Growth of permanent mandibular teeth of British children aged 4 to 9 years

Primary 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. Research design: The design was cross-sectional retrospective study. Sample and method: 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 (M-1) 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 M-1 formation in girls (p < 0.05). Conclusions: These findings failed to demonstrate an ethnic difference in tooth formation in these children.