Orofacial myofunctional disorder refers to improper function of the facial muscles, tongue and mouth. OMDs may directly or indirectly affect facial growth and development, chewing, swallowing, speech articulation, occlusion, oral hygiene, stability of orthodontic treatment, facial esthetics and more. Several factors can contribute to OMDs, one being inherited muscle patterns. Another is airway obstruction. This may be caused by enlarged tonsils or adenoids, anatomical abnormalities or allergies. A tight lingual frenum (the string of tissue that holds the tongue to the floor of the mouth), may restrict the movement of the tongue. The subsequent adaptation of the facial muscles and tongue may advance OMDs. Orofacial myofunctional disorders may negatively impact treatment by orthodontists, speech pathologists and other dental professionals. Correct swallowing depends on a synergistic relationship between muscles of the face, mouth and throat. Muscles and nerves in the tongue, cheeks and throat must work in harmony. When a person swallows correctly, the tip of the tongue firmly presses against the hard palate (the roof the mouth, slightly behind the front teeth), which is designed to withstand the force created by the tongue during swallowing.
During an incorrect swallow, the tip of the tongue presses against the teeth, sometimes pressing between the teeth. This is commonly called tongue thrust.
Constant pressure from the incorrect resting position of the tongue and incorrect swallowing may push the teeth out of alignment. That pressure may also hinder the complete eruption (breaking through the gum) of some teeth. An OMD may lead to malocclusion (misalignment of the teeth), which can contribute to difficulties with biting, chewing, swallowing and digesting food. In an open bite the front teeth do not touch, and leave an “open” space between the upper and lower teeth. The inability of the upper and lower teeth to make contact can impede biting and chewing of food. Some contributing factors to an open bite are tongue thrust, resting posture of the tongue, thumb sucking and prolonged pacifier use.
The face of person with an OMD can have a dull, sluggish appearance because of the muscles not working in harmony. An open mouth, with or without mouth breathing, is often present in a person with tongue thrust and contributes to the undesirable appearance. A person swallowing incorrectly will often tighten the muscles of the cheeks, chin and lips, causing an unsightly facial grimace and a knobby looking chin will result from these muscles overcompensating.
A person with abnormal oral muscle patterns may experience a lisp, or have difficulty articulating sounds. If the muscles of the tongue and lips are postured incorrectly, this can prevent a person from forming normal sounds of speech.
Recent research has shown that myofunctional therapy may reduce the symptoms of sleep disordered breathing, such as snoring, and ameliorate mild to moderate OSA (obstructive sleep apnea). When functioning properly, the muscles of the tongue, throat, and face can reduce obstruction to the airway.
Myofunctional therapy eliminates many of the causes of swallowing abnormalities and incorrect rest posture of the tongue. When certain muscles of the face are functioning correctly, other muscles will become activated and proper coordination of the tongue and facial muscles is attained. Myofunctional therapy is painless and relatively simple to do. For successful results, exercises must be done consistently every day until the patient has corrected their abnormal muscle pattern. It also takes a commitment by the patient, their family and their time. Treatment consists of a regimen of exercises over an 8-12 month period on average, although treatment length may vary per individual.
A properly trained myofunctional therapist is one member of a team that will successfully treat an OMD. Other allied professionals, such as dentists, orthodontists, speech pathologists and osteopaths will help ensure that all the patient’s needs are addressed and treated appropriately.