Figure 5. Definitions of linear and angular variables. A, Anteroposterior displacement (mm): distance between the facial axis (FA) point and the coronal plane. For the difference between pretreatment (T0) and post-treatment (T1), i.e., T0–T1, positive means posterior movement and negative means anterior movement. B, Vertical displacement (mm): distance between the FA point and the horizontal plane. For T0–T1, positive means intrusion and negative means extrusion. C, Molar rotation (°): the angle made with the x-axis of an individual molar tooth and the midsagittal plane on the occlusal plane. For T0–T1, positive means mesial-in rotation and negative means distal-in rotation.
