A CONTROLLED-STUDY OF ASSOCIATED DENTAL ANOMALIES

The purpose of this study was to reveal patterns of association among seven types of dental anomalies (aplasia of second premolars, small si ze of maxillary lateral incisors, infraocclusion of primary molars, en amel hypoplasia, ectopic eruption of first molars, supernumerary teeth , and palatal displacement of maxillary canines) in an untreated ortho dontic population, ages 7 to 14. The prevalence of associated tooth an omalies in seven groups of 100 subjects selected according to one prim arily diagnosed dental anomaly was compared with the prevalence of the examined dental anomalies in a control group of 1,000 subjects. Signi ficant reciprocal associations (p<0.005) were found among five of the anomalies (aplasia of second premolars, small size of maxillary latera l incisors, infraocclusion of primary molars, enamel hypoplasia, and p alatal displacement of maxillary canines), suggesting a common genetic origin for these conditions. Supernumerary teeth appeared to be a sep arate etiological entity with respect to all other examined tooth anom alies. The existence of associations between different tooth anomalies is clinically relevant, as the early diagnosis of one anomaly may ind icate an increased risk for others.