Thyroid hormones and tinnitus in individuals with temporomandibular disorder

TMD has a multifactorial etiology, involving biopsychosocial factors, and is more prevalent in women. This condition presents various signs and symptoms, including headaches, otalgia, and joint noises, with facial pain being the most common symptom. Tinnitus is an auditory perception with or without an external acoustic stimulus; its origin is nonspecific and multifactorial. Somatic tinnitus may be associated with musculoskeletal conditions and metabolic alterations. Its perception can be modulated by cervical stretching, anterior cervical posture, muscle contractions, mandibular movements, and pressure on the temporomandibular joints (TMJs). Thyroid dysfunctions, such as hypothyroidism and hyperthyroidism, affect the function of various organs and are more common in women. These endocrine alterations can impact the auditory, muscular, articular, and thermoregulatory systems. Objective: Through laboratory tests, this study aimed to assess thyroid hormone levels in women with temporomandibular disorders (TMD), with and without tinnitus symptoms. Material and methods: All participants who sought treatment and diagnosis at the center with orofacial pain and temporomandibular disorders underwent an initial interview and assessment at the speech therapy department. Given this, the inclusion criteria included females over >18 years with TMD. The diagnosis was defined through the DC/TMD, and the participants who reported tinnitus complaints answered a tinnitus perception questionnaire (THI). All participants underwent laboratory tests that evaluated the dosage of Free T3, Free T4, and TSH. Results: 35 female patients were included, with a mean age of 44.61. Ranging from 20 to 66 years old without hearing loss. Through the DC/TMD, 100% of the participants were diagnosed with muscular TMD; among them, 65.71% had joint TMD, classified as mixed TMD. According to the questionnaire (THI), 52.9% reported a complaint of tinnitus. Conclusion: There was no direct relationship between the existence of tinnitus and changes in thyroid hormones; further studies on the subject are recommended.