Figure 1.

(A–C) Tooth selection and positioning. Tooth 15 in a distal-mesial (A), vestibular-oral (B), and axial (C) plane. The crosshair is positioned according to the longitudinal axis and CEJ or RM (A,B) and parallel to the cross-axis of the tooth (C). Every single tooth was selected and adjusted manually. (D–F) Setting the reference points. The yellow line marks the longitudinal axis of tooth 15. It is presented in three different cross-sections, oral/vestibular (D), vestibular-distal/oral-mesial (E), and vestibular-mesial/oral-distal (F). Twelve reference points per tooth (as depicted in green and red color) were set on the CEJ or RM and AC for each side. The red dot marks the AC oral (D), oral-mesial (E), and oral-distal (F). The software measures RBL by calculating the distance between the dots.