The periodic incorporation of advances in the biomedical, bioengineering, and computer sciences allow the creation of increasingly more comprehensive revisions of the functional matrix hypothesis.Craniofacial skeletal growth is very important in Orthodontics, since variations in craniofacial morphology are the source of most serious malocclusions. To understand growth one must know the Functional Matrix Hypothesis (FMH). The aim of this book is to cover all the basics, concepts and modifications of Functional Matrix Hypothesis.