Abstract:

Abstract:Objective To evaluate the biomechanical effect of rapid maxillary expansion (RME) with different anchorages at the same load conditions in a  three-dimensional finite element model,and provide a theoretical basis for clinical application.Methods Three-dimensional finite element model of maxilla was made.In the model 1,natural teeth were used as the anchorage; in the model 2,both the teeth and the implant were used as the anchorage. Force 20 N in the Horizontal direction was loaded on model 1 and model 2,respectively,and the displacement on the X-axis,Y-axis and Z-axis were calculated.Then the stress distribution on the bone and the teeth were evaluated,and the displacement trend was depicted.Results Both the two models showed that on the cross-section the median palatine suture opened larger at the front,and on the coronal section the median palatine suture opened like a triangle with its base downward.The cown of the tooth shifted buccally while its root shifted  lingually.The displacement in  model 2 showed less than that in  model 1,and the stress in model 2 was also lower than that in  model 1.Conclusion Compared with the natural teeth,using an implant as an anchorage can increase the bone effect while reduce the tooth effect.

Key words: maxilla；palatal implant；three-dimensional finite element；rapid maxillary expansion