Mouth Breathing and a High-Arched Palate: What It Means for Your Child

Short answer: A high, narrow roof of the mouth is a common sign of long-term mouth breathing in children.

Medically reviewed by Dr. Prashanth R. Reddy, ENT Surgeon (MS ENT) · Last reviewed: 31 October 2026

What is a high-arched palate?

The palate is the roof of the mouth. In a high-arched palate it is deep and narrow instead of broad and gently curved. It often goes with a narrow upper jaw, crowded upper teeth and a crossbite.

How mouth breathing causes it

In nasal breathing, the tongue rests against the palate and helps it grow wide during childhood. With mouth breathing, the tongue sits low, and the cheek muscles press the upper jaw inward. A narrower, higher palate is one of the most consistent findings in mouth-breathing children (Zhao et al., 2021). Animal experiments that blocked nasal breathing produced similar changes (Harvold et al., 1981).

Why it matters for the nose

The palate is also the floor of the nose. A narrow, high palate means a narrower nasal airway, which makes nasal breathing harder still. That's why early treatment, while the child is growing, matters.

Why do people breathe through the mouth?

Usually because the nose doesn't let enough air through. Common reasons are a deviated septum, swollen turbinates, nasal allergy, chronic sinusitis, nasal polyps and, in children, enlarged adenoids and tonsils. Sometimes it starts as a habit and stays even after the nose clears.

Signs you or your child may be a mouth breather

• Lips apart at rest or during sleep
• Snoring, dry mouth or drooling on the pillow
• Waking tired, dark circles under the eyes
• Bad breath and frequent throat clearing
• Always 'blocked' nose, especially at night

What helps

1. Find out why the nose is blocked. An ENT evaluation (examination plus a CT scan of the nose where needed) shows whether it's the septum, turbinates, allergy, sinuses or adenoids.
2. Treat the cause, from allergy control and nasal sprays to correcting a blockage when it's needed.
3. Work with your dentist or orthodontist on the teeth, gums and bite.
4. Re-train nasal breathing once the nose is open, with lips closed at rest.

When to see an ENT

If you or your child breathe through the mouth most of the time, snore, or have a constantly blocked nose, an ENT evaluation can find the cause.

References

• Zhao Z, et al. Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis. BMC Oral Health. 2021;21:108.
• Harvold EP, et al. Primate experiments on oral respiration. American Journal of Orthodontics. 1981;79(4):359-372.

Related reading: Mouth breathing and bad breath · Mouth breathing and tooth decay · Mouth breathing and gum disease · Mouth breathing and crooked teeth · Mouth breathing, a receding jaw and a long face

About the author

Dr. Prashanth R. Reddy is a Senior Consultant ENT Surgeon in Bengaluru (MS ENT; Fellowship in Rhinoplasty, Seoul; MBA, IIM Bangalore) with over two decades of practice. He sees patients at Sakra World Hospital, Marathahalli and at the ENTHealth360 clinic in Koramangala.

For educational purposes only. Not a substitute for medical advice. Please consult a qualified ENT specialist.