Objective To investigate morphologic changes of Angle classⅡand skeletal classⅠpatients during pendulum and straight wire appliances treatment and to analyze the mechanism of this treatment protocol.Methods 10 patients with Angle classⅡand skeletal classⅠmalocclusion were recruited. The lateral cephalometric radiographs were evaluated to determine if there were significant differences among pre-treatment(T1), after molar distalization(T2), and post-treatment(T3) variables in- cluding skeletal, dental and soft tissue relationships.Results Differences between theT1 andT2 meanswere significant for distal movement and distal angulation of the maxillary molars (P0·05). Onlythe mesial movement of lowerfirstmolars and upper and lower jawswere sig- nificant (P
