The Research Behind Mouth Breathing & Airway Health in Children
My son snored, slept with his mouth open, struggled with congestion, developed glue ear, and was eventually diagnosed with sleep apnoea. Along the way there were concerns about his hearing, his behaviour, his sleep, and his development. Each time I sought help, I found another piece of the puzzle, but nobody seemed to be looking at the whole picture.
One professional talked about his ears. Another focused on his tonsils. Another looked at his teeth. Another suggested his behaviour was simply behavioural. As a parent, it was hard to shake the feeling that all of these things might be connected.
The more I researched, the more I found a growing body of evidence exploring exactly that question. Children's bodies do not operate in isolated systems. Breathing affects sleep. Sleep affects behaviour. Facial development can affect breathing. Hearing influences communication and learning. These systems constantly interact with one another, even when healthcare is organised in a way that separates them into different specialties.
This page is a collection of the studies, reviews, and resources that have helped me understand the bigger picture. I am not a clinician, researcher, or medical professional. I am a parent who has spent years trying to understand what was happening to my child, and who wants to share what helped me make sense of it.
I don't expect every parent to read every study here. Most of us are busy enough already. But for those who want to dig a little deeper, challenge assumptions, or understand why so many seemingly unrelated symptoms can appear together, and for parents who want something solid to bring to an appointment if they feel dismissed, I hope this page is a useful starting point.
Contents
Mouth Breathing & Facial Development
Snoring, Sleep Apnoea & Behaviour
Tonsils, Adenoids & Airway Obstruction
Tongue Posture & Myofunctional Therapy
Posture & Breathing
Gut Health & The Gut–Lung Axis
Birth, Feeding & Early Development
General Reviews & Parent-Friendly Overviews
1) Mouth Breathing & Facial Development
One of the most surprising things I learned was that mouth breathing isn't simply about whether a child breathes through their nose or their mouth. Researchers have spent decades studying how chronic mouth breathing may influence facial growth, jaw development, and dental alignment.
The impact of mouth breathing on dentofacial development: a systematic review and meta-analysis (2021) https://pmc.ncbi.nlm.nih.gov/articles/PMC7944632/ This review found that chronic mouth breathing is associated with altered facial growth patterns, changes in jaw development, and an increased risk of dental malocclusion.
Oral breathing and malocclusion in growing children (2025) https://www.mdpi.com/2227-9067/12/1/72 A review exploring the relationship between oral breathing, facial development, and orthodontic outcomes in growing children.
Mouth breathing and dental development (2022) https://pmc.ncbi.nlm.nih.gov/articles/PMC9498581/ This paper discusses the associations between mouth breathing, tongue posture, dental arches, and bite development.
Mouth breathing: adverse effects on facial growth, health, academic performance, and behavioral problems (2010) https://europepmc.org/article/med/20129889 One of the most frequently cited overview papers on the potential effects of chronic mouth breathing on facial development, sleep quality, health, and academic performance. A good one to start with if you only read one paper from this whole page.
2) Snoring, Sleep Apnoea & Behaviour
One of the hardest parts of our journey was watching concerns about sleep, behaviour, and listening skills get treated as separate issues by separate specialists. The research suggests they're often more connected than people realise — and that snoring and sleep-disordered breathing are frequently mistaken for, or misdiagnosed as, ADHD.
Sleep-disordered breathing in a population-based cohort: behavioral outcomes at 4 and 7 years (Bonuck, Freeman, Chervin & Xu, Pediatrics, 2012) https://publications.aap.org/pediatrics/article-abstract/129/4/e857/32299/ A large UK cohort study (over 11,000 children from the Avon Longitudinal Study of Parents and Children) found that children who snored, mouth-breathed, or had witnessed apnoea in early childhood were significantly more likely to show behavioural and emotional difficulties — including hyperactivity — by ages 4 and 7, even after adjusting for other factors.
Increased behavioral problems in children with sleep-disordered breathing (2022) https://pmc.ncbi.nlm.nih.gov/articles/PMC9479439/ This study found that children with sleep-disordered breathing showed more inattentiveness, hyperactivity, and both internalising (anxiety, social difficulties) and externalising (aggression, rule-breaking) problems than children without it — and that even primary snoring and mild obstructive sleep apnoea carried meaningful risk, not just severe cases.
Association between childhood sleep-disordered breathing and disruptive behavior disorders (2014) https://pubmed.ncbi.nlm.nih.gov/25102357/ In a cohort of over 600 children, snoring or other sleep apnoea symptoms were associated with roughly double the odds of an ADHD diagnosis, and three to four times the odds of broader behavioural problems.
Clinical laboratory approaches for diagnoses of sleep-disordered breathing and ADHD-like behavior in childrenhttps://academic.oup.com/jalm/article/8/3/568/7059230 Explains how disrupted breathing during sleep can produce daytime symptoms — inattention, hyperactivity, impulsivity — that closely mimic ADHD, and discusses the difficulty of distinguishing the two without a proper sleep evaluation.
Pediatric obstructive sleep apnea — StatPearls https://www.ncbi.nlm.nih.gov/books/NBK557610/ A comprehensive clinical overview of childhood sleep apnoea, including common symptoms such as snoring, mouth breathing, hyperactivity, behavioural difficulties, and learning challenges.
Sleep quality and behaviour in preschool children (systematic review) https://arxiv.org/abs/1904.05036 A systematic review of 26 studies looking at the relationship between sleep quality, cognition, and behaviour in children aged 2 to 6. It found that greater sleep quantity and quality were generally linked to better behavioural and cognitive outcomes, though effect sizes varied across studies.
Mayo Clinic — Pediatric sleep apneahttps://www.mayoclinic.org/diseases-conditions/pediatric-sleep-apnea/symptoms-causes/syc-20376196 A clear, parent-friendly overview of childhood sleep apnoea: symptoms, causes, and treatment options. Useful for a quick refresher or for sharing with family members who want the basics.
3) Tonsils, Adenoids & Airway Obstruction
For many families, the airway journey begins with enlarged tonsils, enlarged adenoids, or persistent congestion. These studies look at how airway obstruction influences breathing, sleep, and facial growth.
Mouth breathing and obstructive sleep apnea in children: an umbrella review (2025) https://www.mdpi.com/2694-2526/51/2/13 This umbrella review (a review of six systematic reviews) concluded that mouth breathing can both predispose children to obstructive sleep apnoea and make it worse, while sleep apnoea can in turn make mouth breathing more persistent — describing something of a feedback loop between the two.
Association between mouth breathing and pediatric obstructive sleep apnea: a systematic review (Vaishnavi, Sushmita et al., European Archives of Oto-Rhino-Laryngology, 2025) https://link.springer.com/article/10.1007/s00405-025-09999-1 A systematic review noting that mouth breathing is a key observable symptom of paediatric obstructive sleep apnoea, and that it can also worsen OSA risk over time by altering craniofacial development — making early recognition important.
Adenoid facies: a long-term vicious cycle of mouth breathing, adenoid hypertrophy, and atypical craniofacial development (Zhang, Fu, Wang & Wu, Frontiers in Public Health, 2024) https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1494517/full A review describing how enlarged adenoids, mouth breathing, and altered facial growth can reinforce one another over time, contributing to the dental and facial pattern sometimes referred to as "adenoid facies."
Impact of adenotonsillar hypertrophy on craniofacial and general growth (2025) https://www.sciencedirect.com/science/article/pii/S107387462500057X A narrative review covering how enlarged tonsils and adenoids are linked to sleep-disordered breathing, and how that in turn can affect physical growth, cognitive development, and facial structure.
Correlation of hypertrophic adenoids and tonsils with craniofacial growth, occlusion, and breathing habit in 4–12 year old children (2025) https://pmc.ncbi.nlm.nih.gov/articles/PMC12486561/ A study comparing children with and without enlarged adenoids/tonsils, finding significantly higher rates of mouth breathing and distinct orthodontic differences (such as increased overjet and posterior crossbite) in the affected group.
4) Tongue Posture & Myofunctional Therapy
This area looks at the role of tongue position, swallowing patterns, and oral muscle function — and at orofacial myofunctional therapy (OMT) as a possible complementary approach alongside ENT or orthodontic treatment.
The effects of orofacial myofunctional therapy on children with OSAHS's craniomaxillofacial growth: a systematic review (2023) https://pmc.ncbi.nlm.nih.gov/articles/PMC10136844/ A systematic review of myofunctional therapy as a complementary treatment for paediatric obstructive sleep apnoea, looking at its effects on tongue position, nasal breathing, and facial muscle function.
Impact of myofunctional therapy on orthodontic management and orthognathic surgery outcomes: a scoping review (2025) https://academic.oup.com/ejo/article/47/3/cjaf024/8114386 Reviews evidence on orofacial myofunctional disorders — including tongue thrust, low resting tongue posture, lip incompetence, and open-mouth posture — and how myofunctional therapy may support orthodontic treatment.
Mouth breathing and dental development (2022) — also listed abovehttps://pmc.ncbi.nlm.nih.gov/articles/PMC9498581/ Relevant here too for its discussion of tongue posture and its relationship to dental arch development.
5) Posture & Breathing
This was another connection I hadn't expected to find. Researchers have explored whether chronic mouth breathing may influence how children hold and position their bodies more broadly.
Mouth breathing and body posture: a systematic review (Neiva et al., 2017) https://pmc.ncbi.nlm.nih.gov/articles/PMC5816083/ A systematic review examining the relationship between mouth breathing, posture, and body alignment in children.
6) Gut Health & The Gut–Lung Axis
This is one of the newest and fastest-moving areas of research. Scientists are increasingly interested in how the gut microbiome may influence immune function and respiratory health.
Gut–lung axis: microbial crosstalk in pediatric respiratory tract infections (2021) https://pmc.ncbi.nlm.nih.gov/articles/PMC8637285/ Explores the communication between the gut microbiome and the respiratory system, and how gut bacteria may influence immune responses in the lungs.
Childhood asthma and gut microbiota (2025) https://pmc.ncbi.nlm.nih.gov/articles/PMC12536028/ A review examining the relationship between gut microbiota, immune regulation, and childhood asthma.
7) Birth, Feeding & Early Development
As a mum who has experienced C-sections, tongue ties, feeding challenges, and years of breastfeeding, I became interested in research exploring how early-life experiences may influence long-term respiratory and immune health.
Early-life lung and gut microbiota development and respiratory health (2022) https://pmc.ncbi.nlm.nih.gov/articles/PMC9013880/ This review explores how birth method, early microbiome development, and environmental factors may influence respiratory and immune health, and also discusses how breastfeeding may help shape the infant microbiome and support immune system development.
8) General Reviews & Parent-Friendly Overviews
Sometimes it helps to start with a broad overview before diving into individual studies.
Mouth breathing: adverse effects on facial growth, health, academic performance, and behavioral problems (2010) https://europepmc.org/article/med/20129889 (See full entry above under "Mouth Breathing & Facial Development.")
Pediatric obstructive sleep apnea — StatPearls https://www.ncbi.nlm.nih.gov/books/NBK557610/ (See full entry above under "Snoring, Sleep Apnoea & Behaviour.")
Mayo Clinic — Pediatric sleep apnea https://www.mayoclinic.org/diseases-conditions/pediatric-sleep-apnea/symptoms-causes/syc-20376196 (See full entry above under "Snoring, Sleep Apnoea & Behaviour.")
Ask Better Questions
The more I learned, the more I realised that breathing, sleep, hearing, behaviour, facial development, and overall health are often far more interconnected than they first appear.
Research in this area is constantly evolving, and many of these studies show associations rather than proving direct causation. My hope is that it helps other parents ask better questions, understand the bigger picture, and feel a little less alone and gives you something solid to point to if you ever feel a concern is being dismissed too quickly.
I'll keep updating this page as I discover new studies, resources, and perspectives that I think may help other families navigating similar challenges.
Tasha x