Comparative Study of soft and hard tissue changes after mandibular and bimaxillary orthognathic sugery

Objective To compare the changes of soft and hard tissues in patients with Skeletal Angle Class Ⅲ malocclusion following orthognathic surgery. Methods The cephalograms of Adult Skeletal Class Ⅲ malocclusion in 20 cases were measured and analyzed before and after operation. Results T G-Sn-Pg ',UL-E,Cm-Sn-UL,S-N'-Sn are different in two groups.B 'and B,PoS and Po,GnS and Gn,MeS and Me have dramatically correlations.The soft and hard tissue changes in the bimaxillary groups were smaller than mandibular group. Conclusion Bimaxillary surgery is better when the relationship of Skeletal Angle Class Ⅲ malocclusion. In the bimaxillary surgery,the displacement ratio of soft and hard tissue of upper jaw is smaller than the soft tissue of submaxilla and the ratio in maxillary surgery is bigger than bimaxillary surgery.In bimaxillary surgery,the mandibular have a stronger correlation with the corresponding than the upper jaw,and maxillary surgery have a dramatic correlation with the corresponding than bimaxillary surgery.