Advanced dental maturation in New Zealand Maori and Pacific Island children

Abstract

This study employs Demirjian's (1994: CD Rom. Norwood, MA: Silver Platter Education) method for assessing dental maturation to compare the rates of development in children of three ethnic populations living in New Zealand-Maori, Pacific Island, and European. We test the hypothesis that Maori and Pacific Island children will have significantly advanced dental maturation compared with New Zealand children of European extraction. The study population consists of orthopantomographs of 1,343 children (623 females and 660 males) between the ages of 2.5 and 14 years, and involves three ethnic groups-Maori, European, and Pacific Islander. Bland/Altman plots for the mean chronological age against the age difference suggest that dental age as determined by the Demirjian method is consistently lower than the chronological age of the children examined. A mixed model regression analysis shows that this difference between dental and chronological age is significantly greater in Maori than in European children (regression coefficient = 0.414; z = 7.01; P < 0.001) and also significantly greater in Pacific Island children than European children (regression coefficient = 0.574; z = 6.25; P < 0.001). Regression analysis shows that the 50th quantile maturity score of boys and girls differs by 1.49 (t = -6.18, P < 0.01) and the interaction of sex and age is also significantly different (t = -2.44, P < 0.01). Similarly, Maori girls show a difference in maturity score of 1.28 (t = -3.77, P < 0.01). However, the slopes for Maori boys and girls did not differ significantly (age/sex interaction, t = -1.25, P = 0.212). We conclude that Pacific Island children are advanced in dental maturity compared with Maori children who in turn are more advanced than New Zealand children of European origin.