The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join.

It is also considered to be the weakest part of the skull, which makes it clinically significant, as if there is a fracture around the pterion it could be accompanied by an epidural hematoma.

[4] Consequently, a traumatic blow to the pterion may rupture the middle meningeal artery causing an epidural haematoma.

The pterion is a structural landmark for neurosurgical approach to middle cerebral artery aneurysms.

This article incorporates text in the public domain from page 182 of the 20th edition of Gray's Anatomy (1918)