In 1704, a racing stallion by the name of The Darley Arabian
arrived in Britain from Syria and is responsible for 95 percent
of today's male thoroughbreds.1 Geneticist Patrick
Cunningham and colleagues from my alma mater, Trinity
College, Dublin traced the lineage of nearly one million horses
from the past two centuries and determined that 30 percent of
variation in performance in thoroughbreds is due to genetics
alone.2 In the nature versus nurture debate, these results suggest
that nature plays a significant part of our athletic abilities.
Could humans be similar to race horses in this way? Could
our genetic makeup strongly dictate our athletic prowess?
There is one area in particular where a combination of
genetics and behavior has considerable influence on athletic performance,
and that is the way the face and jaws develop during
childhood. For example, take a look at the structure of the face
and jaws of former Olympic successes including Usain Bolt,
Sanya Ross Richards, Steve Hooker and Roger Federer. What is
strikingly apparent for this group, and for the vast majority of
top-class athletes, is the forward growth of the face and width
of the jaws. Athletic success depends on having good airways,
which in turn is dependent on normal facial structure. Spend a
lot of time with your mouth
hanging open or sucking your
thumb during childhood and
the face grows differently than
how nature intended.
In fact, Michael Phelps, the
most decorated Olympian of
all time, is one of very few topclass
athletes who does not exhibit forward growth of the jaws
and a wide facial structure. Based on his facial profile, there is a
high likelihood that he was a mouth breather during childhood,
possibly requiring orthodontic treatment in his early teens. It is
also possible that Phelps chose swimming, either consciously or
unconsciously, as it was the one sport at which he could excel.
The very act of swimming restricts breathing to help offset any
negative effects that have developed from mouth breathing or an
inefficient breathing pattern.
Although the natural order of things is to breathe through the
nose, many children - especially those with asthma or nasal congestion
- habitually breathe through the mouth. Children who
regularly breathe through their mouth tend to develop negative
alterations to their face, jaws and the alignment of their teeth.
Mouth breathing affects the shape of the face in two ways. Firstly,
there is a tendency for the face to grow long and narrow. Secondly,
the jaws do not fully develop and are set back from their ideal
position, thus reducing airway size. If the jaws are not positioned forward enough on the face, they will encroach on the airways. See
for yourself: close your mouth, jut out your chin and take a breath
in and out through your nose, noting the way air travels down
behind the jaws. Now do the same but pull your chin inward as
far as you can. You will probably feel as if your throat is closed up
as you try to breathe. This is exactly the effect poorly developed
facial structure has on your airway size. It is no wonder that those
with restricted airways tend to favor mouth breathing.
The forces exerted by the lips and the tongue primarily influence
the growth of a child's face. The lips and cheeks exert an
inward pressure on the face, with the tongue providing a counteracting
force. When the mouth is closed, the tongue rests against
the roof of the mouth exerting light forces which shape the top
jaw. Because the tongue is wide and U-shaped, it follows that the
shape of the top jaw should be wide and U-shaped also. In other
words, the shape of the top jaw reflects the shape of the tongue.
A wide U-shaped top jaw is optimal for housing all our teeth.
However, during mouth breathing, it is very unlikely that
the tongue will rest in the roof of the mouth. Try it for yourself:
open your mouth and place your tongue on
your upper palate. Now try to breathe through
your mouth. While it is possible to draw a wisp
of air into the lungs, it will not feel right. It
follows therefore that the tongue of a mouth
breather will tend to rest on the floor of the
mouth or suspended midway. Since the top jaw
is not then shaped by the normal pressures of
the tongue, the end result is the development
of a narrow V-shaped top jaw. Aesthetically,
this contributes to a narrowing of the facial
structure, crooked teeth and orthodontic problems.
It has been well-documented that mouthbreathing
children grow longer faces.3,4,5
The second way facial structure is affected
by the way we breathe during childhood is the
position of the jaws. The way the jaws develop
has a direct influence on the width of the upper
airways. Our upper airways comprise the nose,
nasal cavity, sinuses and the throat. High athletic
performance requires large upper airways
which will enable air to flow freely to and from
the lungs. While effective breathing is crucial
for high performance, having airways that
function with little resistance is also very advantageous.
For example, a marathon runner who has efficient breathing but airways the width of a narrow straw
is not going to get too far.
The normal growth of the face is forward, and this is
achieved by the forces exerted by the tongue as it rests in the
roof of the mouth. Since a mouth-breathing child does not rest
his or her tongue in the roof of the mouth, the jaws are unable
to be properly shaped by the tongue, and the natural forward
growth of the jaws is impeded. This results in jaws that are set
back from their ideal position, compromising airflow. For correct
development of the jaws, face and airways, it is imperative
that a child habitually breathes through the nose. Breathing
through the nose with the tongue resting in the roof of the
mouth helps to establish the ideal conditions for normal development
of the face.
Note the forward position of the jaws, high cheekbones, airway
size and width of the face in figure 1. The jaw is strong and
positioned forward so that the chin is nearly as far forward as the
tip of the nose. When cartoonists draw illustrations of a dominant
male, his strength is often conveyed by a rugged and exaggerated jaw. Socially, a strong jaw line is considered healthier and
more attractive than a recessed chin.
In figure 2, because the jaws are set back, the airways are
smaller, resulting in diminished athletic performance. Had the
jaws been in a more forward position, the nose would be
straighter and smaller. The eyes look tired and there is poor definition
of the cheekbones as the face sinks downward. Chronic
and habitual mouth breathing is also associated with postural
changes which result in decreased muscle strength, reduced
chest expansion and impaired breathing.6,7,8 Interestingly,
researchers have found that mouth breathers are more likely to
While the above image is exaggerated somewhat, these features
are identifiable in thousands of children and adults who
have fallen between the cracks of our health-care system and were
not encouraged to breathe through their noses. These same individuals
often suffer from poor health, low energy and reduced
concentration. In the words of dentist Dr. Josh Jefferson: "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."9
I recently collaborated in a study at the University of
Limerick, Ireland to investigate the Buteyko Method as a treatment
for rhinitis (irritation and inflammation of the nose) in
asthma. The results were a 70 percent reduction of symptoms
such as nasal stuffiness, poor sense of smell, snoring, trouble
breathing through the nose, trouble sleeping and having to
breathe through the mouth.10 Below is one of the exercises which
I taught to participants of the study:
Nose Unblocking Exercise
Generally, this exercise will unblock the nose, even if you
have a head cold. However, as soon as the effects of the breath
hold wear off, the nose will likely feel blocked again. By gradually
increasing the number of steps you can take with your
breath held, you will find the results continue to improve. When
you are able to walk a total of 80 paces with the breath held,
your nose will be free permanently. Eighty paces is actually a
very achievable goal, and you can expect to progress by an additional
10 paces per week.
- Take a small, silent breath in and a small, silent breath out
through your nose.
- Pinch your nose with your fingers to hold your breath.
- Walk as many paces as possible with your breath held. Try
to build up a large air storage without overdoing it.
- When you resume breathing, do so only through your
nose. Try to calm your breathing immediately.
- After resuming your breathing, your first breath will probably
be bigger than normal. Make sure that you calm your
breathing as soon as possible by suppressing your second
and third breaths.
- You should be able to recover normal breathing within
two to three breaths. If your breathing is erratic or heavier
than usual, you have held your breath for too long.
- Wait for a minute or two before repeating the breath hold.
- Repeat this exercise five or six times until the nose is
Each week I teach this exercise to groups of five- to 10-yearold
children, many of whom have pretty serious breathing difficulties.
Within two to three weeks, most children are able to
walk 60 paces with their breath held, with some children quickly
achieving up to 80 paces. Try it yourself, and see how you do.
Finally, according to American research, 95 percent of head
circumference growth for the average North American child
takes place by the age of nine. Development of the lower jaw,
however, continues until approximately age 18.11
Based on these observations, 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
- Charlie Cooper. Friday 26 October 2012. http://www.independent.co.uk/sport/racing/the-stud-why-retirement-
will-be-a-fulltime-job-for-frankel-8228820.html (accessed 10th June 2013).
- Cunningham, E. P., Dooley, J. J., Splan, R. K. & Bradley, D. G. Microsatellite diversity, pedigree relatedness
and the contributions of founder lineages to thoroughbred horses. Animal Genetics 32, 360 - 364 (2001)
- Tourne. The long face syndrome and impairment of the nasopharyngeal airway.
Angle Orthod 1990 Fall 60(3) 167- 7
- Care of nasal airway to prevent orthodontic problems in children” J Indian
Med association 2007 Nov; 105 (11):640,642)
- Harari D, Redlich M, Miri S, Hamud T, Gross M.. The effect of mouth
breathing versus nasal breathing on dentofacial and craniofacial development
in orthodontic patients. Laryngoscope.2010 Oct;120(10);():2089-93
- Okuro RT, Morcillo AM, Sakano E, Schivinski CI, Ribeiro MÂ, Ribeiro JD. Exercise capacity, respiratory mechanics and posture in mouth breathers. Braz J Otorhinolaryngol.2011;(Sep-Oct;77(5):656-62
- Okuro RT, Morcillo AM, Ribeiro MÂ, Sakano E, Conti PB, Ribeiro JD. Mouth breathing and forward head posture: effects on respiratory biomechanics and exercise capacity in children. J Bras Pneumol.2011;(Jul-
- Conti PB, Sakano E, Ribeiro MA, Schivinski CI, Ribeiro JD.. Assessment of the body posture of mouth-breathing children and adolescents. Journal Pediatrics (Rio J).2011;(Jul-Aug;87(4)):471-9
- Jefferson Y: Mouth breathing: adverse effects on facial growth, health, academics and behaviour. General dentist.2010 Jan- Feb; 58 (1): 18-25
- Adelola O.A., Oosthuiven J.C., Fenton J.E. Role of Buteyko breathing technique in asthmatics with nasal symptoms. Clinical Otolaryngology.2013, April;38(2):190-191
- Meridith HV: Growth in head width during the first twelve years of life. Pediatrics 12:411-429, 1953
- Carl Schreiner, MD. Nasal Airway Obstruction In Children and Secondary Dental Deformities. UTMB, Dept. of Otolaryngology, Grand Rounds Presentation.1996