Abstract: Objective: To compare and analyze the stress distribution and biomechanic characters of temporomandibular joint (TMJ) by loading on the normal and ClassⅡ division1 occlusion using finite element models. Methods: The normal and ClassⅡdivision1 three-dimensional finite element models were constructed by integrating the data of CT and MRI. And then the stress distribution in the temporomandibular joint parts was conducted after mechanical loading and boundary constraint to two models, respectively. Results: The stress distribution of the TMJ was approximately symmetrical in normal occlusion. No significant difference was found in stress distribution between normal and. However, in ClassⅡdivision1 occlusion, the values on mandibular, condylar and glenoid fossa were higher, the values on joint disc were lower, and the values on top and bottom surface were higher than those in the normal occlusion. Conclusion: The stress distribution of ClassⅡdivision1 occlusion increases its risk of temporomandibular joint disorder syndrome. It should be promptly corrected to provide a good biomechanical environment for the temporomandibular joint.

Key words: ClassⅡdivision1 , Individual normal occlusion, Temporomandibular joint, Three-dimensional finite element