Semilunar hiatus
Hiatus semilunaris
Definition
The semilunar hiatus (a.k.a. hiatus semilunaris) is a curved groove that can be found in the lateral wall of the nasal cavity, specifically in the middle meatus region. It is located beneath the ethmoidal bulla and is formed by the mucosa of the lateral wall spanning the gap between the ethmoidal bulla above and the uncinate process below.
This bony semilunar hiatus continues as a narrow channel called the infundibulum, which further extends into the anterior portion of the ethmoidal bony labyrinth known as the frontonasal duct.
The semilunar hiatus acts as a drainage site for the maxillary air sinus, as well as the frontal air sinus and anterior ethmoidal air cells through the frontonasal duct.
References
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Text written by Muhammad A. Javaid, MD, PhD © 2024 IMAIOS.
Drake, R.L., Vogl, A.W. and Mitchell, A.W.M. (2009). ‘Chapter 8: Head and Neck’ in Gray’s anatomy for Students. (2nd ed.) Philadelphia PA 19103-2899: Elsevier, pp. 1016 & 1022-1023.
Standring, S. (2016). ‘Chapter 33: Nose, nasal cavity and Paranasal sinuses’ in Gray’s anatomy: the anatomical basis of clinical practice. (41st ed.) New York NY: Elsevier, pp. 560.
