Spectral analysis of temporomandibular joint sounds

Results demonstrated significant differences in the spectra of TMJ sounds due to differences in subject, in patients' clinical status, type of jaw movement, and specific axis of motion. We suggest that some of these differences are caused by motion of larger or smaller component structures of the joint. It is apparent that significant additional work is needed to correlate specific features of the sound spectra with anatomic and clinical information. In future work, we plan to do sound spectral analysis recording in conjunction with nuclear magnetic resonance imaging of the joint. Such data will allow us to identify specific frequency bands that correlate with specific structures in the joint or events occurring during the jaw motion, for example, the motion produced by a sudden change in the condyle/meniscus relationship. Once such baseline information is obtained, specific individual subjects can be followed up over a period of time to determine the effects of treatment. We hope that changes in specific frequency bands can be used as quantitative indices of the results of specific treatments. In addition to the guidance afforded the dentist from such quantitative information, a permanent quantitative record of the jaw joint status thus obtained could be of value for clinical as well as legal purposes.