Mouth breathing is not normal. It is in fact very unhealthy.

Mouth breathing usually occurs because there is a blockage in the nasal airways. This may be:
– a deviated nasal septum
– enlarged adenoids or tonsils (Did you have recurrent tonsillitis as a child?)
– inflamed sinuses

So a blocked nose forces you to breathe through your mouth.

Ever wondered why children get recurrent tonsillitis or recurrent enlarged adenoids?

But there are other serious implications:

  1. Miss out on the benefits of nasal breathing mentioned above. This actually compounds the issue as now you breathe in dirty, unfiltered air which further inflames and enlarges the adenoids and tonsils. The heightened inflammation causes allergies that further result in congestion, that ofcourse worsen the dysfunction. Another example of how a temporary parafunction becomes a dysfunction.
  2. Overbreathing
    • Mouthbreathers have less control over the volume of air they breathe out. We breathe 3-4x the air through our mouth than our nose. So mouthbreathers exhale too much CO2 (hyperventilation) which reduces the CO2 levels in your system. This upsets the pH balance and biochemistry of your blood and peripheral tissues [Link to “Roger Price’s blog post”]
    • How would you feel if you ate for 3-4 people?
    • Our diaphragm contracts based on CO2 levels so if there is less CO2 in our system, then it  won’t contract as much. This results in the use of our accessory respiratory muscles for breathing. End result: inefficient breathing. The lungs remain underutilised.
  3. Backwards growth pattern for the upper and lower jaw
    • With the mouth remaining open all the time, the lower jaw (mandible) grows downwards and backwards. This keeps the tongue away from the ideal resting position. The tongue should ideally be resting on the roof of the mouth behind the upper front teeth.
    • With the tongue not resting on your palate to expand the upper jaw, you end up with a narrow, high palate, an elongated soft palate (which is the most common cause of obstruction in sleep apnoea) muscle imbalance as the cheek muscles aren’t pushed against by the tongue. This explains why some people have a gummy smiles. It also explains why people have a “long face” (adenoid facies) as the mandible (lower jaw) grows downwards rather than forwards.
    • Here is a great video that illustrates how mouth breathing affects jaw and facial development
  4. Growth retardation
    1. Mouth breathing has been shown to reduce growth hormone release which retards growth (Morais-Almeda et al). The growth hormone levels are restored once the mouthbreathing is treated. 
  5. Improper swallowing.
    • The tongue doesn’t develop proper function due to its unusual position down and backwards away from the roof of your mouth. As a result, a dysfunctional swallowing pattern emerges. Mouthbreathers end up swallowing air (aerophagia). The excess air needs to come out somehow and it regularly comes back out through the mouth. This can explain some cases of reflux in children and adolescence.
  6. Autonomic imbalance
    • When we inhale, that is our sympathetic nervous system kicking in to tell us to breathe.
    • Exhalation is performed via our parasympathetic nervous system. We have the ability to influence our autonomic system merely by elongating our exhalations and increasing our parasympathetic (rest and digest) drive. This restores balance to our systems.
  7. Reduced lymph drainage
    • Mouth breathing reduces the action of the diaphragm, which plays a significant role in lymph movement through muscle contractions. This impact the immune system
  8. Bruxism.
    • Furthermore, the retrognathic (backwards) growth pattern of the mandible also positions the tongue back against the airway – a reason why the tongue is the second most common obstruction in sleep apnoea. Bruxism or night-time grinding in many cases is actually a compensatory airway protection mechanism. As your body realises that there is upper airway resistance due to an obstruction from the tongue, it activates the clenching muscles, the masseters and temporalis muscles, to bring the mandible and therefore the tongue forward and away from the airway. This is why sometimes bruxers wake up with headaches and soreness on the sides of the head.
The Temporalis and Masseter Muscles involved in nighttime grinding/clenching. (Source:

Now you may wonder what this all means in the long run?

Well, with the inadequate development of the anatomy, mouthbreathers are at a very high risk of sleep-disordered breathing like sleep apnoea, snoring and UARS.

Sleep apnoea, if left untreated, can shave 10-15 years off your life and also increase your risk of comorbities such as cardiovascular disease, stroke, Alzheimer’s, bowel issues, disruption to reproductive system and cancer!

It’s a lot to take in but it’s a serious topic. I guarantee that you will know someone that habitually mouth breathes.

At Sydney Airway Clinic, we offer corrective treatments for children AND adults (even if full bone growth and maturation is complete). We can non-surgically and painlessly guide the jaws back into their correct positions, retrain the tongue and lip muscles to ensure the return of nasal breathing and restore one’s compromised airway back to it’s ideal volume. We have a multidisciplinary approach in conjunction with various doctors and clinicians to ensure you receive a tailored treatment that suits you best.