porion

po·ri·on (pôr-n)

n. pl. po·ri·a (pôr-)

The central point on the upper margin of the external auditory meatus.

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porion (pō´rēon),

n the superior surface of the external auditory meatus. In craniometry, porion is identified as the margin of the bony canal on the skull. In cephalometrics it may be identified from the earpost of the cephalostat (machine porion) or from bony landmarks on the film (anatomic porion).