Facial and dental anomalies in cleidocranial dysplasia: a study of 17 cases.

Seventeen cases of cleidocranial dysplasia were analysed. On average, there was mandibular prognathism due to increased mandibular length, and a short cranial base. The maxilla was short vertically but not antero-posteriorly. In 13 young subjects followed for an average period of 6 years, more than half of the total number of teeth of each type had not erupted at the normal age, with the exception of mandibular incisors. Twice as many maxillary incisors were delayed compared with those in the lower jaw. Only six of 25 mandibular central incisors were delayed. There was a total of 63 supernumerary teeth in the 13 subjects, mostly occurring in the mandibular premolar and maxillary incisor regions. Many more occurred in the maxillary than in the mandibular incisor region. In the molar regions only six supernumerary teeth were found, five in the upper jaw and one in the lower. Two patients had no supernumerary teeth. One patient showed congenital absence of one mandibular incisor and three premolars.