title: A study of caries polarization in 1-, 2- and 3-year-old children.
abstract: BACKGROUND
  The polarization of dental caries is a notion defined as a small percentage of persons with high dental caries rate and a large percentage of caries-free persons. This phenomenon has not been studied sufficiently in children aged 12 to 47 months which has justified the undertaking of this study.
  
  
  OBJECTIVE
  To determine the percentages of persons with different levels of caries incidence and the percentages of their carious and filled teeth (dft) of the total number of dft in the respective age group.
  
  
  METHODS
  The study is representative and was conducted in accordance with the World Health Organization requirements for epidemiological study of dental caries. It comprises 370 children from 12 to 47 months of age selected by a random sampling method. Three age groups were formed: group I (12-23 months), group II (24-35 months) and group III (36-47 months). Dental caries on a cavitation level was diagnosed by means of a probe and a mirror. In all groups we further divided the subjects into subgroups of different level of dft (carious and filled teeth): subgroup I--dft = 0 (caries free), subgroup II--dft = 1, subgroup III--dft = 2 and subgroup IV--dft > or = 3.
  
  
  RESULTS
  Marked dental caries polarization is observed in all studied age groups--a large percentage of persons free of caries and a small percentage of persons with high dental caries rate--P < 0.001. In one-year-old children 8.33% are carriers of 63.08% of the total dft in that age group, in two-year-old children 18.33% are carriers of 81.50% of the total dft in that age group, and in three-year-old children 25.38% are carriers of 74.58% of the total dft of that age group.
  
  
  CONCLUSIONS
  This study support the assertion that early childhood caries affects predominantly high-risk individuals, which requires differentiated approach to caries prevention and treatment.
authors.affiliation: Faculty of Dentistry, Department of Pediatric Dentistry, Higher Medical Institute, Plovdiv, Bulgaria.
authors.forename: M M
authors.initials: MM
authors.lastname: Dimitrova
authors.forename: M P
authors.initials: MP
authors.lastname: Kukleva
authors.forename: V K
authors.initials: VK
authors.lastname: Kondeva
mesh_terms: D002031:Bulgaria / Q000453:epidemiology; D002675:Child, Preschool; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control; D006801:Humans; D007223:Infant; D014094:Tooth, Deciduous / Q000473:pathology