Orofacial Myology: Questions and Answers
OROFACIAL MYOLOGY Questions and Answers
ABSTRACT
Several frequently asked questions about orofacial myology are asked and answered. Additional questions and concerns are addressed in other topics included on this website, especially those topics directed toward parents.
WHAT IS OROFACIAL MYOLOGY?
Orofacial myology is a specialized sub-specialty with either speech-language pathology or dentistry, especially dental hygiene, 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 lead to tooth position changes (malocclusions), or can cause cosmetic problems. The principles involved with the evaluation and treatment of orofacial myofunctional disorders are based upon dental science principles; however, orofacial myofunctional therapy is not dental treatment.
WHO ARE OROFACIAL MYOLOGISTS?
Orofacial myologists (also called myofunctional therapists or orofacial myofunctional therapists) have received specialty training to evaluate and treat a variety of myofunctional conditions and problems. Orofacial myologists have previous professional training in speech-language pathology, dental hygiene, dentistry, or other health-related fields
WHAT ARE MYOFUNCTIONAL DISORDERS AND HOW ARE THEY CORRECTED?
Orofacial myofunctional disorders (OMDs) 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 disruptions involving the lips and tongue can lead to dental malocclusion, cosmetic problems, and even abnormal changes in jaw growth.
Tongue thrusting is a behavior that is the most-often discussed OMD. All infants start out as tongue thrusters but, over time, adapt away from thrusting with maturation of oral functions and if the airway is clear enough for the tongue to rest behind the front teeth. Some children, however, retain a thrusting pattern and a forward tongue rest posture if a respiratory obstruction or allergic condition necessitates this pattern to maintain an open airway.
Tongue thrusting during swallowing or speech has been overemphasized in dentistry as a negative condition. “Thrusting” has often been incorrectly viewed as the cause of dental changes, when in fact, the dental changes often seen with tongue thrusting are the product of an accompanying forward interdental rest posture of the tongue, rather than the thrusting itself. As will be explained in detail elsewhere on this website, the brief contacts of the tongue tip against the upper front teeth during a tongue thrust swallow, or during speech, are insufficient in duration or in the amount of pressure applied to the teeth to account for the dental changes and malocclusions inappropriately linked with thrusting. Instead, a forward rest posture of the tongue, for 6 or more hours per day, can result in tooth position changes. In short, tongue thrusting is a clue to look for a forward rest posture of the tongue that can lead to the development of malocclusions in some individuals, especially growing children whose dental development has not been completed. Otherwise, tongue thrusting itself may not need to be treated if there are no negative cosmetic components associated with the thrusting.
Orofacial myofunctional therapy procedures are designed to eliminate potentially harmful habit patterns, to normalize resting tongue, lips and jaw positions, and to retrain abnormal muscle patterns when there is tongue thrusting.
WHAT CAUSES AN OROFACIAL MYOFUNCTIONAL DISORDER?
While there can be a single cause for an orofacial myofunctional disorder, such as a tongue thrusting pattern without any other factors involved, most disorders involve a combination of factors that may include:
A chronic airway restriction from enlarged tonsils or adenoids or allergies.
Improper and prolonged oral habits such as thumb or finger sucking, cheek or nail biting, teeth clenching or grinding.
Various neurological conditions, sensory deficits or delays in oral growth and development, or speech production
developmental delays.
Structural or physiological abnormalities such as a 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 and even on cosmetic appearance. 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. Children who have a mouth open, lips-apart rest posture may be negatively perceived.
Orofacial myofunctional therapy may be recommended for a variety of reasons for children and adults. A major treatment goal to correct or improve resting tongue and lip relationships can recapture or establish normal patterns of dental eruption and proper alignment of teeth. The elimination of tongue thrusting and lip incompetence can have a positive impact on cosmetic appearance.
For those individuals with orthodontic appliances in place, or who have completed orthodontic treatment, correcting myofunctional disorders can help to insure the success of the orthodontic result by stabilizing the healthy oral environment created by orthodontic treatment.
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, the treatment of resting posture problems of tongue and lips, and other functional problems such as tongue thrusting can be deferred until age eight or nine years of age.
Orofacial myofunctional therapy is also appropriate for adults. In many instances, a myofunctional disorder develops in response to late jaw growth, the worsening of a malocclusion over time, or other factors 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. For example, a tongue thrust without an accompanying speech or dental occlusion variation does not always require correction. The orofacial myologist can provide advice regarding which child or adult will require treatment.
While orofacial myofunctional therapy is not speech therapy, the orofacial myologist who is also trained in speech-language pathology can also correct the speech disorders, which may be associated with orofacial myofunctional disorders. When speech therapy is begun by age 6 or 7, orofacial myofunctional disorders can be corrected along with the speech problem.
DOES OROFACIAL MYOFUNCTIONAL THERAPY WORK?
Yes, there are many published studies that show that myofunctional therapy is effective and that the results of therapy are long- lasting. References to support the claim that therapy is effective are included at the end of several documents on this website.
Therapy procedures to eliminate tongue thrusting and to reposition the tongue at rest have been the primary focus of orofacial myologists. More recently, therapy also includes normalizing the vertical rest posture of the lower jaw which accounts for the resting distance between upper and lower dental arches. The small vertical space between the dental arches at rest is called the interocclusal space, or freeway space (explained and discussed in detail in website documents). To explain this simply, as you are reading this, your lips are likely closed but your teeth are not in contact. The normal teeth-apart rest position is called the dental freeway space. If the freeway space is habitually open too far, dental changes can occur, and if the freeway space dimension is habitually closed down, pain and discomfort occur in the jaw closing muscles.
Orofacial myologists work mutually with orthodontists and others in dentistry to correct oral habits and to establish normal rest postures of tongue and lips. The combination of normalizing behaviors and postures in all dimensions is the particular challenge of orofacial myologists. Specialized training is needed for orofacial myologists to accomplish these goals.