What is a Myofunctional Disorder

Orofacial Myofunctional Disorders (OMDs) are disorders of the muscles and functions of the face and mouth. OMDs may affect, directly and/or indirectly, breastfeeding, facial skeletal growth and development, chewing, swallowing, speech, occlusion, temporomandibular joint movement, oral hygiene, stability of orthodontic treatment, and more.

Most OMDs originate with insufficient habitual nasal breathing or with oral breathing. The subsequent adaptation of the muscles and the orofacial functions to a disordered breathing pattern creates many OMDs. Orofacial Myofunctional Disorders may impact treatments by orthodontists, dentists, dental hygienists, speech-language pathologists, and other professionals working in the orofacial area.

Dental Problems related to an OMD

When a person swallows incorrectly, the tip and/or sides of the tongue press against or spread between the teeth.
This is commonly called a tongue thrust. Constant pressure from resting or incorrectly thrusting the tongue away
from the hard palate may push teeth out of place, creating an open bite or flared teeth. That pressure may later
prevent teeth from erupting (breaking through the gum).

An OMD may lead to an abnormal bite – the improper alignment between the upper and lower teeth known as
malocclusion. This problem may lead to difficulties in biting, chewing, swallowing, and digesting of food.

Many patients with OMDs notice themselves grinding their teeth/bruxing at night and clenching their teeth during
the day.

Oral habits such as thumb or finger sucking are often precursors to OMDs and have impact on dental alignment.

The success of orthodontic treatment is at risk in the future if OMDs are not addressed as dental alignment is affected by improper swallowing techniques.

Facial Development

Often the most obvious symptom of incorrect oral posture involves the muscles of the face. A dull, sluggish
appearance and full, weak lips develop when muscles aren’t operating normally.

Constantly parted lips (with or without mouth breathing) is a signal of a low tongue resting posture, which may accompany tongue thrust. This can also cause a facial growth pattern including a recessed chin and/or elongatedfacial features.

A person swallowing incorrectly will often purse and tighten the muscles of the cheeks, chin and lips – a symptom known as a facial grimace. This can give the chin a knobby appearance because these muscles are being overused.

Speech Problems that may develop from an OMD

A person with abnormal oral muscle patterns may have difficulty pronouncing sounds such as /s/, /z/, /t/, /d/, /n/, /l/ and sometimes “sh”, “ch” and “j”. If muscles in the tongue and lips are incorrectly postured, this can prevent a person from forming sounds of normal speech.

Swallowing Problems that may develop from an OMD

Correct swallowing depends on a proper relationship between muscles of the face, mouth and throat. The act of
swallowing is one function that depends on the body’s vital balance. To swallow properly, muscles and nerves in the
tongue, cheeks and throat must work together in harmony. When a person swallows normally, the tip of the tongue
presses firmly against the roof of the mouth or hard palate, located slightly behind the front teeth. The tongue acts in
concert with all the other muscles involved in swallowing. The hard palate, meanwhile, absorbs the force created by
the tongue.

Because a person swallows 500-1000 times per day, improper swallowing can cause a variety of problems. It is the tongue’s overall resting posture, however, that does the most damage because it is more constant.

Health Problems associated with OMDs may include:

Mouth breathing

Increased risk of TMJ symptoms

Chronic headaches

Pain in the jaw

Neck &Backache

Digestive Problems

Changes in posture (forward head carriage posture)

Sleep apnea

Sleep disordered breathing symptoms


Tightening of the cheek, chin and lips