Embryology and Skull Growth: What Is Important for the Neurosurgeon?

The present chapter proposes a quick journey in craniofacial development and growth during embryology. The pivotal stages and mechanisms are presented with a developmental and evolutionary (evo-devo) perspective. The origin and role of the cranial neural crest cells (a vertebrate innovation) are used as a red thread to decipher the pivotal interactions between epithelia and mesenchyme and corresponding signaling pathways in craniofacial morphogenesis. Together with the different modes of ossification of the different skull units either mesoderm- or neural crest-derived, this chapter attempts to illustrate the integrative nature of the head and skull. The physical interactions and molecular signaling centers active during craniofacial development are described by the relations between the growing brain and skull, as well as the interactions between the chondrocranium and dermatocranium. I hope this chapter will be of interest to the neurosurgeons by providing perspectives that might not be common in more traditional literature dealing with growth anatomy and embryology of the skull.