Tongue thrust is when a child pushes their tongue forward against or between the front teeth while swallowing, speaking, or resting, and if it continues past the toddler years it is one of the more common causes of an open bite, where the front teeth do not meet even when the back teeth are closed together. It is a habit pattern, not a structural problem on its own, which is good news because it usually responds well to the right kind of therapy, especially the earlier it is picked up.
Key takeaways
- Tongue thrust is the persistence of an infant swallowing pattern beyond the age most children outgrow it.
- It is commonly linked to thumb or finger sucking, prolonged dummy use, and mouth breathing from enlarged adenoids or tonsils.
- Left untreated, it can contribute to an anterior open bite, where the front teeth do not touch, along with speech and chewing changes.
- Myofunctional therapy retrains tongue and swallowing patterns and is often the first-line treatment.
- Dental appliances such as a tongue crib, and orthodontic treatment for the bite itself, are sometimes needed alongside therapy.
What causes tongue thrust in children
Every baby swallows using a tongue-thrust pattern, pushing the tongue forward against the gums because they do not yet have teeth to push against. Most children transition to an adult swallowing pattern, tongue against the roof of the mouth, by around age four to six as teeth come in and oral muscles mature. Tongue thrust becomes a concern when this transition does not happen. Common contributing factors include prolonged thumb, finger, or dummy sucking habits that keep the tongue in a low, forward position, and mouth breathing caused by enlarged adenoids or tonsils, allergies, or chronic nasal congestion, which pushes the tongue down and forward to help keep the airway open. Genuine structural causes, such as tongue-tie, can also contribute in a smaller number of children.
How tongue thrust leads to an open bite
Every time your child swallows, the tongue exerts gentle but repeated pressure somewhere in the mouth. In a typical swallow, that pressure goes against the roof of the mouth, which does not disturb tooth position. In a tongue-thrust swallow, the pressure goes against or between the front teeth, hundreds of times a day. Individually, each swallow exerts very little force, but repeated over months and years during the window when the jaw and teeth are still developing, it is enough to hold the front teeth apart and prevent them from meeting normally, producing the gap dentists call an anterior open bite.
Signs to watch for
| Sign | What it can indicate |
|---|---|
| Tongue visible between the front teeth at rest or when swallowing | Active tongue-thrust pattern |
| Gap between the upper and lower front teeth when the back teeth are together | Developing or established open bite |
| Lisping or difficulty with "s" and "th" sounds | Tongue position affecting speech, common alongside tongue thrust |
| Mouth breathing, snoring, or a habitually open mouth posture | Possible airway contributor that should be assessed alongside the bite |
| Ongoing thumb, finger, or dummy sucking past age three to four | A habit that can both cause and reinforce tongue thrust |
How it is treated
Treatment usually starts with addressing any active habit, such as thumb sucking or prolonged dummy use, since the tongue-thrust pattern often will not resolve while the underlying habit continues. From there, treatment generally follows a step-up approach depending on how established the pattern is and how much the bite has already been affected.
Step 1: Habit management
Simple behavioural strategies, encouragement, and sometimes a habit-reminder appliance are tried first for straightforward thumb or dummy habits, alongside the everyday hygiene routine covered in our guide to helping a reluctant child brush.
Step 2: Myofunctional therapy
A structured program of tongue, lip, and cheek exercises retrains the muscles involved in swallowing and resting tongue posture. This is considered the primary treatment for an established tongue-thrust pattern and can be delivered by a speech pathologist or a dentist trained in orofacial myofunctional therapy.
Step 3: A tongue crib or similar appliance
For children who do not respond to therapy alone, an orthodontist may fit a small fixed appliance, often called a tongue crib, behind the front teeth. It creates a physical barrier that stops the tongue from thrusting forward, and is usually worn for around six months to a year while the new pattern becomes automatic.
Step 4: Orthodontic correction of the bite
If an open bite has already developed, braces or aligners may be needed once the tongue-thrust habit itself is under control, since correcting the bite while the underlying muscle pattern is still active tends to relapse. Many children benefit from an early orthodontic assessment around this stage, well before the point of getting braces fitted for comprehensive treatment. This is a similar window to when many children are also managing the arrival of their second permanent molars, so a combined check often covers both.
Why addressing a mouth-breathing cause matters
If enlarged adenoids, tonsils, or chronic allergies are driving mouth breathing and, in turn, a low forward tongue posture, dental treatment alone will have limited long-term success without also addressing the airway issue, usually in partnership with a GP, ENT specialist, or paediatrician. This is one of the more common reasons a straightforward-looking dental habit does not fully resolve with dental treatment alone, and it is worth raising with your dentist if your child snores, breathes through their mouth during the day, or has a history of chronic congestion.
Frequently asked questions
At what age should tongue thrust be treated?
There is no single fixed age, but many clinicians start assessing once a child is still showing the pattern by around age six to seven, when the front adult teeth are coming through and the effect on the bite becomes more visible.
Will my child outgrow tongue thrust on their own?
Many children do transition naturally, but if the pattern is still present by school age, especially alongside a visible open bite or speech changes, it usually needs active treatment rather than waiting.
Is tongue thrust the same as tongue-tie?
No. Tongue-tie is a structural restriction of the tongue's movement, while tongue thrust is a swallowing habit pattern. Tongue-tie can occasionally contribute to tongue thrust, but most cases of tongue thrust occur with a normally mobile tongue.
Can tongue thrust cause speech problems?
Yes, it is commonly associated with lisping and difficulty producing certain sounds clearly, which is one reason speech pathologists are often involved in treatment.
Does thumb sucking cause tongue thrust?
It is one of the more common contributing habits, since prolonged sucking habits keep the tongue in a low, forward resting position that can carry over into the swallowing pattern.
Will my child need braces even after myofunctional therapy?
Sometimes. Myofunctional therapy addresses the muscle pattern, but if an open bite has already developed, orthodontic treatment is often still needed to correct the tooth position itself.
Booking with Lumi Dental
If you have noticed your child's tongue resting between their front teeth, an open bite, or ongoing mouth breathing, an early dental check can help identify what is driving it and who else might need to be involved. See our current offers or read more about general dental care for the whole family.
This article is general information only and is not a substitute for an individual dental or medical assessment.
