There are two of these air cavities in your forehead (frontal sinuses), several between your eyes and behind your nose (ethmoid sinuses), and two in your cheeks (maxillary sinuses), adds Glen ...

Artist's rendition of sinus anatomy. F= Frontal sinuses; E=Ethmoid sinuses; M=Maxillary sinuses; O=Maxillary sinus ostium; ST=Superior turbinate; T=Middle turbinate; IT= Inferior turbinate ...

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 ...

However, plain film radiographs provide poor visualization of the ethmoid sinus due to density averaging. Plain films are therefore useful for diagnosing frontal and maxillary sinus disease but ...