The face has four pairs of air-filled nasal cavities or sinuses. These are-
1. Maxillary sinus: A pair of maxillary sinuses are located in the cheek in the maxillary region. Its inflammation causes pain in the cheeks, teeth and head.
2. Ethmoid sinus: A pair of ethmoid sinuses is located between the two eyes. Its inflammation causes pain in front of the eyes, behind and in the head.
3. Sphenoid sinus: A pair of sphenoid sinuses are located behind both eyes. Its inflammation causes pain behind the eyes and on top of the head.
4. Frontal sinus: A pair of frontal sinuses are located above the eyes. Its inflammation causes pain above the eyes and on top of the head.