Temporomandibular disorder symptoms in Chinese and the U.S. University students: A cross-sectional study of oral behaviors, anxiety, depression, and country-level moderation

Objectives This study compared temporomandibular disorders (TMD) prevalence and its association with oral behaviors and psychological factors between Chinese and U.S. university students.Methods A cross-sectional survey of 435 students (224 China, 211 U.S.) assessed TMD (5Ts), oral behaviors (OBC-21), depression (PHQ-9), and anxiety (GAD-7). Adjusted multivariable logistic regression evaluated associations.Results Chinese students showed significantly higher TMD prevalence (OR = 3.214, 95%CI: 2.094–4.991, p < .001) and more TMD symptoms (IRR = 1.951, 95%CI: 1.602–2.382, p < .001) than U.S. students. Higher PHQ-9 scores (OR = 1.092, 95%CI: 1.018–1.175, p = .015) and OBC-21 scores (OR = 1.025, 95%CI: 1.002–1.049, p = .037) were positively associated with the odds of screen-positive TMD symptoms. Country significantly moderated the depression-TMD association: each 1-unit increase in PHQ-9 was associated with higher odds of TMD among Chinese students (OR = 1.191, 95%CI: 1.069–1.328, p = .002) than U.S. students (OR = 1.047, 95%CI: 0.970–1.131, p = .238), with an OR ratio of 1.138 (95% CI: 1.018–1.277, p = .025).Conclusions Chinese students exhibited higher TMD burden with a stronger depression-TMD link. These cohort differences remain hypothesis-generating and require longitudinal clinical confirmation.