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Blog · Mouth breathing · August 18, 2026 · 6 min

Mouth breathing in children: why it matters.

A child who breathes through their mouth most of the time isn't just “being a mouth breather.” It's a sign that something is off — and over time, it shapes how their face grows, how their teeth line up, and how well they sleep.

By Gina Sabbak, RDH — Myofunctional Therapist

What it looks like

Mouth breathing in children usually shows up as: lips apart at rest; dry mouth on waking; snoring or noisy sleep; chronic nasal congestion; forward head posture; dark circles under the eyes; and sometimes bedwetting in older children (when paired with the other signs).

Why it matters

Nasal breathing is the anatomical default. The nose filters, humidifies, and warms the air. It produces nitric oxide, which helps the lungs absorb oxygen. The diaphragm works more efficiently.

Mouth breathing bypasses most of this. The air that reaches the lungs is colder, drier, and less filtered. The diaphragm works harder. And over time, the lack of lip-seal and tongue-up posture shapes how the face grows.

Research has linked chronic mouth breathing in children with longer-face growth patterns, narrower dental arches, crowded teeth, and disrupted sleep. Disrupted sleep in turn affects mood, focus, and school performance.

Causes

Common causes include: enlarged adenoids or tonsils; chronic nasal congestion from allergies; tongue-tie that limits the tongue's ability to rest against the roof of the mouth; and habit.

The work is to find the cause (or causes). Sometimes the answer is structural — see an ENT. Sometimes it's muscular and habitual — see a myofunctional therapist. Often it's both.

What can be done

Three things, often together:

  • Address the structural cause. If the child has enlarged adenoids, allergies, or a tongue-tie, those need to be addressed by the appropriate provider.
  • Establish nasal breathing as the default. Lip-seal training, breathing exercises, and day-time cues.
  • Establish correct tongue rest posture. Tongue up, lips closed, nasal breathing — at rest, all the time.

If you're worried

Call our office at (502) 901-8089. We're happy to talk on the phone about whether an evaluation is the right next step.

This post is educational and is not medical advice. Please do not act on it without talking to your own healthcare provider.