Figure 3. Angles between the maxillary occlusal plane and the Frankfort horizontal (FH) plane at pre-treatment (T0) and post-treatment (T1) were measured on lateral cephalometric radiographs. The angular difference between the occlusal planes at T0 and T1 of the three-dimensional (3D) virtual models was compared with that of the lateral cephalometric radiographs. If the angular difference between the 3D virtual model and the lateral cephalometric radiograph was greater than 5°, superposition of the 3D virtual models was reattempted to correct the error.18.