A Study Of Cephalometric Analysis On Skeletal Calls â…¡ Malocclusion With High-angle After Tooth-extraction Treatment

Objective To evaluate changes of skeletal and soft tissue of skeletal classⅡhigh-angle malocclusion after tooth-extraction treatment.Methods Twenty skeletal classⅡhight-angle malocclusion patients in permanent dention,aged 11 to 14 years old,were selected.Based on following criteria,SN-MP≥40 ,ANB> 5°.all patients with extraction premolar were treaed with straight wrie appliance.During treatment,high-headgear was used.Cephalometric analysis were carried out before and after treatment, and the results were analyzed with statistics.Results All patients achieved normal overbite and overjet in anterior teeth,and class I occlusion in molar relationship.Upper incisors protrusion and facial profile were improved signficantly. The average of lingual movements of upper incisors and U1-SN were 5.87mm and 9.54°respectively and there are statistically significant differences(P <0.001).The average of mesial movements of upper and lower first molars were 2.27 mm and 3.42 mm respectively and there are statistically significant differences(P< 0.01).The average of decreasing of Angle SN-MP,SNA, A-RL was 0.59°,0.64°respectively,there were no statistically differences(P>0.05).The average of reduction of UL-RL,NLA were 2.36mm and 3.41°respectively,and and there are statistically significant differences(P<0.01).Conclusion To correct the skeletal class II high-angle malocclusion by orthodontic extracion treatment, there are obvious results in incisors and molars without changes in the vertical relationship.