A clinical study of twin-block appliance on treatment of class II divis ion I malocclusion

Objective To inv estigate the clinical effect of Twin-block functional appliances in the treatme nt of skeletal class Ⅱ division Ⅰ malocclusion. Method Total 12 growth pat ients with skeletal class Ⅱ division Ⅰ malocclusion were treated with Twin-block functional appliances and SWA.Pre-and post-treatmen t cephalograms were compared. Results After a treatment by Twin-block appliance,the growth of the mandible was stimulated.Overbite, Overjet and ANB decre ased significantly,while SNB increased significantly.The sagittal disharmony o f Angle S class Ⅱ malocclusion was corrected.A harmonious relationship of uppe r and lower jaws and a better profile was obtained. Conclusion Twin-block fun c tional appliances is fit for the early orthodontic treatment of skeletal class Ⅱ division Ⅰ malocclusion.It possesses the orthopedic effect on this kind of ma locclusion.