Radiographic diagnosis of congenital bony nasal stenosis.

Congenital bony nasal stenosis (CBNS) is a rare condition that causes respiratory distress in neonates. Between 1986 and 1996, we encountered 13 cases of CBNS. Recently, CT measurements have been used to evaluate the features of this type of stenosis, but no satisfactory investigation of the severity of bony nasal stenosis has been reported. We compared the nasal width (NW), facial width (FW), and interorbital distance (IOD) measured from occipitofrontal (Caldwell's) projections of plain radiographs in nine CBNS patients and nine normal infants. NW was significantly narrower in the CBNS patients than in the controls, and never exceeded the IOD in any of the CBNS patients. This measuring method can be used to diagnose CBNS, because NW in normal subjects of all age groups is always greater than IOD on Caldwell's view. We also investigated one patient radiographically, to determine how NW increased until the age of 4 years. However, there was no significant change in nasal width, although the FW increased significantly. This method seems useful for determining the severity of stenosis, and its simplicity makes it useful for routine investigation of breathing difficulty in neonates and infants. We review and discuss the CT images of CBNS reported in the literature.