Development and validation of TMJ viscoelasticity analyzer.

We developed a TMJ viscoelasticity analyzer for non-invasive evaluation of the soft tissues of the TMJ region. We used this device to measure the viscoelastic parameters, viscosity (c), elasticity (k) and mass (m), of the TMJ region for two volunteers. Experiments were performed to determine the optimum measurement conditions for the preload magnitude, head posture and clenching level. We determined measurement variability and carried out statistical analysis by analysis of variance (ANOVA). We found that the values for c and k varied significantly depending on preload magnitudes (p < 0.001). In addition, all parameters varied significantly depending on head posture. However, clenching level did not significantly affect any of the parameters. Measurement variability was below 10% for all parameters. Examination of viscoelasticity of the TMJ region provides valuable information about functional and pathological changes in the soft tissues of this area. In this study, we were able to determine the fundamental characteristics of the TMJ viscoelasticity analyzer and develop methods for examining patients with temporomandibular disorders.