Fig. 4From: Facial alveolar bone thickness and modifying factors of anterior maxillary teeth: a systematic review and meta-analysis of cone-beam computed tomography studiesFacial alveolar bone thickness mean values and ranges expressed in mm. The anterior maxillary teeth measured are represented in the following figures: a, f CI; b, g LI; c, h C; d, i 1PM; e, j 2PM. FAB thickness taking FBC as the anatomical reference point is represented in a–e. FAB thickness taking CEJ as the anatomical reference point is represented in figures f–jBack to article page