Prevalence and morphology of supernumerary teeth in the population of a Swiss community. Short communication.

The objective of the study was to determine the current prevalence of supernumerary teeth (PST) in the population of a Swiss community. 3,004 orthopantomograms (OPTs) routinely produced during the annual school dental examinations in the Winterthur municipality from 1990 to 2005 served as the study basis (average age 9.45 years, 1391 girls, 1613 boys, age range 6-15 years). The study found 44 supernumerary teeth, which yields a prevalence of 1.5%. The prevalence among boys was higher than among girls, with 1.1% and 0.4%, respectively. The greatest proportion of supernumerary teeth was found in the maxillary anterior region (38 of 44 teeth, 86%). Based on their position, 33 of these were classified as mesiodens. Five supernumerary teeth had the same shape as a maxillary lateral incisor. In the mandibular anterior region, five supernumerary teeth were shaped the same as the permanent mandibular incisors. 70% of the supernumerary teeth were conical. The prevalence of supernumerary teeth is low (1.5%) and comparable to similar studies in the literature. The majority (86%) of supernumerary teeth are located in the maxillary anterior region. Thus, in the case of retention or delayed eruption, dentists should bear in mind that supernumerary teeth may be the cause.