OBJECTIVETo analyze the stress distribution of temporomandibular joint (TMJ) in posterior cross-bite of individual teeth and in normal occlusion during the intercuspal occlusion (ICO).

METHODSOn the basis of the geometric TMJ model of normal occlusion, the TMJ finite element model of posterior cross-bite of individual teeth was reconstructed. The occlusal force and boundary conditions were applied on the model. Using three-dimensional finite element method (FEM), the stress distribution of TMJ in posterior cross-bite of individual teeth was analyzed by simulating the ICO load.

RESULTSNo significant differences were found in stress distribution in various TMJ structures between posterior cross-bite of individual teeth and normal occlusion. However, the stress level was higher and the stress distribution was more inhomogeneous in posterior cross-bite of individual teeth than in normal occlusion. In the cross-bite malocclusion of individual posterior teeth, the maximum of von Mises stress was 0.792 MPa, the maximum principal stress was 0.598 MPa and the minimum principal stress was -0.744 MPa. But in normal occlusion, the maximum of von Mises stress was 0.592 MPa, the maximum principal stress was 0.395 MPa and the minimum principal stress was -0.554 MPa.

CONCLUSIONSWhen the ICO load was applied, the stress distribution of TMJ was more inhomogeneous and the stress level was higher in posterior cross-bite of individual teeth than in normal occlusion.