Three dimensional finite element analysis of rapid maxillary expansion using implant anchorage

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. (authors)