Objective To use the straight wire appliance in treatment for patients of skeletal class Ⅱ malocclusion with the computer- assisted digital cephalometric analysis system（CADCAS）. Methods The computer- assisted digital cephalometric analysis system was used to take a skull lateral position film before the treatment. 8 cases of skeletal class Ⅱ malocclusion patients were selected and then treated with straight wire appliance to correct the malocclusion. After the treatment, the wire were removed, then the lateral position films of the skull were taken at the same condition as that before treatment. The data were compared in order to find out the changes of the facial profile after treatment. Results The straight wire appliance slightly changed the facial profile of skeletal class Ⅱ malocclusion patients, but the correction of the deep overbite and deep- cover needed the lower front teeth's tilt to compensate. Conclusion To correct the skeletal class Ⅱ malocclusion by using the straight wire appliance in
permanent teeth, it has an obvious result in arrangement of the teeth or adjustment occluding relation. It is limited to improve the facial profile. The using of straight wire appliance alone can not get the ideal result.
