ABSTRACT
Objective:To investigate the changes of occlusal plane in the process of retracting maxillary anterior teeth with different vertical traction force.Methods:The three dimensional finite element model of maxillary anterior teeth en-masse retraction by micro-implant was constructed with cone beam CT scanning and MIMICS and ANSYS software.Then the movement tendency of tooth and the changes of the maxillary occlusal plane was calculated when the vertical traction force was 0,0.5,0.75 and 1 N in the process of en-mass retraction,respectively.Results:Lingual tipping of anterior teeth,distal tipping of the first molar and the maxillary occlusal plane clockwise rotation by the retraction forces were observed.With the vertical traction force increasing,lingual tipping of anterior teeth and distal tipping of the first molar were decreased,and the occlusal plane clockwise rotation was prevented.Conclusion:The upper dentition movement and occlusal plane rotation can be changed effectively by the vertical traction with different force.When retract anterior teeth,0.5-0.75 N vertical traction force is beneficial to prevent clockwise rotation of the maxillary occlusal plane.