Space to Breathe Well
How compromised nasal airways and mouth breathing reshape the developing face and starve the body of its most basic need — air.
Observation
“Does the person breathe through their mouth, have a narrow palate, or struggle with nasal congestion that never seems to go away?”
Impact
Mouth breathing is not a harmless habit. It changes the architecture of the face, narrows the airway, and forces the body into a chronic state of compensated breathing that affects every system downstream.
Source: Kahn et al., BioScience, 2020
Evidence & Quick Guides
8 resourcesThe Jaw Epidemic: Recognition, Origins, Cures, and Prevention
Researchers from Stanford make a compelling case in this paper: human jaws are shrinking, and it's not because of our genes. The change has happened far too quickly — over centuries, not millennia — to be driven by evolution. Something about how we live is causing it. The culprits they identify are surprisingly everyday: soft, processed diets that don't require much chewing, bottle-feeding instead of breastfeeding, and chronic mouth breathing. All of these reduce the physical forces that help a child's jaw grow to its full size. Humans are designed to have room for 32 teeth. Most of us don't. The consequences aren't just cosmetic. A jaw that's too small means crowded teeth, impacted wisdom teeth, and a narrower airway — all connected, all stemming from the same problem. The good news is that the authors believe early intervention — helping children develop proper tongue posture, nasal breathing, and chewing habits — could prevent much of this epidemic before it starts.
The Effect of Teeth Extraction for Orthodontic Treatment on the Upper Airway
When an orthodontist pulls teeth to make room for the rest to line up, what happens to the airway behind those teeth? This review looked at seven studies to find out. The answer depends on why the teeth were extracted. In children whose teeth stuck out significantly, pulling four premolars and pushing the remaining teeth back narrowed the airway. That makes intuitive sense — moving teeth backward pushes the tongue backward too, leaving less room for air to flow. But in children with simple crowding (teeth that are crooked but don't stick out), extractions actually increased airway space, because the remaining teeth shifted in a way that gave the tongue more room. The honest takeaway: we don't yet know for sure whether these changes actually affect a child's breathing in practice. None of the studies measured real breathing function. But the anatomical concern is real, and it's a question every parent should feel comfortable asking their orthodontist: "Will this treatment affect my child's airway?"
Forward Head Posture and Its Relationship with Mouth Breathing in Children
When someone can't breathe well through their nose, the body does something clever but destructive: it tilts the head forward. This opens the airway by straightening the path from mouth to lungs, but it creates a cascade of structural problems throughout the spine. This study compared mouth-breathing children with nasal-breathing children using stereophotogrammetry to measure head, scapular, and thoracic posture. The clearest measured difference was increased scapular superior position in the mouth-breathing group, which the authors connected to forward head position and mandibular positioning. The critical insight is not that posture alone proves the airway problem. It is that posture belongs in the same clinical conversation as breathing, jaw position, and oral function.
Effects of Mouth Breathing on Facial Skeletal Development in Children
Researchers reviewed 10 studies comparing the faces of children who breathe through their mouths to those who breathe through their noses. The differences were consistent and significant. Children who mouth-breathe tend to develop longer, narrower faces — sometimes called "long face syndrome." Their jaws grow downward and backward instead of forward, their upper teeth push outward, and their airways get narrower. It creates a vicious cycle: the narrow airway makes mouth breathing worse, which makes the face grow even more in the wrong direction. This matters because it shows that mouth breathing in childhood isn't just a habit — it physically changes the shape of a child's face. The earlier it's identified and addressed, the better the chance of guiding the face back toward healthy development. Left alone, these changes become permanent.
Orofacial Myofunctional Therapy and Its Effect on Tongue Posture and Swallowing
Myofunctional therapy is, in essence, physiotherapy for the face and tongue. It involves a series of exercises designed to retrain the muscles of the mouth and throat — particularly the tongue — to function the way they were designed to. This meta-analysis looked at nine studies and found something remarkable: simply exercising the tongue and retraining its resting position cut sleep apnoea severity in half for adults and by nearly two-thirds for children. No surgery. No devices. Just teaching the body to hold its own airway open. The mechanism is straightforward. During sleep, the muscles relax. If the tongue habitually rests low in the mouth (a "low tongue posture"), it falls backward and blocks the airway. Myofunctional therapy trains the tongue to rest on the palate — which is where it was always supposed to be. When the tongue is up, the airway stays open. This evidence bridges the gap between "Space to Swallow Well" and "Space to Breathe Well" — because swallowing correctly and breathing correctly are, in the end, the same structural challenge.
Paediatric Maxillary Expansion and Nasal Breathing: A Systematic Review
This review looked at 12 studies involving over 300 children who had their palate widened using an expander — a dental device that gradually pushes the upper jaw wider. The question was simple: does widening the palate help a child breathe through their nose? The answer was unanimous. Every single study found that children breathed better through their nose after palatal expansion. Air resistance dropped, and airflow increased by a meaningful amount. Why does this work? Because the roof of the mouth is also the floor of the nose. When you widen the palate, you're physically opening up the nasal passages at the same time. It's one of the clearest examples of how dental treatment and breathing are connected — and why treating the structure of the face can solve problems that nasal sprays and allergy medications never will.
Postural Disorders in Mouth Breathing Children: A Systematic Review
This systematic review assessed studies of posture in children diagnosed with mouth breathing. Ten studies covering 417 children met the criteria, using methods including postural rating scales, photography, and motion capture. The finding was suggestive but not definitive: the authors concluded there was low evidence that mouth-breathing patterns in children aged 5-14 are associated with postural deviations. The weakness of the underlying studies matters because it prevents overclaiming. The practical takeaway is that posture should be assessed as part of the broader airway and oral-function picture, while recognising that better studies are still needed.
Adenotonsillectomy Outcomes in Treatment of Paediatric Obstructive Sleep Apnoea
Removing the tonsils and adenoids is the most common surgery for childhood sleep apnoea. But how well does it actually work? This study followed 578 children across eight sleep centres to find out. The good news: surgery dramatically reduced the number of times children stopped breathing per hour of sleep — from about 18 to about 4. That's a major improvement for most families. The important caveat: only 27% of children were completely cured. The rest still had some degree of sleep apnoea after surgery — especially children over 7 and children who were overweight. Their tonsils and adenoids were gone, but the underlying problem — a jaw and face that hadn't grown large enough — was still there. This doesn't mean surgery isn't worth it. For many children, it makes a huge difference. But it does mean that tonsil removal alone isn't always enough. The structure of the face itself — the size of the jaw, the width of the palate — may need to be addressed as part of a complete treatment plan.
The Difficult Question
Why isn't an airway assessment standard practice for every person with a narrow face or crowded teeth?