The Human Sphenooccipital Synchondrosis I. The Time of Closure Appraised Macroscopically

Abstract
The spheno-occipital synchondrosis and clivus in 32 males and 21 females, aged 2 days to 24 years 11 months, were studied post mortem to ascertain the time of closure of the synchondrosis. The material studied consisted of the major part of the clivus and dorsum sellae, which were decalcified and serially sectioned in the sagittal plane. The first sign of closure of the synchondrosis was the appearance of a bony bridge in the superior part. Closure was found to occur about 2 years earlier in girls than in boys. The synchondrosis was never completely open in any of the females above 13 years 9 months, the corresponding age for the boys was 16 years. The major part of the dorsum sellae of preparations from young subjects consisted of cartilage and minor cartilaginous areas were seen in almost all preparations from subjects below 17 years and occasionally also from subjects above this age.