Is Demirjian’s original method really useful for age estimation in a forensic context?
The suitability of Demirjian’s method for forensic age estimation has been systematically questioned. The aim of this study is to further assess the reliability of Demirjian’s original method in forensic age estimation using a sample of Portuguese children.
564 panoramic radiographs of Portuguese boys and girls between 6 and 16 years of age were evaluated using Demirjian’s method. Dental age (DA) was determined using the 50th percentile for the maturity score obtained for each age group. The mean difference between chronological age (CA) and dental age (DA) and the mean absolute difference between CA and DA were calculated for each age group. Paired t tests were used to test the statistical significance of mean differences between CA and DA. For each individual, a 94 % confidence interval was calculated for estimated DA, using the 3rd and 97th percentiles in Demirjian’s conversion tables.
Chronological age was overestimated in boys, in every age group; mean differences between CA and DA were statistically significant, expect for age 7. In girls, chronological age was overestimated in the 10–15 year-old age group. The difference between CA and DA was highest in the 12 years olds for both sexes. The 94 % confidence intervals did not include the true chronological age in all 6, 13, and 15 year-old girls, and all 14 and 15 year-old boys. Only a small portion of the individuals in the remaining age groups had their true chronological age falling within the probable age interval.
Results show a systematic bias and consistent inaccuracy in estimating age from dental development using Demirjian’s original method, making this methodology unsuitable for age estimation in the study sample. These results add to published evidence which suggests that Demirjian’s method is not suitable and should be abandoned altogether for forensic age estimation purposes.
KeywordsForensic odontology Age estimation Dental development Demirjian’s method
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