Many dental practitioners and others see a tongue thrust and dental malocclusions (or teeth out of normal alignment) and presume that the tongue thrust is the cause. What is often missed in oral evaluations is the rest position of the tongue, especially the tongue tip. It is well documented in dental science that a forward rest position of the tongue tip against or between the teeth can, over time, result in dental changes when there is a long period (at least 4-6 hours per day) of an abnormal tongue rest position. It does not take a lot of pressure for a forward rest position of the tongue tip to move some teeth to a new, abnormal position. Only light, continuous pressure is needed to move teeth, whether by orthodontic appliances or a forward tongue rest position. In the same way, sucking habits, when a digit pressure is applied hours per day, can cause a change in the shape of the dental arches.
A tongue thrust and a forward rest position of the tongue tip often occur together. When they do, a malocclusion (malposition) of teeth is the likely result. However, not all individuals with a tongue thrust habit will need treatment since the thrusting alone is not linked as a cause of changes in dental position. But still, a tongue thrust most often presents a cosmetic or an eating problem and, when accompanied by a forward tongue rest posture, dental changes will likely result. Some patients show a rest position of the tongue between the side (back) teeth. In such cases, dental alignment problems can develop in these areas of the dental arches. Where there is a tongue thrust, clinicians will look closely for an accompanying abnormal rest position of the tongue. In either case, treatment may be indicated. A primary goal of orofacial myofunctional therapy in children is to re-establish a normal oral environment in which normal processes of dental eruption can be achieved. In adults, the goal is to normalize oral postures and functions to create stability in the dental arches. Working on the elimination of a tongue thrust as a cosmetic concern is also an appropriate reason for therapy in some individuals. This is done by re-positioning the tongue at rest, or eliminating a tongue thrust during the function of swallowing.
When the house in which the tongue resides becomes normal with regard to where the tongue rests and how it functions during eating, swallowing and speech functions, the dental structures can then be placed in a normal position that should remain stable, with no future problems anticipated. However, follow-up appointments will be needed after the completion of therapy to monitor success and to identify any possible recurrence of problems.
One final thought: what is seen at the front of the mouth can often serve as a clue that something is not normal at the back of the throat. A tongue thrust, a forward rest position of the tongue, or the mouth resting in an open position are diagnostic observations that raise suspicions of a problem at the back of the throat that interferes with normal breathing. Examples of such problems are enlarged tonsils, adenoids, or allergies that can affect the nasal cavity or reduce the size of the throat cavity. Such problems can result in a need for the tongue to adapt by positioning forward at rest or thrusting forward during the first part of a swallow to maintain an open airway for breathing.
Why the Emphasis on Tongue Thrusting?
In fairness to those orthodontists, dentists, or others who may have told you that your child has a tongue thrust, and have expressed concerns about it as related to the orthodontic treatment anticipated or already underway, this term has been around for more than 50 years and continues to be a popular overall description of a problem with the tongue that orthodontists may feel will hamper their orthodontic work or cause the orthodontic result to be compromised. However, it is the rest posture of the tongue, lips and jaws that is the primary link with developing problems of dental alignment that may necessitate orthodontic treatment.
Although parents can expect orthodontists, dentists, and orofacial myologists to mention tongue thrusting as a primary clinical finding, or descriptive diagnosis, a more detailed evaluation by an orofacial myologist will reveal that treatment recommendations will include normalizing the rest posture of the tongue, lips and jaws. The tongue thrust will be treated as a part of the overall problem list, but tongue thrusting itself should be viewed as an opportunistic behavior, or an adaptation to problems already there with abnormal rest posture of tongue, lips and jaws.
You may have been told that tongue thrusting can lead to dental malocclusions due to the “excessive” forces applied against the front teeth during speaking and swallowing as has been falsely claimed by many for over 50 years. Such claims have been shown to be incorrect since the 1970s when some classic research studies were published (some classic research articles by Proffit and colleagues will be referenced elsewhere on this website for those who may want additional information and supporting proof). Actually, the term tongue thrusting is a misnomer; that is, it is an inaccurate term since the action of the tongue is not a “thrust” which implies an excessive force, when in fact tongue contacts during “thrusting” are insufficient in force and duration to move teeth. The reason that tongue thrusting does not cause dental problems, such as protrusion of upper front teeth, spacing between teeth, or the development of other malocclusions such as an open bite discrepancy between the upper and lower dental arches, is because of the short duration and small amount of force applications by the tongue against the teeth that are insufficient to account for the movement of teeth.
Why has the myth persisted that tongue thrusting can lead to changes in the dentition, or malocclusions?
The primary reason is that tongue thrusting is a very visible behavior as compared to the less obvious observation of a forward rest posture of the tongue. When clinicians see individuals with a tongue thrust habit and a malocclusion, they often conclude incorrectly that the thrusting caused the dental condition; whereas the less obvious forward rest posture of the tongue is often missed in favor of the more visible thrusting habit. As mentioned above, the thrusting is an opportunistic behavior an adaptation to a developing dental alignment problem already there. Where there is a space, the tongue fills in the space as an adaptive and opportunistic response.
Many clinicians have also assumed incorrectly that the forces or pressures of the tongue applied against the anterior teeth during thrusting are excessive. This has also proven to not be true. Here are some details: The fleeting contacts of the tongue tip at the upper or lower incisor teeth are not excessive, nor are those claims made correct that for each swallow, from 1 to 7 pounds of pressure is applied by the tongue. In truth, the forces of the tongue at the teeth fall within the normal range of 50 grams (there are 454 grams in a pound). In addition, swallow pressures do not add up from one swallow to the next, so it is irrelevant how many times an individual swallows each day. The supporting structures of the bone and soft tissue coverings (the periodontium) that support teeth have a great capacity to rebound and are not affected by fleeting contacts by the tongue.
In short, although tongue thrusting poses no threat to the position of teeth, a thrusting habit may contribute to the maintenance of problems that do impact the position of teeth. As a consequence of the ability of a tongue thrust to further contribute to or exacerbate a developing malocclusion, there are reasons to correct tongue thrusting in addition to the cosmetic issue that may be created. What parents should know is that a forward rest posture of the tongue, rather than thrusting, is what can lead to dental alignment problems. Unfortunately, clinicians have focused more on thrusting than the rest posture of the tongue, and the negative impact of an abnormal rest posture will be discussed next. For now, parents, please relax if your child has been diagnosed with a tongue thrusting habit. While treating a tongue thrust swallow may be beneficial, especially if coupled with an abnormal, forward rest posture of the tongue, it is the abnormal rest posture that is the true link with the development of dental and teeth alignment problems. We will equip you to ask appropriate questions that can serve to clarify what is going on between the tongue and the dentition.
Many, perhaps most of you have found this website because of questions and concerns you may have about a diagnosis of tongue thrusting that some professional has linked to your child. One of the purposes of this website is to provide accurate information to the public and professionals about tongue thrusting and the other associated conditions that together are regarded as orofacial myofunctional disorders, abbreviated OMDs. We hope to discuss concerns you may have and to provide current and accurate information that can dispel many myths that persist among professionals, and the public, about OMDs, especially tongue thrusting.There is no need to be fearful about a diagnosis of tongue thrusting. Many children and adults with a tongue thrusting habit will never require any treatment when the thrusting is not accompanied by other conditions that canimpact the position of teeth and lead to a malocclusion. Before even listing the host of conditions included under orofacial myofunctional disorders, and providing definitions of terms used, tongue thrusting should be discussed very directly and specifically since this diagnostic label continues to dominate any discussions of OMDs.
Tongue Thrusting – An Explanation
A normal relaxed or rest position of the mouth would include having the lips together, teeth slightly parted rather than touching, and tongue resting behind the front teeth usually on the palate tissue just behind the upper teeth, or in some cases, behind the lower teeth. A tongue thrust is a condition where the tongue becomes a prominent feature either when talking, swallowing, or eating. The term ‘thrust’ is misleading since it implies that the tongue is forcefully pushed against the teeth, leading to a change from the normal position of the front teeth. Actually, the amount of pressure exerted by the tongue against or between the teeth during a swallow is not sufficient to cause them to move out of a normal position. In many cases, a misalignment of teeth is already there and the tongue moves forward into the space available as a way of sealing the front of the mouth during swallowing. In this case, the tongue is said to be ‘opportunistic’ or filling in an available space.
Understanding the Terminology: What are OMDs?
Before embarking on a discussion that will illuminate how the rest posture of the tongue can impact the position of teeth in the dental arches, some terminology should be discussed. As mentioned, orofacial myofunctional disorders (OMDs) includes a host of conditions, including thumb, lip, tongue and finger sucking habits; a mouth-open, lips-apart posture; a forward, interdental rest posture of the tongue; a forward rest position of the tongue against the maxillary (upper jaw) incisors (front teeth); a lateral posterior, interdental tongue rest posture; and thrusting of the tongue during speaking and swallowing. These abnormal habit patterns, functional activities and postures, can open the bite beyond the normal rest position. This can lead to a disruption of dental development in children and over-eruption of selected teeth in adults.
Over time, dental malocclusions, cosmetic problems, and even changes in jaw growth and position are observed in some patients with OMDs. Examples of changes that can occur from a chronic open mouth rest posture include an increased vertical height of the face, a retruded chin, downward and backward growth of the lower face (rather than downward and forward), and weak and open lips.
Is There Commonality among OMDs?
As you read this, it is expected that your lips are closed but your teeth do not touch; that is, your normal dental rest position is characterized by a small vertical open space between upper and lower teeth. This normal resting space is referred to as the dental freeway space, or inter-occlusal space. It measures 2-3 mm at the molars, and 4-6 mm at the incisors. The common denominator of orofacial myofunctional disorders is that all OMDs involve a change in the vertical dimension, or freeway space. The OMD, whether digit habit or altered oral posture, causes the mandible to hinge open slightly, while also increasing the resting inter-occlusal space between the upper and lower jaws and teeth. Only a slight increase in resting freeway space for hours per day is needed to initiate continued and unwanted vertical tooth eruption. Conversely, some patients have a habit pattern of clenching that involves keeping teeth together, or the bite closed, for hours per day. Closure of the normal freeway space for extended periods (hours per day) can lead to dental trauma and dysfunction of the temporomandibular joint apparatus. Altogether, a disruption of the normal resting dental freeway space, either too far open, or closed, leads to negative consequences in dental eruption that can affect the position of teeth. This important component of the etiology of OMDs is news to many dental clinicians.
Orofacial Myofunctional Therapy (OMT): Does Myofunctional Therapy Work?
If you are relatively unfamiliar with the field of orofacial myology, a natural inclination in investigating this website is to question whether therapy for orofacial myofunctional problems works, or not. You may already know of orthodontists who recommend patients to orofacial myologists, and continue to do so because of their confidence in the therapy process. This continued referral support provides an ongoing legitimacy to the treatment protocols provided by orofacial myologists. But this is not enough to claim on a larger scale that myofunctional therapies actually work. Therapies have been shown to be effective and stable long-term. The most recent report of orofacial myofunctional therapy results, published by orofacial myologist/speech language pathologist JoAnn Smithpeter and orthodontist and Department Chair David Covell in the primary orthodontic journal (American Journal of Orthodontics and Dentofacial Orthopedics, 2010) compares the relapse rate of orthodontic appliances with and without orofacial myofunctional therapy. Results revealed that: “OMT (orofacial myofunctional therapy) with orthodontic treatment was efficacious in closing and maintaining closure of dental open bites in Angle Class I and Class II malocclusions, and it dramatically reduced the relapse of open bites in patients who had forward tongue posture and tongue thrust” (page 613). There are a host of other studies to confirm that myofunctional therapy is effective and stable long-term for the variety of conditions involved. For the interested parent, some selected evidence-based reports are referenced at the end of other documents under the heading For Parents.
What Can Orofacial Myofunctional Therapy Do about Freeway Space Variations?
A primary goal of orofacial myofunctional therapy (OMT) is to recapture a normal freeway space vertical dimension by eliminating deleterious sucking habits, retro-positioning a forward interdental tongue posture, teaching a closed lips nasal breathing posture, retraining and eliminating a tongue thrust, or normalizing (opening) a closed dental rest posture. The varieties of exercises involved are based on individual evaluation and treatment protocols. A key challenge in the evaluation process is to identify the multifactoral causes of the OMD; the primary factor being nasal airway interference linked to structural issues such as enlarged tonsils. Other causative factors include unresolved sucking habits, and airborne issues associated with allergies. Most often, a team approach to diagnosis and management of OMDs, involving dentists, orthodontists, allergists, or ENT physicians, will be needed.
How Does Orofacial Myofunctional,Therapy (OMT) Differ from Dental Treatment?
While the theoretical principles of OMDs are derived from dental science, orofacial myofunctional therapy (OMT) is not dental treatment. Dentists and orthodontists are concerned with teeth-together relationships, while orofacial myofunctional therapists are concerned with teeth-apart postures and behaviors. This distinguishes the muscle retraining work of the OMT from the dental occlusal and jaw manipulations of dental/orthodontic providers. It also highlights how therapy procedures can aid in the creation or restoration of an oral environment wherein normal processes of dental development can occur. This is a primary goal of orofacial myofunctional therapy (OMT).
Not all clinicians who provide therapy for orofacial myofunctional disorders are alike or are equally well trained. Most orofacial myologists are either speech-language pathologist, or dental hygienists who have obtained additional training in orofacial myology. To date, such training has been provided by individual practitioners who offer courses outside of a university curriculum since there is no current university degree or training program in orofacial myology. Accordingly, the field of orofacial myology is a specialty area that is an off-shoot of speech-language pathology or dental hygiene, rather than qualifying as a separate profesion.
How to Evaluate Orofacial Myologists?
In choosing an orofacial myologist to work with your child, parents would want to inquire about the specific training of the clinician and as well, their goals of therapy. Some guidelines for parents are as follows:
Be wary of clinicians that focus primarily on tongue thrusting and discuss it as a deleterious habit that can negatively impact the dentition. In fairness, however, many orthodontists and other dentists are the ones who continue to discuss tongue thrusting as having a negative impact on the dentition, when in fact the abnormal forward rest posture and maintenance of an open freeway space beyond the normal range have been shown to be the key links with developing malocclusions.
Be wary of orofacial myologists and those in dentistry that portray orofacial myology as offering competent services with sleep apnea, TMJ disorders, orofacial pain, and specialized care for Down syndrome and other physical conditions that are medically related. To date, there are not enough supporting data to merit any claims of success for orofacial myologists who are offering services for such conditions. Sleep-related problems are serious medical conditions for which the techniques of orofacial myology have not been demonstrated to be effective or even indicated. Those dentists and orthodontists who advance the claim that orofacial myologists are currently competent to work with any of the disorders mentioned above should be viewed with skepticism until appropriate supporting documentation has been demonstrated and well-accepted within the medical community. To date, this is not the case.
Myofunctional therapy is not an appropriate treatment for wrinkles removal, nor can orofacial myologists claim any expertise with facial rejuvenation or any exercises directed toward the removal of wrinkles. Be wary of those that claim expertise in this area.
Myofunctional therapy should focus on the elimination of noxious oral habits, such as tongue thrusting and an abnormal tongue posture and jaw rest position. Myofunctional clinicians should express the goal of creating or recapturing an oral environment and rest postures wherein normal processes of facial and dental growth and develop can be regained and continued. For adults, the elimination of noxious oral habits and establishing proper rest postures of tongue, lips and jaws should help to insure dental stability over the long run.
Be wary of those clinicians who claim that they are working to balance muscles where there are muscle imbalances. At no time are the muscles of the tongue and lips in balance, and the concept of “muscle imbalance” is one that has no basis in fact. No clinician is able to demonstrate that they have created “muscle balance” between the tongue and lips since none ever exists. This naïve view of the teeth being in the middle of a dynamic muscle force field with the tongue on one side, and the balancing and opposing forces of the lips on the other, and the need to balance muscle forces in therapy, is a false goal that is unproductive, and unattainable. Fortunately those that have advocated such nonsense are now few in number.
Orofacial myology is not physical therapy for the face as some advertise. Manipulating the lower jaw is not an appropriate activity for non-dentists, and manipulating muscles for the goal of releasing tension is not a part of orofacial myology and should raise skepticism when mentioned as a clinical service.
As mentioned previously, pain control is not a part of orofacial myology. Therapy to relieve muscle stress is also an inappropriate activity for orofacial myologists who are not physical therapists.
Orofacial myologists are not trained to provide whole-body breathing exercises. Some speech-language pathologists have undergone breathing training in their academic curriculum, but not as a part of orofacial myology. Whole body breathing problems are not a traditional part of orofacial myology, and those that claim expertise in the area of whole body breathing should be viewed with skepticism. However, establishing a nasal pattern of breathing and eliminating a mouth breathing habit are appropriate goals of orofacial myology – that is, if any previous airway issues that may have been involved have been eliminated.
Do We Recommend or Endorse any Individual Orofacial Myologists?
While this website is dedicated to providing current and useful information about orofacial myology and the various conditions included under OMDs, we refrain from recommending specific orofacial myologists or commenting on the level of expertise of any individual clinicians. Although the qualifying cautions stated above are many, we remain confident in the training and skills of orofacial myologists. We support orofacial myologists and express our confidence in their training, goals of treatment, and dedication to serving the public. Hopefully, the guidelines discussed above will help you to find an appropriate orofacial myologist to address any family issues that may develop in the area of orofacial myology.