Which is not a pa of paranasal sinus?
Paranasal sinuses are air containing cavities in ceain bones of skull. They are four on each side. Clinically,paranasal sinuses have bern divided into Anterior-Maxillary,Frontal, Anterior ethmoidal. posterir-Posterior ethmoid,sphenoid sinus. Ref Dhingra 6/e,p 187.
frontal
Ethmoid
Sphenoid
Pyriform
Nose and paranasal sinuses