Osteomeatal complex(OMC) connects:
Osteomeatal complex lies in the middle meatus. It is final common drainage pathway for the maxillary,frontal,and anterior ethmoid sinuses into the nasal cavity. Ref.Scott Brown 7/e,Vol 2 p 1345
Nasal cavity with maxillary sinus
Nasal cavity with sphenoid sinus
The two nasal cavities
Ethmoidal sinus with ethmoidal bulla
Nose and paranasal sinuses