Causal Relationship Between Obstructive Sleep Apnea and Temporomandibular Disorders: A Bidirectional Mendelian Randomization Analysis

Objective: This study was conducted to investigate the bidirectional causal relationship between obstructive sleep apnea (OSA) and temporomandibular disorders (TMD). Methods: Using an online pooled dataset of genome-wide association studies (GWAS), a two-sample bi-directional Mendelian randomization (MR) method was implemented. Inverse variance weighting was used as the primary analyses approach, and other methods of MR Egger, weighted median method, MR-Egger, Simple mode, and Weighted mode analysis were conducted as supplements to evaluate the causal relationship between OSA and TMD with odds ratios (OR) and 95% confidence interval (CI). Furthermore, the Cochran Q, MR-Egger, and MR-PRESSO approaches were used to perform the heterogeneity test and multiple validity. Results: The general results of the forward MR analysis indicated that OSA had a significant causal influence on TMD (OR=1.241, 95% CI: 1.009– 1.526, P=0.041), but no significant correlation was observed in the reverse MR analysis (IVW: OR=0.975, 95% CI=0.918– 1.036, P=0.411). Conclusion: In summary, our research demonstrated a hereditary causative relationship between OSA and TMD, indicating that appropriate intervention is required for both prevention and treatment of TMD.