ABSTRACT
Objective:To study the tooth movement in the orthodontic treatment by Empower appliance following tooth extraction. Methods:40 cases with bimaxillary dentoalveolar protrusion were divided into 2 groups(n =20).After extraction of all first premolars of each case,the patients were treated by Empower appliance and Damon3-Mx appliance respectively without palatal enhance measure. Before and after treatment the patients were examined by cephalometric roentgengraphy with 1 9 measurements,the data were analysed by independent sample t test.Results:Tooth indicators∠UI-SN,∠UI-PP,∠L1 -MP,∠U1 -L1 ,UIE-PTV and LIE-PTV before and after the treatment in each group,and the variations between the 2 groups were significantly different(P 0.05).Conclusion:Empower appliance is more effective than Damon3-Mx in the treatment of bimaxillary dentoalveolar protrusion by anterior tooth torque control,upper and lower front teeth adduction and improvement of soft tissue lateral profile.