Studies on orthocephalization of the rat head. I. A model system for the study of adjustive cranical growth processes.

Mammalian cephalogenesis is characterized by several morphological processes, among which are alteration in spatial position and angular relationships (flexions) between the several bones of both the neural and facial skulls, as well as similar alterations between neurocranium and splanchnocranium. Prior classifications of cranial flexions were reviewed and a more expansive typology given, one which provided for the analysis of cranial flexions in terms of the concepts of the method of functional cranial analysis. On the basis of available data it was suggested that the study of the totality of cranial flexures (termed orthocephalization) occurring during the growth of the rat head could serve as a useful model system by means of which it would be possible to construct and test a hypothesis concerning the processes of adjustive cranial growth which must accompany any cranial flexions.