title: Growth of permanent mandibular teeth of British children aged 4 to 9 years.
abstract: OBJECTIVE
  The aim of this study was to investigate ethnic differences and describe tooth formation of mandibular permanent teeth in a group of London children.
  
  
  METHODS
  The design was cross-sectional retrospective study.
  
  
  METHODS
  The sample was a non-random group of healthy British children (n = 521) attending a dental hospital. The children aged between 4 and 9 years were of Bangladeshi or white Caucasian origin. Developing permanent mandibular teeth were staged from radiographs according to criteria described by Demirjian, Goldstein and Tanner (1973, Human Biology, 45, 211-227). Data were grouped in 6-month intervals and analysed using probit analysis. Formation was also expressed relative to stages of the first permanent molar (M1) and the distribution of stages tested between the groups and sexes using Mann Whitney U-test.
  
  
  RESULTS
  Tooth formation was not significantly different between the two ethnic groups. Girls attained almost all stages of tooth formation earlier than boys; in addition, the canine showed significant advancement relative to M1 formation in girls (p < 0.05).
  
  
  CONCLUSIONS
  These findings failed to demonstrate an ethnic difference in tooth formation in these children.
authors.affiliation: Department of Paediatric Dentistry, St Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary and Westfield College, University of London, UK. h.m.liversidge@mds.qmw.ac.uk
authors.forename: H M
authors.initials: HM
authors.lastname: Liversidge
authors.forename: T
authors.initials: T
authors.lastname: Speechly
mesh_terms: D000366:Age Determination by Teeth; D000367:Age Factors; D001459:Bangladesh / Q000208:ethnology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003481:Cuspid / Q000254:growth & development; D019229:Dentition, Permanent; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D008131:London; D008297:Male; D008334:Mandible; D008963:Molar / Q000254:growth & development; D011862:Radiography, Panoramic; D012016:Reference Values; D012189:Retrospective Studies; D012727:Sex Characteristics; D014070:Tooth / Q000000981:diagnostic imaging / Q000254:growth & development*; D044465:White People