Association Between Tinnitus and Temporomandibular Disorders: A Systematic Review and Meta-Analysis

Objectives: Tinnitus is one of the most common otological symptoms in patients with temporomandibular disorders. This study aimed to investigate the possible association between tinnitus and temporomandibular disorders. Methods: The online databases of PubMed, Ovid, ScienceDirect, and Web of Science were explored for all English articles published until September 2018 using the combined keywords tinnitus and temporomandibular. Cross-sectional, cohort, or case-control studies that investigated the association between tinnitus and temporomandibular disorders (TMDs) were considered. The quality of the included papers was assessed by the Crowe Critical Appraisal Tool. Results: Twenty-two papers met the eligibility criteria and were included in the systematic review. Meta-analysis was performed on 8 papers to investigate the possible relationship between tinnitus and TMDs by calculating the odds ratios. Odds ratios ranged from 1.78 to 7.79 in the studies related to tinnitus frequency in temporomandibular disorders and from 1.80 to 7.79 in the papers linked to temporomandibular disorder frequency in tinnitus, indicating a significant association between tinnitus and temporomandibular disorders. Conclusions: There was a strong relationship between tinnitus occurrence and TMDs. The findings implied the significance of exploring the signs of TMDs in patients with tinnitus as well as tinnitus in those who complain from temporomandibular disorders.