Association Between Dietary Habits and the Risk of Temporomandibular Disorders: A Bidirectional Mendelian Randomisation Study

ABSTRACT Background Temporomandibular disorders (TMD) are complex conditions influenced by multiple factors, including dietary habits. This study aimed to explore the potential causal relationships between dietary patterns and TMD risk using bidirectional Mendelian randomisation (MR). Methods A bidirectional two‐sample MR analysis was performed to assess the causal effects of 83 dietary habits on TMD risk, and vice versa. Five MR methods, including inverse variance weighting ( IVW ), were applied. Associations with p ‐values < 0.05 were considered suggestive of causality. Results Ten dietary habits were found to be significantly associated with TMD risk. Protective factors included muesli consumption (OR = 0.53, 95% CI = 0.34–0.82, p = 0.00458), fresh fruit intake (OR = 0.73, 95% CI = 0.58–0.92, p = 0.00676), decaffeinated coffee (OR = 0.70, 95% CI = 0.54–0.91, p = 0.00789), and red wine intake (OR = 0.73, 95% CI = 0.53–1.00, p = 0.0477). Risk‐enhancing factors included frequent consumption of white or brown bread, cornflakes/frosties, low‐fat spreads, and complete sugar avoidance. Reverse MR indicated potential reverse causality for red wine intake (OR = 0.99, 95% CI = 0.97–1.00, p = 0.00937). Conclusion Our findings suggest that specific dietary habits may causally influence the risk of TMD. These insights could inform dietary recommendations for TMD prevention and highlight the need for mechanistic and longitudinal studies to validate these associations.