The four paranasal sinuses (maxillary, frontal, ethmoid and sphenoid) develop as outpouchings of the nasal mucosa. They remain connected to the nasal cavity via narrow ostia with a lumen diameter ...

Fungal balls in the paranasal sinuses, particularly in the maxillary and sphenoid sinuses, represent a common form of non-invasive fungal sinusitis. These conditions are characterized by the ...