title: Agenesis of permanent teeth in 8138 Danish schoolchildren: prevalence and intra-oral distribution according to gender.
abstract: OBJECTIVE
  The purpose of this study was to describe agenesis of permanent teeth in children with respect to prevalence and intra-oral distribution according to gender.
  
  
  METHODS
  The study was population based and included all children in one district of the municipality of Aarhus, Denmark, in 1974-1979 (1657 girls and 1668 boys) and 1992-2002 (2409 girls and 2404 boys). The children underwent systematical clinical and radiographic examination.
  
  
  RESULTS
  The period prevalence rates were almost identical for the two time periods (1972-1979: 7.8%; 1992-2002: 7.1%). Girls were affected more frequently than boys, and affected girls had more congenitally missing teeth than affected boys. Unilateral agenesis of the second premolars was more frequent than bilateral agenesis. In children with only one congenitally missing tooth, agenesis of the upper lateral incisors was asymmetrical in girls, but not in boys, whereas the opposite was true for the lower second premolars in boys.
  
  
  CONCLUSIONS
  The prevalence of agenesis of permanent teeth in Danish schoolchildren seems to be constant over time, and similar to that found in other large, population-based studies. Intra-oral distributions of congenitally missing teeth indicate gender-specific patterns.
authors.affiliation: Municipal Dental Service, Aarhus, Denmark.
authors.forename: Steen
authors.initials: S
authors.lastname: Rølling
authors.forename: Sven
authors.initials: S
authors.lastname: Poulsen
mesh_terms: D000848:Anodontia / Q000145:classification / Q000453:epidemiology*; D001641:Bicuspid / Q000002:abnormalities; D002648:Child; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D015995:Prevalence; D012737:Sex Factors