Temporomandibular Disorder–Related Symptoms and Health-Related Quality of Life among Japanese Adults

Introduction: Temporomandibular disorders (TMDs) are among the most prevalent musculoskeletal conditions affecting the orofacial region. However, their association with preference-based health-related quality of life (HRQOL) has not been fully examined. Objectives: This study evaluated the association between TMD-related symptoms and HRQOL using a 5-level EuroQol 5-dimensional questionnaire (EQ-5D-5L) in Japanese adults. Methods: A cross-sectional analysis was conducted using data from the Japan COVID-19 and Society Internet Survey, which included participants aged 20 to 79 y. TMD-related symptoms were assessed using the Screening Questionnaire for TMD (SQ-TMD) and the TMD Pain Screener (TMD-PS). Regression standardization based on linear regression models, including sociodemographic and health-related covariates, was applied, and mean differences (MDs) with 95% confidence intervals (CIs) were estimated. Results: Among the 23,916 participants, the prevalence of TMD-related symptoms assessed using the SQ-TMD and TMD-PS was 19.8% and 6.7%, respectively. The mean EQ-5D-5L score was 0.894 (SD = 0.156). After being standardized for sociodemographic and health-related covariates, TMD-related symptoms were significantly associated with lower EQ-5D-5L scores (SQ-TMD: MD = −0.045 [95% CI, −0.054 to −0.037]; TMD-PS: MD = −0.061 [95% CI, −0.080 to −0.042]; both P < 0.001). Conclusion: The present study suggested that the presence of TMD-related symptoms was significantly associated with lower EQ-5D-5L scores. The observed differences were close to or exceeded the previously reported reference value for the minimally important difference of the EQ-5D-5L in the Japanese population. Knowledge Transfer Statement: This study demonstrates that symptoms of temporomandibular disorders (TMDs) are associated with clinically meaningful reductions in health-related quality of life, as measured by the EQ-5D. These findings underscore the substantial individual and societal burden of TMDs and provide evidence to inform prevention strategies, clinical management, and health economic evaluations. Addressing TMDs through public health and clinical interventions may contribute to improved overall well-being.