Intra-articular pressure of the temporomandibular joint increases along with occlusal force

Abstract

To clarify the correlation between occlusal force and intra-articular pressure of the temporomandibular joint, we simultaneously measured occlusal force and intra-articular pressure in the upper joint space.
Four patients (4 joints) with closed lock of the temporomandibular joint, and 4 volunteers (4 joints) without temporomandibular disorders, were selected for this study. A prescale 50 H type R, and a transducer for monitoring arterial blood pressure, were used to measure occlusal force and intra-articular pressure, respectively.
The correlation coefficient between occlusal force and intra-articular pressure ranged from 0.710 to 0.954, and the coefficient of determination ranged from 0.504 to 0.910. These results show that intra-articular pressure is in direct proportion to occlusal force. The regression coefficient of the subjects ranged widely (15.3∼270.9).
These results indicate that an increase of occlusal pressure is one factor for weighting of overload in the temporomandibular joint.