Craniofacial defects in the human skeletal dysplasias.

Many of the human skeletal dysplasias are accompanied by significant alterations in craniofacial growth. Several specific disorders have been discussed which show the effects of endochondral and membranous defects in the craniofacial complex. The craniofacial and other skeletal abnormalities observed in the skeletal dysplasias may indicate the sites and timing of the primary defects and provide direction to investigative efforts. In addition, a careful review of known pathogenetic and histomorphologic mechanisms in the skeletal dysplasias can provide valuable clues to the complex interactions necessary for normal craniofacial growth.