What Happens If You Ignore Mouth Breathing in Children?

A sleeping child with mouth open, highlighting the importance of addressing mouth breathing issues early to prevent potential developmental concerns.

Does your child sleep with their mouth open? Do they snore, wake up tired, or seem to breathe through their mouth throughout the day?

It can be easy to assume that mouth breathing in children is simply a habit or something they will eventually outgrow. Occasional mouth breathing during a cold or stuffy nose is common. But when a child regularly breathes through their mouth—during the day, while sleeping, or both—it may be a sign that something else is going on.

Persistent mouth breathing can be associated with problems involving sleep, oral function, dental development, and the airway. Because children are constantly growing and developing, recognizing these signs early can help families find the underlying cause and determine whether treatment or additional evaluation is needed.

A child sits on a man's shoulders, enjoying a sunny day in a grassy field, illustrating the carefree moments that can accompany mouth breathing.

What Is Mouth Breathing?

Mouth breathing means a child regularly breathes through their mouth instead of primarily through their nose.

Our noses are designed for breathing. As air passes through the nose, it is filtered, warmed, and humidified before reaching the lungs.

A child may temporarily breathe through their mouth when they have a cold or nasal congestion. Persistent mouth breathing, however, can occur for many different reasons, including:

• Chronic nasal congestion or allergies

• Enlarged tonsils or adenoids

• Structural problems affecting the nasal airway

• Oral habits

• Low tongue resting posture

• Difficulty keeping the lips comfortably closed

• Orofacial muscle dysfunction

This is an important distinction: mouth breathing can be a symptom, not simply a bad habit.

Trying to remind a child to “close your mouth” may not solve the problem if they are struggling to breathe comfortably through their nose.

What Can Happen If Mouth Breathing Is Ignored?

Every child is different, and mouth breathing does not mean that a child will develop all of the problems below. However, persistent mouth breathing has been associated with several concerns that parents should be aware of.

A young child peacefully asleep, illustrating the importance of addressing mouth breathing during sleep for healthy development.

1. Mouth Breathing Can Be a Sign of Poor Sleep

One of the first places parents may notice a problem is at night.

A child who regularly sleeps with their mouth open may also:

• Snore

• Toss and turn frequently

• Sleep in unusual positions

• Wake up during the night

• Sweat excessively while sleeping

• Wake up with a dry mouth

• Seem tired despite getting enough hours of sleep

Mouth breathing is also associated with sleep-disordered breathing, which includes a range of breathing difficulties during sleep.

This does not mean that every child who mouth breathes has sleep apnea. However, persistent mouth breathing—particularly when combined with loud snoring, pauses in breathing, gasping, or significant daytime sleepiness—is worth discussing with your child’s healthcare provider.

Good sleep isn’t only about the number of hours your child spends in bed. Sleep quality matters, too.

A young child resting her head on her arms appears pensive, highlighting the potential impact of poor sleep on mood and energy.

2. Poor Sleep May Affect Mood, Energy, and Concentration

When children aren’t sleeping well, the effects may become noticeable during the day.

Parents may notice:

• Difficulty concentrating

• Irritability

• Mood changes

• Daytime sleepiness

• Low energy

• Hyperactive behavior

• Difficulty getting up in the morning

• Problems paying attention at school

These symptoms can have many possible causes, so mouth breathing should never be assumed to be the only explanation.

However, if your child has daytime difficulties and regularly snores, sleeps restlessly, or breathes through their mouth, their nighttime breathing is worth investigating.

Family bonding over oral hygiene: A young child practices brushing techniques under the guidance of attentive parents, highlighting the importance of proper oral habits to support healthy tongue posture and function.

3. Mouth Breathing May Affect Tongue Posture and Oral Function

Where is your child’s tongue when they aren’t talking or eating?

At rest, the tongue normally sits comfortably against the roof of the mouth, with the lips closed and breathing occurring through the nose.

Children who frequently breathe through their mouths may develop a different resting pattern. The lips may remain apart and the tongue may rest lower in the mouth.

Over time, these patterns can be associated with difficulties involving:

• Chewing

• Swallowing

• Tongue movement and coordination

• Speech

• Lip closure

• Oral habits

• Feeding

This is one reason looking at the whole child is important. Breathing, tongue posture, chewing, swallowing, sleep, and oral development are closely connected functions.

A young boy at the dentist highlights the importance of addressing mouth breathing, which can impact facial and dental development.

4. Mouth Breathing Is Associated With Facial and Dental Development

A child’s face, jaws, palate, and teeth continue developing throughout childhood.

Research has found associations between chronic mouth breathing and differences in craniofacial and dental development. These may include:

• A narrow or high palate

• Dental crowding or bite problems

• Increased vertical facial growth

• Changes in jaw position

• Open-mouth resting posture

A systematic review and meta-analysis examining mouth breathing in children found differences in facial skeletal development and dental relationships between mouth-breathing and nasal-breathing children.

However, it is important to understand that facial growth is complex. Genetics, airway health, oral habits, tongue function, and many other factors can influence development.

Mouth breathing should therefore be considered one important piece of the puzzle rather than the sole cause of a child’s facial or dental development.

A child demonstrating mouth breathing, which can develop into a persistent habit if not addressed early.

5. Mouth Breathing May Continue as a Long-Term Pattern

A pattern that begins during childhood doesn’t necessarily disappear on its own.

If the reason a child is mouth breathing isn’t identified, the child may continue relying on mouth breathing as they grow.

This is particularly important when mouth breathing is connected with nasal obstruction, enlarged tonsils or adenoids, sleep-disordered breathing, or abnormal oral resting patterns.

Early evaluation gives families an opportunity to determine why the mouth breathing is happening instead of simply trying to correct the visible habit.

A young girl participates in an early developmental assessment with a professional, highlighting the importance of early evaluation.

Why Early Evaluation Matters

Children’s bodies are constantly growing and changing.

Identifying problems during childhood can give parents and healthcare professionals an opportunity to support healthy breathing and oral function while development is still taking place.

For younger children, including children around ages 2–6, this may involve watching for early signs and helping establish healthy oral patterns when appropriate.

Parents may notice things such as:

• An open mouth while watching TV or playing

• Sleeping with the mouth open

• Snoring

• Restless sleep

• A tongue that appears to rest low in the mouth

• Difficulty chewing certain foods

• Messy or picky eating

• Drooling beyond the expected age

• Frequent nasal congestion

• Teeth beginning to crowd

• Difficulty keeping the lips comfortably together

These signs don’t automatically mean your child needs myofunctional therapy. They do mean it may be worth asking questions.

A therapist uses myofunctional therapy to help a young girl improve her nasal breathing, promoting better oral health and overall well-being.

How Can Myofunctional Therapy Help With Mouth Breathing?

Orofacial myofunctional therapy focuses on the function and coordination of the tongue, lips, cheeks, jaw, and other muscles involved in breathing, chewing, swallowing, and oral posture.

Depending on a child’s age, needs, and ability to participate, therapy may work on areas such as:

• Establishing healthy oral resting posture

• Improving tongue posture

• Developing lip strength and coordination

• Supporting appropriate chewing and swallowing patterns

• Building awareness of nasal versus mouth breathing

• Replacing unhealthy oral habits with healthier patterns

For younger children, therapy and guidance may look different from treatment for an older child or adult. Activities should be appropriate for the child’s developmental level.

Most importantly, myofunctional therapy does not replace medical evaluation or treatment for an obstructed airway.

If a child’s nose is blocked because of allergies, enlarged tonsils or adenoids, or another structural or medical problem, simply teaching the child to breathe through their nose will not fix the obstruction.

That’s why collaboration may be important.

Depending on the child, care may involve a pediatrician, ENT (ear, nose, and throat specialist), dentist, orthodontist, allergist, speech-language pathologist, occupational therapist, myofunctional therapist, or another healthcare professional.

The goal is not simply to make a child keep their mouth closed. The goal is to understand why the mouth is open in the first place.

A mother comforts her young child, who is holding a tissue, as she sits on the couch, highlighting concerns about mouth breathing and when to seek medical advice.

When Should Parents Be Concerned About Mouth Breathing?

Consider speaking with a healthcare professional if your child:

• Regularly breathes through their mouth when they are not sick

• Sleeps with their mouth open most nights

• Snores frequently

• Has very restless sleep

• Wakes up tired despite getting enough sleep

• Frequently wakes with a dry mouth

• Has difficulty breathing comfortably through their nose

• Has ongoing feeding, chewing, or swallowing concerns

• Has noticeable changes in their bite or dental development

• Regularly rests with their lips apart and tongue low

If you notice pauses in breathing, choking or gasping during sleep, significant difficulty breathing, or other concerning respiratory symptoms, contact your child’s healthcare provider promptly.

Parents consult with a professional to address their child's mouth breathing concerns.

What Should You Do If Your Child Is a Mouth Breather?

Start by observing.

Watch your child when they’re relaxed—not just when you’re asking them to close their mouth.

Are their lips normally together or apart?

Do they breathe through their mouth while watching television or playing?

What happens when they’re asleep?

Do they snore?

Is their sleep peaceful or restless?

Can they comfortably breathe through their nose?

Writing down what you notice can make it easier to discuss your concerns with a qualified healthcare professional.

Most importantly, don’t assume that persistent mouth breathing is something your child will simply outgrow.

Help Your Child Build Healthier Breathing and Oral Habits

Mouth breathing can look harmless because it’s so easy to see it as “just a habit.” But persistent mouth breathing may be an important clue about your child’s airway, sleep, oral function, or development.

The earlier you recognize the pattern, the sooner you can start asking the right question:

Why is my child breathing through their mouth?

At Myo Matters, we work with children and families to evaluate oral function and identify patterns involving breathing, tongue posture, chewing, swallowing, feeding, and other orofacial functions.

When appropriate, myofunctional therapy can be part of a collaborative approach to helping children develop healthier oral habits and function as they grow.

If you’ve noticed that your child frequently breathes through their mouth, snores, sleeps with their mouth open, or struggles with tongue posture, feeding, chewing, or swallowing, consider scheduling an evaluation with Myo Matters.

Early awareness can make an important difference—and understanding the reason behind the mouth breathing is the best place to start.