Temporomandibular joint sounds in asymptomatic volunteers.
Abnormalities within the temporomandibular joints often produce audible sounds. Electronic recording of joint sounds has been used as a method of staging internal derangement. This study had three objectives: first, to determine whether the characterization of temporomandibular sounds can provide a sensitive and accurate measure for the presence or absence of joint abnormalities in asymptomatic volunteers; second, to evaluate the reproducibility of the sounds, when present, with successive recordings; and third, to evaluate the sound characteristics to determine their predictability for the types of internal derangement. Fifty asymptomatic volunteers (100 joints) were evaluated with an electronic device for the presence of joint sounds. Of the patients, 24% (N = 50, five men and seven women) (16% of all joints) had one or two abnormal joints as diagnosed by magnetic resonance imaging. Forty-four percent of all joints had identifiable sounds; 50% of the sounds were produced when the condyle was located at the apex of the articular eminence. Sounds often occurred in the early opening phase of jaw movement in joints diagnosed as normal by magnetic resonance imaging. Finally, the characteristics of these events did not produce adequate separation to stage the internal derangement.