Associations between caffeine consumption, anxiety, temporomandibular disorders, and oral behaviors in university students in Brazil—a cross-sectional study

Abstract

Background: This cross-sectional study investigated the associations between caffeine consumption, caffeine-related expectations, anxiety symptoms, painful temporomandibular disorder (TMD) symptoms, and oral behaviors in university students. Methods: Students from the Faculty of Health Sciences at the University of Brasília completed a self-administered questionnaire assessing their sociodemographic characteristics, caffeine consumption frequency, expected effects of caffeine, anxiety symptoms, painful TMD symptoms, and oral behaviors. Associations between categorical variables were analyzed using the chi-square or Fisher’s exact tests, and correlations between caffeine consumption and expectancy domains were assessed using Spearman’s correlation coefficient. Statistical analyses were performed at a significance level of 5%. Results: A total of 182 students participated in this study. Painful TMD symptoms were significantly more prevalent among students with severe anxiety (p < 0.001). A higher prevalence was also observed among female participants and those who reported frequent oral behaviors. Oral behaviors were significantly associated with both anxiety symptoms and female sex (p < 0.001). No significant association was found between overall caffeine consumption and oral behaviors. However, daily black coffee consumption was significantly associated with severe anxiety (p < 0.001). Additionally, specific types of caffeinated products were positively correlated with distinct expectations about their effects, such as increased energy, dependence, and mood enhancement. Conclusions: Although overall caffeine consumption was not directly associated with oral behaviors or painful TMD symptoms, daily black coffee intake was associated with higher anxiety levels in this study sample. These findings suggest a possible association between black coffee consumption, anxiety symptoms, and painful TMD-related outcomes; although causality cannot be established because of the observational design of the study.