Objective: In the study we use the image of three dimensional computed tomography (3D-CT) to assess the different widths of the bony framework of congenital nasal pyriform aperture stenosis (CNPAS).
Methods: We select 17 infants under 4 months old diagnosed as CNPAS for this study. There were four categories of distance measurement. The distance between the caudal end of the nasal bone (nasal tip) and the anterior nasal spine (NPAH). The distance between bilateral bony inner wall of the nasal pyriform aperture at the midpoint of the aperture height (MIVD). The interprocess distance at the level of lower 1/4 of the pyriform aperture height (IPD). The narrowest distance between the bilateral nasal processes (NIPD).
Results: There were 17 infants, nine males and eight females. At the time of performing 3D-CT, the mean age was 49.5+/-35.9 days. The results of measurement were: NPAH: 10.9+/-1.23mm, MIVD: 8.2+/-0.89mm, IPD: 4.9+/-0.93mm, and NIPD: 4.4+/-0.73mm. The MIVD is significantly wider than both IPD and NIPD (p<0.01). There is high correlation between IPD and NIPD. There is no significant difference on age between gender in this study. However, the IPD (4.4+/-0.74) and NIPD (3.9+/-0.47) of male patients are broader, respectively, than those of female patients with significant difference (p<0.05).
Conclusion: The measurement of CNPAS by means of 3D-CT may provide useful data for evaluation of the width in different parts of nasal pyriform aperture. These may be used for evaluation of pre- and postoperative status and future investigation in CNPAS patients.