Radiation-induced hypoplasia of the teeth and mandible. A case report.

Hypoplasia of the mandible and teeth is reported in a 4-year-old boy who had cystic hygroma. At age 7 months he had been treated with 60Co-gamma-radiation (24 Gy to the head and neck, 45 Gy to the mediastinum) followed by surgery. Panoramic and periapical radiographs showed hypoplasia of the roots of the primary canines, molars, and permanent teeth and no evidence of tooth germs. The patient was followed up to age 13 years.