FRONTONASAL AND CRANIOFRONTONASAL DYSPLASIA - PREOPERATIVE QUANTITATIVE DESCRIPTION OF THE CRANIO-ORBITO-ZYGOMATIC REGION-BASED ON COMPUTEDAND CONVENTIONAL TOMOGRAPHY

The unoperated cranio-orbito-zygomatic complex of 18 children (mean 4. 7 years) with frontonasal dysplasia (FND) and 12 children (mean 1.1 ye ars) with craniofrontonasal dysplasia (CFND) was quantified by 15 stan dard measurements performed on either computed tomography scans or fac ial tomograms. The results were compared with age-matched control valu es. In the FND group, the mean anterior interorbital and mid-interorbi tal distances were significantly increased at 148% and 118% of normal, and in the CFND patients, at 177% and 140% of normal. Excessive media l orbital wall protrusion (mean, 145% of normal in FND and 177% in CFN D), shortened zygomatic arch lengths (mean, 94% of normal in FND and 9 1% in CFND), and reduced cephalic lengths (mean, 96% of normal in FND and 83% in CFND) were all observed. An expanded interzygomatic buttres s distance was documented only in the CFND group, at 111% of normal. T he clinical presentation of craniofacial deformities such as FND and C FND can be objectively described by a numerical analysis of the bony p athology.