The Correlation Between Soft And Hard Tissue Changes Of Mandible Retruding Cases After Functional Treatment

Objectives: To evaluate the changes of soft tissue and hard tissue in curing Class II division 1 malocclusion cases with Headgear-activator appliance and Twin-block appliance, analyze the correlation between these changes, and provide the theoretical basis for predicting soft tissue changes by correcting hard tissue's abnormity. It is helpful to the effective treatment of mandible retruding cases in orthodontics clinical practice.Methods: Selecting 60 Class II division 1 malocclusion subjects whose hand-wrist radiographs were in FG-G stage. 20 of them who had abandoned treatments were put in the control group (C), and they were observed for 14.5 months without any treatments. The other 40 subjects were put in two groups randomly. One group was treated with Headgear-activator appliance (A) and another group was treated with Twin-block appliance (T). The time of treatment and retention were 14.2 months and 14 months. Selecting 29 soft tissue variables and 9 hard tissue variables to measure. All the subjects were taken head lateral projections with X-ray. Scanning the projections into computer and using special software to measure. Analyzing the acquired data of three groups statistically with SPSS 11.0.