# Evaluation of the salivary biomarker cortisol in patients with temporomandibular disorders

## TL;DR

This study found that patients with temporomandibular disorders have higher cortisol levels in their saliva, suggesting a link between stress and the condition.

## Contribution

The study provides new evidence linking TMD with elevated salivary cortisol, indicating HPA axis dysregulation.

## Key findings

- TMD patients had significantly higher salivary cortisol levels than healthy controls.
- No significant correlation was found between age and cortisol levels in participants.

## Abstract

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: Salivary cortisol levels were significantly higher in TMD
patients (mean = 17.55 nmol/L) compared with controls (mean = 11.09 nmol/L;
p = 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.