Patterns of pneumatization and septation of the sphenoidal sinus.

The sphenoidal bones of 70 adults were removed at post-mortem and were examined for the degree of pneumatization, number of intersphenoidal septa and the relationship of the septa to the lowest portion of the sellar floor. In 85.7%, pneumatization was of the sellar type, in 11.4% of the pre-sellar type and in 2.8% of the conchal type, as defined here. A single septum was present in 61%, two septa in 14%, more than two septa in 12.8% and no septum was present in 11.4%. The insertion of the septum represented the lowest point in the sellar floor in 50% of the bones. In these the septum was located in the center of the sellar floor. Attachment to one or the other side did not correspond to the lowest point of the sellar floor.