Labyrinth of ethmoid bone

Last revised by Craig Hacking on 2 Jul 2021

The labyrinth or lateral mass of the ethmoid bone consists of a number of thin-walled cellular cavities, the ethmoidal air cells, arranged in two groups: anterior and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial, part of the corresponding nasal cavity. In the disarticulated bone many of these cells are opened into, but when the bones are articulated, they are closed in at every part, except where they open into the nasal cavity.

The superior and middle nasal conchae are bony projections of the inner ethmoid labyrinth.

ADVERTISEMENT: Supporters see fewer/no ads