When it comes to speech development, many parents are surprised to learn that certain speech issues, like lisping, may be linked to an underlying swallowing pattern known as tongue thrust. This forward tongue posture can impact more than just pronunciation—it also affects oral health, feeding, and overall facial development. Addressing tongue thrust in therapy isn’t only about clear speech; it’s about creating a strong foundation for proper oral function. In this blog, we’ll explore what it is, the cause, how it affects speech and other functions, as well as what you can do about it.
Tongue thrust, sometimes called a “reverse”, “immature” or “atypical” swallow, is when the tongue pushes forward, pressing against or between the front teeth. This often happens during swallowing, speech, and even when a child’s mouth is at rest. Tongue thrusts aren’t just about speech—it’s a pattern that can affect swallowing, feeding, even dental and facial development. Therefore, this forward tongue movement and position can also be known as an Orofacial Myofunctional Disorder (OMD).
In a typical, mature swallow, which usually develops by age three, the tongue presses firmly against the roof of the mouth (called the palate) and then pulls back into the oral cavity. This upward and backward movement helps guide food and liquids smoothly down the throat. When the tongue follows this pattern, it rests comfortably against the palate without putting pressure on the front teeth. This mature swallowing pattern supports clear speech and promotes healthy development of the mouth, teeth, and jaw.
With tongue thrust, however, the tongue pushes forward instead of moving up and back. This forward motion often presses against or even between the teeth, which can impact not only speech sounds but also the alignment of the teeth and the overall structure of the mouth.
I want to remind parents that the tongue thrust we’re talking about here in this blog is different from the natural reflex that all babies have in their early months, often also called the “tongue-thrust reflex”. This form of tongue thrust is completely normal in the first months of life!
This reflex is triggered by touch on the lips or front of the tongue and causes the tongue to push forward in the mouth, helping babies latch and safely feed from a breast or bottle. This reflex is actually a good thing—it keeps them from choking on solid foods too early. Parents often see this reflex when they first introduce solids around 4 to 6 months, as the baby’s tongue may push food out of their mouth.
As babies grow, this tongue thrust reflex naturally fades, and they gain better control over their swallowing. By around 6 months, most babies are ready for solid foods and begin to move their tongues in ways that support smooth swallowing. A mature swallow pattern, with the tongue moving up and back rather than forward, typically develops by age 3.
Now, back to the tongue thrust we’re talking about – If you’re wondering whether your child may have a tongue thrust, here are some signs to look for. Identifying these early can be helpful in addressing any potential challenges in speech, feeding, or dental health:
If your child has difficulty pronouncing certain sounds, especially /s/ and /z/, resulting in a lisp, or has trouble with other sounds like “sh”, “ch”, “t”, “d”, “n” and “l”, it could be linked to tongue thrust. This happens because the tongue’s forward position can make it harder to form certain sounds.
Your child may frequently rest with their mouth open. In this position, their tongue might rest low in the mouth, push up against the front teeth, or even protrude slightly between them.
Take a look at your child’s bite when their teeth are together. An open bite—where there’s a noticeable gap between the upper and lower front teeth—can be a result of the tongue pressing against the teeth over time.
If your child tends to breathe through their mouth rather than their nose, it might be connected to a tongue thrust. Mouth breathing forces the tongue to sit lower in the mouth or push forward, rather than resting comfortably against the roof of the mouth.
Watch your child when they swallow. If you see their tongue moving forward between or against their teeth or lips rather than moving up and back, this may indicate a tongue thrust swallowing pattern.
Children with tongue thrust may often appear to be messy eaters. This is because their tongue, positioned forward, tends to push food out of their mouth rather than guiding it smoothly to the back for swallowing. As a result, food or liquids may spill, making eating more challenging to manage neatly. This forward tongue position can lead to slower or quicker-than-normal eating as they try to compensate, sometimes resulting in extra mess.
Tongue thrust can develop for a variety of reasons, often starting in early childhood. Here are some common causes to keep in mind:
If your child has used a pacifier, sucked their thumb, or bottle-fed for an extended time, these habits may have encouraged their tongue to push forward. When these habits continue beyond infancy, they can affect the tongue’s natural resting position and swallowing pattern.
Chronic mouth breathing is another common contributor to tongue thrust, especially when nasal airflow is blocked. For instance, your child might have enlarged nasal turbinates (small structures inside the nasal passages that filter and moisturize the air we breathe) that are swollen or inflamed, which can make it hard to breathe through the nose. In these cases, your child may rely more on mouth breathing, which often leads the tongue to rest lower and more forward in the mouth. This positioning can continue even after nasal breathing is restored. In some situations, medical treatments like turbinate reduction surgery can help open up nasal airflow and support a healthier tongue resting position.
Allergies, especially those accompanied by chronically swollen tonsils or adenoids, can also further obstruct nasal airflow, forcing a child to rely on mouth breathing.
Sometimes, a shorter lingual frenum (the small tissue connecting the tongue to the floor of the mouth) can limit how freely the tongue moves. This restriction can make it harder for your child to develop a mature swallowing motion, where the tongue moves up and back.
Certain inherited facial structures, like a long, narrow face or an open bite, may make a forward tongue posture more likely. The tongue may adapt to these features, leading to a tongue thrust pattern.
From my experience as a speech pathologist, I often see that tongue thrust can significantly impact a child’s speech clarity, sometimes resulting in a range of noticeable speech characteristics. When the tongue rests forward or pushes between the teeth, it disrupts the production of sounds like /s/ and /z/, which often leads to a lisp. I also notice that a forward tongue position often affects sounds like /t/, /d/, /n/, and /l/, with the tongue pushing through the teeth instead of staying behind the top, central teeth.
While research does indicate a link between tongue thrust and these speech characteristics, it’s essential to remember that not every child with a tongue thrust pattern will experience all of these issues. However, when multiple speech characteristics like these appear together, addressing both the swallowing pattern and the specific speech sounds in therapy can provide children with the support they need for clearer, more confident communication.
Tongue thrust doesn’t just affect speech—it can impact other important areas, too. Here are some additional ways it can influence everyday functions:
For children with neuromotor disabilities, like cerebral palsy, tongue-thrust swallowing can sometimes add to eating and drinking challenges. While tongue thrust itself does not cause dysphagia (a swallowing disorder), it may make swallowing more difficult by disrupting the ability to gather food into a single piece to swallow easily. Tongue thrust can also complicate saliva control, making it harder to manage effectively.
Mouth breathing can sometimes lead to improper oxygen intake or dry mouth, which may impact oral health over time.
The tongue plays a role in shaping facial muscles and structure. A persistent forward posture of the tongue can influence the development of the facial profile, sometimes leading to a longer or narrower face shape, as the oral muscles and bones adapt to the tongue’s positioning.
Tongue thrust can also affect how the front teeth grow and align. Repeated forward pressure from the tongue can cause the front teeth to shift outward or create an open bite, where the upper and lower teeth don’t meet when the mouth is closed.
In some cases, tongue thrust and associated mouth breathing can affect sleep quality. When children consistently breathe through their mouth, it can sometimes lead to snoring, disrupted sleep, or even contribute to sleep-related issues like obstructive sleep apnea.
When a child has a lisp or other noticeable differences in how they speak, it can sometimes make them feel a bit self-conscious. They might be less eager to speak up in class, join in conversations, or interact with others if they’re worried about how they sound.
If you’re noticing signs of tongue thrust in your child, there are some helpful steps you can take to support their speech and oral development:
Many speech pathologists are trained to help with both the speech sound issues and the underlying tongue posture. Look for someone who can work on your child’s oral resting posture, swallowing, and any specific speech sounds.
Myofunctional therapy is a common approach for tongue thrust and focuses on building a healthy, natural resting position for the mouth—where the lips are closed, the teeth come together, and the tongue rests just behind the upper front teeth. This therapy involves simple exercises to guide the tongue into the right spot during swallowing, which can be especially helpful if your child is also receiving orthodontic treatment.
If tongue thrust is affecting your child’s speech sounds, like making /s/ or /z/ sound slushy, speech therapy can help. A speech therapist will work with your child to learn the correct placement for sounds, boosting their clarity and confidence.
It’s a good idea to check in with a doctor or ENT to see if anything like enlarged tonsils or adenoids could be affecting your child’s airway. If there’s any nasal blockage, it may lead to mouth breathing, which can encourage a forward tongue posture. Treating any airway issues can be a big help in supporting better tongue and mouth positioning.
Some children benefit from orthodontic appliances that guide the tongue into the right position. Your dentist or orthodontist can work alongside myofunctional and speech therapy to support healthy alignment of both the teeth and tongue.
Addressing your child’s tongue thrust with the right support can make a big difference. A team that includes a speech therapist, possibly an orofacial myologist, and specialists like a dentist or ENT can guide your child toward clearer speech, easier swallowing, and a healthy oral motor development. With the right support, your child will build skills that will improve their communication, eating, and overall oral health.
Arvedson JC, Brodsky L. Pediatric Swallowing and Feeding: Assessment and Management. 2nd ed. Singular Publishing Group; 2002.
Hanson ML, Mason RM. Orofacial Myology: International Perspectives. Int J Orofacial Myology. 2003;29:5-23.
Proffit, W. R., & Fields, H. W. (2000). Contemporary Orthodontics (3rd ed.). Mosby. This textbook explores the development of normal swallowing patterns, the physiology behind tongue thrust, and the effects on dentition and jaw alignment.
Rivera, C. (2015). The Prevalence of Tongue Thrust and Its Effects on Swallowing and Speech Patterns. American Journal of Speech-Language Pathology, 24(3), 348-354.
Mason, R. M. (2005). “A Retrospective and Prospective View of Orofacial Myology,” International Journal of Orofacial Myology, 31(1), 5-14. This article reviews tongue thrust, typical swallowing patterns, and the developmental timeline for these behaviors, including their implications for speech and oral health.
Turbinate Reduction Surgery. Stanford Health Care. Available at: https://stanfordhealthcare.org/medical-treatments/n/nasal-surgery/types/turbinate-reduction.html