Dynamic compressive properties of the mandibular condylar cartilage.

The mandibular condylar cartilage plays an important role as a stress absorber during function. However, relatively little information is available on its dynamic properties under compression. We hypothesized that these properties are region-specific and depend on loading frequency. To characterize the viscoelastic properties of the condylar cartilage, we performed dynamic indentation tests over a wide range of loading frequencies. Ten porcine mandibular condyles were used; the articular surface was divided into 4 regions, anteromedial, anterolateral, posteromedial, and posterolateral. The dynamic complex, storage, and loss moduli increased with frequency, and these values were the highest in the anteromedial region. Loss tangent decreased with frequency from 0.68 to 0.17, but a regional difference was not found. The present results suggest that the dynamic compressive modulus is region-specific and is dependent on the loading frequency, which might have important implications for the transmission of load in the temporomandibular joint.