatment, while the improvement in adult group was limited. Thus, the study suggested that early treatment of mandible deviation was very needed.