Temporomandibular joint vibration in bruxers.

Temporomandibular joint vibration is considered an important physical sign of joint dysfunction and/or joint pathology. The aim of this study was to compare the difference of joint vibration between bruxers and asymptomatic individuals, evaluate the effect of bruxism on the temporomandibular joint (TMJ) and the association between bruxism and temporomandibular disorders. Twenty-four (24) bruxers and 16 asymptomatic subjects were included in the study. Bilateral joint vibrations with jaw tracking were recorded using a TMJ detecting instrument during rhythmic jaw opening and closing movement. The results showed that the vibratory energy and amplitude of the moderate to severe bruxers were significantly higher than that of the mild bruxers and asymptomatic subjects. The percentage of joint vibration occurrence in asymptomatic subjects, mild bruxers, and moderate to severe bruxers was 75.0%, 77.8%, and 100%, respectively. It was concluded that bruxism might induce abnormal joint vibrations, and that the energy of abnormal vibrations might increase with the degree of bruxism.