Orofacial Myofunctional Therapy and Positive Airway Pressure-CPAP Trial for Mild-to-Moderate Obstructive Sleep Apnea

The goal of this clinical trial is to evaluate the isolated and combined effects of orofacial myofunctional therapy (OMT) and continuous positive airway pressure (CPAP) in adults with mild-to-moderate obstructive sleep apnea. The main questions it aims to answer are whether OMT alone, CPAP alone, or combined OMT plus CPAP improves obstructive sleep apnea severity at Week 12, as measured by the apnea-hypopnea index (AHI), and whether these interventions improve mandibular excursion. Researchers will compare 4 groups-sham plus standard of care, OMT plus standard of care, CPAP plus standard of care, and combined OMT plus CPAP plus standard of care-to assess differences in respiratory and anatomical-functional outcomes. Participants will be randomized to 1 of the 4 study arms. During the 12-week supervised intervention phase, participants will receive their assigned intervention together with standardized sleep-hygiene and lifestyle counseling. Assessments include sleep recording, mandibular excursion measurements, questionnaires on sleepiness and sleep quality, dento-occlusal and anthropometric measurements, and treatment adherence monitoring. After Week 12, participants will enter an observational follow-up phase through Week 52 to evaluate durability of treatment effects, treatment persistence, symptom recurrence, and clinically indicated treatment modifications.