Evaluation of the salivary biomarker cortisol in patients with temporomandibular disorders

BACKGROUND: Temporomandibular Disorders (TMD) are musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory muscles, and related structures. Stress can trigger dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, leading to increased cortisol secretion. Salivary cortisol assessment provides a non-invasive method to investigate this relationship. METHODS: A total of 98 participants were recruited-49 patients diagnosed with TMD and 49 healthy controls-at the Faculty of Medicine of the University of Coimbra. Participants were evaluated according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Saliva samples were collected between 9:00 and 11:00 AM, processed with Enzyme-Linked Immunosorbent Assay (ELISA), and analyzed statistically using Shapiro-Wilk and Mann-Whitney tests, with a 95% confidence level. RESULTS: = 0.0032). No significant correlations were found between age and cortisol levels. CONCLUSIONS: Patients with TMD present higher salivary cortisol levels, suggesting dysregulation of the HPA axis associated with stress. These findings support the integration of psychosocial factors into the management of TMD. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT06874868.