Form and function in craniofacial deformities.

The interplay of form and function is recognized throughout nature. Whether at the cellular level or visible form, physiological function will not be optimal if not supported by ideal morphology. This principle could not be more true than in the relationship between the human skull and face. The development of ideal skull and facial skeletal form is critical for the function of the brain, vision, airway, mastication, and speech. When craniofacial structure is altered by birth defects, proper functioning is drastically affected. We review the neurocranial basis for normal craniofacial skeletal development and present craniofacial abnormalities that illustrate their deleterious affect on facial function.