The Link Between Tongue Posture and Jaw Development in Kids

Where should the tongue rest?

When your child is not talking, eating or swallowing, the ideal resting posture is:

• The tongue up. The body of the tongue rests gently against the palate, with the tip just behind the upper front teeth rather than pressing on them.
• The lips closed. Sealed comfortably, without strain or visible effort.
• Breathing through the nose. Quietly, with no audible mouth breathing at rest.

Clinicians sometimes call this oral rest posture. It is one of the things a pediatric dentist looks at during a routine exam, alongside bite, eruption pattern and the other markers covered in our guide to spotting oral development delays early.

Why the resting position matters more than the swallow

This is the single most useful thing to understand, and it is where most parent-facing content gets it wrong.

Tooth position is governed by what orthodontists call equilibrium theory: teeth sit where the opposing soft-tissue forces balance out, and what moves them is light, continuous pressure — the same principle braces work on. Reviewing the causes of open bite, Ngan and Fields note that under this framework it is resting tongue posture rather than tongue thrust that plausibly contributes, because abrupt, intermittent forces such as those generated during swallowing are much less likely to be causative.¹ Proffit’s original work established that the duration of a force matters more than its magnitude.²

1. A forward tongue posture held for hours a day is the mechanism of concern. Not a dramatic-looking swallow.
2. Therapy aimed at the swallow is aiming at the wrong target. The same review cites Proffit and Mason’s long-standing recommendation that therapy for anterior tongue position is not warranted before adolescence, with or without malocclusion.¹
3. Tongue thrusting is often opportunistic. When there is already a gap between the front teeth, the tongue fills it to seal the mouth for swallowing. The thrust follows the open bite as often as it precedes it.³

Signs of low or forward tongue posture

Watch your child when they are relaxed and not aware of being observed — reading, watching a screen, falling asleep. Signs worth noting:

• The tongue rests on the floor of the mouth, or visibly between the teeth
• Open-mouth resting posture — lips apart at rest, jaw slightly hinged open
• Chronic mouth breathing, especially during sleep
• Visible strain, grimacing or chin muscle tension when swallowing
• Dry, chapped lips, or a persistently dry mouth on waking
• Snoring, restless sleep or noisy breathing at night
• Difficulty with tongue-tip sounds — s, z, t, d, l, n, th — including the interdental patterns covered in our guide to lisps
• Messy or effortful eating, or difficulty clearing food from the cheeks and palate, which overlaps with the skills in oral motor development for speech and feeding

Three checks you can do at home

None of these diagnose anything. They give you something concrete to bring to an appointment.

1. The rest check. Glance at your child ten times over an evening. How many times are the lips together? Consistently apart is worth mentioning.
2. The lip-seal minute. Ask them to close their lips and breathe through their nose for sixty seconds while sitting quietly. Struggling, gasping or opening early usually points to the nose, not the tongue.
3. The reach check. Ask them to open wide and lift the tongue tip toward the palate without moving the jaw. Note whether the tip reaches, and whether the middle of the tongue lifts or stays anchored down. Limited lift is one of the signs of a possible oral restriction — though as the tongue-tie section below explains, that finding on its own means less than it is often claimed to.

Write down what you see. A dentist can do far more with “lips apart most evenings, snores four nights a week, tip will not reach the palate” than with “I read something about tongue posture.”

Cause, consequence, or company?

Low tongue posture, a narrow palate, mouth breathing and crowded teeth genuinely do travel together. What is much harder to establish is which one causes which.

The debate is long-running in the orthodontic literature. Some investigators treat tongue size and dysfunction as an essential cause of malocclusion; others hold that tongue thrust swallowing is a result rather than a cause, on the reasoning that when an overjet or open bite already exists it becomes difficult to seal the front of the mouth during swallowing, and the tongue moves forward to do it.³

In real children these overlap and reinforce each other. That is exactly why a good assessment looks at the nose, the tonsils and adenoids, the sleep history, the habit history and the arch shape — not just the tongue.

What actually drives jaw development

The tongue is one input. Here are the others, ordered roughly by how well the evidence supports them.

Mouth breathing and airway obstruction

This is the association with the most data behind it. A systematic review and meta-analysis of cephalometric measurements in children — ten studies in the final quantitative synthesis — found that in mouth breathers the maxilla and mandible rotated backward and downward, the occlusal plane was steeper, and the upper front teeth tended to tip forward. Airway dimensions were also smaller in the mouth-breathing group.⁴

That is a consistent pattern, and it is the clinical picture people mean when they describe a long face. But it should be read with the caveat reviewers themselves apply: a review in Frontiers in Public Health concluded that there is no high-quality evidence establishing the effects of mouth breathing on dentofacial development, largely because well-designed clinical studies are lacking, and that the mechanism remains unclear.⁵

Non-nutritive sucking habits

Thumb, finger and pacifier habits have a clearer, more dose-dependent relationship with malocclusion than tongue posture does.

A 2026 systematic review and meta-analysis of twelve studies found that both digit-sucking and pacifier-sucking significantly increased the risk of anterior open bite and posterior crossbite. Pacifier habits carried a significantly higher risk than digit habits for posterior crossbite specifically (odds ratio 2.66), while the two did not differ significantly for open bite.⁶ A separate 2025 meta-analysis pooled the evidence on non-nutritive sucking and anterior open bite across ever-versus-never, longer-versus-shorter and daily-versus-not-daily comparisons.⁷

Duration is the key variable. In a study of occlusal characteristics in the mixed dentition, anterior open bite and posterior crossbite were associated with habits lasting 36 months or more; sustained pacifier habits including those of 24 to 47 months were associated with anterior open bite and Class II molar relationships, while digit habits were associated with anterior open bite when sustained for 60 months or longer.⁸

The reassuring read: a habit that stops in the toddler years is a very different proposition from one that continues into the school years. Our guide to when thumb sucking becomes a problem covers how to approach stopping without turning it into a battle, and what the evidence says about pacifiers covers the trade-offs in infancy, where pacifiers also carry established benefits.

Infant feeding

A systematic review and meta-analysis of 48 studies, with 41 studies and 27,023 participants pooled, found that children ever breastfed were less likely to develop malocclusions than those never breastfed (odds ratio 0.34), that exclusively breastfed children had lower odds than those without exclusive breastfeeding (odds ratio 0.54), and that longer breastfeeding was likewise associated with lower odds (odds ratio 0.40).⁹

Two honest caveats. This is observational evidence, so breastfeeding travels with a great many other factors. And it is not actionable for a parent of a seven-year-old. It belongs here because it is part of why arches develop as they do, not as something to feel badly about.

Genetics and growth pattern

Face shape, arch width and jaw relationship are substantially inherited. This is not a small factor that habits override. A child can have textbook tongue posture and still need orthodontic treatment, and a child with poor posture may need none. Any program implying that habits alone determine facial outcome is overstating what habits can do.

Tongue-tie: what the evidence supports, and what it does not

Ankyloglossia is a real anatomical finding and a genuine cause of specific problems. It is also the area of this topic where commercial enthusiasm has most clearly outrun the science, and parents deserve to know that before booking a procedure.

Where the evidence is reasonable. Frenotomy may relieve nipple pain in breastfeeding mothers of affected infants, and systematic reviews support considering it in that specific situation.¹⁰

Where it is not. A 2025 systematic review asked directly whether ankyloglossia surgery promotes normal facial development. Seven articles covering 1,349 patients with ankyloglossia and 90 controls were analyzed, and the quality of the included studies was assessed as low. The strongest signal concerned reductions in intercanine and intermolar arch widths.¹¹ That is a long way from establishing that releasing a frenulum improves jaw growth.

On speech, systematic reviews have concluded there is no evidence that ankyloglossia causes speech disorders — which is why frenotomy should be recommended sparingly in newborns and rarely, if ever, for speech disorders.¹⁰

On the field as a whole. A 2025 systematic review of the tongue-tie literature examined 462 articles published between 2017 and 2024 and documented a continued exponential rise in publications without a corresponding rise in evidence clarifying the underlying controversies. It also noted a lack of objective endpoints, and that none of the existing classification systems focuses primarily on function rather than appearance.¹² Commentary in the BMJ has described posterior tongue tie and lip tie as a lucrative private industry where the evidence is uncertain.¹³

When snoring is worth investigating

The airway is where this topic stops being cosmetic.

Obstructive sleep apnea syndrome in children has prevalence estimates ranging from 1.2% to 5.7% in higher-quality studies. The American Academy of Pediatrics guideline recommends that all children and adolescents be screened for snoring, and that polysomnography be performed in those with snoring plus symptoms or signs of the condition.¹⁴ Adenotonsillar hypertrophy is the predominant cause in younger children, and adenotonsillectomy is the first-line treatment when it is present.¹⁵

Surgery is not always the end of the story. American Thoracic Society guidance notes that up to 40% of children have an apnea-hypopnea index of 5 or more despite adenotonsillectomy, with higher risk among children with severe baseline disease, obesity, craniofacial or genetic conditions, or chronic cardiopulmonary and neuromuscular disorders. For children aged six to the onset of puberty with persistent apnea and a posterior crossbite, rapid maxillary expansion can resolve it.¹⁶

Untreated sleep-disordered breathing has consequences well beyond the teeth, which is the theme of our article on the mouth-body connection. Poor sleep is not a jaw problem to be solved with tongue exercises. It is a medical problem that sometimes has a jaw component.

What you can actually do at home

Ordered by how confident anyone should be about it.

1. Find out why the nose is not working. The highest-value action on the list. Chronic congestion, allergic rhinitis and enlarged tonsils or adenoids all force the mouth open. Saline rinses, allergy management and an ENT assessment address the cause; tongue exercises address the downstream effect. If your child cannot breathe through their nose, no amount of posture coaching will hold.
2. Address prolonged sucking habits, gently. The evidence on duration is clear enough to act on.⁸ Aim to have thumb and pacifier habits wound down well before the permanent front teeth arrive, using positive strategies rather than shaming.
3. Cue rest posture lightly, and briefly. “Lips together, breathe through your nose” as an occasional cue is harmless and may help. Long daily drilling regimens for a young child are not supported by good evidence and can turn a non-problem into a source of anxiety — a real concern for children with sensory sensitivities, as we cover in sensory-friendly dentistry.
4. Feed them things that require chewing. Whole fruit and vegetables, meat, bread with crust. This is not a jaw-widening protocol; it is normal oral motor development, and it supports the skills discussed in how dental alignment affects chewing and swallowing.
5. Protect sleep. Consistent timing and a dark, quiet room will not change jaw shape, but they make sleep-disordered breathing easier to spot when it is present, because you stop attributing every bad night to a late bedtime.

What myofunctional therapy can and cannot do

Orofacial myofunctional therapy is a real discipline with a real evidence base. The evidence is just much stronger in one place than in the place it is usually marketed for.

Where it is well supported: sleep apnea. A systematic review and meta-analysis found that in nine adult studies covering 120 patients, the apnea-hypopnea index fell from 24.5 to 12.3 events per hour, lowest oxygen saturation improved, and snoring and sleepiness measures improved. In the pediatric data, one study of 14 children saw the index fall from 4.87 to 1.84 events per hour, and a second found that children cured after adenotonsillectomy and palatal expansion who continued therapy remained cured at four years while controls had recurrence. Overall the review reported reductions of roughly 50% in adults and 62% in children.¹⁷

A later pediatric meta-analysis found myofunctional therapy decreased the apnea-hypopnea index by 43% in children and increased mean oxygen saturation in mild to moderate residual apnea, including in children without adenotonsillar hypertrophy, and reduced the odds of persistent mouth breathing — concluding it can serve as an adjunct treatment.¹⁸ Adjunct is the operative word.

A 2026 overview that re-analyzed nine systematic reviews covering 21 unique primary studies and 716 participants again found myofunctional therapy more effective than control for apnea severity and daytime sleepiness — while noting that the methodological quality of the reviews was generally critically low.¹⁹

Where it is not established: preventing malocclusion or avoiding braces. The most current synthesis on this question is a scoping review.²⁰ A scoping review maps evidence rather than pooling it, and researchers choose that design when the literature is too heterogeneous to combine. That choice is itself the finding.

Who to see, and when

The American Association of Orthodontists recommends that all children have a check-up with an orthodontic specialist no later than age 7, when a mix of baby and permanent teeth allows developing problems to be identified. The AAO does not advocate comprehensive orthodontic treatment at that age, though interceptive treatment is appropriate for certain problems.²¹ Most seven-year-olds who are seen are simply monitored.

Which professional does what:

• Pediatric dentist — bite, arch form, eruption, habit counseling, and the first look at whether any of this warrants further attention.
• Orthodontist — growth and jaw relationship; the age-7 screening.
• ENT — the nose, tonsils, adenoids and airway. Usually the highest-yield referral when mouth breathing is the presenting problem.
• Sleep physician — when snoring, pauses or unrefreshing sleep suggest sleep-disordered breathing.
• Speech-language pathologist — articulation, swallowing and, where the clinician is trained in it, myofunctional therapy. You can find a speech therapist through our directory, or browse all providers by state.
• Occupational therapist — where feeding, oral sensory tolerance or sensory aversion is limiting what any of the above can achieve. Our occupational therapy directory covers pediatric providers.

For what these evaluations typically cost and how insurance treats them, see our therapy cost and insurance guides.

Five claims to be skeptical of

1. “Correct tongue posture will prevent braces.” Not established. The synthesis on myofunctional therapy and orthodontic outcomes is a scoping review precisely because the evidence is not consistent enough to pool.²⁰
2. “Your child’s face is being ruined by mouth breathing.” The association with a longer face pattern is real,⁴ but reviewers note the absence of high-quality evidence and an unclear mechanism.⁵ Alarming a parent is not the same as informing one.
3. “A tongue-tie release will improve facial growth.” The systematic review addressing this rated the underlying studies as low quality.¹¹
4. “Tongue thrust therapy will fix the open bite.” Under equilibrium theory the swallow is too brief to move teeth; resting posture is the plausible mechanism, and the long-standing recommendation has been that therapy for anterior tongue position is not warranted before adolescence.¹
5. Any before-and-after photo used as evidence. Children grow. Facial change between ages 7 and 12 happens with or without intervention.

A useful test: does the provider recommending treatment also profit from it, and are they willing to send you for a second opinion? Good clinicians say yes without hesitation.

Popular next reads

• Nasal breathing development in children
• How to spot oral development delays early
• Signs of a hidden oral restriction
• How dental alignment affects chewing and swallowing
• Dental and oral development

Frequently Asked Questions

Where should my child’s tongue rest?

Against the roof of the mouth, with the tip just behind the upper front teeth rather than pressing on them, lips closed, breathing through the nose. The tongue should rest up, not forward — sustained forward pressure on the incisors is the mechanism that displaces teeth.

Can tongue posture really affect my child’s face and jaw?

It is one contributing input. Teeth respond to light, continuous force, so a tongue held low or forward for hours a day is a plausible influence on tooth position, while brief forces such as swallowing are much less likely to be causative.^1,2 But tongue posture sits alongside airway, sucking habits, feeding history and genetics — and it is frequently a consequence of a blocked nose rather than an independent cause.

Is mewing safe for my child?

The general idea of resting the tongue on the palate with lips closed is unobjectionable. The social-media version — forceful, prolonged tongue pressing and jaw clenching marketed as facial restructuring — is not supported by evidence and carries a real risk of jaw joint strain. Children with joint symptoms should be assessed; see our guide on whether TMJ issues can start in childhood. A light occasional cue is enough.

Does mouth breathing change your child’s face?

Mouth breathing is consistently associated with a distinct pattern: the maxilla and mandible rotated backward and downward, a steeper occlusal plane, upper front teeth tipped forward, and smaller airway dimensions — from ten studies pooled in a meta-analysis.⁴ Reviewers caution, however, that high-quality evidence establishing causation is lacking and the mechanism remains unclear.⁵ Either way, chronic mouth breathing warrants finding out why the nose is not working.

Does thumb sucking or a pacifier cause an open bite?

Both are associated with increased risk of anterior open bite and posterior crossbite, with pacifier habits carrying a significantly higher risk than digit habits for posterior crossbite (odds ratio 2.66).⁶ Duration drives it: open bite and crossbite were associated with habits of 36 months or more, and digit habits with open bite when sustained 60 months or longer.⁸ A habit that ends in toddlerhood is a much smaller concern than one continuing into school age.

Does breastfeeding prevent crooked teeth?

It is associated with lower odds. Pooling 41 studies and 27,023 participants, children ever breastfed had lower odds of malocclusion than those never breastfed (OR 0.34), and exclusively breastfed children had lower odds than those without exclusive breastfeeding (OR 0.54).⁹ This is observational evidence, and it is not something you can act on retroactively.

Does tongue-tie affect jaw development?

The evidence is weak. A systematic review of seven studies covering 1,349 patients with ankyloglossia and 90 controls rated study quality as low, with the strongest signal concerning reduced intercanine and intermolar arch widths.¹¹ Frenotomy has reasonable support for relieving nipple pain during breastfeeding, but systematic reviews found no evidence that ankyloglossia causes speech disorders and concluded it should rarely, if ever, be recommended for that reason.¹⁰

Can tongue posture cause a lisp?

Tongue placement and articulation are related, and interdental placement is a common pattern in frontal lisps. But most lisps in young children are developmental and many resolve. A speech-language pathologist can distinguish a developmental pattern from one needing intervention; our guide to lisps covers what is typical at what age.

Does myofunctional therapy prevent the need for braces?

Not established. Its strongest evidence is in obstructive sleep apnea, where a meta-analysis found the apnea-hypopnea index fell by roughly 50% in adults and 62% in children,¹⁷ and a pediatric meta-analysis found a 43% reduction with improved oxygen saturation.¹⁸ For malocclusion, the current synthesis is a scoping review — a design used when evidence is too inconsistent to pool.²⁰

My child snores every night. Is that normal?

Habitual snoring warrants assessment. Obstructive sleep apnea syndrome affects an estimated 1.2% to 5.7% of children, and guidelines recommend screening all children for snoring and performing sleep studies in those with snoring plus additional symptoms or signs.¹⁴ Snoring most nights, witnessed pauses, gasping, unrefreshing sleep, or new daytime behavior changes should be raised with your pediatrician promptly.

Will my child’s tonsils need to come out?

Not necessarily, but adenotonsillar hypertrophy is the predominant cause of pediatric sleep apnea in younger children, and adenotonsillectomy is first-line treatment when it is present.¹⁵ Note that up to 40% of children still have an apnea-hypopnea index of 5 or more after surgery, and for children aged six to puberty with persistent apnea and a posterior crossbite, rapid maxillary expansion can resolve it.¹⁶

At what age should my child see an orthodontist?

No later than age 7. The American Association of Orthodontists recommends screening at that age because a mix of baby and permanent teeth allows problems to be identified early; it does not advocate comprehensive treatment at 7, though interceptive treatment is appropriate for certain problems.²¹ Most children screened at 7 are simply monitored.

How long does it take to change tongue posture?

There is no reliable answer, because the outcome measures in this literature are inconsistent — which is part of why the malocclusion evidence remains unpooled.²⁰ Programs commonly run several months. Before starting one, ask what specific, measurable problem is being treated and how progress will be judged.

My child has autism or sensory differences and hates anything near their mouth. What then?

Start with tolerance rather than technique. Oral defensiveness makes exercise-based programs and dental exams alike very hard, and forcing them tends to set things back. Our guide to sensory-friendly dentistry covers how to make appointments workable, and an occupational therapist experienced in oral sensory work is often the right first referral.

Do baby teeth matter if they are going to fall out anyway?

Yes. They hold space for the permanent teeth, and they matter for chewing and speech — the relationship covered in baby teeth and speech development. Early loss to decay is one of the more direct routes to crowding.