Axial computed tomograms showed an overgrowth of the medial maxilla, with marked narrowing of the bony inlet (Figure 1and Figure 2, note that the posterior choanae are patent).
Neonates are obligate nasal breathers; therefore, any nasal airway obstruction can have severe consequences. Prompt recognition and appropriate therapy are required to prevent asphyxia. Common causes of nasal airway obstruction include septal displacement or hematoma, displaced nasal bone fractures, and choanal stenosis or atresia.1 Congenital nasal pyriform aperture stenosis was first described in 1988.2 It manifests during the neonatal period and is clinically indistinguishable from the more common bilateral choanal atresia.3 The anterior nasal aperture, or bony inlet, is the pear-shaped opening leading from the external nose to the nasal cavity. It is bounded superiorly by the nasal bones and laterally by the nasal processes of the maxilla. The exact mechanism for the development of CNPAS is unclear, but it has been postulated that a bony overgrowth in the area of the nasal process of the maxilla is responsible for the anomaly.4
Quiz Case 1. Arch Otolaryngol Head Neck Surg. 2000;126(1):94. doi: