A Cephalometric Investigation of Hypohidrotic Ectodermal Dysplasia

Abstract

The characteristic features of hypohidrotic ectodermal dysplasia were first reported in 1848 by Thurnam. Since this first classification, the characteristic facies of this syndrome have often been reported. Individuals with this disease have been described by various authors as having a prognathic mandible, an underdeveloped mandible, a small face, an elongated maxilla, an anteriorly positioned maxilla, a midface hypoplasia, and more. Only one cephalometric study of this syndrome exists and it was performed to study growth. The present study was designed to describe and quantify, through the use of cephalometric analysis, any facial and cranial variations in these patients. The study also attempted to describe the variations found in female heterozygotes.

Nine hypohidrotic ectodermal dysplasia patients and their families were studied. A total of 31 individuals participated. When the data obtained from the cephalometric measurements were grouped into probands, gene carriers (heterozygous females), and normals, it was found that certain variations did exist. The size and position of cranial base and the mandible in all three groups were within normal limits (±2 S.D.). The maxillae of the probands were significantly short, yet positioned normally. The gene carriers also showed this trend, but the results were not significant. Profiles (soft and hard tissue) were significantly concave in the proband and gene carrier groups due to a combined effect of altered maxillary and mandibular positions.