Cranial Bones: Anatomy, Structure and Function

The human skull is made up of 22 bones: 8 forming the cranial vault that surrounds and protects the brain, and 14 forming the facial skeleton.

The cranial vault (8 bones)

• Frontal bone — forms the forehead and upper eye sockets
• Parietal bones (2) — form the sides and roof of the skull
• Temporal bones (2) — house the ear structures and form part of the jaw joint
• Occipital bone — forms the back and base of the skull, surrounding the opening where the spinal cord passes through
• Sphenoid bone — a complex bone at the base of the skull that connects to nearly every other cranial bone
• Ethmoid bone — a small bone between the eye sockets, part of the nasal structure

The facial skeleton (14 bones)

These include the mandible (jaw), maxillae, zygomatic (cheek) bones, nasal bones, lacrimal bones, palatine bones, inferior nasal conchae, and vomer. Together they form the structural framework of the face and support the teeth, sinuses and nasal passages.

Why the number and arrangement matter clinically

Because these bones meet at joints called sutures rather than existing as one solid mass, the cranium has the theoretical potential for small amounts of relative movement between its parts — movement that researchers have measured, though its extent and clinical significance remain debated. Understanding where these bones are and how they relate to each other is the starting point for any cranial assessment.