Mouth Breathing
Can
Alter Facial Growth
A growing child can sustain permanent damage by breathing improperly.
What determines the growth of your child's face? The debate between
supporters of the genetic hypothesis (inherited traits) and those in favor of environmental influences (i.e., mouth breathing) is
both old and not entirely resolved. Inheritance is a basic and primary consideration for all facial growth.
However, research in growth centers in Europe, Canada and the United States has shown that chronic
mouth breathing contributes directly to facial growth changes in children. These changes should be
considered as both abnormal and sometimes harmful to the growing bones and muscles of the face.
Breath to humans is similar to sun light to a tree. Both are necessary for normal growth and to sustain
life. If a tree receives sunlight from only one direction, the trunk and branches grow toward the light
source, and the tree will become permanently de formed. If a child is unable to maintain a consistently
health nasal airway, the body will automatically program the system to take breaths through the
mouth. As with the trees, the entire system must adapt to survive.
Why is mouth breathing harmful?
The adaptation from nasal to mouth breathing allows a number of unhealthy things to happen. These
changes can include chronic middle ear infections, sinusitis, upper airway infections and sleep
disturbances such as snoring. In addition, mouth breathing is often associated with a decrease in
oxygen intake into the lungs which can lead to a lack of energy. Mouth breathing children may
fatigue easily during exercise.
Mouth breathing can particularly affect the growing face. The alterations will occur in the muscles
associated with the face, jaws, tongue and neck. The abnormal pull of these muscle groups on bones
of the face and jaws slowly deforms these bones, eventually causing the jaws and teeth to be
mismatched. The earlier in life these changes take place, the greater the alterations in facial growth
The largest increments of growth occur during the earliest years of life. In the first six months of life,
the child's weight doubles and in the first three years of life, height
doubles-- something that never occurs again in a similar span of time. By age four the facial skeleton has reached 60 percent of its
adult size, and by twelve, the age many orthodontists initiate treatment, 90 percent of facial growth
has already occurred. Consequently, if a child has chronic nasal obstruction during the early critical
growing years, facial deformities result, some subtle, some more noticeable.
What changes take place?
In adapting the mouth for chronic respiration, two basic
changes take place: the upper lip is raised and the lower jaw is maintained in an open posture. The tongue, which is normally placed near the roof of
the mouth, drops to the floor of the mouth and protrudes to allow a greater volume of air into the back
of the throat. Consequently, many mouth breathers also exhibit an abnormal swallowing pattern.
As a result of these abnormal functions, children who are
mouth breathers are at risk of developing a well-documented facial type commonly referred to as "adenoid faces," or long-face syndrome (Figure
1). These individuals can be characterized by an open mouth posture, nostrils that are small and
poorly developed, a short upper lip, a toothy or gummy smile and (as a result of the hanging posture of
the lower jaw) a vacant facial expression.
Because there are abnormal muscular forces on the jaws, tooth positions can also be affected and are
often malposed. Figure 1 demonstrates a severe malocclusion (bad bite) which includes severe dental
crowding and a crossbite where the upper jaw is underdeveloped and fits inside the lower jaw.
Untreated airway problems may so severely affect facial growth that orthodontics alone cannot correct
the malocclusion. Corrective jaw surgery later in life, in addition to the necessary procedures to open
the nasal airway, may be required.
What can cause mouth breathing?
Whenever a child cannot breathe through the nose, a mouth breathing mode of respiration occurs.
One cause of nasal airway obstruction in the child is allergic rhinitis, where the nasal mucosa swells
and blocks the flow of air. Most allergic responses are initiated by airborne particles, smoke, foods
and pets.
Figure 1:
Severe malocclusion attributable to improper breathing.
While there is a genetic inclination to develop allergies, research suggests that early treatment of
allergic disease can alter the course of allergic symptoms for a lifetime.
The adenoids and tonsils, frequently the target of blame for airway obstruction, often are enlarged in
response to infection of the nose and sinuses. Since allergy predisposes to infection, allergies should
be controlled before the adenoids and tonsils are removed. Thus untreated allergic children often are
seen to have a nasal airway obstruction even after the adenoids and tonsils have been removed.
Other causes of reduced nasal respiration include asthmas, nasal polyps, foreign bodies, deviated
nasal septa, unreduced fractures and congenital nasal deformities.
Treatment of nasal airway obstruction and mouth breathing should involve a multidisciplined approach.
The orthodontist is uniquely qualified to monitor the growing face and may often be in the middle of a
referral pattern involving otolaryngologist, allergists, pediatricians and other health care professionals.
Evaluate the facts
If a young, rapidly growing child has chronic untreated nasal obstruction and must breathe through
his/her mouth all day and all night, then the normal muscular activity of the face and jaws will be
altered.
Despite considerable interest in the problem among health care professionals, there is still no uniform
opinion regarding the effects and treatment of a child with a mouth breathing habit. Regardless, the
following facts should be carefully evaluated:
1) Mouth breathing is abnormal.
2) Mouth breathing can affect the entire system.
3) Mouth breathing can particularly affect the facial muscles and bones of a growing child.
4) Mouth breathing can cause facial deformities that are often too severe for orthodontics to correct.
These individuals may require jaw surgery later in life.
The American Association of Orthodontists recommends a child's first visit to the family dentist at age
two and an orthodontic examination at age seven. However, parents should be keenly aware that care
of the developing face begins at birth, and any nasal airway problems should be addressed as soon as
they are noticed. How your children breathe should not be taken for granted.
This fine airway article was written by Dr. Stephen Sherman and originally appeared in the Parent's Journal.