Short answer: If a child breathes through the mouth for a long time and continuously, this changes the balance of the tongue and lips and can affect jaw and tooth development. Because the cause may be nasal congestion, adenoids or allergy, the first step is to understand the cause; when signs recur frequently, an assessment from both an ENT and an orthodontic perspective is recommended.
Why does mouth breathing occur?
Mouth breathing does not have a single cause. Common factors include the following:
- Allergic rhinitis and constant nasal congestion
- Enlarged adenoids or tonsils
- Structural causes such as a deviated nasal septum
- Habit: continuing to breathe through the mouth after the nasal congestion has passed
For this reason, it should not be assumed that every child who breathes through the mouth will have a jaw problem; however, long-lasting situations should be monitored carefully.
Possible effects on the jaw and teeth
When breathing through the nose, the tongue rests against the palate and supports the lateral development of the upper jaw. When the mouth stays open, the tongue sits low, and the lip and cheek muscles can compress the upper jaw from the outside. In the long term, the following may be seen in most cases:
- A narrow and high palate
- Crowding of the upper teeth and a crossbite in the back teeth
- Forward tilting of the upper front teeth and a deep or open bite
- A recessed lower jaw or a face that looks long
- Dry lips, redness of the gums and an increased risk of decay related to dry mouth
We discussed the relationship between jaw development and breathing in a wider framework in our article on airway and orthodontics.
Which signs call for a specialist?
- The child walking around with the mouth open during the day, or having difficulty keeping the mouth closed
- Snoring, sleeping with the mouth open or frequent waking during sleep
- Dry mouth in the mornings, waking up tired, lack of attention during the day
- Frequently recurring ear, tonsil or upper respiratory tract infections
- Crowded teeth, a crossbite or a markedly long facial structure
If one or more of these signs are present, it is useful to first see an ENT specialist and have the nasal and adenoid structures assessed. Afterwards, jaw and tooth development is examined from an orthodontic point of view.
When does the orthodontist get involved?
If the palate has stayed narrow even though the nasal passage is clear, or if a crossbite has developed, appliances that widen the palate during the growth period may in most cases come into question. For this topic, you can look at our page on jaw and palatal expansion and our article on the palatal expander. If the position of the tongue also plays a role, the tongue thrust habit is also assessed. The need for treatment and its timing are determined by the clinician through examination and imaging.
What can be done at home?
- Observing the breathing calmly, without making the child self-conscious
- Paying attention to nasal cleaning (saline, etc.) in line with the clinician’s advice
- Reducing environmental triggers if allergy is suspected
- Looking into the cause instead of constantly telling the child to “close your mouth”
Mouth breathing and sleep
In children who breathe through the mouth at night, sleep quality can be affected. Snoring, restless sleep, sweating and morning tiredness may accompany this picture. These signs are not related only to the teeth and jaw; because they can be a sign of sleep-disordered breathing, an ENT and, if needed, a paediatrician’s assessment is important. The orthodontist interprets, through examination, how much the jaw structure contributes to this picture.
What is assessed at the examination?
- The resting position of the lips and the facial profile
- Palatal width, tooth alignment and the bite relationship
- The position of the tongue and the swallowing pattern
- If considered necessary, jaw development with X-rays and measurements
Why is the growth period important?
The upper jaw and palate show their fastest change in childhood. Breathing and tongue position problems noticed during this period offer a wider range of options for guiding jaw development. After growth is complete, more extensive treatments may be needed for the same findings. For this reason, when you notice continuous mouth breathing, snoring or crowded teeth, it is appropriate to have an assessment rather than wait and see.
What does the treatment approach depend on?
If the cause of mouth breathing is a blockage in the nasal passage, this is addressed first. Treatment directed at the cause is planned with the ENT specialist’s assessment. If there are dental and jaw findings such as a narrow palate or a bite problem, these are monitored separately from an orthodontic point of view. In some children, the focus is on the balance of the tongue and lip muscles that have turned breathing into a habit. Treatment differs for each child; for this reason, a method recommended for a friend’s child may not be suitable for your child.
Frequently asked questions
Does the jaw become affected in every child who breathes through the mouth?
No. The effect varies with the length of time, the cause and the child’s growth period. Noticing it early makes it easier to manage the possible effects.
Should we see an ENT first or an orthodontist?
To understand the cause, an ENT assessment is often the first step. If there are dental and jaw findings, an orthodontic examination can be carried out in parallel.
Does the jaw correct itself once the nose is clear?
Some changes can recover during the growth period, but if structural findings such as a narrow palate remain, a separate assessment is needed.
How can you find out what suits you?
The information here is general; the right plan for your child is determined by examination and clinical assessment. At our clinic in Oran, Çankaya, Ankara, we go through your questions together during the first orthodontic examination.
