Objective      To construct a nonlinear three-dimensional (3-D) finite element model with highly geometric similarity and mechanical similarity for maxillary anterior teeth lingual retraction force system with micro-implant anchorage.       Methods      The 3-D geometrical model of maxillary bone and teeth was constructed based on the data from spiral CT scanning with high resolution by using MIMICS software

and the model of lingual appliance and micro-implant were constructed in the Solidworks CAD software. The parameters of periodontal membranes were set as nonlinear and the maxilla bone as non-homogeneous and anisotropy. ANSYS software was used to mesh the model and construct the nonlinear 3-D finite element model of maxillary anterior teeth lingual retraction force system with micro-implant anchorage.       Results      The nonlinear 3-D finite element model of maxillary anterior teeth lingual retraction force system with micro-implant anchorage was constructed with good similarity in geometrics and mechanics. Under the load of 100 g retraction force

retroclination initial displacements of maxillary anterior teeth were observed. Pressure stress concentration zone was located in the lingual marginal and buccal apical area

while stretching stress concentration zone was located in the buccal marginal and lingual apical area.       Conclusion      The nonlinear 3-D finite element model of maxillary anterior teeth lingual retraction force system is demonstrated to be an ideal biomechanical tool in the study on such complicated lingual orthodontic force system.