Dental and oral development

Development of Nasal Breathing for Children

Why breathing through the nose matters for a child’s jaw, sleep and bite, what makes a child breathe through the mouth instead, and when to have the airway looked at.

  • Expert Reviewed
  • Plain Language
  • Patient Focused
A young child asleep on a striped pillow, holding a teddy bear, breathing through a closed mouth

Reviewed by Dr. Yana Pekarski, DDS · Last updated August 28, 2026

Key Takeaways

  • Nasal breathing filters, warms and humidifies air, and lets the tongue rest against the palate with the lips closed — the position that helps shape the upper jaw as a child grows.
  • A blocked nose is the most common reason a child breathes through the mouth, and usually the most treatable. Enlarged tonsils or adenoids are the next, and have the clearest treatment path.
  • Long-term mouth breathing is associated with a longer, narrower face. Which way the causation runs is still argued, so this is a reason to have the airway checked rather than a prediction about a child's face.
  • Non-nutritive sucking is associated with malocclusion: across 5,560 children, pacifier sucking carried a risk ratio of 1.42 for posterior crossbite in the baby teeth against digit sucking, and longer habits carried more risk.
  • Snoring is the symptom not to wait out. The AAP asks that every child be screened for it, and that a child who snores with other signs of sleep apnea have a sleep study.

Why does it matter whether a child breathes through the nose?

Breathing through the nose does two things a mouth cannot. It filters, warms and humidifies air before it reaches the lungs, and it lets the tongue rest where it belongs — up against the palate, with the lips closed. That resting position is part of what shapes the upper jaw as a child grows.

A child who breathes through the mouth most of the time keeps the tongue low and the lips apart. The association between long-term mouth breathing and a longer, narrower face has been described for over a century. What is still argued is which way the causation runs — whether the breathing shapes the face, or a narrow airway produces both. That is worth knowing before anyone promises to change your child's face.

Why is my child breathing through their mouth?

A blocked nose

Allergic rhinitis, a lingering cold, or chronic congestion. The most common reason, and often the most treatable.

Enlarged tonsils or adenoids

The cause with the clearest path. Where obstructive sleep apnea comes with adenotonsillar hypertrophy, the American Academy of Pediatrics recommends adenotonsillectomy as first-line treatment.1

Habit, after the cause has gone

A child who breathed through the mouth for months during an illness may carry on afterward out of habit.

Structural differences

A deviated septum or narrow nasal passages. Worth an ENT opinion rather than a home remedy.

Do pacifiers and thumb sucking affect the bite?

Yes, and there are numbers rather than opinions here. A systematic review and meta-analysis of 15 studies found non-nutritive sucking associated with malocclusion, and put a figure on one part of it: for posterior crossbite in the baby teeth, pacifier sucking carried a risk ratio of 1.42 against digit sucking, across 5,560 children.2 The longer the habit runs, the higher the risk.

Proportion matters. Malocclusion has many causes and sucking is one modifiable factor among them — the review's own authors make that point. This is a reason to help a habit fade rather than a reason to panic about a two-year-old with a pacifier. → When thumb sucking is a problem

What can I actually do about it?

  • Get the nose looked at first. Nothing else works while the airway is blocked. Allergies, congestion and enlarged adenoids are treatable, and treating them is what lets nasal breathing return on its own.
  • Ask about snoring, specifically. The AAP asks that every child be screened for it, and that a child who snores with other signs of sleep apnea have a sleep study rather than be watched.1 → Sleep disorders in children
  • Where adenoids are the problem, ask what the options are. Surgery is first-line with sleep apnea and hypertrophy, but an intranasal steroid has randomized evidence behind it too, and is worth asking about.3
  • Help a sucking habit fade rather than fighting it. Duration is the part that carries risk. → Thumb sucking · What the evidence says about pacifiers

When should I raise this with someone?

Worth an appointment rather than watching: snoring most nights, pauses in breathing during sleep, waking unrefreshed, a permanently open mouth at rest, or a nose that never seems clear. Sleep symptoms are the ones not to wait out.1

The people to ask are your pediatrician first, then an ENT if the airway looks like the issue. A dentist will notice how the teeth are meeting and can say whether the bite is changing. → Mouth breathing and dental health · Tongue posture and jaw development

Frequently Asked Questions

Can a pacifier affect my child's teeth?

Yes. When a binky is used, the constant pressure on the front teeth and the improper positioning of the tongue can create an open bite.

Can a child learn to breathe through their nose again?

Usually, once the reason they stopped is dealt with. A blocked nose, enlarged adenoids or allergy are treatable, and nasal breathing often returns on its own afterward. Where the habit persists after the airway is clear, that is worth raising with your pediatrician or dentist.

How does chewing help my child's teeth and jaw?

Chewing can reduce fidgeting and improve the development of strong dental arches, because the bone that supports the teeth strengthens itself when stimulated, while lack of stimulation results in weaker bone.

Can chewing toys help my child stop thumb sucking or nail biting?

A chewing necklace can give an alternative for children who would like to break the habit of thumb sucking or nail biting, and it should be used on both sides of the mouth.

Why is nasal breathing important for my child's mouth development?

Nasal breathing helps the tongue stay in the correct posture, pressed up against the palate, which shapes the palate into a healthy U-shape.

Sources

  1. Marcus CL, Brooks LJ, Draper KA, et al. Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics. 2012;130(3):576–584. doi:10.1542/peds.2012-1671 (PMID 22926173)
  2. Doğramacı EJ, Rossi-Fedele G, Dreyer CW. Establishing the association between nonnutritive sucking behavior and malocclusions: a systematic review and meta-analysis. Journal of the American Dental Association. 2016;147(12):926–934.e6. doi:10.1016/j.adaj.2016.08.018 (PMID 27692622)
  3. Chohan A, Lal A, Chohan K, Chakravarti A, Gomber S. Systematic review and meta-analysis of randomized controlled trials on the role of mometasone in adenoid hypertrophy in children. International Journal of Pediatric Otorhinolaryngology. 2015;79(10):1599–1608. doi:10.1016/j.ijporl.2015.07.009 (PMID 26235732)

Medical disclaimer. This page is for general educational purposes and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your child.