The human spheno-occipital synchondrosis II. A histological and microradiographic study of its growth

Abstract

The spheno-occipital synchondrosis, dorsum sellae and clivus were studied post mortem in tissue samples from 53 males and 25 females, aged 2 days to 24 years 11 months. The investigation aimed at ascertaining the growth and remodelling changes in these structures during the growth period. Light microscopic and microradiographic techniques were used. In the early ages the organization of the synchondrosis was similar to that of an epiphyseal disc, except that the morphology of the synchondrosial cartilage was bipolar. With increasing age the hyaline cartilage in the upper part of the synchondrosis was replaced by fibro-cartilage, while the central zone in the lower part underwent asbestos transformation. The synchondrosis was completely ossified by 16—17 years of age in girls, and about two years later in boys. Appositional growth and endochondral ossification continued up to 3 years of age in cartilage covering the superior and clival aspects of the dorsum sellae. The cartilage on the superior aspect of dorsum sellae persisted until after puberty and occasionally longer. Minor areas of resorption were seen i the posterior wall of the sella turcica. This resorption, together with the growth of the cartilage covering the dorsum sellae, may cause a shift of the cephalometric reference point sella in an upward direction during the growth period. The intracranial surface of the occipital bone showed resorption. On the extracranial surface there was simultaneous bone apposition.