Purpose: To describe the computed tomographic (CT) measurements and features that enable accurate diagnosis of congenital nasal piriform aperture stenosis (CNPAS).
Materials and methods: The clinical and imaging features of six patients (age range, 0-11 months) with CNPAS were retrospectively evaluated and compared with those of 61 control subjects younger than 24 months.
Results: The average widths of the piriform aperture in patients aged 0-3, 4-6, and 10-12 months were 4.8, 7.0, and 6.0 mm, respectively, compared with 13.4 (P < .001), 14.9, and 15.6 mm, respectively, in the age-matched control subjects. The average areas of the piriform aperture in patients in the three age groups measured 0.24, 0.46, and 0.36 cm2, respectively, compared with 0.67 (P < .001), 0.86, and 1.11 cm2, respectively, in the age-matched control subjects. The width of the nasal cavity in patients with CNPAS was in the less than 5th percentile compard with that in the control subjects. Abnormal dentition and a midline bone ridge projecting from the inferior palate were present in all six patients.
Conclusion: CT measurement of the piriform aperture width is a simple and accurate method for diagnosing CNPAS; a width less than 11 mm in a term infant is considered to be diagnostic. An abnormal dentition and a bone ridge along the underside of the palate are confirmatory imaging findings.