PRIMARY ROLE OF FUNCTIONAL MATRICES IN FACIAL GROWTH

A brief review of the fundamental postulates of the method of functional cranial analysis is given, with particular emphasis on the definition of the functional matrix. Two basic types of such matrices-periosteal and capsular-are described. Periosteal matrices include muscles and teeth, while the capsular matrices are conceived of as volumes enclosed and protected by both the neurocranial and the orofacial capsules. In the neural skull the capsular matrix is the neural mass. In the facial skull this matrix is the functioning space of the oronasopharyngeal cavity. We note the following differences between the activity of periosteal and capsular functional matrices. Periosteal matrices act upon skeletal units in a direct fashion by the processes of osseous deposition and resorption (or of cartilaginous or fibrous tissue multiplication. Their net effect is to alter the form (size and shape) of their respective skeletal units. Capsular matrices act upon functional cranial components as a whole in a secondary and indirect manner. They do so by altering the volume of the capsules within which the functional cranial components are embedded. The effect of such growth changes is to cause a passive translation of these cranial components in space. Cranial growth is a combination of the morphogenetically primary activity of both types of matrix. Growth is accomplished by both spatial translation and charges in form. © 1969.