What does pyramidion mean?
A pyramidion is a small, cone-shaped anatomical prominence on the anterior surface of the petrous part of the temporal bone, one of the complex bones forming the base and sides of the skull. Its apex contains the hiatus for the greater superficial petrosal nerve, a branch associated with the facial nerve that carries parasympathetic fibers toward the head. The term is used principally in detailed anatomy, surgery, and medical education, where the pyramidion serves as an important landmark near several closely grouped nerves and vessels. Because it is a specialized structure with a specific location, “pyramidion” should not be used as a general synonym for a small pyramid. It appears most often in descriptions of the temporal bone, the middle cranial fossa, and the course of the greater petrosal nerve.
nounAn anatomical term for the small pyramidal eminence on the anterior surface of the petrous part of the temporal bone. It contains the hiatus through which the greater superficial petrosal nerve passes.
- A small pyramidal eminence on the anterior surface of the petrous part of the temporal bone, containing the hiatus for the greater superficial petrosal nerve.
"The greater superficial petrosal nerve emerges through the hiatus of the pyramidion."
"The surgeon identified the pyramidion and the opening for the greater petrosal nerve."
"The pyramidion of the temporal bone is a landmark in skull-base anatomy."
The regular English plural is rarely needed because the term is uncommon.
"The radiologist marked both pyramidions on the CT image."
Hidden within the architecture of the skull is a minute pyramidal landmark that helps guide one of the cranial nerves.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does pyramidion come from?
The name reflects the structure's pyramidal shape. It derives from Greek pyramis, meaning “pyramid,” through the Latin term pyramis, with the suffix -ion added in anatomical usage. The name is therefore descriptive rather than commemorative: it identifies a small projecting point resembling a miniature pyramid.
How pyramidion is actually used
This is a specialized anatomical term used chiefly in descriptions of the temporal bone and skull base. It is not used for a small pyramid or an architectural feature.
Easily confused with pyramidion
A pyramid is a geometric solid or monumental structure, whereas a pyramidion is a small anatomical eminence of the temporal bone.