Objective：To investigate the remodeling of alveolar bone and the changes of roots after anterior retraction with maximum anchorage by analyzing CBCT data from adult cases.Methods: The sample comprised 48 incisors and 24 canines from 12 patients (18 to 40 years of age) with problems of ma-xillary protrusion or upper arch protrusion. CBCT scans were exposed before and after treatment, and la-teral cephalometric images as well as multiple planar reconstruction images were reconstructed. Tracing superimpositions of sagittal sections and three-dimensional reconstructions were done for qualitative analysis. For all maxillary anterior teeth, changes of root length, alveolar bone height and labial-palatal thicknesses at different levels were evaluated. The average of measurements taken by the same tester in three times was processed by SPSS 17.0 statistical package.Results: In 6 of the 12 cases, alveolar thickness became thinner on labial side ［apical area: (-0.64±1.18) mm］ while thicker on palatal side ［apical area: (0.93±2.0) mm］ and the root length decreased［(-0.95±0.79) mm］. In the other 6 cases, the incisors’ alveolar bone became thicker on labial side ［apical area: (2.12±1.46) mm］ while thinner on palatal side ［apical area: (-2.88±0.58) mm］and the loss of root length was obvious［(-2.12±1.43) mm］. In all the 12 cases, the canines’ alveolar bone became thinner on labial side especially on the apical level［(-0.27±1.86) mm］ while greatly thicker on palatal side ［apical area: (6.40±6.00) mm］and the root resorption was slight ［(-1.12±1.19) mm］. For all the anterior teeth, the height of alveolar bone reduced around them after retraction.Conclusion: When the root apical moved more palatally, more root resorption would occur and the alveolar bone would get thicker on labial side but thinner on palatal side and thinner as a whole after anterior retraction with maximum anchorage.In the vertical direction, the height of the alveolar bone generally decreased on all sides and decreased the most on the palatal side.