Congenital tooth anomalies and malocclusions: a genetic link?

The aim of the present study was to investigate putative relationships between different malocclusions such as Class III and Class II division 1, and congenital tooth anomalies. Two-hundred Class III and 215 Class II division 1 patients were examined for the presence of any of the following congenital tooth anomalies: maxillary incisor hypodontia, maxillary canine impaction, transpositions, supernumerary teeth, and tooth agenesis. Their occurrence rates were then calculated as a percentage of the total sample and were compared for statistical differences. The results revealed no statistical difference (P > 0.05) in the occurrence rates of upper lateral incisor agenesis, peg-shaped laterals, impacted canines, or supernumerary teeth between the Class III and the Class II division 1 malocclusions. When the occurrence rate of all congenital tooth anomalies was compared between the two malocclusions, Class III subjects showed significantly higher rates (P < 0.05). Comparison with published surveys on general populations showed similar occurrence rates. It can be concluded that subjects with Class III and Class II division 1 malocclusions show patterns of congenital tooth anomalies similar to those observed in the general population. Congenital tooth anomalies may represent another criterion for the study of malocclusion, with respect to their origin and development.