The two names are close enough that they get swapped in the same sentence: tongue tie, tongue thrust. Families arrive at our Dallas office having been told one and meaning the other, sometimes after a procedure was already scheduled. Clinicians do it too — the terms get used interchangeably in a hallway conversation in a way they never would in a chart.
The distinction is worth getting right, because it decides who you see next and what the treatment even is. One of these is something the tongue cannot do. The other is something the tongue does out of habit. You cannot operate on a habit, and you cannot retrain your way out of a tether.
The One-Sentence Version
A tongue tie is a piece of tissue. A band under the tongue — the lingual frenulum — is short or tight enough to hold the tongue down, so certain movements are physically unavailable. It is a structural finding, and the question that follows is whether to release it.
A tongue thrust is a pattern. The tongue pushes forward against or between the teeth when swallowing, speaking, or simply sitting at rest. Nothing is anchoring it. The tongue has learned a position and repeats it automatically, hundreds of times a day, and the question that follows is whether to retrain it.
Structure versus function. That is the whole axis, and almost every other difference between the two follows from it.
Tongue Tie: A Limit on What the Tongue Can Do
In 2020 the American Academy of Otolaryngology–Head and Neck Surgery published a clinical consensus statement on ankyloglossia in children, built by running 89 candidate statements past a panel of pediatric otolaryngologists through three rounds of a modified Delphi process. On the core definition the panel agreed: "ankyloglossia is a condition of limited tongue mobility caused by a restrictive lingual frenulum."
Read that definition carefully, because the operative word is mobility. A tongue tie is not diagnosed by how the frenulum looks in a photograph. It is diagnosed by what the tongue cannot do — lift to the palate, sweep to the molars, extend past the lower gum.
How common is it? A 2021 systematic review and meta-analysis in Pediatric Research by Hill, Lee, and Pados pooled 15 studies covering 24,536 children under one year of age and found an overall prevalence of 8% (95% CI 6–10%), with 7% in boys and 4% in girls. The same review added the caveat that matters most: "available assessment tools for diagnosis of tongue-tie do not have adequate psychometric properties." Two trained clinicians frequently grade the same infant differently.
The AAO-HNS panel also agreed that "in some communities, infants and children are being over-diagnosed with ankyloglossia." This is not a document trying to talk anyone out of a frenotomy; it is a document asking that the diagnosis mean something specific before a scalpel is involved.
Tongue Thrust: A Pattern in What the Tongue Does
A tongue thrust belongs to a different category entirely. ASHA's practice portal on orofacial myofunctional disorders defines the family these patterns belong to as "movement patterns that involve oral and orofacial musculature" which "result in incorrect positioning of the tongue at rest and during swallowing, breathing, and speech production." Of the specific pattern it says: "tongue thrusting, or protrusion of the tongue between the teeth, may impact swallowing and articulation."
Two things follow. First, a thrust is not an abnormality of tissue, so no imaging or grading scale identifies it — a clinician has to watch the person swallow and look at where the tongue sits when nothing is happening. Second, a forward tongue is not automatically a problem. In infancy it is normal and useful for feeding, and it typically matures into an adult swallow where the tongue lifts to the palate instead of pressing forward. ASHA notes that past the expected age, it "may be a sign of an OMD or other underlying diagnosis."
Prevalence figures for tongue thrust are wildly inconsistent, and the reason is instructive. ASHA reports school-age estimates ranging "from 5.4% (Kasparaviciene et al., 2014) to 62.3% (Sasigornwong et al., 2016)" and explains that estimates "vary according to the definition and criteria used to identify symptoms of OMDs." An eleven-fold spread is not a disagreement about children. It is a disagreement about where a normal variation ends and a disorder begins.
How to Tell Which One You Are Looking At
The functional test is more useful than any description, because it separates cannot from does not.
- Ask the tongue to lift. With the mouth open wide, can the tongue tip reach the roof of the mouth and stay there? A restricted frenulum makes that elevation difficult or impossible regardless of effort or instruction. A tongue thrust does not — the tongue can get there; it simply does not go there on its own.
- Watch the frenulum under load. When the tongue lifts or extends, a tight frenulum tents the floor of the mouth, blanches, or pulls the tongue tip into a notch or heart shape. A thrust produces none of that.
- Watch a swallow. Give a sip of water and watch what the tongue does. A forward push against or between the front teeth is the thrust. A tie does not show up in the swallow as a push; it shows up as a workaround.
- Look at the resting posture. Where does the tongue sit when nothing is happening — up against the palate, or low and forward against the lower teeth? ASHA describes abnormal resting posture as "either forward, interdental, or lateral posterior."
That last point is where the two conditions start to blur, which brings us to the part most families are never told.
They Can Both Be Present — and One Can Feed the Other
These are not mutually exclusive diagnoses, and the relationship between them is not symmetrical.
ASHA's list of causes for orofacial myofunctional disorders includes "orofacial muscular or structural differences that encourage tongue fronting," and ankyloglossia appears on it. The mechanism is intuitive: a tongue that cannot lift to the palate still has to rest somewhere, and low and forward is where it lands. Months or years of resting low becomes the default, and the default shows up in the swallow.
So a tongue tie can help produce a tongue thrust. The reverse is not true — a habit cannot create a tethered frenulum.
But the causal arrow does not run cleanly in practice either, and ASHA is direct about it: "a single cause of orofacial myofunctional disorders is unknown," and "many researchers report multifactorial causes." The portal lists blocked nasal breathing ("airway incompetency due to obstructed nasal passages") and "chronic nonnutritive sucking and chewing habits past 3 years of age" among the contributors. Plenty of children with a clear tongue thrust have a perfectly normal frenulum, and the cause is mouth breathing or a thumb habit instead.
The clinically important version of this is what happens after a release. Freeing the frenulum restores range of motion. It does not rewrite a motor pattern the nervous system has been running automatically since infancy. That gap — new mobility, old habit — is the most common reason families come to us after a procedure, and our guide to what happens after a tongue tie release covers how the retraining is staged.
What Each One Does to Speech
Here the two diverge sharply, and the popular assumption has them backwards.
On tongue tie, the AAO-HNS panel reached consensus that ankyloglossia does not typically affect speech, and it encouraged "a consultation with a speech pathologist... before frenotomy/frenuloplasty in an older child who is undergoing the procedure for speech concerns." A 2023 scoping review in the American Journal of Speech-Language Pathology by Cordray and colleagues screened 1,568 studies, kept 26 covering more than 1,228 patients, and mapped the symptoms attributed to ankyloglossia after infancy — articulation difficulties and dental malocclusion among them — before concluding that "current data regarding the impact are inconclusive." A tongue tie may matter for a particular child's speech. It is not the default explanation.
On tongue thrust, the association with speech is better established, and specific: an interdental or forward tongue during /s/ and /z/ is the classic frontal lisp. If that is what brought you here, our guide to speech therapy for lisps explains the four lisp types and why drilling the sound often fails to hold when a thrust swallow sits underneath it.
What muscle work will and will not do for the sound itself has been measured. A randomized pilot study in the European Journal of Orthodontics by Van Dyck and colleagues at KU Leuven followed 22 children aged 7.1 to 10.6 with an anterior open bite and a forward swallowing pattern, randomly assigning them to orofacial myofunctional treatment or no treatment. The therapy "did significantly change tongue elevation strength, tongue posture at rest, and tongue position during swallowing of solid food." And then the honest finding: "articulation of /s,l,n,d,t/ was not improved by OMT."
That is exactly what we tell families. Myofunctional therapy changes the resting posture and the swallow. The lisp needs articulation therapy on its own terms — which is why ASHA advises that SLPs "exercise caution before using OMT as a standalone approach" for speech sound errors. Both pieces, in the right order.
What Each One Does to the Bite
Orthodontists refer families for both, but the evidence behind the two referrals is not equal.
For tongue tie, the Cordray review found malocclusion and dental crowding among the symptoms reported in the literature and still landed on "inconclusive," specifically calling for "controlled efficacy research on frenotomy for symptoms in older children and on possible longitudinal benefits of early frenotomy for maxillofacial development." Nobody has shown that releasing a frenulum changes an orthodontic outcome.
For tongue thrust, the strongest evidence is about holding a correction rather than creating one. A 2010 study in the American Journal of Orthodontics and Dentofacial Orthopedics by Smithpeter and Covell followed 76 patients with dental anterior open bites: 27 who received orofacial myofunctional therapy alongside orthodontic treatment, and 49 with a history of orthodontics and open-bite relapse. Overbite relapse averaged 0.5 mm in the therapy group and 3.4 mm in the control group, a difference the authors called "clinically and statistically significant" (P < 0.0001).
The interpretation is narrow and worth stating plainly: this was a retrospective comparison of referred patients, not a randomized trial. But the finding is consistent with the mechanism everyone in orthodontics already accepts — braces move teeth, and a tongue that keeps pressing forward keeps pushing them back. Our page on tongue thrust signs and treatment covers what the pattern looks like at different ages, and tongue thrust exercises walks through the retraining itself.
Who Diagnoses Which
This is the most practical difference of all, and it is why the mix-up costs families time.
A tongue tie is a medical and dental diagnosis. It belongs to a pediatrician, ENT, pediatric dentist, or oral surgeon, because the decision attached to it is surgical. An SLP can describe tongue mobility in detail and should — the AAO-HNS panel wants that assessment on the table before an older child has a procedure for speech — but the diagnosis and the release are not ours to make.
A tongue thrust is a functional diagnosis and sits squarely in speech-language pathology. ASHA states that "orofacial myofunctional interventions are conducted by appropriately trained speech-language pathologists" working as part of a team, usually with the dentist or orthodontist who noticed the bite.
If you were told "tongue tie" and the finding was really a forward swallow, a surgical referral will not help and may add a procedure you did not need. If you were told "tongue thrust" and there is genuinely a restrictive frenulum underneath it, exercises alone will keep running into a ceiling the tongue cannot clear. Both errors are common, and both are avoidable with one functional assessment.
While we are on name confusion: a tongue tie is also routinely bundled with a lip tie, and those two do not rest on the same evidence either — our comparison of lip tie vs. tongue tie covers what the AAO-HNS consensus statement and the AAPD's frenulum policy actually say about the upper lip.
What Bloom Does
We do not diagnose ankyloglossia, decide whether a release is warranted, or perform frenectomies. Those belong to a dentist, ENT, or oral surgeon together with your pediatrician, and we will say so rather than guess.
What Laura Friedman, MS, CCC-SLP, QOM assesses is function: tongue elevation and range of motion, resting oral posture, lip seal, nasal versus mouth breathing, and the swallow itself. That assessment tells you which of these two things you are actually dealing with — and often that you are dealing with both, in which case the sequence matters. Orofacial myofunctional therapy runs in person at our Dallas office or through online myofunctional therapy nationwide.
Frequently Asked Questions
What is the difference between a tongue tie and a tongue thrust?
A tongue tie is anatomy; a tongue thrust is behavior. The AAO-HNS defines ankyloglossia as "a condition of limited tongue mobility caused by a restrictive lingual frenulum" — tissue holds the tongue down, so some movements are unavailable. A tongue thrust is one of the orofacial myofunctional disorders ASHA describes as "movement patterns" that "result in incorrect positioning of the tongue at rest and during swallowing, breathing, and speech production." Nothing is tethered; the tongue has learned a position. A tie can be a candidate for a procedure. A thrust never is.
Can a tongue tie cause a tongue thrust?
It can contribute. ASHA lists ankyloglossia among the "orofacial muscular or structural differences that encourage tongue fronting" — a tongue that cannot lift has to rest somewhere, and low and forward is where it lands. But it is one contributor among several, alongside blocked nasal breathing and sucking habits past about age three, and ASHA says plainly that a single cause is unknown. Many children with a clear tongue thrust have a normal frenulum.
If my child has a tongue tie released, will the tongue thrust go away on its own?
Usually not. A release changes what the tongue can do, not what it has spent years doing automatically. Swallowing runs hundreds of times a day without conscious thought, and that pattern lives in motor memory, not in the frenulum. New range of motion with an unchanged habit is the most common reason families come to us after a procedure.
Does a tongue tie cause a lisp?
Typically no. The AAO-HNS panel reached consensus that ankyloglossia does not typically affect speech, and the 2023 scoping review in the American Journal of Speech-Language Pathology called the data on ankyloglossia beyond breastfeeding "inconclusive." A tongue thrust is the more common finding underneath an interdental /s/ and /z/ — ASHA notes that tongue thrusting "may impact swallowing and articulation." If a lisp is the concern, check the swallow before the frenulum.
Who diagnoses each one?
A tongue tie is a structural diagnosis and belongs to a physician or dentist, because the decision that follows is surgical. A tongue thrust is a functional diagnosis within the scope of a speech-language pathologist — ASHA states that "orofacial myofunctional interventions are conducted by appropriately trained speech-language pathologists" as part of a team. Bloom does not diagnose ankyloglossia and does not perform releases.
Will myofunctional therapy alone fix a lisp caused by a tongue thrust?
Not by itself. The randomized pilot study in the European Journal of Orthodontics found that myofunctional treatment "did significantly change tongue elevation strength, tongue posture at rest, and tongue position during swallowing of solid food," but that "articulation of /s,l,n,d,t/ was not improved by OMT." The muscle work changes the posture and the swallow; the sound needs articulation therapy. ASHA advises caution before using myofunctional therapy as a standalone approach for speech sound errors.
Does a tongue thrust have to be treated?
Not every forward tongue pattern needs therapy. In infants it is normal and helps with feeding, and it usually matures on its own. Treatment is worth discussing when it persists past the expected age and something measurable is attached to it — a lisp that keeps relapsing after drills, orthodontic movement that will not hold, or a resting posture an orthodontist flags before treatment. The 2010 AJO-DO study found mean open-bite relapse of 0.5 mm with myofunctional therapy alongside orthodontics versus 3.4 mm without.
Not Sure Which One You Were Told?
One functional assessment answers it. Schedule a free consultation with Laura Friedman, MS, CCC-SLP, QOM — in person in Dallas or online nationwide — for an honest read on tongue mobility, resting posture, and the swallow, and on whether a procedure is even the question.