Craniofacial morphology of children with Williams syndrome

Facial dysmorphology is considered to be a major diagnostic feature in patients with Williams syndrome (WS). The dysmorphology is composed of soft tissue and skeletal components. In this study the skeletal component of the facial dysmorphology was examined by analyzing the lateral cephalometric radiographs of 8 children with WS. Seven anatomic areas were judged by means of the analysis of 48 cephalometric variables. Four skeletal features contributed to the facial appearance of children with WS: (1) the anterior cranial base was short, although the cranial base angle (N-S-Ba) was normal; (2) the angle of the mandibular plane was steep, although total facial height was normal; (3) despite the normal facial height, there was an unusual proportion of upper to lower anterior facial height and posterior to anterior facial height; and (4) the chin button (pogonion to N-B line) was deficient, although the mandible could not be classified as retrognathic. The common skeletal components were not dominant enough to characterize the facial dysmorphology completely.