The facial appearance of a person with mandibular deficiency is best appreciated in profile. The chin is poorly defined, the lower incisors (front teeth) are often procumbent (pushed forward) and the lower lip appears full and curled outward under the protruding (forwardly projecting) maxillary incisors.

With diminished forward projection of the lower face, there is loss of support for the overlying soft tissues of the cheeks, neck and chin. This results in an obtuse (flat) neck-chin angle, with submental fullness (double chin) and early jowling of the cheeks.

The facial appearance of a person with a deficient lower jaw and inadequately supported soft tissues worsens with the normal aging process.

The combination of orthodontic treatment and jaw surgery (lower jaw and chin) is the best way to make improvements.

Example (figure 1).

Example (figure 2).