title: Space conditions and prevalence of anterior spacing and crowding among nine-year-old schoolchildren.
abstract: OBJECTIVE
  To give detailed insight into the space conditions and prevalence of spacing and crowding in schoolchildren at nine years of age. The reliability and validity of screening methods was also assessed.
  
  
  METHODS
  Epidemiological survey.
  
  
  METHODS
  South-western part of Germany (Rhein-Neckar-Kreis); elementary schools in a region with a low orthodontic care rate.
  
  
  METHODS
  494 nine-year-old German schoolchildren (237 males, 257 females, median age 9 years) were examined orthodontically in cooperation with the local community dentistry service. A special measurement ruler was developed to enhance validity and reliability of space measurements on location in the schools.
  
  
  CONCLUSIONS
  Concerning space conditions in the incisor segments: in the maxilla the variety encountered comprised both space excess and moderate to severe crowding. This was considerably larger in the maxilla than in the mandible. Severe crowding (> 5 mm) was found more often in the maxilla than in the mandible and affected around 2-3% of the maxillary dentitions. Also severe contact point displacements (IOTN Grade 4) were mainly restricted to the maxilla (prevalence approximately 3%). In the canine-premolar segments, the arch segments in males were in general around 0.5 mm larger than among the females, also within each dental stage. In general, the maxilla was more often affected by posterior crowding than the mandible. Anterior crowding seemed to be more prevalent than posterior crowding. With respect to the screening methods used in the present study, reliable and valid measurements were also found to be possible in schools. This may open up further opportunities for orthodontic screening by community dentistry services or similar organizations.
authors.affiliation: Department of Orthodontics, University of Jena, 07740 Jena, Germany. christopher.lux@med.uni-jena.de.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lux
authors.forename: Britta
authors.initials: B
authors.lastname: Dücker
authors.forename: Maria
authors.initials: M
authors.lastname: Pritsch
authors.forename: Uwe
authors.initials: U
authors.lastname: Niekusch
authors.forename: Gerda
authors.initials: G
authors.lastname: Komposch
mesh_terms: D001641:Bicuspid / Q000473:pathology; D002648:Child; D003481:Cuspid / Q000473:pathology; D003724:Dental Arch / Q000473:pathology*; D003970:Diastema; D016021:Epidemiologic Studies; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008310:Malocclusion / Q000453:epidemiology*; D008334:Mandible / Q000473:pathology; D008403:Mass Screening / Q000706:statistics & numerical data; D008437:Maxilla / Q000473:pathology; D015995:Prevalence; D015203:Reproducibility of Results; D012737:Sex Factors