The Three-dimensional Finite Element Analysis Of Distalizing The Upper Molar By Different Molar Propulsion Device In Different Anchorage Tapes

Objective: Using the three dimensional finite element models to study the movement tendency and the stress analysis of maxillary upper molars and the anchorage teeth under the force provided by different molar propulsion device to provide a reference for clinic treatment.Methods: An adult female volunteer was selected to scan the upper jaw and maxillary tooth by CBCT.Using Mimics software to complete the three dimensional reconstruction of the CBCT images.Then the final model of maxillary complex was prepared for four different molar propulsion device to analyze the movement tendency and the stress analysis of the maxillary first molars and anchorage teeth in different anchorage tapes.Results:1.When using the improved molar propulsion to push the first molar distal movement,the first molar distal transposition is obvious,the anchorage teeth would move mesially,the incisors would be on lip exhibition while the movement distance was small in the second premolar as an anchorage.The first molar distal transposition is small,the anchorage teeth would move to mesial great in body movement,the incisors would be on lip exhibition in the first premolar as an anchorage.2.When using the modified screw expansion device to push the first molar distal movement,the first molars' displacement amount is larger,the maxillary incisors have the trend to move distally,but the first molar elongation effect is obvious in the micro-implant as anchorage.The first molars' displacement amount is small and the first premolar and the maxillary incisors have no obvious change in the Nance as anchorage.