If your child habitually breathes through their mouth — during the day, at night, or both — it's worth paying attention. What seems like a minor habit can have far-reaching effects on your child's facial development, dental health, sleep quality, and even behavior.
Why Nasal Breathing Matters
The nose is designed to be the primary pathway for breathing. Nasal breathing:
- Filters air, trapping particles, bacteria, and allergens
- Warms and humidifies air before it reaches the lungs
- Produces nitric oxide, which improves oxygen absorption and has antimicrobial properties
- Supports proper tongue posture — when breathing through the nose, the tongue naturally rests against the palate
When a child breathes through their mouth instead, they miss all of these benefits — and the downstream effects can be significant.
How Mouth Breathing Affects Facial Development
This is perhaps the most concerning long-term effect. In growing children, the tongue is a powerful force that shapes the upper jaw (maxilla). When the tongue rests against the palate — as it does during nasal breathing — it exerts gentle outward pressure that helps the palate develop to its full width.
When a child mouth breathes, the tongue drops to the floor of the mouth. Without that upward pressure, the palate can develop narrow and high-arched, leading to:
- Crowded teeth — a narrow palate means less room for permanent teeth
- Long face syndrome — the face grows longer and narrower
- Recessed chin — the lower jaw may not develop forward as it should
- Dark circles under the eyes ("allergic shiners")
- Narrow dental arches — often requiring orthodontic treatment
These changes to facial structure are much harder to correct once growth is complete, which is why early intervention is so important. Mouth breathing is also closely linked to tongue thrust, which can compound these effects.
The Sleep Connection
Mouth breathing and sleep problems are closely linked. Children who mouth breathe often experience:
- Snoring
- Restless sleep — tossing, turning, unusual sleeping positions
- Night sweating
- Bedwetting — associated with sleep-disordered breathing
- Difficulty waking up or morning fatigue
Poor sleep quality can then cascade into daytime symptoms:
- Difficulty concentrating in school
- Hyperactivity or behavioral issues — some children with sleep-disordered breathing are misdiagnosed with ADHD
- Irritability and mood changes
- Poor academic performance
Signs Your Child Is a Mouth Breather
- Lips are apart at rest (open mouth posture)
- Audible breathing during the day
- Snoring at night
- Dry, cracked lips
- Bad breath (mouth breathing dries out the oral cavity)
- Frequent upper respiratory infections
- Dark circles under the eyes
- Elongated facial structure
- Crowded or misaligned teeth
- Fatigue or difficulty concentrating
Common Causes
- Enlarged adenoids or tonsils — physically blocking the nasal airway
- Allergies — chronic nasal congestion from allergies
- Deviated septum — structural blockage in the nose
- Chronic sinus infections
- Habit — some children develop mouth breathing as a habit even after the original cause is resolved
What to Do
Step 1: Address Underlying Causes
See your pediatrician or an ENT (ear, nose, and throat specialist) to rule out structural or medical causes like enlarged adenoids, allergies, or a deviated septum.
Step 2: Myofunctional Therapy
Once any airway obstruction is addressed, myofunctional therapy can help your child:
- Re-establish nasal breathing as the default
- Correct tongue resting posture — training the tongue to rest on the palate
- Strengthen lip muscles to maintain a closed-lip seal
- Improve swallowing patterns that may have been affected
Step 3: Monitor and Maintain
Changing a habitual breathing pattern takes time and consistent practice. Your myofunctional therapist will work with your child on daily exercises and strategies to reinforce nasal breathing throughout the day and night.
The Bottom Line
Mouth breathing is not just a cosmetic concern or a bad habit — it can affect your child's facial development, sleep, dental health, and cognitive function. The good news is that with appropriate intervention, these patterns can be corrected, and the earlier you start, the better the outcomes. Learn more about our dedicated mouth breathing treatment program.
"When parents learn about the effects of mouth breathing on facial development and sleep, it's often a lightbulb moment. The great news is that myofunctional therapy is very effective at retraining these patterns, especially when we catch it early." — Laura Friedman, MS, CCC-SLP, QOM
Ready to Take the Next Step?
If your child is a mouth breather, getting an evaluation is the first step toward healthier breathing habits. Schedule a consultation to discuss how myofunctional therapy can help your child.