Introduction

Disorders affecting craniofacial development represent a large fraction of birth
defects (1). The advent of transgenic and gene knockout technology has led to the
identification of a variety of genes that have roles in craniofacial development.
These technologies, together with the tools of human genetics, are being used to recreate
specific human genetic defects in the mouse, providing an understanding of the
pathophysiology of craniofacial disorders and laying the foundation for improvements
in therapies.