ABSTRACT
This study was performed to assess the accuracy of computer-based treatment prediction for soft tissue profile using Quick Ceph Image Pro(TM) & Quick Ceph 2000(TM) in bimaxillary protrusion cases. The pre- and post-treatment lateral cephalograms of 21 female adults treated by four first premolar extraction were imaged and 9 landmarks and 27 specific soft tissue mesurements were digitized for comparing actual treatment results with computer simulations. The results of this study showed that Quick Ceph Image Pro(TM) & Quick Ceph 2000(TM) tends to overestimate horizontal changes and underestimate vertical changes. In the computer simulation, upper lip showed rolling tendency. The upper lip measurements were disposed to be regular direction but lower lip measurements were varied case by case even if it was statistically insignificant.