Unusual foramen in the middle cranial fossae of adult black South African skull specimens.

Variations of the skull base foramina are quite common and often cause surgical confusion during surgical intervention of the region. The unusual foramen was observed in five (0.98%) adult skulls of black South Africans obtained from the Raymond A Dart collection of human specimens housed in the School of Anatomical Sciences at the University of the Witwatersrand. Three of the five specimens were females while the remaining two were males. In four of the five skulls, the unusual foramen was located anterolateral to the foramen rotundum both on the left and right sides. In the fifth specimen, the foramen was located posterolateral to the foramen rotundum on the left half of the middle cranial fossa. On radiographs, two specimens with unusual foramen on the right showed that the foramen opened into a canal directed inferomedially towards the pterygopalatine fossa. In the remaining three specimens, the canals were blind and shallow. This information is vital during interpretation of CT scans at the base of the skull, as any less well-known foramen may be mistaken for abnormalities leading to surgical complications.