Orofacial Myofunctional Disorders (OMD) (sometimes called “oral myofunctional disorder", and “tongue thrust”) are muscle disorders of the face, mouth, lips, or jaw due to chronic mouth breathing. Recent studies on the incidence and prevalence of tongue thrust behaviors are not available. However, according to previous research, 38% of various populations have OMD. The incidence is as high as 81% in children exhibiting speech/articulation problems (Kellum, 1992).