Bony inlet stenosis as a cause of nasal airway obstruction.

Two cases of congenital bony stenosis of the nasal piriform aperture (anterior nares) are presented. Both patients experienced episodes of respiratory distress and clinical symptoms similar to those seen in patients with posterior choanal atresia. The underlying anatomic abnormalities in congenital bony inlet stenosis are quite different from those in choanal atresia and require different surgical approaches for correction. Computed tomography demonstrates in detail the underlying anatomic abnormality and allows differentiation of bony inlet stenosis from choanal atresia.