Dissociation of functional and static mechanical risk indicators for temporomandibular disorders: A cross-sectional study using DC/TMD.

STATEMENT OF PROBLEM: The relative contributions of sustained static mechanical loading and dynamic functional activities to temporomandibular disorders (TMD) risk remain unclear.

PURPOSE: The purpose of this cross-sectional study was to investigate TMD prevalence in medical students and differentiate the risk contributions of self-reported dynamic functional activities and sustained static mechanical loading.

MATERIAL AND

METHODS

A cross-sectional study of 220 medical students was conducted. TMD was diagnosed using the DC/TMD Axis I protocol. Psychological status, oral behaviors, and suicide risk were assessed with the Depression, Anxiety, and Stress Scale-21, Oral Behavior Checklist (OBC), and Suicidal Behaviors Questionnaire-Revised. Data were analyzed using univariable and multivariable logistic regression (α=.05).

RESULTS

TMD prevalence was 42.3%. In univariable analysis, the TMD group exhibited significantly higher scores for static nonfunctional behaviors, specifically self-reported jaw-loading sleep position (P=.004) and awake jaw rigidity (P=.003). Self-reported dynamic functional activities (P=.071 to .643) and sleep bruxism (P=.099) showed no significant associations. In the multivariable model, female sex (adjusted odds ratio=2.695; P=.003) remained the sole independent predictor, rendering static behaviors statistically nonsignificant (OBC P=.201).

CONCLUSIONS

Female sex was the primary independent predictor of TMD in this population. Although not independent predictors in the multivariable model, self-reported sustained static loading behaviors act as clinically relevant univariable risk indicators. Initial clinical assessments may benefit from screening for these static postural habits alongside traditional functional evaluations.