[A three-dimensional finite element study of the temporomandibular joint with different curve of Spee]

To analyze the stress distribution in temporomandibular joint (TMJ) with different depth of curve of Spee (CS) by three-dimensional finite element model (3D-FEM).

FEM with different depth of CS were established. The depth was 2.50, 0 and 4.50 mm (model 0, 1, 2). The stress distribution were analyzed by software Abaqus. The change of stress were analyzed by paried t test.

The stress distribution patterns in TMJ with different depth of CS were similar. The Von Mises on the anterior surface of condyle and the Von Mises on the intermedial zone of the disc was higher. The S. Max. Principal of the condyle was mainly tensile stress. The S. Min. Principal of the condyle was mainly compressive stress. The S. Max. Principal of the disc was mainly tensile stress. The S.Min. Principal of the disc was mainly compressive stress.In model 0, the eviations of the Von Mises, the S.Max. Principal and the S.Min. Principal on the anterior surface of condyle were 0.1057 - 0.2298 MPa, -0.2243 - -0.3738 MPa and -0.3494 - -0.1165 MPa. The eviations of the Von Mises, the S.Max. Principal and the S. Min. Principal on the intermedial zone of the disc were 0.1099 - 0.6880 MPa, -0.3217 - 0 MPa and -1.2000 - -0.1000 MPa. The D-values of of Von Mises of condyle and disk between different models were extremely significant (P < 0.01).

With the same plane of occlusion, the stress distribution patterns of TMJ with different depth of CS is similar to that of normal occlusion. The final results also validate the anterior surface of condyle and intermediate zone of articular disc are the weight-bearing areas in TMJ. The changes of depth of CS change the value of the stress.