Treatment on Class IIdivision 2 malocclusion patients with improved Twin-Block appliances

Objective To evaluate the therapeutic effects of Twin-block appliances on treating ClassⅡdivision 2 malocclusion patients.Methods 27 patients aged 9~12 years old were treated with Twin-block appliances.Cephalograms were taken before and after treatment to compare the changes before and after treatment.Results The overjet and the rela tionship of the molars changed significantly.The mandibular development was remarkablely improved,and the profile became balanced.Conclusions The Class Ⅱ correction with the Twin-block appliance is achieved through normal growth with mandibular skeletal and dentoalveolar changes.