Figure 6. Angular measurements (°). A, Inclination. For the difference between pre- and post-treatment (T0–T1), positive means labioversion or buccoversion and negative means palatoversion; B, Angulation. For T0–T1, positive means distal crown tipping and negative means mesial crown tipping; C, Rotation. When the occlusal line was inclined inward and backward to the midsagittal plane, the angle of rotation was taken to be negative. For T0–T1, positive means distal-in rotation and negative means mesial-in rotation; D, Angles of anterior occlusal plane (AOP) and posterior occlusal plane (POP). When the AOP or POP was inclined forward and upward with respect to the horizontal plane, the angle of AOP or POP was taken to be negative. For T0–T1, positive means counterclockwise rotation and negative means clockwise rotation.