Miniplaca de titânio para utilização do aparelho extrabucal com sustentação esquelética: desenvolvimento e estudo com método dos elementos finitos

Abstract

The porpose of the present study was to develop a titanium miniplate for the use of the skeletally supported Extraoral Traction Appliances and to identify and compare, using the Finite Element Method (FEM), the stress distribution patterns performed in the sutures by two forms of support inner arch of the Extraoral Traction Appliance with cervical traction. Skull bones, teeth, periodontal ligament, 9 sutures and Extraoral Traction Appliances were modeled; and 2 different models were simulated with different internal arc fitting shapes. Model number 1 simulated the inner arch fixed to the geometric center of the buccal face of the first molar, model number 2 simulated the inner arch supported by a “Y” miniplate fixed to the zygomatic process of the maxilla. Boundary conditions were imposed on the models: bilateral symmetry, force direction and crimp area. The mechanical conduct of the structures represented was determined with specific properties of each material and a force of 500 grams was applied to the outer arch end of the Extraoral Traction Appliances posteriorly, forming 25º with the occlusal plane, towards the cervical traction. The models were analyzed mathematically and the result visualized in the HYPER VIEW 2017 software. The stresses performed on the sutures after the Extraoral Traction Appliances force simulation were similar in both models. The use of Extraoral Traction Appliances with miniplate, promotes in the sutures, the same pattern of force distribution promoted by the Extraoral Traction Appliances supported on the first permanent molars.