Congenital nasal pyriform aperture stenosis. Isolated abnormality vs developmental field defect.

Congenital nasal pyriform aperture stenosis has recently been described as a cause of nasal airway obstruction in the newborn. As some investigators have observed, the nasal pyriform aperture is narrowed owing to bony overgrowth of the nasal process of the maxilla. This overgrowth is confirmed by computed tomography. In six previously reported cases, follow-up as long as 16 months revealed normal facial growth. We describe six patients with congenital nasal pyriform aperture stenosis. On eruption of deciduous dentition, four of the six patients were found to have a single prominent central maxillary incisor, ie, "megaincisor." Computed tomographic scans have confirmed this dental anomaly as well as maxillary bony overgrowth. A single maxillary incisor has been described as an autosomal dominant microform of holoprosencephaly, a developmental field defect. We propose that in some patients congenital nasal pyriform aperture stenosis may represent more than an isolated congenital abnormality of the airway and may, in fact, be a midfacial dysostosis with associated endocrine and central nervous system abnormalities.