Dental Abnormalities in the Deciduous and Permanent Dentitions of Individuals with Cleft Lip and Palate

¹ Cleft Palate Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania, and Cleft Palate Research Center, Center for Handicapped Children, University of Illinois, Chicago, Illinois

Casts of the deciduous and permanent dentitions of 39 individuals afflicted with clefts of the lip and/or palate were studied for the presence of morphological irregularities of crown structure. Whereas previous studies had been confined to dental abnormalities in the immediate area of the cleft, the present investigation included the entire deciduous and permanent dentitions with the exception of the second and third permanent molars.

In all types of clefts, none of the teeth were consistently normal in structure, except the permanent cuspids and maxillary bicuspids. In palatal clefts, in which the alveolar ridge is intact, dental abnormalities are relatively more frequent than in clefts in which the alveolar ridge is involved. In the former, 15.9 per cent of the deciduous and 13.8 per cent of the permanent dental units are affected. In complete lip and palate clefts, 7.6 per cent of the deciduous and 8.5 per cent of the permanent dental units are affected. Also, in palatal clefts, mandibular teeth are affected as frequently as are maxillary teeth. In clefts of the lip and palate the maxillary dentition is affected far more frequently than the mandibular, even when supernumerary and missing teeth are not considered. Out of a total of 1,716 dental units examined, 189 (11 per cent) were abnormal (morphologically irregular, supernumerary, or missing). There was no indication that an affected deciduous tooth was succeeded by an affected permanent tooth. The apparent haphazard distribution of abnormalities in both arches and in both deciduous and permanent dentitions, as well as the higher frequency of dental abnormalities in clefts where the alveolar ridge is not involved, cannot be explained on the basis of current knowledge of cleft development and mechanism.