Abstract:

Objective

To analyze the flow pattern and pressure distribution of synovial fluid in upper compartment of temporormandibular joint （TMJ） with early stage disc perforation during jaw movement susing the fluid dynamics model.

Methods

Five patients with unilateral small disc perforation were included. Three-dimensional images of TMJ at different jaw-opening positions were obtained by arthrography and computed tomography. Andthe constructedmodel of TMJ was defined by the mimics software and meshed by the Gambit software. Thensynovial fluid dynamics were analyzed by the Fluent software. Finally， the model was validated with the intra-articular pressure measurement data during jaw-opening movements.

Results

The fluid dynamics model of right TMJ showed that the synovial fluid in the upper compartment formed an anticlockwise circulation. The intra-articular fluid pressure was lower than the threshold level and the synovial fluid generated a regular flow pattern at jaw-closing or jaw opening up to 2 cm. When the jaw-opening reached 3 cm， the pressure increased to the threshold with an abnormal flow field and a communication of fluid in the upper and lower compartments associated with the small disc perforation， which is unfavorable for self-repair of the joint disc.

Conclusion

The simulated synovial fluid dyanmic model of TMJ with disc perforationis effectively used for analysis of the pathogenesis of TMJ disorders， providing the basis for diagnosis and prevention.

Key words: Temporomandibular joint, Small disc perforation, Synovial fluid, Computational fluid dynamics, Numerical simulation