Rapp-Hodgkin syndrome (RHS) is a rare form of ectodermal dysplasia with variable involvement of the hair, eyes, sweat glands, nails, and teeth. Oral findings may include hypodontia, hypoplastic enamel, cleft lip/palate, and a pronounced midfacial hypoplasia. The objective of this study was to determine if the pronounced midfacial hypoplasia is the result of a true tissue hypoplasia or displacement of midfacial tissues. We have identified a family in which three members, a mother and two daughters, display clinical features characteristic of RHS. Clinical and intraoral examination of these affected persons showed manifestations characteristic of RHS, and several new findings were observed, including subcutaneous abscesses, palmoplantar keratosis, and keratotic lesions located on the chest and trunk. To assess the midfacial hypoplasia, lateral cephalometric analysis was performed on lateral headplates. Results of the cephalometric analysis suggest that the midfacial hypoplasia results from both a deficiency and a displacement of the maxilla. These findings are significant because successful dental treatment of RHS relies upon accurate assessment of current and projected orofacial development, particularly for the skeletal relations of the maxilla and mandible.