Onodi cells are seen in?
Ethmoidal sinuses are divided into two groups :A) Anterior groupi) Anterior ethmoidal air cellsAnterior ethmoidal air cells drain into- either the ethmoidal infundibulum or the frontonasal duct. Some air cells may invade the orbital floor. These are known as the Haller' cells.ii) Middle ethmoidal air cellsAlso known as bullar sinuses. The middle ethmoidal air cells drain- into the middle meatus by one or more orifices on or above the ethmoidal bulla.B) Posterior groupPosterior ethmoidal air cells usually drain- into the superior meatus. The posterior group lies very close to the optic canal and optic nerve. 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.
Sphenoid sinus
Maxillary sinus
Anterior ethmoidal sinus
Posterior ethmoidal sinus