1. Pyramid shaped maxillary sinus that is the largest of the paranasal sinuses, and drains into the middle meatus of the nose. It is present at birth as rudimentary air cells, and develops throughout childhood. (wikipedia.org)
2. A large, pyramidal in shape, air-filled paranasal sinus within the body of the maxilla, communicating with the middle meatus of the nose on the same side. (biology-online.org)
Syn: maxillary antrum, maxillary sinus, Highmore’s antrum