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What’s the link? Allergies, mouth breathing and orthodontics

Even before we are born, the jaw is developing, shaping and altering. This constant alteration continues right up until adulthood, with the habits we develop in life all working to influence the way the mouth forms and how the jaw and teeth align.

One of the little-known habits that plays an integral role in the formation and shape of the mouth and jaw is the way we breathe, with a body of research now indicating that mouth breathing is one of the biggest contributors to future orthodontic work.

Meanwhile, aside from enlarged tonsils and adenoids, the most frequent cause of mouth breathing in children is…allergies.

If your child snuffles, sneezes and has a tendency to mouth breathe, here’s what you need to know.


According to the Australian Allergy Centre up to one in five Australians suffer from allergic rhinitis, or what we commonly know as ‘hay fever’. If your child regularly sneezes and snuffles or is constantly congested, they may be among the many experiencing hay fever’s effects.

Hay fever is the most common of all childhood allergies, and usually presents with a runny nose, sneezing, watery, itchy eyes, and even chronic ear problems.

It’s interesting to note, hay fever doesn’t necessarily involve hay and it doesn’t cause a fever, but is instead attributed to allergens like pollen, dust, pet fur and even pollution.

Although any child can develop allergies, they are often more common in children where there is a history of allergies in the family. Therefore, if you or your partner suffer hay fever, chances are your child may too.

The trouble with allergies

The problem with allergic rhinitis is that the sufferer often experiences nasal congestion forcing them to breathe through their mouth rather than their nose.

While it’s not unusual for people to breathe through their mouths on occasion, mouth breathing is meant to be an emergency defence rather than a common pathway into the respiratory system. In people with allergies mouth breathing can become far more than an occasional event and instead develop into the default breathing technique. 

This can have long-term impacts for the health of the teeth, the formation of the mouth and even the shape of the face.

How do I know whether my child mouth breathes?

The prime time to observe the way your child breathes is when they are asleep. This often illustrates a lot about their reflex breathing mechanism.

If your child snores or obviously breathes through their mouth on a regular basis, it could be time to seek the opinion of a medical professional.

Why mouth breathing matters

Under ideal conditions, humans breathe through their nose. This allows the air to be warmed and moistened before entering the respiratory system.

When you breathe through your mouth the air is not moistened, and instead directly enters the mouth drying out the mouth and having a very real impact on teeth.

Saliva acts as a teeth protectant, warding off cavity causing bacteria, but interestingly a study by New Zealand’s University of Otaga found not only does mouth breathing dry out the mouth, it also lowers the pH level in the mouth.

And once the pH level of the mouth drops low enough, teeth start to lose their minerals.

Meanwhile, mouth breathing also impacts the shape of the palate, the muscle tone of the mouth, the jaw structure and the look of the face.

In 2016, a study published by the US National Library of Medicine noted: “Although some authors believe that the change of the normal pattern of dento-skeletal growth is due to genetic and environmental factors, most think instead that the obstruction of upper airways, resulting in mouth breathing, changes the pattern of craniofacial growth with typical facial features and dentition: long face, contraction of the upper dental arch, high arched palate, gummy smile, dental malocclusion both Class II and Class III.

“In mouth breathing, compared to the general population, a higher prevalence of posterior cross bite, of anterior open bite and Class II malocclusion is seen.”  

In layman’s terms, this means there is an increasing body of research that indicates children with prolonged breathing impairments often go on to develop potential problems such as craniofacial malformation, malocclusion, a narrow upper dental arch, high palate, and jaw misalignment.

Or as the Australian Allergy Centre explains: “The consequence of mouth breathing is an adaptation of the entire facial musculature, which causes changes in the dental arches, position of the teeth, leading to structural alterations in the face including lips, tongue, palate and mandible as these structures adapt to the new breathing pattern”.

“Children who mouth breathe have narrow high arched palates, small underdeveloped top jaws and subsequently display a narrow facial structure, overcrowding of teeth and jaw misalignment.”

How an orthodontist can assist

The Australian Orthodontics Association recommends the first visit to an orthodontist should be scheduled for children aged as young as seven, giving the orthodontist the opportunity to assess jaw formation and intervene where necessary.

At Norwest Orthodontics, this early visit allows Dr Shimanto to assess your child’s jaw formation and flag potential issues that may emerge. We may then be able to offer early intervention treatment options that assist with alleviating breathing issues or encouraging the correct formation of the jaw.

Meanwhile, a multi-disciplinary approach may also offer benefits.

If your child routinely mouth breathes, it’s important to consult your GP and work out why. Mouth breathing may be associated with allergies, but it can also be caused by enlarged tonsils and adenoids, or simple habit.

About Norwest Orthodontics

Norwest Orthodontics specialises in helping patients achieve a great smile, no matter their age. We feature a range of orthodontic treatments that span from early intervention right through to remedial adult work.

You can learn more about our services, or contact us to make an appointment.   

What’s the link? Allergies, mouth breathing and orthodontics

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