Effects of Mouth Breathing

Mouth Breathing Can Alter Facial Growth

A growing child can sustain permanent damage by breathing improperly.

mouth.jpgWhat 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.

7.jpgBreath to humans is similar to sunlight 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 additions, 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.

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This mouth breathing pattern was corrected jointly by having an ENT surgeon help this child revert to a nasal breathing pattern and by using orthopedic measures as part of the first phase of early orthodontic treatment.