title: Spacing and crowding among African and Caucasian children.
abstract: OBJECTIVE
  To determine spacing and crowding according to ethnic group, gender and dental emergence stage among Tanzanian African and Caucasian children.
  
  
  METHODS
  Cross-sectional epidemiological clinical study.
  
  
  METHODS
  A total of 869 African (428 boys, 441 girls) and 706 Caucasian (319 boys, 387 girls) school children, aged 3(1/2)-16 years.
  
  
  METHODS
  Comparison of spacing and crowding between African and Caucasian children according to gender and dental emergence stage.
  
  
  RESULTS
  Spacing was more often found in the maxilla, while crowding was more common in the mandible. Only during the transition of the maxillary permanent front teeth was there significantly more spacing in Caucasians. No gender differences were found. In both samples spacing decreased during later emergence stages. Crowding was more often found in Caucasian children than in African children. In Caucasian children the frequency of crowding increased with advanced emergence stages, while for Africans the trend was not consistent.
  
  
  CONCLUSIONS
  When planning resources for orthodontic treatment for different populations as well as planning treatment for individuals, ethnic background and emergence stage of the dentition need to be considered.
authors.affiliation: Department of Preventive and Community Dentistry, Muhimbili University College of Health Sciences (MUCHS), Dar Es Salaam, Tanzania.
authors.forename: E A
authors.initials: EA
authors.lastname: Mugonzibwa
authors.forename: R
authors.initials: R
authors.lastname: Eskeli
authors.forename: M T
authors.initials: MT
authors.lastname: Laine-Alava
authors.forename: A M
authors.initials: AM
authors.lastname: Kuijpers-Jagtman
authors.forename: C
authors.initials: C
authors.lastname: Katsaros
mesh_terms: D000293:Adolescent; D044383:Black People / Q000208:ethnology / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003481:Cuspid / Q000473:pathology; D003818:Dentition, Mixed; D003970:Diastema; D016021:Epidemiologic Studies; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008310:Malocclusion / Q000453:epidemiology / Q000208:ethnology*; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D012737:Sex Factors; D013636:Tanzania / Q000453:epidemiology; D014078:Tooth Eruption / Q000502:physiology; D014094:Tooth, Deciduous / Q000473:pathology; D044465:White People / Q000706:statistics & numerical data