Fig. 3

Assessment of the morphological changes of alveolar bone surrounding the central incisor. (a) the linear and angular measurement parameters, including the bending points for the labial and palatal cortex (LBP and PBP), the bending angle (θ1, θ2 and θ3) and the bending height (R1-R4). The surface modeling area (A1, A2) and inner remodeling area (A3, A4) of the labial and palatal alveolar cortex were also calculated (b, c). After registration, we cut the alveolar bone of the central incisors at the labial bending point level and then calculated the volumes of T1 and T2 alveolar bone surrounding the central incisors for subsequent comparison (d)