Timing of Demirjian tooth formation stages

University of Adelaide, Tarndarnya, South Australia, Australia
Annals of Human Biology (Impact Factor: 1.27). 07/2006; 33(4):454-70. DOI: 10.1080/03014460600802387
Source: PubMed


Global differences in Demirjian et al.'s method of assessing dental maturity are thought to be due to population differences.
The aim of this study was to investigate the timing of individual tooth formation stages in children from eight countries.
This was a meta-analysis of previously published data from retrospective cross-sectional studies of dental maturity.
Data of mandibular permanent developing teeth from panoramic radiographs (Demirjian's stages) were combined from Australia, Belgium, Canada, England, Finland, France, South Korea and Sweden (n = 9002, ages 2-16.99 years). Age-of-attainment was calculated using logistic regression for each group by sex and meta-analysis of the total. Overlapping 95% confidence intervals of the means was interpreted as no significant difference.
Mean ages for each group and total were significantly different in 65 out of 509 comparisons (p < 0.05). Some of these were of small sample size but there was no consistent pattern. Apex closure of the first molar was significantly later in children from Quebec and this might explain differences found in the dental maturity score.
These results suggest no major differences in the timing of tooth formation stages between these children. This fails to explain previous findings of differences using Demirjian's dental maturity method.

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Available from: Helen M Liversidge
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    • "These groups are similar in their dental maturity and only small differences in mean age entering permanent tooth stages have been shown (Liversidge , 2011). Another comparative study of mostly White children in various world regions failed to show any meaningful difference or consistent pattern in the timing of tooth formation (Liversidge et al., 2006). This does not hold true for all teeth and there is some evidence of group difference in the timing of the third molars (Liversidge, 2008; Thevissen et al., 2010). "
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    • "However, compared with the dental maturation in French-Canadian children, dental maturation of children in Kuwait was found to be delayed by approximately 0.7 years.[19] In addition, dental age in the Demirjian method is exactly as predicted in certain populations.[20] The age of the sample group, the statistical method, method reliability and each child's individual genetic and geographic variation can influence the differences reported in the results.[1521] "
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