Figure 3.

Location of the tooth measurement plane. (A–C) The axial plane, coronal plane, and sagittal plane of the teeth, respectively. Red, green, and orange lines in the pictures represent the axial plane, sagittal plane, and coronal plane, respectively. (A) The location of the axial plane was obtained by drawing the red line through the CEJ of the selected tooth in sagittal view; then, the orange line was rotated until the intersecting line was the shortest. (B) The green line was rotated until it passed through the root apex and the midpoint of the incisal margin. (C) The orange guideline was rotated until it passed through the root apex and the midpoint of the CEJ line. (D) A magnification of the sagittal view shows the measurement plane.