Figure 2. Confirmation of the accuracy of superimposition of the three-dimensional (3D) virtual maxillary models. The angle between the Frankfort horizontal (FH) plane and the maxillary occlusal plane in the lateral cephalogram was measured pretreatment (T0) and post-treatment (T1) to verify a change in the occlusal plane of the 3D virtual maxillary models between T0 and T1. If the angular difference between the 3D virtual models and lateral cephalograms was greater than 5o, superimposition of the 3D models was repeated to correct the error.