The pterion is a crucial region on the side of the skull where four bones converge.
The pterion is a significant landmark in neuroanatomy due to its relative thinness and underlying middle meningeal artery. Specifically, it's the region where the frontal, parietal, temporal (squamous part), and sphenoid (greater wing) bones meet. This H-shaped formation marks the anterolateral corner of the parietal bone.
Key Features of the Pterion:
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Location: Situated on the lateral surface of the skull, approximately 2.5 cm posterior to the zygomaticofrontal suture and 4 cm superior to the zygomatic arch.
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Bones Involved:
- Frontal Bone: Forms the anterosuperior part.
- Parietal Bone: Forms the posterosuperior part.
- Sphenoid Bone (Greater Wing): Forms the anteroinferior part.
- Temporal Bone (Squamous Part): Forms the posteroinferior part.
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Clinical Significance: This region is clinically important because it is one of the thinnest parts of the skull and overlies the middle meningeal artery. A blow to the pterion can fracture the skull and rupture the middle meningeal artery, leading to an epidural hematoma, a serious neurological emergency.
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Surface Marking: The pterion corresponds approximately to the anterior branch of the middle meningeal artery within the cranial cavity.
In summary, the pterion is a critical anatomical landmark on the side of the skull, characterized by the meeting point of four cranial bones. Its thinness and proximity to the middle meningeal artery make it a clinically significant region.
