Tongue thrust is a pattern where the tongue pushes forward against or between the front teeth when you swallow, speak, or rest. In a normal swallow, the tongue presses against the roof of the mouth. In tongue thrust, it presses forward instead. This pattern is common in young children, but it can continue into adulthood and affect tooth alignment, speech, and the shape of the face over time.
What Is Tongue Thrust at Rest and During Swallowing?
Your tongue is a powerful muscle. It performs thousands of movements every day. Most people do not think about where their tongue sits when their mouth is closed. The natural resting position is with the tip of the tongue lightly touching the roof of the mouth, just behind the front teeth.
In tongue thrust, the tongue sits lower and pushes forward. During a swallow, the tongue moves forward rather than upward. You may see the tongue push between the teeth when the person swallows. This is often visible from the outside, especially in children.
Swallowing happens about 500 to 1,000 times a day. When the tongue pushes against the teeth that often, it applies constant pressure. Teeth can shift in response to that pressure. This is why tongue thrust is linked to open bite, a condition where the front teeth do not meet when the mouth is closed.
What Causes Tongue Thrust?
There is no single cause. Several factors can contribute to the pattern developing or persisting.
Extended thumb or finger sucking is one of the most common causes in children. The thumb sits in the mouth and the tongue naturally pushes against it. Over time, this trains the tongue to rest and move forward.
Allergies and enlarged tonsils can also play a role. When nasal passages are blocked, a person breathes through the mouth. Mouth breathing changes the position of the tongue. The tongue drops to the floor of the mouth to keep the airway open. This low, forward tongue position can become a habit.
Tongue tie, a condition where the tissue under the tongue is tight, can interfere with proper tongue movement. Some research suggests this may contribute to tongue thrust, though the relationship is not fully understood.
Neurological conditions can cause tongue thrust as well. Conditions that affect muscle tone or coordination, such as cerebral palsy, can produce this swallowing pattern. In these cases, tongue thrust is part of a broader motor issue.
How Does Tongue Thrust Affect Teeth and Speech?
The most visible effect is on the teeth. When the tongue pushes against the front teeth hundreds of times a day, it can move them forward. This creates an open bite, where the upper and lower front teeth do not touch. It can also cause the upper teeth to tip outward.
These changes are not just cosmetic. An open bite can make it harder to bite into food. It can also affect how clearly a person speaks.
Speech sounds that require the tongue to touch the roof of the mouth or the back of the teeth can be distorted. The most common speech issues are with the sounds “s,” “z,” “t,” “d,” “n,” and “l.” A person with tongue thrust may produce an “s” sound that is slushy or lisp-like. This happens because the air escapes around the tongue instead of over it in a controlled stream.
Not everyone with tongue thrust has a speech problem. Some people produce all sounds correctly despite the tongue position. Others have noticeable distortion. The severity varies from person to person.
Can Tongue Thrust Fix Itself?
In infants, tongue thrust is normal. Babies are born with a reflexive tongue thrust that helps them breastfeed. This reflex typically disappears between 4 and 6 months of age. It should be gone by the time solid foods are introduced.
In older children and adults, tongue thrust does not typically resolve on its own. The pattern becomes habitual. The tongue has learned a movement pattern that feels normal, even if it is not ideal.
If thumb sucking stops early, the tongue thrust may improve without treatment. But if the habit continues past age 4 or 5, the pattern is more likely to persist. By the teenage years, the facial bones and teeth have largely settled into their positions. Changing the tongue pattern at that point requires active intervention.
How Is Tongue Thrust Treated?
Treatment depends on the cause and the person’s age. There are two main approaches: myofunctional therapy and orthodontic treatment. Often they are used together.
Myofunctional therapy is a series of exercises that retrain the tongue. A trained therapist teaches the person to place the tongue correctly at rest and during swallowing. The exercises strengthen the tongue and build new muscle memory. Sessions typically last several months. This therapy is the primary treatment for tongue thrust itself.
Orthodontic treatment addresses the dental effects. Braces or aligners can close an open bite and straighten the teeth. But orthodontics alone does not fix the tongue pattern. If the tongue continues to push forward, it can move the teeth again after treatment. This is why many orthodontists recommend myofunctional therapy before, during, or after braces.
Appliances are sometimes used. A tongue crib is a metal device attached to the upper teeth that physically blocks the tongue from pushing forward. These are effective at stopping the habit but are generally a short-term solution. They do not teach the correct tongue position. Therapy is still needed to establish a healthy pattern.
When Should You See a Professional?
If your child is past age 4 and you can see the tongue pushing between the teeth when swallowing, it is worth an evaluation. The same is true if a lisp or other speech distortion is present.
For adults, the main reason to seek help is dental. If your teeth are shifting, or if you have had orthodontic treatment and the teeth are moving back, tongue thrust may be the cause. A dentist or orthodontist can assess whether tongue pressure is a factor.
Treatment is not urgent in a medical sense. Tongue thrust does not cause pain or health emergencies. But the dental and speech effects are real and can be permanent if left untreated. Earlier intervention generally produces better results.
Frequently Asked Questions
Can tongue thrust be corrected in adults?
Yes, adults can correct tongue thrust with myofunctional therapy. The process takes longer than in children because the habit is deeply established, but the tongue can be retrained at any age.
Does tongue thrust cause a lisp?
Tongue thrust can cause a lisp, particularly on “s” and “z” sounds, but not everyone with tongue thrust has a speech problem. The severity of speech distortion varies from person to person.
Is tongue thrust a sign of a serious medical condition?
In most cases, tongue thrust is a habit, not a sign of disease. In rare cases, it is related to a neurological condition or structural issue like tongue tie. A professional evaluation can determine the cause.
Can braces fix tongue thrust?
Braces can fix the dental problems caused by tongue thrust, such as open bite, but they do not correct the tongue pattern itself. Myofunctional therapy is needed to retrain the tongue, otherwise the teeth can shift back after braces are removed.
