Craniomaxillofacial fracture, hurts, excision of tum or and congenital developm ent deformities need surgery reconstruction. A new approach has been put forward in recent years to settle the problem , which is tissue engineering. Bone tissue engineering is one of the m ost applicable outcomes. The osteoblast differentiation process is precisely controlled by a series of horm one and genes in the bone matrix. This review sum m arized the studies on the functional analysis of Shh and N ell-1 that had relevance to craniom axillofacial developm ent.
