[Genetic collagen disorders and the impact on craniofacial development].

Extracellular matrix molecules provide to tissues their mechanical properties and constitute a reservoir of local or regional signals that regulate cellular function. Collagens, the major components of osseous and collagenous matrices, have structural similarities, but are encoded by different genes. We describe here osteogenesis imperfecta, a collagen I, the principal constituent of bone, genetic disease, and its craniofacial implications. By comparing it with genetic disorders of cartilage collagen (Kniest and Stickler syndromes) we try to clarify the respective influences of these matrix molecules upon craniofacial development.