[A case of Prader-Willi syndrome].

Prader-Willi syndrome is characterized by hypotonia, hypomentia, hypogonadism and obesity. A case of a 10-year-5-month-old girl who was diagnosed to have the typical symptoms associated with the Prader-Willi syndrome is described in the present report. The following are the dental findings. 1) Enamel hypoplasia, crowding over the anterior teeth and narrow dental arch were found. However there was no high palate in the maxilla. 2) The mesio-distal width of the present teeth were small compared with the national average. 3) According to X-ray cephalometric analysis, a retardation of the growth of the maxilla and mandible was found. 4) Because of hypomentia and the difficult management of the patient, dental treatment was performed under general anesthesia.