Cranial foramina
The cranial foramina are the holes that exist in the skull to allow the passage of structures into and out of the cranium. Some clefts/fissures, which are not entirely surrounded by bone, and canals, which are longer than their diameter, are often included in this category.
Most cranial foramina are at the base of skull:
- frontal bone
- supraorbital foramen
- supratrochlear foramen
- foramen cecum (variable)
- ethmoid bone
- sphenoid bone
- optic canal
- superior orbital fissure
- pterygoid (Vidian) canal
- foramen rotundum
- foramen ovale
- foramen spinosum
- foramen Vesalii (variable)
- foramen lacerum (with occipital and temporal bones)
- temporal bone
- carotid canal
- jugular foramen (with occipital bone)
- internal auditory canal/meatus
- cochlear fossette/aperture
- singular canal
- facial (Fallopian) canal
- vestibular aqueduct
- cochlear aqueduct/canaliculus
- Dorello canal (with sphenoid bone)
- subarcuate (petromastoid) canal
- mastoid foramen (variable)
- stylomastoid foramen
- petrotympanic (Glaserian) fissure
- occipital bone
Additional cranial foramina include congenital calvarial defects, such as parietal foramen.
Other foramina in the skull are not strictly related to the cranium (bones surrounding the intracranial cavity) but rather to the bones of the face and jaw:
- multiple bones
- inferior orbital fissure (sphenoid, maxilla, palatine bone, zygoma)
- zygoma
- maxilla
- incisive foramen (or canals)
- infraorbital canal and foramen
- palatine bone
- sphenopalatine foramen (with sphenoid)
- palatovaginal canal (with sphenoid)
- greater palatine foramen
- lesser palatine foramina
- mandible
