Orofacial Myofunctional Disorders
The prefix, "myo" stands for muscle. Orofacial Myofunctional Disorders involve behaviors and patterns created by inappropriate muscle functional and incorrect habits involving the tongue, lips, jaw and face. A tongue thrust is the most common orofacial myofunctional variation. During the act of swallowing, (deglutition), and/or during rest posture, an incorrect positioning of the tongue may contribute to improper orofacial development and maintenance of the malalignment of the teeth. An orofacial variation that relates to the lips is an open mouth, lips apart resting posture. This is often referred to lip incompetence and can distract from a pleasing facial appearance.
Orofacial myofunctional disorders may have a negative effect on the development of the dentition, particularly dental eruption patterns and/or alignment of the teeth and jaws. A person with abnormal swallowing symptoms may display a lisp (tongue between teeth for the s and z sounds) or have difficulty articulating sounds. If the muscles in the tongue and lips are imbalanced, that can prevent a person from forming speech sound correctly.