A 14-year old boy with cleidocranial dysplasia was referred because of an almost complete presence of the deciduous dentition. Diagnostics by means of a panoramic radiograph, lateral headfilm, CT scan and 3D computer images of the dentomaxillary complex showed 7 supernumerary permanent teeth: 13', 11', 21', 23', 28', 35' and 45'. A combined orthodontic-surgical treatment was started. The supernumary teeth were removed surgically and the impacted teeth are exposed. The closed eruption technique was used to extrude these teeth orthodontically.