Orofacial Myology and OMDs

For Dentists and Physicians  •  Parent's Page

What is an Orofacial Myofunctional Disorder?

The prefix, "myo" stands for muscle. Orofacial Myofunctional Disorders involve behaviors and patterns created by inappropriate muscle function and incorrect habits involving the tongue, lips, jaw and face. Of the many possible myofunctional variations, those involving the tongue and lips receive the most attention. 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 misalignment of the teeth.
An orofacial variation that relates to the lips is an open mouth, lips apart resting posture. This is often referred to as lip incompetence and can distract from a pleasing facial appearance.

What Causes an Orofacial Myofunctional Disorder?

Often it is difficult to point to one particular source as the sole cause of an orofacial myofunctional disorder. In most cases it is the result of a combination of factors. Many authorities suggest that orofacial myofunctional disorders may result from the following:
Improper oral habits such as thumb or finger sucking, cheek/nail biting, tooth clenching/grinding.
Restricted nasal airway due to enlarged tonsils/adenoids and/or allergies.
Structural or physiological abnormalities such as a short lingual frenum (tongue-tie) or abnormally large tongue.
Neurological or developmental abnormalities.
Hereditary predisposition to some of the above factors.

Why Be Concerned?

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. Speech patterns may become distorted or misarticulated. Parafunctional habit patterns may have a negative influence on the functioning of the temporomandibular joint.Correcting or improving resting tongue or lip relationships can be instrumental in aiding the development of normal patterns of dental eruption and alignment. Myofunctional therapy for tongue thrusting and lip incompetence may be recommended for a variety of functional or cosmetic reasons.

If the patient already has orthodontic appliances, correcting the myofunctional disorder can help stabilize the orthodontic result by creating a more desirable and healthier oral environment. Usually the therapy programs are designed to retrain patterns of muscle function and to aid in the creation and maintenance of a healthy, adaptive orofacial environment. Therapy can help in the retention of the dental and/or orthodontic treatment, in the enhancement one's appearance and in the maintenance of optimum dental health for a lifetime of benefits.
  • Is Treatment Necessary?
  • Who Should Treat?
  • At What Age Should Therapy Begin?
  • Is Treatment Effective?
There are many possible variations of orofacial myofunctional disorders just as there are many patterns of normal function. Some patterns are more common than others. The effects of these patterns need to be evaluated individually, especially when there are dental, medical, or speech concerns. The decision to treat or not to treat should be made by a professional trained in Orofacial Myology. Orofacial Myology treatment goal include the improvement of muscle tonicity and establishing correct functional activities of the tongue, lips, and mandible so that normal growth and development can take place or progress in a stable, homeostatic environment.
Treatment should be completed by a specially trained professional certified as an Orofacial Myologist. Speech pathologists, dentists, registered dental hygienists, psychologists, special educators, allied health professionals, and nurses are among the specialists who seek additional training in this area. The qualifications of professionals who provide treatment for you and your family should always be checked. The International Association of Orofacial Myology (IAOM) is a professional organization that can help identify professionals in your area who are trained and/or certified to provide this specialized treatmet.
Children as young as four years old can benefit from an evaluation session to determine if any preventative steps should be prescribed. Children of seven or eight years of age are often mature enough to receive complete training. Adults of all ages are capable of success in treatment.
How Prevalent Are Orofacial Myofunctional Disorders?
Recent research examining orofacial myofunctional disorders in various populations have found a prevalence of anywhere from 38% in the general population to 81% in children exhibiting speech/articulation problems. (Kellum,1992, Maul, et.al,1999).
Many recent scientific studies have shown that treatment for orofacial myofunctional disorders can be 80-90% effective in correcting swallowing and rest posture function and that these corrections are retained years after completing therapy, (Hahn&Hahn,1992)
There are many factors that contribute to the success of the therapy program. Of these, cooperation is an essential factor. Another important factor is the cooperation and communication between the therapist and the referring dental community. A team effort is essential to success.

Questions and Answers

What is Orofacial Myology?
Orofacial myology is a specialized professional discipline that evaluates and treats a variety of oral and facial (orofacial) muscle (myo-) postural and functional disorders and habit patterns that may disrupt normal dental development and also create cosmetic problems. The principles involved with the evaluation and treatment of orofacial myofunctional disorders are based upon dental science tenets; however, orofacial myofunctional therapy is not dental treatment.
How does myofunctional therapy differ from dental or orthodontic treatment?
Dental evaluations and treatments focus primarily on providing health and stability of teeth in occlusion, or contact. By contrast, myofunctional therapy is concerned with orofacial functional patterns and postures when teeth are apart, which they are for over 95% of each day and night.
What are myofunctional disorders and how are they corrected?
An oral myofunctional disorder includes a variety of habit patterns, postures and functional activities that open the dental bite beyond a normal resting or functional range. Thumb and finger sucking; a mouth-open posture with lips apart; a forward rest posture of the tongue; and thrusting of the tongue during speaking and swallowing characterize myofunctional disorders. Such disorders can lead to a disruption of normal dental development in children and over-eruption of selected teeth in adults. The consequence of postural and functional variations involving the lips and tongue are associated with dental malocclusion, cosmetic problems, and even abnormal changes in jaw growth in some patients.

Orofacial myofunctional clinicians are trained to identify and successfully treat the variety of myofunctional disorders. Myofunctional therapy can be basically described as rest posture therapy. Specific treatments involve establishing and stabilizing normal rest postures for tongue and lips, eliminating habit patterns, and correcting swallowing patterns when tongue thrusting is involved. Improvements in appearance are observed during and following therapy.

Myofunctional therapy often restores normal processes of dental eruption. It can also aid in the retention process following orthodontic treatment. In addition, therapy that is coordinated with dental or orthodontic treatment helps to enhance and maintain dental health for a lifetime of benefits.
What causes an orofacial myofunctional disorder?
It is often difficult to identify a single cause for an orofacial myofunctional disorder. Most disorders involve a combination of factors that may include:
• An airway restriction from enlarged tonsils or adenoids, allergies or anatomical deviations involving the nasal cavity or pharynx.
• Improper oral habits such as thumb or finger sucking, cheek or nail biting, teeth clenching or grinding.
• Neurological and sensori-neural developmental delays or abnormalities.
• Structural or physiological abnormalities such as short lingual frenum (tongue-tie).
• Hereditary predisposition to any of the above factors.
Why be concerned?
Orofacial myofunctional disorders can have a negative effect on the growth and development of the dentition. Dental eruption patterns and dental alignment can be disrupted. Speech articulation patterns may become distorted. The temporomandibular joint apparatus can become impaired or damaged from abnormal oral functional patterns.

Orofacial myofunctional therapy may be recommended for a variety of reasons for children and adults. A major treatment goal of correcting or improving resting tongue and lip relationships can aid in the development of normal patterns of dental eruption and alignment. The elimination of tongue thrusting and lip incompetence can have a positive effect on cosmetic appearance. If the patient has orthodontic appliances in place or has completed orthodontic treatment, correcting the myofunctional disorder can help to stabilize the orthodontic result by creating a more desirable and healthy oral environment.

Orofacial myofunctional therapy procedures are designed to eliminate harmful habit patterns, to normalize resting tongue, lips and jaw positions, or to retrain muscle patterns when there is tongue thrusting.
At what age should therapy begin?
Children as young as five years of age can benefit from evaluation or therapy to eliminate sucking habits. Age five years is usually a good age to initiate digit sucking therapy or refer a patient for medical evaluation of an airway interference issue. However, resting posture problems of tongue and lips, and other functional problems such as tongue thrusting are not indicated for treatment until age eight or nine.

Orofacial myofunctional therapy is also appropriate for adults. In many instances, a myofunctional disorder develops in response to late jaw growth, worsening of a malocclusion over time, or other reasons such as tooth loss. Therapy for adult patients is typically efficient. Adults of all ages are capable of achieving success in treatment.

In some instances, evaluation will reveal that no treatment is needed in a child or adult. A tongue thrust without an accompanying speech or dental occlusion variation does not always require correction. The orofacial myofunctional clinician can provide advice on which child or adult will require treatment. While orofacial myofunctional therapy is not speech therapy, the orofacial myofunctional clinician who is also trained in speech-language pathology can also correct the speech disorders which may be associated with orofacial myofunctional disorders.