Exploring the causal relationship between chronic pain and temporomandibular disorders: A two-sample Mendelian randomization study

Abstract

Objectives

This study investigates the causal effects of chronic pain on temporomandibular disorders using two-sample Mendelian randomization analysis.

Design

Two-sample bidirectional Mendelian randomization analysis was adopted to systematically explore the causal relationship between temporomandibular disorders and 7 types of chronic pain, including headache, hip, neck/shoulder, stomach/abdominal, back, knee, and facial chronic pain. Genetic variants from genome-wide association studies data served as instrumental variables. Inverse variance weighted, weighted median, and Mendelian randomization-Egger regression were applied, with sensitivity analyses to ensure robustness. And p < 0.05 indicated statistical significance.

Results

Mendelian randomization analyses revealed a significant causal effect of neck or shoulder pain on the risk of temporomandibular disorders, with an Odds ratio of 6.317 (95 % CI: 1.730–23.062, p = 5.30E-3). Additionally, a reverse causal effect was observed where temporomandibular disorders may increase the risk of back pain, with an Odds ratio of 1.008 (95 % CI: 1.002–1.013, p = 8.40E-03). No significant causal relationships were found between other types of chronic pain (headache, hip pain, stomach or abdominal pain, facial pain, or knee pain) and temporomandibular disorders.

Conclusions

This study provides compelling evidence for the causal relationships between specific chronic pain conditions (neck or shoulder pain) and the risk of temporomandibular disorders. These insights highlight the importance of an integrated approach to patient care and emphasize the need for further research into the biological mechanisms underlying these relationships to guide the development of targeted preventive and treatment strategies.