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.
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.
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.
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.
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.
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.