Depressive symptoms, oral health behaviors, and self-reported oral health conditions among Chinese university students: a cross-sectional study

Abstract

Introduction Depression has been associated with adverse oral health behaviors and conditions, but the mechanisms underlying these associations remain incompletely understood, particularly the potential role of oral health behaviors. This study examined these associations of depressive symptoms with oral health behaviors and self-reported oral health and explored statistical indirect associations through oral health behaviors among Chinese university students. Methods This cross-sectional study included 2,695 undergraduate students from seven universities in Shandong, China. Data were collected using an online questionnaire. Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10). Oral health was self-reported and included self-rated oral health and six predefined oral health problems, including dental caries, gingival bleeding, oral ulcers, tooth sensitivity, oral malodor, and other periodontal-related problems. Ten favorable oral health behaviors were summarized using an unweighted composite score. Multivariable linear, multinomial logistic, negative binomial, and binary logistic regression models were used as appropriate. Exploratory mediation analyses with 5,000 bootstrap resamples assessed statistical indirect associations through oral health behaviors. Results Higher CESD-10 scores were associated with poorer oral health behaviors and worse self-reported oral health. Each 1-point increase in CESD-10 score was associated with a lower oral health behavior score (β = −0.049, 95% CI: −0.063 to −0.036; P < 0.001) and a greater number of self-reported oral health problems (IRR = 1.026, 95% CI: 1.020–1.033; P < 0.001). For self-rated oral health, the strength of association increased progressively across worsening categories, with adjusted ORs ranging from 1.039 (95% CI: 1.010–1.069; P = 0.009) for good vs. very good oral health to 1.213 (95% CI: 1.154–1.274; P < 0.001) for very poor vs. very good oral health. Mediation analysis showed significant statistical indirect associations through oral health behaviors, accounting for 14.41% of the association with self-rated oral health (95% CI: 9.73%–20.30%; P < 0.001) and 5.76% of the association with the number of oral health problems (95% CI: 2.17%–10.79%; P = 0.0004). Conclusion Depressive symptoms were associated with poorer oral health behaviors, worse self-rated oral health, and a greater burden of self-reported oral health problems among university students. Oral health behaviors explained a modest proportion of these statistical associations. These findings support further investigation of integrated mental and oral health promotion strategies in university populations.