# The potential association between sedentary behaviors and risk of temporomandibular disorders: evidence from Mendelian randomization analysis

## TL;DR

This study finds a genetic link between prolonged driving and increased risk of temporomandibular disorders, suggesting a need for monitoring drivers for TMD symptoms.

## Contribution

The study provides novel evidence of a potential causal association between driving time and TMD risk using Mendelian randomization.

## Key findings

- Prolonged driving time is significantly associated with increased TMD risk (OR = 2.797, p = 0.024).
- No significant association was found between watching TV or using a computer and TMD risk.
- Sensitivity analyses confirmed the robustness of the observed association between driving and TMD.

## Abstract

The role of sedentary behaviors in temporomandibular disorders (TMD) has not
been thoroughly investigated. This study aims to investigate the potential
association between sedentary behaviors and TMD using Mendelian randomization
(MR) analysis. The MR method was employed to assess the causal association
between sedentary behaviors and the risk of TMD. Genetic variants associated with
sedentary behaviors, such as watching TV (Television), using computers and
driving, were used as instrumental variables (IVs). MR analysis was performed
using inverse variance-weighted (IVW) and weighted median methods, alongside
MR-Egger regression to assess pleiotropy and statistical heterogeneity.
Furthermore, leave-one-out analyses were conducted to assess whether any single
SNP (single nucleotide polymorphism) or subset of SNPs influenced the
results. Our analysis identified a significant association between
driving time and the risk of temporomandibular disorders (IVW: OR (Odd ratio) =
2.797, 95% CI (Confidence interval) = 1.148–6.811, p = 0.024; weighted
median OR = 4.271, 95% CI = 1.226–14.871, p = 0.023). In contrast, no
significant associations were observed between time spent watching TV and using a
computer and TMD risk. The robustness of the findings was confirmed through
sensitivity analyses, including leave-one-out analysis. This study provides
evidence of a potential genetic link between prolonged driving and TMD risk,
suggesting that individuals frequently engaged in long-duration driving should be
monitored for TMD symptoms. Further research is warranted to explore the complex
interactions between sedentary behaviors and TMD, incorporating longitudinal and
comprehensive assessments.