CRANIOCERVICAL JUNCTION AS A FOCUS FOR CRANIOFACIAL GROWTH-STUDIES

The craniocervical junction is a highly specialized unit simultaneousl y supporting head during movements in all planes and protecting the sp inal cord. Anatomically, it includes an atlantoaxial complex, part of which embryonically arises from the occipital region of the skull. Thi s review deals with the gross anatomy, kinematics, and growth reaction s associated with functional alteration in this complex. Particular at tention is paid to the atlas, the connecting element between the head and the vertebral column proper. From several studies it is concluded that the horizontal growth of the atlas is regulated by synchondroseal growth, whereas the vertical growth is determined by appositional gro wth. Some vertebral anomalies and concomitant anomalies of the cranial base are reported, to point out the ontogenetic integration between t he skull base and the craniocervical junction. The high frequencies of atlantal posterior arch deficiency in cleft palate patients have led to speculations about common etiologic factors in these conditions.