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Read the articleMouth Breathing and Jaw Development
How are mouth breathing and jaw development related? Learn the signs, the roles of ENT and orthodontic assessment, and how follow-up is coordinated.
Author: Assoc. Prof. Dr. Halise Aydemir, Orthodontic Specialist.
Mouth breathing can occur alongside certain patterns of tooth and jaw development in children, but it does not mean that every child who breathes through the mouth will develop a jaw problem. Persistent mouth breathing or sleeping with the mouth open calls for assessment of both the breathing symptoms and any dental or jaw findings. Open lips alone do not identify the cause or establish a need for treatment. The aim is to investigate possible nasal or sleep problems while checking whether there is also an orthodontic concern.
What signs may suggest mouth breathing?
Sleeping with the mouth open, morning dry mouth, snoring, restless sleep and frequently keeping the mouth open during the day are observations worth describing during an assessment. Cracked lips may also occur, but none of these signs alone identifies the cause of mouth breathing or establishes a jaw problem.
Distinguish symptoms during a temporary cold from those that continue after the nasal congestion has settled. Note how long they have been present and whether they occur only during sleep or also during the day. Mention persistent snoring or observed pauses in breathing separately.
How is difficulty breathing through the nose assessed?
Open mouth posture is not the name of a single disease. Nasal congestion, allergic complaints, adenoids or other airway factors, habits and sleep problems may play a role in different people. The family can note when the complaint started, whether it occurs only at night or throughout the day, and whether it is accompanied by snoring. The pediatrician or ear, nose and throat specialist evaluates the respiratory cause; the orthodontist examines tooth and jaw development.
Using a jaw expansion device without knowing the cause of nasal congestion may not address the source of the problem. Likewise, it is not correct to diagnose "maxillary constriction" just by looking at the photo of the mouth open. The aim is to separately identify the cause affecting breathing and the dental or jaw-related findings.
How should the relationship between mouth breathing and jaw development be interpreted?
Mouth breathing can occur alongside certain dental and jaw features, but the same changes do not develop in every child. Growth patterns, tooth eruption, and muscle and tongue posture are considered together. Facial appearance alone cannot establish a cause or predict a treatment outcome.
A 2026 review of mouth breathing and craniofacial development in children brought together 16 studies and reported associations with a narrow upper jaw, increased vertical facial growth and bite problems. However, study methods and definitions of mouth breathing varied. Much of the evidence was observational, and the review did not conduct a formal risk-of-bias assessment. These findings cannot predict how an individual child’s face will develop or guarantee that treatment will reverse a change.
When evaluating long-term open mouth posture, upper jaw width, crossbite, relationship of front teeth and vertical features of the face can be examined. These are clinical findings recorded together. The cause of nasal congestion and breathing during sleep are separate medical questions. The open-mouth photograph confirms neither maxillary constriction nor sleep apnea.
To understand the relationship, three questions should be distinguished:
| Question | Why is it answered separately? |
|---|---|
| Why does the child breathe through the mouth? | It may require evaluation of nasal and airway factors. |
| What findings are there in tooth and jaw development? | It is explained by orthodontic examination and development records. |
| What is the goal of the proposed procedure? | This separates treatment of the breathing problem from correction of the bite. |
Hypothetical example: In a child with constant nasal congestion, the bite may be normal. In another child, both obstruction and crossbite may be detected. Finding an orthodontic target in the second child does not prove that the entire breathing problem is caused by the jaw alone. Likewise, the fact that orthodontic intervention is not required in the first child does not mean that the respiratory complaint is unimportant.
This association does not mean that mouth breathing will inevitably change the jaw, or that expansion will necessarily resolve a nasal problem. NHLBI pediatric sleep apnea guide discusses mouth breathing among the symptoms that can be seen during sleep and explains the medical evaluation path for diagnosis.
When symptoms persist, the aim is to identify respiratory and orthodontic findings separately and coordinate follow-up when needed, rather than choose an appliance in advance. The guide to maxillary constriction explains how a suspected width discrepancy is assessed.
When is an ENT assessment needed?
If breathing through the nose is difficult or nasal obstruction persists, an ear, nose and throat assessment can help investigate the cause. For children, a pediatrician can also be the first point of contact. Describe persistent open-mouth posture, snoring and observed pauses in breathing together. Do not postpone assessment of breathing symptoms while waiting for the teeth to be straightened.
If an orthodontic examination identifies a bite or jaw-development concern, assessments can be coordinated. A pediatric dentist or a clinician working in sleep medicine may also be involved when needed. There is no single referral order for everyone; the breathing problem and the orthodontic treatment goal should each be identified.
What can an orthodontic assessment establish, and what are its limits?
Orthodontic examination can evaluate the development of teeth and jaws in a person suffering from mouth breathing. The width of the upper and lower dental arches, bite, inclination of the teeth, resting posture of the lips and position of the tongue can be recorded. However, these records alone do not determine the cause of nasal breathing difficulty or the severity of respiratory events during sleep.
The stage of dentition and growth in the child is important. During the period when milk and permanent teeth are present together, the direction of tooth eruption, available space and habit history are examined. Findings such as sideways shifting of the jaw when closing or crossbite in the posterior region are also evaluated. AAO bite guide defines these dental relationships; these are not synonymous with a diagnosis of apnea.
| Finding examined | Question answered from an orthodontic perspective |
|---|---|
| Transverse relationship of the dental arches | Is there a crossbite or width mismatch? |
| Alignment of teeth and tooth eruption | Do available space and the direction of eruption need monitoring? |
| Relationship of the front teeth | Is there an open bite or an increased gap between the front teeth? |
| Resting posture of lips and tongue | What characteristics are observed with other records? |
| Habit history | How persistent is the habit, and how might it relate to the bite? |
Photographs, scans and any necessary imaging are selected to answer specific questions. The appearance of an airway on an x-ray or three-dimensional image does not mean that repeated pauses in breathing during sleep have been tested. Any necessary sleep study and medical diagnosis are considered separately.
Hypothetical example: A person who is found to have maxillary constriction during an orthodontic examination and who also snores may be offered a plan for the constriction. The effect of this plan on sleep complaints cannot be assumed at the outset; medical evaluation of snoring and possible apnea should be continued.
At the end of the consultation, it should be clear which finding is the target of treatment, which finding will be monitored alone, and which complaint requires assessment by another specialty. An orthodontic appliance is not offered as a general solution for every mouth breathing problem of unknown cause. If treatment is required, the result is compared to predefined dental and jaw targets.
What should you do if your child snores or pauses breathing during sleep?
If there is loud or continuous snoring at night, stopping breathing, frequent waking up, daytime sleepiness, or changes in attention and behavior, consult a pediatrician for sleep breathing problems. If necessary, an ear-nose-throat and sleep specialist evaluation is performed. NHLBI guide to sleep apnoea in children lists mouth breathing and snoring as possible symptoms; it explains the roles of medical assessment and sleep studies in diagnosis.
During this process, the orthodontic examination can examine the bite, upper jaw width and the development of the teeth. However, the severity of the respiratory symptom cannot be determined from the dental photograph alone. The guide to snoring and sleep apnoea explains in more detail which specialist to consult for which symptom.
How can families organize the evaluation and follow-up process?
A useful starting point is to describe when and under what circumstances the child breathes through the mouth. Keeping the mouth open all day, doing so only during sleep, and breathing through the mouth during a temporary cold are different histories. Nasal congestion, snoring, frequent waking and daytime behavioral changes may also be noted.
Observations can be kept short and concrete: How long has it been there, does it happen every night, is it accompanied by nasal congestion, has there been a pause in breathing during sleep? A phone recording may help explain the symptoms; an app score or an image alone cannot establish a diagnosis. It is not necessary to force the child to take breath tests again and again.
The general evaluation path can be understood as follows:
- Report persistent breathing symptoms. The pediatrician or appropriate ENT evaluation can investigate a possible airway cause.
- Describe sleep symptoms separately. Persistent snoring, suspected pauses in breathing and daytime effects may indicate a need for sleep assessment.
- Evaluate dental and jaw findings. Orthodontic examination determines bite and development goals.
- Clarify the purpose of each plan. Medical treatment may address the cause of breathing symptoms; orthodontic treatment may address relevant dental and jaw findings.
- Report symptoms that continue. Just because a treatment has been performed does not mean that all other symptoms disappear on their own.
At the consultation, you can ask: “Which finding is this treatment intended to address, how will we check the result, and whom should we contact if mouth breathing or snoring continues?” Correcting a crossbite and assessing a sleep complaint are different follow-up goals. The steps above are not a mandatory referral sequence; the plan depends on the findings.
Taping lips at home, forcibly closing the jaw, or choosing a device online is no substitute for investigating the cause. Focusing only on closing the mouth is not the right approach, especially if there is an inability to breathe easily through the nose. Personal practices should be discussed with the healthcare team.
NHLBI guide explains that symptoms in children may not be just daytime sleepiness. More information on sleep assessment is available in the article on snoring and sleep apnoea. Acute, significant breathing difficulty requires emergency care rather than waiting for a routine appointment.
Frequently asked questions
Does mouth breathing necessarily damage teeth?
No. Effects vary from person to person; when signs persist, it is important to investigate the cause and monitor jaw development.
Does snoring indicate an orthodontic problem?
Snoring alone is not an orthodontic diagnosis. Medical evaluation should not be delayed if there is a suspicion of continuous snoring or sleep apnea, especially in children.
Which specialist should we consult first?
For children, breathing and sleep symptoms can be discussed with a pediatrician or an appropriate ENT specialist, with further assessment guided by the findings. An orthodontist can examine the jaws and bite. Do not leave persistent snoring or suspected breathing pauses solely for an orthodontic appointment.
Note: This article is not a substitute for diagnosis or treatment. For more information about early monitoring in children, see the preventive orthodontic treatment page.
Resources
Grande and colleagues, 2026: systematic narrative review of mouth breathing and craniofacial development in children; NHLBI: Sleep apnea in children.
Related reading
Assoc. Prof. Dr. Halise Aydemir
Specialist in Orthodontics · İzmir Folkart Towers
Meet your orthodontist →This article provides general information and does not replace an individual examination. Diagnosis and treatment planning are based on a personal assessment.