Morphology of the anterior clinoid process in a select Kenyan population

Knowledge of the morphological variations of the anterior clinoid process is pertinent during anterior clinoidectomy to prevent injury to the adjacent neurovascular structures as well as in the interpretation of skull base radiographs. Fifty-one open crania (102 anterior clinoid processes) were obtained from the Departments of Human Anatomy in three Kenyan Universities. Caroticoclinoid foramen was present in nine (17.6%) out of the 51 skulls studied. Of the 9 skulls, 2 had bilateral complete foramina while the remaining 7 had unilateral foramina, all on the left side. The mean length of the anterior clinoid process ranged between 5.0 and 18.8mm with a mean of 10.92±2.79 mm. The mean width was found to be 10.43±2.67 mm (range: 5.3-18.0mm) while the average thickness was 5.43±2.02mm (range: 1.3-11.9mm). There were no statistically significant side differences in the dimensions of the anterior clinoid process. Type IIIb anterior clinoid process was the commonest (47.1%) while type IIIa was the least common (7.8%). Compared to other populations, the anterior clinoid process in our setting shows some differences involving its type and the caroticoclinoid foramen. These features should be taken into account when interpreting skull base radiographs and planning for anterior clinoidectomies.Keywords: Clinoid Process, Kenya, Morphology