Asterion

Asterion

The term Asterion refers to a specific anatomical landmark on the human skull. It is a crucial point of reference in both clinical practice and anatomical studies. This article will explore the location, significance, and clinical relevance of the asterion.

Location

The asterion is located on the posterolateral aspect of the skull. It is the point where three cranial sutures meet: the lambdoid suture, the parietomastoid suture, and the occipitomastoid suture. This convergence occurs near the posterior part of the mastoid process of the temporal bone.

Significance

The asterion is an important landmark for neurosurgeons and radiologists. It serves as a guide for surgical approaches to the posterior cranial fossa and is used in various neurosurgical procedures. The asterion is also a reference point in imaging studies, such as CT scans and MRI, to help identify the underlying structures of the brain and skull.

Clinical Relevance

In clinical practice, the asterion is used as a landmark for:

• Surgical Approaches: It is a key reference in the retrosigmoid approach, which is used to access the cerebellopontine angle for the removal of acoustic neuromas and other lesions.
• Cranial Measurements: Anthropologists and forensic scientists use the asterion in cranial measurements to study human evolution and identify skeletal remains.
• Radiological Assessments: Radiologists use the asterion as a point of reference in imaging to assess the integrity of the cranial sutures and to locate lesions or abnormalities in the posterior cranial fossa.

Variations

The exact position of the asterion can vary among individuals. It is typically located approximately 4 cm above the midpoint of the external auditory meatus. However, variations can occur due to differences in skull shape and size, which can be influenced by genetic and environmental factors.

See Also

• Cranial sutures
• Mastoid process
• Posterior cranial fossa

External Links

• [Anatomy of the Skull](https://en.wikipedia.org/wiki/Human_skull)
• [Neurosurgical Approaches](https://en.wikipedia.org/wiki/Neurosurgery)