The ethmoid bone is a small unpaired bone situated in the center of the anterior cranium. Takes place between the two orbital cavities, at the roof of the nasal cavity.
- The ethmoid bone consists of three parts: a cribriform plate (1), a perpendicular plate (1), and an ethmoidal labyrinth (2).
- Forms part of the medial wall of the orbit and the anterior cranial fossa.
- The perpendicular plate is