Age modifies the association between oral behaviors and orofacial pain in painful TMD patients: a cross-sectional study

OBJECTIVE: To examine the association between oral behaviors and orofacial pain among painful TMD patients. METHODS: 343 adults with painful TMD completed the Oral Behaviors Checklist (OBC) and Numeric Rating Scale (NRS) for pain intensity; Characteristic Pain Intensity (CPI) was calculated. Patients were grouped as moderate-to-high CPI (≥ 30) or low CPI (< 30), and group differences were compared. Regression analyses were performed, adjusting for age, sex, education, and TMD diagnosis. RESULTS: Group comparisons between moderate-to-high CPI (n = 191) and low CPI (n = 152) groups showed no association between the total OBC score and CPI (p = 0.217). Correlation analysis showed the total OBC score correlated with age (ρ=-0.376), sex (ρ = 0.152), and education (ρ = 0.240). CPI correlated with age (ρ = 0.139) and education (ρ=-0.125). After adjusting for age, sex, education, and TMD diagnosis, the total OBC score was positively associated with CPI (per 10 points: mean ratio [MR] = 1.103; 95% CI 1.025-1.187). A significant interaction between age and total OBC score was also observed (MR = 0.919; 95% CI 0.855-0.987), indicating that the association between oral behaviors and CPI weakened with increasing age. CONCLUSIONS: Age correlated positively with CPI and negatively with the total OBC score. Although no significant crude association was observed, the total OBC score became positively associated with CPI after adjustment for age and other covariates. These findings suggest that age-related modification may influence the observed association between oral behaviors and orofacial pain in painful TMD patients.