Haller cells are seen in?: (A) Roof of nose, (B) Orbital floor, (C) Lateral nasal wall, (D) Maxillary sinus
Answer is B. The Onodi and Haller cells are ethmoidal air cells. Some air cells may invade the orbital floor. These are known as the Haller' cells. The Onodi cell is usually regarded as the most posterior ethmoid cell that pneumatizes lateral and superior to the sphenoid sinus and is intimately associated with the optic nerve.