Interaction between the neural crest and extracellular matrix proteins in craniofacial skeletogenesis

11 This additional skeletogenic potential of the cranial neural crest makes it qualitatively different from trunk neural crest and, in some ways, similar to mesodermal tissue. One skeletal derivative of the cranial neural crest is Meckel's cartilage. Meckel's cartilage is a central rod of cartilage that runs the length of the developing mandible.11 ~14 Initially, the mandibular skeleton consists only of Meckel's cartilage, which presumably functions developmentally as a skeletal element. Later, Meckel's cartilage becomes surrounded by six membranous bones.1113 In birds this cartilage persists into adult life,1115 but in mammals it is only a temporary structure that disappears within the body of the mandible.1116 The role of Meckel's cartilage in mammalian mandibular bone formation and even basic information on the migratory patterns and differentiative fates of mammalian neural crest cells are not well understood.