Obstructive sleep apnea (OSA) is a prevalent medical condition with important implications for overall health and quality of life in both children. Therefore, it is important to treat OSA early and effectively. However, adenotonsillectomy, the standard therapeutic approach for children with OSA, is often inadequate. Research shows that 20-40% of children still have residual OSA symptoms after surgery. Therefore, exploring other treatment options, specifically for those patients who currently have insufficient therapeutic options, is an interesting and relevant avenue for research. This study will evaluate the effectiveness of orofacial myofunctional therapy as a treatment option for children with obstructive sleep apnea (OSA). Orofacial myofunctional therapy consists of a set of oropharyngeal exercises to correct abnormal orofacial functions and strengthen upper airway muscles that are involved in maintaining airway patency. Both objective and subjective/patient-reported outcomes are collected to obtain a comprehensive understanding of the potential of orofacial myofunctional therapy as a treatment for OSA.