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Primary double teeth. A retrospective clinical study of their morphological characteristics and associated anomalies.

AIM
To investigate the relationship between morphology and position of double teeth, and the occurrence of other dental anomalies in the same subjects and in their siblings. SAMPLE OF CHILDREN AND METHODS: Fifty-three double teeth in a group of 50 Spanish children were included in the study. All of these children were examined clinically and had radiographs and photographs taken at the time of examination. Twenty-two of the children had a total of 30 siblings who were also examined for the presence of anomalies.


RESULTS
Of the 50 subjects, 47 had one and three subjects had two double teeth. Statistically there were no significant differences in occurrence between boys and girls, left and right sides or between maxilla and mandible. Four morphological types were identified: type I, bifid crown-single root; type II, large crown-large root; type III, two fused crowns-single root; type IV, two fused crowns-two fused roots. Type I was seen only in the maxilla and types II and III only in the mandible. Type IV was seen mostly in the maxilla. More than half of the cases showed associated anomalies in the permanent dentition and anomalies of number or shape were also present in six of the siblings.


CONCLUSION
It is suggested that both double teeth and other anomalies in the same children or in their siblings may be manifestations of a primary abnormality in the distribution of dental material.