The hiatus is the gap-like opening into the maxillary sinus. This large opening is in the medial wall of the maxillary body. In the articulated skull this large gap is filled with the inferior nasal concha, the perpendicular process of the palatine bone, and the uncinate process of the nasal bone, reducing its total size.

The term maxilla is a corrupted form of the Latin term mala meaning cheek. Another possibility is that it comes from the Latin verb macerare meaning to chew. Originally the Romans used the word to define both upper and lower jaw bones. Hiatus is a Latin term meaning a cleft or gap. It takes its origin from the Latin verb hiare meaning to yawn or gape.

Hiatus maxillaris

Hiatus maxillaire