A child breathes through the mouth: how it affects the bite
Parents rarely arrive saying «my child is a mouth breather». They arrive with crooked teeth, and mention the open mouth in passing — when I ask whether the child sleeps with the mouth open and snores. In paediatric orthodontics this is one of the most important signals: it explains why the teeth ended up where they did.
Why the way you breathe shapes the jaws
A child's jaws are not a finished structure. They form under load — and the main load here is not chewing, as most people assume, but where the tongue rests.
When a child breathes through the nose, the lips are closed and the tongue sits up against the palate. It works as an internal scaffold: every day, around the clock, for years, it supports the upper jaw from inside and widens it as the child grows.
With mouth breathing everything changes. The mouth has to stay open, otherwise air cannot pass. The tongue drops to the floor of the mouth. The upper jaw loses its inner support while the cheeks keep pressing from outside. A few years of that imbalance are enough for the palate to become narrow and high — and for the teeth to run out of space before they even erupt.
So the crooked teeth are the consequence, not the cause. Treat only the teeth without changing the breathing, and the result tends to come back.
What actually changes — the visible signs
A narrow palate. The upper arch becomes V-shaped instead of a horseshoe. There is not enough room for the permanent teeth.
Crossbite. The narrow upper jaw stops overlapping the lower one, and the back teeth meet the wrong way round.
Open bite. The front teeth do not meet: a gap remains even with the mouth closed. It often comes together with the tongue pushing between the teeth.
Head posture. To keep the airway open, the child pushes the head slightly forward. It shows on a profile photo.
Dry lips and inflamed front gums. The airflow dries the mucosa: the gums around the upper front teeth turn red and bleed even though the child brushes.
One more symptom parents raise themselves: poor sleep — tossing, snoring, sluggish mornings. That alone is a reason not to postpone the visit.
ENT first, orthodontist second — in that order
Mouth breathing almost always has a cause an orthodontist does not treat: adenoids, chronic rhinitis, a deviated septum, enlarged tonsils, allergy.
So the first stop is an ENT specialist. While the nose physically cannot breathe, any orthodontic appliance works against circumstance: we widen the palate, the child keeps breathing through the mouth, and it all returns.
Once the airway is clear, the next question is whether the habit has settled in. It often has: the nose is free, but years of habit keep the mouth open. Then the child needs to relearn — exercises that bring the tongue back up and close the lips.
The orthodontist works in parallel, assessing how far the jaw shape has already changed and whether there is still time to fix it through growth.
Why age decides everything
The upper jaw consists of two halves joined by a suture along the middle of the palate. In a child this suture has not fused — which is exactly why a narrow palate can be widened with an appliance relatively easily: the halves separate and bone fills the gap.
Around adolescence the suture begins to ossify. After that, the same result takes either much longer treatment or surgical help.
This is why paediatric orthodontics does not say «let's wait for all the teeth». It says the opposite: a first check-up at 6–9 years. Not to start treatment immediately — often the doctor simply puts the child under observation. But so as not to miss the window when growth can still be steered.
What we do in practice
A palatal expander. A removable plate with a screw, or a fixed appliance, depending on the case. It widens the upper jaw, frees space for the teeth and — just as important — increases the volume of the nasal cavity.
Myofunctional therapy. Simple daily exercises for the tongue and lips with one goal: return the tongue to the palate and the lips to a closed resting position. Without it the appliance does its part and the habit undoes it.
Trainers. Elastic mouthguards worn at night and part of the day. They do not move teeth by force the way braces do — they retrain the muscles and show the tongue where to sit.
Observation. Sometimes the right decision is to do nothing now and look again in six months to see how growth is going. That is a clinical tactic too, not a refusal to help.
If you recognise your child here, start with an examination. At the consultation we look at the bite, the shape of the palate, the tongue position and a profile photo, and we say it plainly: act now, wait, or see an ENT first.
Frequently asked questions
My child only breathes through the mouth at night. Is that already a problem?
Yes, it matters. At night the tongue and lips hold their position for hours on end, which is why night-time mouth breathing shapes the jaws no less than daytime. If snoring or restless sleep is involved, see an ENT specialist.
At what age should I bring a child in with this?
Ideally at 6–9 years, when the first permanent teeth erupt. But if mouth breathing is obvious earlier, come earlier — at 4–5 there is already something to assess and something to do.
Will it correct itself as the child grows?
The shape of the jaws does not revert on its own. Remove the cause early and growth works for you. Wait, and growth is no longer available — the same job then takes longer.
The adenoids were removed but my child still breathes through the mouth. Why?
That is typical: the airway is clear but the habit remains. The body got used to it over years and does not switch automatically. Myofunctional therapy — retraining the tongue and lips — is what helps here.
Does mouth breathing affect the shape of the face?
Yes. With long-term mouth breathing the face grows downward more than forward: it looks longer, the chin less defined, the lips do not meet at rest. The earlier the breathing changes, the smaller this effect.
Can we manage with exercises alone, without an appliance?
Sometimes — if the changes are still minimal and the child is young. But once the palate has narrowed, exercises will not widen it: an appliance is needed, and the exercises hold the result.
How long does such treatment take?
Palatal expansion usually takes a few months of active phase, followed by a retention period. The doctor will give exact timing after an examination and an X-ray, since it depends on age and the degree of narrowing.
Is this the same as braces later?
No, these are different stages. Working with breathing and growth is the early phase, at 6–12 years. Braces, if needed, come later once the permanent teeth are in. After an early phase, brace treatment is often shorter.
How much is a paediatric orthodontic consultation?
An orthodontic consultation costs UAH 690: examination, bite diagnostics and a treatment plan. If X-rays are needed, the doctor will say so at the appointment.
Orthodontic treatment for children and adults: brace systems, aligners, bite correction. Modern protocols, thorough diagnostics and individual planning at every stage.
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We will assess the shape of the palate, the tongue position and the bite — and tell you plainly whether there is still time to use growth. An orthodontic consultation costs UAH 690.
Or book by phone 067 478 88 78
Show your child to an orthodontist
We will assess the shape of the palate, the tongue position and the bite — and tell you plainly whether there is still time to use growth. An orthodontic consultation costs UAH 690.
Book now