Objective: The aim of this article is to describe the orthodontic therapy for Parry-Romberg syndrome. The therapeutic goal is to minimize the wasting effects of progressive atrophy on facial development of a part of the face. Design: To correct problems affecting craniofacial development of these patients, occurring during puberty, an orthodontic appliance was employed, which helps maintain parallelism of the facial planes, in particular the mandibular plane. Setting: Orthodontic care was carried out in the Dental Clinic of the Catholic University of the Sacred Heart of Rome. Intervention: Two patients underwent orthodontic therapy for 6 years. Appliances were checked every month and modified periodically so as to adapt to facial bone growth. Results: At the end of craniofacial growth, the mandible was almost symmetric and the problem relating to atrophy remained confined to the initial area. Cephalometric analyses demonstrated that the occlusal plane and the mandibular plane maintained a straight orientation in relation to the bizygomatic plane. The ratio between the left and right side of the ramus and condyle, in the mandible, improved. Conclusions: The use of orthodontic therapy allows patients affected by hemifacial progressive atrophy to present a more harmonic face at the end of puberty when final reconstruction can be planned. These results provide for a limitation of surgical intervention to the sclerodermic area alone.