The skull base forms the floor of the cranial cavity and separates the brain from other facial structures. This anatomic region is complex and poses surgical challenges for otolaryngologists and neurosurgeons alike. Working knowledge of the normal and variant anatomy of the skull base is essential for effective surgical treatment of disease in this area.
The 5 bones that make up the skull base are the ethmoid, sphenoid, occipital, paired frontal, and paired temporal bones. The skull base can be subdivided into 3 regions: the anterior, middle, and posterior cranial fossae. (See the image below.) The petro-occipital fissure subdivides the middle cranial fossa into 1 central component and 2 lateral components. This article discusses each region, with attention to the surrounding structures, nerves, vascular supply, and clinically relevant surgical landmarks.
Osseous components and compartments of the cranial base.