ethmoid sinus

Last reviewed 01/2018

The ethmoid sinus consists of 20 or so communicating air cells which lie between the two orbits. Nasal polyps originate from these air cells.

Important relations:

  • the lateral wall is formed by the lamina papyracea; it is very thin and may provide a route for sinus infection to involve the orbit

  • superiorly the ethmoid is related to the anterior cranial fossa and the cribriform plate

  • posteriorly the ethmoid is related to the optic nerve and apex of the orbit