Frontonasal and Craniofrontonasal Dysplasia: Preoperative Quantitative Description of the Cranio-Orbito-Zygomatic Region Based on Computed and Conventional Tomography

Abstract

The unoperated crano-orbito-zygomatic complex of 18 children (mean 4.7 years) with frontonasal dysplasia (FND) and 12 children (mean 1.1 years) with crainofrontonasal dysplasia (CFND) was quantified by 15 standard measurements performed on either computed tomography scans or facial tomograms. The results were compared with age-matched control values. In the FND group, the mean anterior interorbital and mid-interorbital distances were significantly increased at 148% and 118% of normal, and in the CFND patients, at 177% and 140% of normal. Excessive medial orbital wall protrusion (mean, 145% of normal in FND and 177% in CFND), shortened zygomatic arch lengths (mean, 94% of normal in FND and 91% in CFND), and reduced cephalic lengths (mean, 96% of normal in FND and 83% in CFND) were all observed. An expanded interzygomatic buttress distance was documented only in the CFND group, at 11% of normal. The clinical presentation of craniofacial deformities such as FND and CFND can be objectively described by a numerical analysis of the bony pathology.

Phenotypes of craniofrontonasal syndrome in patients with a pathogenic mutation in EFNB1

“…7,14,30 In other studies, some patients were classified as having frontonasal dysplasia, whereas they actually match the typical phenotype of CFNS. 13,32,35 Figure 3 Patient with typical chest and breast deformities.…”

“…Besides the obvious increased interorbital distance, they also found a degree of horizontal midface retrusion demonstrated by a shortened zygomatic arch length and an expanded interzygomatic buttress distance, suggestive for a brachycephalic morphology. 13 In addition, another study also described a short upper facial height 8 and compared it to anthropometric measurements. However, the short upper facial height seemed to be present in only 66% of their cases.…”

“…Most commonly depicted phenotypic features were coronal synostosis, [1][2][3][4][5][6][7][8][9][10][11] hypertelorism, 1,4-14 bifid nasal tip, 1,4,5,[8][9][10]12,13 frizzy and curly hair [8][9][10][11]15 and longitudinal ridging and splitting of nails. 3,4,6,8,9,[11][12][13] It became clear that the majority of CFNS patients were female. In addition, the female patients appeared to be affected more severely than male carriers, who showed only few mild signs or no clear features at all.…”