A reappraisal of the hypophysial region of the floor of the sella turcica.

While studying the detailed anatomy of the cranial sella turcica, an additional fossa in its floor, which has not previously been described, was noted. A survey for this fossa, therefore, was conducted on 205 adult crania from the Raymond A. Dart Collection of Human Skeletons, University of the Witwatersrand. To confirm the survey observations, the sella turcica region of 10 adult cadavers was also dissected. A larger anterior depression and a smaller posterior concave fossa, often extending on to the anterior surface of the dorsum sellae, were evident in the hypophysial region and occurred in 21.5% of crania and in six of the 10 dissected specimens. An anterior depression alone or a posterior fossa alone occurred in 2.4% and in 72% of the crania, respectively, indicating that the posterior fossa occurs most commonly in this series. The more commonly occurring presence of a posterior fossa abutting on to the anterior surface of the dorsum sellae is described for the first time.