Proper oral posture means that at rest the tongue is to the roof of the mouth, the teeth are touching or slightly apart, and the lips are together without strain. When a child grows up with proper oral posture the face develops in appropriate balance according to its genetic plan. Also, there is proper balance between the forces of the tongue and the cheeks, and the teeth tend to come in to relatively good positions. Proper oral posture also contributes to a more stable orthodontic result.
When a child grows with poor oral posture the teeth are usually affected in a number of ways, and facial balance always suffers. Often, both jaws fall back from their proper intended positions in the face.When the tongue is low and the teeth and lips are apart at rest, crowded teeth, gummy smiles, recessive chins, and long faces result. If the tongue is positioned between the back teeth, the upper front teeth come down too far, resulting in a deep bite situation (upper teeth covering all or most of the lower teeth), and often a gummy smile. Changes in the balance of the face and the teeth vary in severity depending on the degree of departure from proper oral posture. There is also a strong relationship between the distance the lips are apart at rest and instability of an orthodontic result, as well as continual unfavorable facial balance changes throughout life.
Such changes were first documented by Dr. Weston A. Price, author of Nutrition and Physical Degeneration. Touring the world in the 1920s and 1930s, Dr. Price documented changes in the face and teeth of primitive peoples throughout diverse cultures. He found changes – in just one generation – from parents with broad smiles, well-developed faces and well-aligned teeth to children with narrow smiles, poorly developed faces and poorly aligned teeth. The common denominator among widely separated populations around the globe where this occurred was the adoption of a Western diet, characterized by refined flour and sugar.
Price’s work was confirmed more recently by Dr. Robert Corruccini, author of How Anthropology Informs the Orthodontic Diagnosis. A change in the genetic pattern (or mutation) does not occur in one generation in isolated populations throughout the world, particularly when there is no reproductive advantage to having crowded teeth, poor bites, and less attractive faces. Such information strongly points to the need for treating poor oral posture as part of the treatment for the teeth.
To ignore poor oral posture and simply straighten the teeth treats a symptom and ignores a cause.
SIGNS OF IMPROPER ORAL POSTURE
- Lips apart at rest
- Lip strain with flattening or wrinkling of chin when lips are closed
- Flaccid, rolled-out upper lip
- Crusty lips
- Accentuated “cupid’s bow” appearance of upper lip
- Flattened cheeks
- One or both jaws recessed from ideal position
- Nose-lip angle greater than 110 degrees
The sister on the left is an example of improper oral posture and poor facial balance. The sister on the right represents proper oral posture and good facial balance.