CBCT measurements. (A) Tooth orientation of CBCT: the sagittal plane running transversely through the midpoint of the tooth’s long axis. (B) CBCT measurements of (1) to (4) on labial side: (1) labial alveolar bone thickness, (2) labial alveolar bone height, (3) labial cortical bone thickness, (4) labial cortical bone height. CBCT measurements of (5) to (9) on palatal side: (5) palatal alveolar bone thickness, (6) palatal alveolar bone height, (7) palatal cortical bone thickness, (8) palatal cortical bone height, (9) palatal cancellous bone thickness, (10) root diameter, and (11) total root-bone thickness.