Temporomandibular disorders as an etiological factor for tinnitus

Tinnitus is the sensation of hearing a sound with no external auditorystimulus present. Tinnitus is very prevalent and increases withincreasing age. The most common presentation is high pitched cricketsounds, buzzing or ringing in both ears and often but not alwaysassociated with hearing loss. There are many possible causes oftinnitus, but few specific established treatments. Epidemiologic dataindicate a frequent association between TMD and tinnitus. Disordersof the masticatory system may exert an influence on tinnitus viamechanical connections between the temporomandibular system andthe ear or via neuronal influences. This hypothesis explains how thefusimotor system of the muscles innervated by the trigeminal motornucleus is affected by inadequacies in the occlusion of the teeth thatcause changes in posture and movement of the mandible. Inadequateocclusal contacts give rise to an adapted function of the mandibleand the most common compensatory muscular response is hypertoniainvolving all mandibular muscles, including the tensor tympani. Thetreatment of tinnitus is very complex and etiologically defined. Thisarticle reviews the effect of TMD therapy on tinnitus