Association between temporomandibular disorders and mental and behavioural disorders - a nationwide population-based cross-sectional study.

Objectives: Growing evidence suggests associations between temporomandibular disorders (TMDs) and mental health conditions, but methodological issues such as including lack of control groups or reliance on self-reported questionnaires in previous studies have limited conclusive findings. This study aimed to determine whether TMD patients have higher incidence of specific mental and behavioural disorders (MBDs) using a large-scale dataset with matched controls.

Materials and methods: This study used the National Health Insurance Service (NHIS) customised database of South Korea. Individuals who diagnosed with TMDs between 2006 and 2019 were recruited. 713,473 individuals were included in each of the TMD and non-TMD groups through propensity score matching. Cox proportional hazard regression was performed to determine the adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for MBD according to the presence or absence of a TMD diagnosis.

Results: Patients with TMD showed significantly stronger associations with neurotic, stress-related, and somatoform disorders (aHR = 1.65), mood disorders (aHR = 1.58), and behavioural syndromes associated with physiological disturbances (aHR = 1.50). Specific MBDs with stronger associations included somatoform (aHR = 1.79), anxiety (aHR = 1.65), depression (aHR = 1.61), and sleep disorders (aHR = 1.50).

Conclusions: TMD is positively associated with MBDs. Patients with TMDs should be monitored for possible co-occurrence of MBD-related symptoms that could aggravate TMD.

Clinical relevance: These findings highlight the importance of multidisciplinary TMD management. Clinicians should implement MBD screening when treating TMD patients, particularly for somatoform, anxiety, depression, and sleep disorders. Early identification enables timely psychological interventions alongside conventional therapies, potentially improving treatment outcomes through integrated care.