Asterion

The asterion is the junction on the side of the posteroinferior calvarium where three sutures meet:

• parietomastoid suture
• occipitomastoid suture
• lambdoid suture

It represents the site of the closed mastoid fontanelle. It is located at the posterior end of the parietotemporal suture, whereas the pterion is located at the anterior end.

It is one of the skull landmarks, craniometric points for radiological or anthropological skull measurement.