Abstract: Objective Three dimensional finite element method analysis is used in stress analysis of the temporomandibular joint in patient under treatment of junior classⅡmalocclusion with AdvanSync appliance to explore whether the temporomandibular joint has adaptive remodeling under localized stimulus. Methods An 11yearold classⅡDivision 1 malocclusion patient was selected as a volunteer in this research. CBCT was used in scanning the head of the patient. And the data was output as graphic data， which was established into threedimensional finite element model of appliances maxilla mandible and dentition by mimics17.0 software. ANSYS workbench 15.0 software was used in threedimensional model boundary and loading force valued 5.7 N， and making the stress analysis of the temporomandibular joint. Results Threedimensional model of AdvanSync functional appliances was established. When the appliance was leaded force，the left side and the right side of the temporomandibular joint stress distribution were basically the same. Equivalent stress mainly concentrated in front of the condylar slope near the neck of condyle， condylar cartilage，， and articular disc cavity. The maximum principal stress distribution of equivalent stress analysis results were basically the same， mainly bear tensile force; the minimum principal stress mainly concentrated on the top of condyle and condylar cartilage at the top， which is mainly bear compressive stress. Conclusion When AdvanSync functional appliance leads submaxila forward， condylar process and condylar chondrocyte have the adaptive trend under pressure. But articular disc and fossa have little effect.

Key words: temporomandibular joint, malocclusion, finite element analysis, stress, AdvanSync