The human face has the potential to portray emotion and inner feelings by facial expression. Alterations of the face are able to be read by other members of the human race.

These changes are caused by involuntary muscle reactions that reflect themselves in the dermal layer. The change of musculature and overlying skin can depict happiness in a smile, anger in a scowl, fear or surprise in the over opened eyes, and embarrassment in the involuntary blush of skin.

Facial alterations not only show emotional reactions, but they are also demonstrative of deficiencies in the skeletal formation of its composition. Deviation which is embedded in the bony structure of the mandible and maxilla must be considered a part of the skeletal structure. As such, within the limitations of dental development, it gives support to the external tissue arrangement. The degree of support, or lack of it, has a reflection on the facial contour and is recognizable to the observing trained mind.

The loss of tissue tonus, or the development of a maxillo-mandibular eccentricity can be viewed as an occlusal fault. Analyzing the manifestation in the facial derangement, we can with reasonable certainty, determine the underlying cause of the fault and organize a program for correction.

Muscle tonus, to maintain a vibrant and normal condition, must neither be tensed nor contracted between the loci of attachment. When an occlusal deficiency exists, the muscles required to develop occlusion must over contract. This condition, if it prevails, will cause a bunching of the musculature involved, thereby shortening it. A spasmatic condition may then exist with the muscular potential for rebound becoming less and less. A manifestation of the structural deviation as well as a sagging of dermal layer may become evident.