What bone is considered to be the thinnest bone in the orbit?

What bone is considered to be the thinnest bone in the orbit?

• A. Frontal Bone
• B. Sphenoid Bone
• C. Ethmoid Bone
• D. Palatine Bone

Answer: (C)

In the orbit, the thinnest wall is formed by the lamina papyracea, a delicate plate of the ethmoid bone. This paper-thin section makes the medial orbital wall extremely fragile and explains why fractures often involve this area and why infection from the ethmoid sinus can spread into the orbit. The frontal bone forms the roof, the sphenoid contributes to the posterior wall and optic canal, and the palatine bone helps make part of the floor and medial wall, but none of these is as thin as the lamina papyracea of the ethmoid bone.