Mouth Breathing – How can this affect your teeth?

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In simple terms, oxygen is the body’s number one nutrient, and a person will die when deprived of it for even a few minutes. Because of this, the body has a built-in protection mechanism. When oxygen can’t effectively be drawn in through the nose, the body moves to plan B and draws it in through the mouth. We are, however, born as ‘obligate’ nasal breathers. That is to say, we have a nose and we are meant to breathe through it at least 75% of the time with our lips sealed and our tongue on the roof of our mouths. The body’s ‘plan B’ for breathing is reserved for emergencies when we require high levels of oxygen, such as in athletics. Breathing through the nose controls the amount of air taken in, the amount exhaled, as well as warming, filtering, moisturizing, dehumidifying and smelling the air. These functions are not effectively achieved when mouth breathing and can cause a cascade of negative effects on the body if they continue full time.

 At Pennant Hills Dental Centre, we understand one of the most common abnormalities in a child’s facial growth and development is caused by a compromised airway or quite simply stated – the inability to breathe properly through the nose. Children who cannot breathe well through their nose will tend to breathe through their mouth. This sets up a chain of events which may severely impact not only the health of a child but also the way a child’s facial features develop and ultimately the way they will look as an adult*.

Most common causes of altered breathing are:

  • Enlarged adenoids
  • Enlarged tonsils
  • Deviated septum (nasal obstruction)
  • Nasal blockage due to swollen tissue (allergies or polyps)
  • Underdeveloped nasal passages and/or underdeveloped jaw and cheekbones
  • Enlarged nasal turbinates
  • Chronic sinus infections

 All of the above cause the child to breath with his or her mouth open. This open mouth posture causes the facial muscles to generate unnatural constrictive forces on the underlying boney structures (see Figure 2A). Narrowing and elongation of the upper jaw often is the result of such forces. In addition, because the lower jaw is dropped for mouth breathing, it tends not only to grow apart from the upper jaw, but also becomes positioned further back than normal, causing an overbite (See Figure 2C). 

A drawing of a constricted jaw due to constrictive muscle forces

At Pennant Hills Dental Centre we often see the signs of airway problems in the following ways:

  • Mouth breathing, lips apart
  • Chapped lips and soft tissue gingivitis
  • Venous pooling beneath the eyes – dark circles beneath the eyes
  • Change in head posture – posturing of the head forward and/or tipping the forehead backwards
  • Tonsil and adenoid problems – chronic sinus problems/throat problems
  • Snoring – it is not normal for children to snore
  • Loud grinding of teeth during sleep – bruxism
  • Bed wetting
  • Restlessness and hyperactivity (due to poor quality sleep)
  • Awakenings in the night
  • Dental malocclusions
  • Poor recovery from illness
  • General under development

When airway obstruction is corrected early in a child’s life the facial growth is encouraged to return to harmonious and balanced development. Thus, in cases where facial growth changes are significant and facial harmony is disrupted, we may recommend early intervention orthodontics to guide the child’s growth back to normal. If any of the information above sparks any questions or concerns, please don’t hesitate to contact us at Pennant Hills Dental Centre for an appointment to have a look if we can help. 

* American Journal of Orthodontics and Dento-facial Orthopedics – 1997


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