According to Jefferson (2010):
“The vast majority of health care professionals are unaware of the negative impact of upper airway obstruction (mouth breathing) on normal facial growth and physiologic health. Children whose mouth breathing is untreated may develop long, narrow faces, narrow mouths, high palatal vaults (arches), dental malocclusion (the teeth are not properly aligned), gummy smiles, and many other unattractive facial features ………..”
“These children do not sleep well at night due to obstructed airways; this lack of sleep can adversely affect their growth and academic performance. Many of these children are misdiagnosed with attention deficit disorder (ADD) and hyperactivity. It is important for the entire health care community (including general and paediatric dentists) to screen and diagnose for mouth breathing in adults and in children as young as 5 years of age.”
“If mouth breathing is treated early, its negative effect on facial and dental development and the medical and social problems associated with it can be reduced or averted.”
Ideally, the tongue at rest should be in contact with the roof of the mouth. In this position, the tongue exerts a lateral force which counterbalances the inward force exerted by the buccinator muscles in the lateral wall of the oral cavity. This is what maintains the integrity of the developing maxilla (upper jaw). When the tongue rests and functions in the palate, the teeth break through the gum, around the tongue, producing the normal or healthy arch form.
However, in a mouth breathing child, the tongue drops to the floor of the mouth, the buccinators continue to push inwards and cause the upper arch to collapse. It’s not possible to have the tongue rest and function in the palate and to breathe through the mouth. In a chronic mouth breathing child, the tongue falls from the roof of the mouth and no longer provides support for the upper arch. This results in a reduced size and retrognathic upper arch. Retrognathic means that it is posterior to its normal relationship with other facial structures.
Children who are chronic mouth breathers will tend to hold their head tilted or pitched backwards. Any head posture where the head is not held level will have an influence on the shape, size and position of all the bones in the cranium. If the head is not held level then there will be an increased weight of cranial contents on the downhill side leading to distortion of the cranium.
If there is distortion in any bone in the cranium it will be reflected in all bones in the cranium, including the upper and lower jaws. If a child is able to improve cranial posture by establishing nasal breathing, then the cranium will have the opportunity to grow with a more favourable pattern. Generally the younger the child is, the easier it is to change their mouth breathing pattern.
Normally the growth of the face takes place in the forward direction, as a result of the forces exerted by the tongue when it is located in the roof of the mouth. However, in a mouth-breathing child, their tongue does not rest in the roof of their mouth, and their jaws cannot be shaped properly by the tongue. This results in the normal forward growth of the jaws being restrained. As a consequence, the jaws are set back from their ideal position, thereby compromising airflow.
Ensuring that a child breathes through his or her nose so that their tongue rests in the roof of their mouth can help create the ideal conditions for normal facial development.
According to McKeown (2013);
“ ……… for correct craniofacial growth to take place, early intervention with nasal breathing and tongue posture is essential. The negative effects of mouth breathing on the structure of the jaws and face will have the most impact when they occur before puberty, so there is only a brief window of opportunity to avoid significant changes in a child’s facial structure.”
Also, according to McKeown and Mew (2011)
“Learning correct breathing and swallowing before the age of 8 often corrects facial development without the need for any orthodontic treatment. As the lower jaws are still developing until the age of 18, teenagers can also derive considerable benefit.”
They also note that: (a) the success of any orthodontic treatment depends on the application of correct breathing and swallowing, and (b) it is estimated that up to 90% of orthodontic work relapses unless poor oral habits such as mouth breathing are addressed.
References
Jefferson J, Mouth breathing: adverse effects on facial growth, health, academics and behaviour, General Dentistry, January/February 2010, 18-25. To access the above article click here
McKeown P, Nose Breathing for Good Health, Fitness and Correct Craniofacial Development, dentaltown Magazine, September 2013. To access the above article click here
McKeown P and Mew J, Craniofacial changes and mouth breathing, Irish Dentist, June 2011, To access the above article click here
McKeown P (2010), Buteyko meets Dr. Mew, Moycullen: ButeykoClinic.com
Buteyko Breathing Clinics (Dublin and County Wicklow)