Analysis On Features Of Skeletal Class Ⅲ Malocclusion With Facial Asymmetrical

Objective: By measuring the line distance between the teeth,bone landmarks and reference plane of patients with skeletal Class Ⅲ malocclusion facial asymmetry,and studying the correlation between these and the degree of facial asymmetry,the characteristics of patients with facial asymmetry are analyzed.Method: We collected 51 CT images(20 males and 31 females)of adults with skeletal Class Ⅲ malocclusion in Xinjiang that meet the inclusion criteria,and then used Mimics Research 19.0 software for CT 3D reconstruction,and finally the line distance between the landmarks and the three reference planes were measured in Geomagic Wrap(64 bit).The data were analyzed by SPSS 21.0 statistical software.Results: The Rmn,Rma,Jr,Md F,Mt F,U6 MB to the sagittal plane(S)is greater than the opposite side in deviated side of the subjects in facial asymmetry group,the distance from Md F,Mt F to the coronal plane(C)is less than the opposite side of the deviation(P<0.05).Except for the distance between Mt F and sagittal plane(S),there was a difference between the left and right sides(P < 0.05)in facial symmetry group,and there was no statistically significant difference in the other measurement indicators(P > 0.05).In the facial asymmetry group,Me-S was strongly positively correlated with the Mt F-S in deviated side(r=0.805,p=0.000),and strongly negatively correlated with Mt F-S(r=-0.796,p=0.000)in the opposite side.Conclusion: In addition to the sagittal discrepancy,the facial asymmetry group is also accompanied by horizontal rotation and dental compensation.The degree of asymmetry can be judged according to Mt F-S.In the facial symmetry group,the upper and lower jaws were unbalanced in sagittal direction and the bilateral symmetry was better.