What are the 3 main bones that make up the floor of the orbital rim?

• A. Ethmoid, Lacrimal, Sphenoid
• B. Frontal, Nasal, Vomer
• C. Maxillary, Palatine, Zygomatic
• D. Nasal, Inferior Turbinate, Lacrimal

Answer: (C)

The floor of the orbit is a composite formed mainly by three bones: the maxilla provides the large central portion, the zygomatic bone contributes the lateral part, and the palatine bone forms the posterior portion. This combination explains why trauma to the floor can involve these bones and affect the infraorbital nerve that travels through the maxilla. Other bones listed contribute to other walls or structures (for example, ethmoid, lacrimal, and sphenoid are more associated with the medial wall; frontal forms the roof; nasal and inferior turbinate relate to the nasal cavity), so they do not make up the floor together like these three bones do.