Your child sleeps with their mouth open, and nobody has explained why
Mouth breathing is not a habit a child chooses. It is usually a sign that something is making nose breathing hard. That something is findable, and it is usually treatable.
Breathing through the mouth is a symptom, not a habit
A child breathes through the mouth when the nose is not working well enough. The usual reasons are allergy, long-running nasal inflammation, or enlarged adenoids and tonsils, and sometimes a deviated septum.[4] None of those is a dental problem. All of them are findable.
That is why this page starts with the nose and not with the teeth, and why telling a child to “keep your mouth closed” does not work. You cannot close a door the air still has to get through.
Six things parents notice first
- 1
Mouth open at rest
Not just asleep. Watch them read, or watch television.
- 2
Snoring, or noisy sleep
Any night, not only when there is a cold.
- 3
Restless sleep
Odd positions, kicked-off covers, waking tired.
- 4
Dry lips, thirsty in the morning
Air moving over the mouth all night dries it out.
- 5
Tired in the daytime
Or wired and unable to settle. Both look like poor sleep.
- 6
Crowded or protruding teeth
Worth checking together with the breathing, not instead of it.
One of these on its own means little. Three or four together, on ordinary nights, is worth an assessment. See all treatments at Tooth Tales.
Some of what you have read about this is not settled
Airway care attracts confident claims. Two of the biggest are weaker than they sound, and you deserve to know which before anyone sells you a device.
We would rather tell you the evidence is thin than let you buy something on a promise it cannot keep.
When we would act, and when a child genuinely grows out of it
Plenty of mouth breathing is temporary. A cold, a bad allergy season, a few restless weeks. What does not resolve on its own is a structural cause, and the difference matters because one needs treating and the other needs leaving alone.
✓ Worth assessing
- ✓ It happens on ordinary nights, not only when your child is unwell.
- ✓ Snoring most nights, or long pauses in breathing that you have noticed.
- ✓ Sleep that is broken, and days that are tired or wired.
- ✓ The mouth sits open at rest, awake, when nobody is watching.
✗ We would wait
- ✗ It started with a cold and has not outlived it.
- ✗ It is only at night, sleep is otherwise fine, and there is no snoring.
- ✗ A single crowded tooth with no breathing symptoms at all.
- ✗ Your child is mid-allergy season and has not been treated for it yet.
One thing a dentist cannot do is diagnose sleep apnoea. Guidance is explicit that dental teams should screen and then refer to a doctor, an ENT specialist or a sleep physician for the diagnosis itself.[1] We will tell you when that is the appointment you actually need.
Is myofunctional therapy legit?
Enough parents type that exact question that it finishes itself in the search bar. Here is a straight answer: it is a real treatment, with real but limited evidence, and it is oversold.
Myofunctional therapy fixes children’s sleep-disordered breathing.
The Cochrane review of myofunctional therapy for obstructive sleep apnoea pooled nine studies and 347 people. Thirteen of them were children.[2] For children specifically, the evidence is thin rather than negative.
The reviews all agree it works.
A 2026 overview re-analysed nine systematic reviews covering 21 primary studies. It rated the methodological quality of five of those nine reviews as critically low.[3]
Mouth breathing will reshape your child’s face.
A 2020 systematic review of allergic rhinitis and malocclusion in children concluded no firm correlation could be established, and rated the risk of bias in the available studies as high, with none following standard reporting protocols.[4]
A pre-orthodontic trainer such as Myobrace will sort it out.
A systematic review screened 355 publications and found only four that qualified, all at high risk of bias. Where it has been compared directly, a conventional twin-block appliance outperformed it on skeletal change.[5]
So what do we actually do with it? We use myofunctional therapy as support alongside treating the cause, never instead of it. It costs nothing but effort, there is reasonable evidence it helps daytime sleepiness and sleep quality,[3] and it does not commit you to buying anything. If a clinic offers you exercises or an appliance before anyone has looked at why the nose is blocked, that is the wrong order.
Does it hurt? No. It is mostly homework.
There is no needle, no drilling and nothing to be frightened of in an airway assessment. We look, we ask questions, and we watch your child breathe. The treatment that follows is mostly exercises done at home: lips together, tongue resting on the roof of the mouth, breathing through the nose while doing something ordinary.
The hard part is not pain, it is repetition. Exercises only work if they happen most days for months, and the honest failure mode here is a family who stops after three weeks. We would rather set you two minutes a day you will actually do than ten you will not.
What happens at an airway assessment
Forty minutes, and most of it is talking and looking. Nothing is decided in the first appointment except what to check next.
- 1
We listen to the history first
When it started, what the nights are like, whether there are colds and allergies.
- 2
We look at the nose and the throat
Tonsils, the back of the nose, how your child breathes with the lips closed.
- 3
We check how the teeth have grown
A narrow arch or an open bite is information, not a diagnosis on its own.
- 4
We say what we cannot tell you
A dentist cannot diagnose sleep apnoea. That needs a doctor.
- 5
We refer when it needs a doctor
To an ENT specialist, and to your child’s own doctor if sleep is the concern.
- 6
You leave with a plan, not a device
What to do, in what order, and what would change our mind.
The order we work in, and why it matters
This is the part that separates careful airway care from selling an appliance. The cause comes first. Everything else is built on top of it.
Find the cause
With an ENT specialist. A blocked nose has a reason, and the reason is treatable.
With an ENTTreat the blockage
Allergy, adenoids or tonsils. That is a doctor’s job, not a dentist’s.
ENT or paediatricianRetrain the breathing
Orofacial myofunctional therapy. Exercises for the lips and tongue, done at home.
At homeGuide the growth, if needed
An appliance or braces, once the airway itself is dealt with. Not before.
OrthodonticsAirway focused care at Tooth Tales runs in collaboration with ENT specialists, and the team holds ISAAI membership. Braces and appliances are covered on the orthodontics side of the practice.
GAP · blocked on the clinicTwo things to confirm before this ships. First, what ISAAI stands for in full, since a parent will not know the acronym. Second, whether the clinic delivers orofacial myofunctional therapy in house or refers it, and if in house, who is trained and in what.Questions parents ask us about mouth breathing
These are the questions parents ask us most, in the words they ask them.
You do not stop the breathing, you remove the reason for it. Nose breathing comes back on its own once the blockage is treated. That usually means finding the cause with an ENT specialist first, whether that is allergy, adenoids or tonsils. Telling a child to keep their mouth shut does not work, because the air still has to get in somewhere.
It is a real treatment with real but limited evidence. The Cochrane review on it included 347 people, of whom only 13 were children, so for children specifically the evidence is thin rather than negative. It is worth doing alongside treating the cause. It is not worth paying a lot for as a treatment on its own.
Sometimes yes. A blocked nose from a cold or a passing allergy clears and normal breathing returns. What does not resolve on its own is a structural cause such as enlarged adenoids or tonsils. The test is whether it happens on ordinary nights, not only when your child is unwell.
This is claimed far more confidently than the evidence supports. A 2020 systematic review looking at allergic rhinitis and malocclusion in children found no firm correlation could be established and rated the risk of bias in the studies as high. Treat any clinic that shows you dramatic before-and-after faces with caution.
Prices vary widely between clinics, so any single figure you read online is unreliable. The more useful question is whether your child needs one at all. The evidence behind pre-orthodontic trainers is weak, and an appliance fitted before anyone has treated the reason the nose is blocked is money spent in the wrong order. Ask us what we would do first.
Yes. Airway focused care here runs in collaboration with ENT specialists, because the cause of a blocked nose is usually a medical problem rather than a dental one. We can look, screen and refer. We cannot diagnose sleep apnoea, and we will say so rather than guess.
References
Every clinical claim on this page is numbered and links to its source. Guideline bodies and peer-reviewed research only, including the research that does not support the popular claim. All URLs checked 10 September 2026.
- 1
American Academy of Pediatric Dentistry. Policy on Obstructive Sleep Apnea (OSA). Screening by oral health professionals, and referral to an otolaryngologist, sleep physician or pulmonologist for diagnosis.
https://www.aapd.org/research/oral-health-policies–recommendations/obstructive-sleep-apnea/ - 2
Rueda J-R, Mugueta-Aguinaga I, Vilaró J, Rueda-Etxebarria M. Myofunctional therapy (oropharyngeal exercises) for obstructive sleep apnoea. Cochrane Database of Systematic Reviews. 2020, Issue 11, CD013449. PMID 33141943. Nine studies, 347 participants, 13 of them children.
https://pubmed.ncbi.nlm.nih.gov/33141943/ - 3
Pisoni L, et al. Myofunctional therapy in adults and children with obstructive sleep apnea: an overview and re-analysis of systematic reviews. Journal of Sleep Research. 2026. PMID 41045206. Nine systematic reviews, 21 primary studies; methodological quality critically low in five of nine.
https://pubmed.ncbi.nlm.nih.gov/41045206/ - 4
Farronato M, Lanteri V, Fama A, Maspero C. Correlation between malocclusion and allergic rhinitis in pediatric patients: a systematic review. Children (Basel). 2020;7(12):260. No firm correlation established; risk of bias rated high.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7760209/ - 5
Management of malocclusion in children using the Myobrace appliance: a systematic review. F1000Research. 2024;13:53. 355 publications screened, four eligible, all at high risk of bias.
https://f1000research.com/articles/13-53 - 6
Tooth Tales clinic fact base, service list of 19 August 2026, and the client’s own brand positioning minutes confirming airway focused care, ENT collaboration, orofacial myofunctional therapy and ISAAI membership. Internal source, not publicly linkable.
Internal source, no public URL