Most superior sinus in the face

Frontal sinus: They are situated between the inner and outer tables of frontal bones, above and deep to the supraorbital margin. Maxillary sinus: It occupies the body of the maxilla. Ethmoid sinus: They are thinned walled air cavities int he lateral wall of the ethmoid bones. Spehnoid sinus: it occupies the body of the sphenoid. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 209 and 210)