Validity and Cut-Off Scores of the OMES Protocol for Orofacial Myofunctional Disorders Across Different Age Groups

The Orofacial Myofunctional Evaluation with Scores (OMES) protocol is a standardized clinical instrument developed to assess orofacial myofunctional disorders (OMD); however, diagnostic cut-off values have not previously been established for different age groups. This study aimed to strengthen the validity and psychometric evidence supporting the OMES protocol and to establish diagnostic cutoff values for OMD across different age groups. A cross-sectional observational study based on a retrospective database review was conducted with 302 participants, including children, young adults, and adults with clinical conditions associated with a high probability of OMD or healthy controls matched by age and sex. All participants were assessed using the OMES protocol. Instrument performance was examined using a known-groups approach, internal consistency analysis, and receiver operating characteristic (ROC) curve analysis. Internal consistency was high across all age groups (Cronbach’s alpha: 0.91 for children, 0.87 for young adults, and 0.84 for adults). All OMES categories and the total OMES score discriminated between individuals with and without OMD. ROC analyses demonstrated high diagnostic accuracy. The OMES protocol demonstrated strong psychometric performance and can be applied across different age groups, supporting the identification of OMD, informed clinical decision-making, therapeutic planning, and treatment outcome evaluation.