Symptoms of Orofacial Myofunctional Disorders (OMDs)

Dental Problems related to OMDs

Tongue thrust

Sometimes when a person swallows incorrectly, the tip 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. That pressure may later prevent teeth from breaking through the gum.

Anterior open bite and crowding

A patient with anterior crowding and an open bite

Tongue thrust may also prevent the teeth from biting together. This is known as an open bite. An open bite can cause numerous problems.

  • Speech issues – The front teeth play a critical role in the way we form language. If they’re in the wrong place that can cause lisping and other speech issues.
  • Smile issues – Since the front teeth are most prominent when we smile, an open bite is a particularly noticeable condition


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.

An open bite is one type of malocclusion, but it can occur at any part of the bite.

A woman mouth breathing with her lips open. Mouth breathing can be a symptom of orofacial myofunctional disorders

Cosmetic problems related to OMDs

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) also signal this disorder. 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.

  • The face can have a dull sluggish appearance when the muscles are not in proper balance.
  • An incorrect swallow will purse and tighten the muscles of the cheeks, chin, and lips, causing a facial grimace
  • Mouth breathing or constantly open lips is a cause and/or signal of tongue thrust and low tongue rest posture.


Sleep disordered breathing and mild to moderate obstructive sleep apnea (OSA)

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 and used properly, the muscles of the tongue, throat, and face, can reduce obstruction to the airway.

Learn more about obstructive sleep apnea in this video

Video Credit: SPEAR Dental Education

Orofacial myofunctional disorders can cause speech problems. Here, a young boy with malocclusion visits a speech therapist

Speech problems related to OMDs

A person with abnormal oral muscle patterns may suffer a lisp or have difficulty in articulating sounds. If muscles in the tongue and lips are incorrectly postured, this can prevent a person from forming sounds of normal speech.

Improper oral muscle function may additionally lead to TMJ dysfunction, headaches, stomach distress (from swallowing air), airway obstruction, and other health challenges.

OMDs and Temporomandibular Joint Disorder (TMD)

TMD is a term used to describe pain and dysfunction of the temporomandibular joint – the joint that connects the jaw and skull. TMD can be caused or exacerbated by OMDs.

Learn more about TMD in this video

Video Credit: SPEAR Dental Education

Ready to set up an appointment? Get in touch with Southwest Myofunctional Therapy on the Contact Us page. Online consultations available!