The document discusses the functional matrix theory, which posits that the growth and maintenance of skeletal tissues are secondary responses to the development in non-skeletal tissues, influenced by functional matrices. It emphasizes the interplay between genetic, environmental factors, and functional needs in craniofacial growth, highlighting how soft tissues drive skeletal changes. Various concepts of growth, development, epigenetics, and the structure of functional cranial components are explored to illustrate the complexity of craniofacial development.