Abstract: Objective To construct a three-dimensional finite element model of maxillary, mandible, denture, and temporo-mandibular joint by using Advansync appliance. To explore the efficacy of guided forward movement, the labial inclination of lower anterior teeth, and occlusal plane change under the different mandible condition of centric position, rest position and the maximum opening position. Methods The patients with the malocclusion of Angle Class Ⅱ division 1 after the initial alignement and leveling stage were selected. CBCT was used to scan the skull. Mimics17,Geomagic Studio 2013, and Unigraphics NX8.5 software were used for computer image processing, then ANSYS Workbench15.0 software was applied to establish a three-dimensional finite element of Advansync appliance. Results The three-dimensional finite element model of Advansync appliance including MBT straight-wire appliance was obtained. With Advansync appliance the action of mandible and lower incisors had the tendency to move forward and downward, and the occlusal plane mainly had the trend of upward and backward movement, which decreased with the increase of opening. Conclusion The result suggests that the main effect of Advansync appliance is to cause forward and downward mandibular modification in the opening and closing movement process.

Key words: Advansync appliance, CBCT , Finite element analysis, Mandibular