Relationship of Occupational Stress and Temporomandibular Disorders by Measuring Salivary Cortisol and Immunoglobulin Levels in Iranian Dental Students

The present study aimed to investigate the relationship between stress and temporomandibular disorders (TMDs) by quantification of occupational stress using the Dental Environment Stress (DES) questionnaire as well as measuring the stress markers in the saliva, including cortisol and immunoglobulin A (IgA), in fourth to sixth-year dental students of Qom Dental School.

In the present study, 60 students were included. A clinical examination was first performed using the Research Diagnostic Criteria/Temporomandibular Disorder (RDC/TMD) criteria in order to determine the temporomandibular joint (TMJ) status, and then the DES questionnaire was completed in order to determine the occupational stress level of dental students. Finally, saliva samples were obtained from the students, and the levels of salivary cortisol and IgA were measured using enzyme-linked immunosorbent assay (ELISA). Independent t-test, ANOVA, Chi-square test, and Pearson's correlation coefficient were used for data analysis (alpha=0.05).

The mean salivary levels of cortisol and IgA were found to be 4.74 ± 2.80 ng/mL and 220.26 ± 121.22 µg/mL, respectively. The mean DES score was 2.48 ± 0.58. Of all students, 24 (40%) suffered from TMDs. There was no correlation between cortisol and IgA levels and the DES score (P>0.05). No significant relationship was found between TMD and salivary cortisol, salivary IgA, or DES score (P>0.05).

Stress is one of the most important causes of TMDs. Although salivary biomarkers are known as useful markers for detection of stress in patients with TMDs, this issue was not confirmed in the present study.