Association Between Temporomandibular Joint Disorders and Salivary Cortisol Levels: A Systematic Review and Meta-analysis

Context: Salivary cortisol could be a good marker for temporomandibular joint disorders. This article aimed to study the association between salivary cortisol and temporomandibular joint disorders (TMD). Methods: PubMed, Web of Science, Scopus, and Embase were searched according to the PRISMA guidelines without restricting the publication start date until October 2022. Only case-control studies were included in the study. The critical appraisal checklist of the Joanna Briggs Institute was utilized to appraise the selected articles. Results: Of 1173 articles found, 23 studies were eligible, and 18 were meta-analyzed. A total of 696 TMD patients and 785 controls were included. Meta-analysis showed that salivary cortisol was significantly higher in patients with TMD than the controls. Meta-regression showed that the difference in mean salivary cortisol decreased significantly between the two groups with increasing age. Conclusions: The salivary cortisol in patients with TMD is significantly higher than in the controls. As the heterogeneity among the studies was high, more studies are required to verify this association.