[Characteristics of temporomandibular joint sounds in reducible anterior disc displacement of youth]

Abstract

Objective: To compare the vibration parameters in reducible anterior disc displacement and symptomless youth, and explore the clinical diagnostic value of frequency spectrogram of temporomandibular joint (TMJ) sounds.

Methods: 21 youth with anterior disc displacement were included as experimental group, and 26 symptomless youth were included as control group. The joint vibrations during rhythmic maximal open-close jaw movement of all subjects were recorded. The sensitivity and specificity of total integral in diagnosis of reducible anterior disc displacement were calculated.

Results: All TMJ vibration parameters, include total integral, integral < 300 Hz, integral > 300 Hz, > 300/< 300 Hz radio, peak amplitude, peak frequency and median frequency, were significantly higher in experimental group than that in control group (P < 0.05). Along with the increasing of disc displacement degree, the TMJ vibration parameters were increasing, and total integral significantly increased (P < 0.05). The total integral demonstrated a high sensitivity and specificity in diagnosis of anterior disc displacement with reduction (0.86 and 0.85, respectively).

Conclusion: The TMJ vibration parameters are significantly higher in youth with reducible anterior disc displacement than that in symptomless youth. Different pathological stages of disc displacement show different TMJ sounds.