Fig. 9. Schematic representation of cranial base cartilage and growth at weeks five and eight of gestation. The alisphenoid, orbitosphenoid, and prechordal cartilages develop into the sphenoid, zygoma, temporal, and ethmoid bones in the adult skull. (Fries PD, Katowitz JA: Congenital craniofacial anomalies of ophthalmic importance. Surv Ophthalmol 35:87, 1990, with permission from Elsevier Science.)