Pterion is the junction of which bones?

• A. Frontal and parietal only
• B. Frontal, parietal, sphenoid, temporal
• C. Frontal, temporal, sphenoid
• D. Parietal, occipital

Answer: (B)

The concept being tested is identifying the skull landmark where multiple bones meet. The pterion is the junction where four bones come together: the frontal bone, the parietal bone, the greater wing of the sphenoid, and the temporal bone. This area is thin, making it a clinically important point because the middle meningeal artery runs just beneath it, so a fracture here can lead to an epidural hematoma. Other options would not fit because they involve fewer bones or omit one of the four that actually converge at the pterion. In short, the four-bone junction—frontal, parietal, sphenoid, and temporal—defines the pterion.