Evaluation of a technique for recording temporomandibular joint sounds.

Analysis of temporomandibular joints sounds may contribute to the differential diagnosis of temporomandibular joint disorders. In this article an advanced system for the recording of joint sounds is presented. The method proved to be reliable. The problem of filtering out artifacts has been solved to a great extent but not completely. Temporomandibular joint sounds measured with this technique vary considerably in energy, frequency spectrum, and peak-to-peak amplitude over 3 months, as well as within 1 day. These differences seem to reflect natural variations in joint sounds caused by the physical impossibility of performing identical jaw movements. The results indicate that joint sound characteristics do not yet offer a solid basis for inferences concerning the development of temporomandibular joint abnormalities in the clinical setting.