Somatosensory tinnitus and temporomandibular disorders: A common association

Background: Although the association between tinnitus and temporo-mandibular disorders (TMD) has been frequently reported, their rate of association in the literature shows a great variability. Objective: We aimed to investigate the prevalence of TMD in patients with somatosensory tinnitus and, vice versa, the occurrence of somatosensory tinnitus in patients with TMD. Methods: The study included patients with somatosensory tinnitus (audiological group) and patients with TMD (stomatological group), evaluated at the audiologic and stomatologic clinics of the Policlinic Hospital of Milan, Italy. Common causes of tinnitus, such as hearing and neurological disorders, were excluded. A cervicogenic somatic tinnitus was also ruled out. Different TMD symptoms, including joint noise and joint pain, were considered. The collected data were analysed using descriptive statistical methods, and the Pearson's Chi-squared test was performed to study the prevalence of the different symptoms by clinical groups. Results: Audiological group included 47 patients with somatosensory tinnitus. Overall, TMD was diagnosed in 46 patients (97.8%), including TMJ noise in 37 (78.7%), clenching in 41 (87.2%) and pain in 7 (14.8%) patients. Stomatological group included 50 patients with TMD, including joint noise in 32 (64.0%), clenching in 28 (56.0%) and TMJ pain in 42 (84.0%) patients. A somatosensory tinnitus was diagnosed in 12 (24.0%) patients. Conclusion: Our study showed a high prevalence of TMD in patients with tinnitus, as well as a not uncommon occurrence of tinnitus in patients presenting with TMD. The distribution of TMD symptoms, such as joint noise, and joint pain was different between the two groups.