R. Nykanen et al., VALIDITY OF THE DEMIRJIAN METHOD FOR DENTAL AGE ESTIMATION WHEN APPLIED TO NORWEGIAN CHILDREN, Acta Odontologica Scandinavica, 56(4), 1998, pp. 238-244
Dental age was studied in a sample of 261 Norwegian children by using
the maturity standards of Demirjian & Goldstein (1976) to examine the
applicability of these standards as a reference for overall dental mat
urity in a Norwegian population. The sample comprised 128 boys and 133
girls included in 'the Oslo Growth Material', from whom orthopantomog
rams (total, 783) had been longitudinally obtained, with intervals of
about 3 years and covering 3 age spans (5.5-6.5 years, 8.5-9.5 years,
and 11.5-12.5 years), each divided into 3 half-year age groups. Reliab
ility was analyzed by repeated assessments of 134 of the radiographs,
and the overall mean difference between duplicate dental age determina
tions was 0.5 months for intra- and 1.8 months for inter-examiner comp
arisons. The Norwegian children were generally somewhat advanced in de
ntal maturity compared with the French-Canadian reference sample. Amon
g the boys the mean difference between dental age and chronologic age
varied in the different age groups from 1.5 to 4.0 months. Among the g
irls the difference increased with age, varying from 0 to 3.5 months i
n the younger age groups (5.5 to 9.0 years) and from 4.5 to 7.5 months
in the age groups 9.5 years and above. The variability in individual
dental age was marked and increased with age. For the older age groups
95% of the individual age estimates were within +/-2 years of the rea
l age. The applied standards appear to be adequate for studying dental
age in groups of children from a Norwegian population. Given the cons
iderable individual variation in dental maturity, estimation of chrono
logic age in individual children should be supplemented by other indic
ators of biologic maturity.