Temporomandibular joint sounds in patients with disc displacement

Temporomandibular joint sounds have been viewed as signs of different pathological changes. However, the correlation between joint sounds on the one hand and function and morphology of the joint on the other, are not well documented. We have therefore presurgically recorded sound from 35 operated joints with disc displacement and have studied arthrographically and during surgery the position, function and configuration of the disc as well as arthrotic changes. 12 joints were silent, 12 elicited reciprocal clicking, 3 single clicking, and 8 crepitation. Joints with reciprocal clicking consistently showed disc displacement with reduction and silent and crepitating joints showed disc displacement without reduction. All joints with reciprocal clicking as well as most silent joints demonstrated non-arthrotic articular surfaces, whereas crepitation was recorded in both arthrotic and non-arthrotic joints. Our results implied that crepitation is a rather unreliable sign of arthrosis. Reciprocal clicking can be considered as an accurate sign of reduction of anteriorly displaced discs. However, neither the degree of displacement nor the degree of deformation of the disc could be disclosed by analysis of the sound. This information can only be obtained by further examination, such as arthrotomography.