One of the following opens into middle meatus of nose
The middle meatus presents the ethmoidal bulla,the hiatus semilunaris,the infundibulum and the opening of frontal,maxillary and the middle ethmoidal air sinuses.Sphenoidal air sinus opens into the sphenoethmoidal recess,which is a triangular fossa just above the superior concha. REF.BDC VOL.3,5th edition.
Naso-lacrimal duct
Eustachian tube
Sphenoidal sinus
Maxillary sinus
Head and neck