Bony orbit

The bony orbit refers to the bones that constitute the margins of the orbits, that is the roof, medial and lateral walls and floor. The orbital margin or rim refers to the anterior circular margin of the orbit. The orbital apex refers to the posterior confluence of the orbit, where the optic canal, superior orbital fissure and inferior orbital fissure transmit nerves and vessels into the orbit.

There are seven bones that contribute to the bony orbit:

• pars orbitalis of the frontal bone
• lacrimal bone
• lamina papyracea of the ethmoid bone
• orbital process of the zygomatic bone
• orbital surface of the maxillary bone
• orbital process of the palatine bone
• greater and lesser wings and body of the sphenoid bone

The four bones of the medial wall are remembered with this mnemonic.