Fig. 4. Measurements of the root inclination: the angle between the root axis vector and basal bone plane. A, Measurements of the root inclination for maxillary dentitions. B, Measurements of the root inclination for mandibular dentitions. The value of the root axis vector is obtained from the ra point to the rc point. ra point, root apex point; rc point, root center point, the cemento-enamel junction for single-root teeth or the root furcation for multi-root teeth.
