A comparison of Demirjian's four dental development methods for forensic age estimation in South Australian sub-adults.

The aim of this study was to compare the accuracy of Demirjian's four dental development methods for forensic age assessment in a South Australian population. The sample comprised orthopantomograms (OPGs) of 408 sub-adult individuals (211 male; 197 female) with an age range of 4.9-14.5 years. The OPGs were obtained from various dental schools and clinics in urban Adelaide. The following Demirjian methods were evaluated: the original 7-tooth technique; the revised 7-tooth system; the 4-tooth method; and the alternate 4-tooth approach. The left mandibular teeth in each OPG were assessed and rated according to the eight stages (A-H) defined and illustrated in Demirjian et al.(5) Differences between chronological and estimated ages were calculated for males and females separately; 95% confidence intervals of mean age differences were calculated and ANOVA used to assess the significance of mean differences. When comparing all four methods there were significant differences overall (and in individual age groups) between mean chronological and estimated age in both sexes. In addition, each method consistently overestimated chronological age. We also demonstrate that the accuracy of the dental age methods evaluated varies in different subsets of an Australian population, a finding that parallels previous research in other global populations. Based on our analyses we conclude that population-specific standards based on dental maturity curves, as opposed to estimated ages, would provide more accurate and statistically robust age estimations.

A comparison of Demirjian's four dental development methods for forensic age assessment.

The aim of this study was to determine the comparative accuracy of Demirjian's four dental development methods for forensic age estimation in the Western Australian population. A sample comprising 143 individuals aged 4.6 to 14.5 years were assessed using Demirjian's four methods for dental development (original 7-tooth: M(2), M(1), PM(2), PM(1), C, I(2), and I(1); revised 7-tooth: M(2), M(1), PM(2), PM(1), C, I(2), and I(1); 4-tooth: M(2), M(1), PM(2), and PM(1); and an alternate 4-tooth: M(2), PM(2), PM(1), and I(1)). When comparing all four methods, the 4-tooth method overestimated age in both males and females by 0.04 and 0.25 years, respectively. The original 7-tooth was least accurate for males, while the original 7-tooth, the revised 7-tooth, and the alternate 4-tooth were unsuitable for females. Therefore, we recommend the 4-tooth method to be used for forensic age estimation in Western Australian males and females, as it has the lowest overall mean deviation and the highest accuracy.

To evaluate the utility of smaller sample sizes when assessing dental maturity curves for forensic age estimation.

Dental maturation and chronological age estimation were determined from 144 healthy Western Australian individuals aged 3.6-14.5 years. The results were compared with Farah et al.'s previous study which comprised a larger heterogeneous sample of Western Australian individuals (n = 1450). Orthopantomograms were analyzed with the application of Demirjian and Goldstein's 4-tooth method based on eight stages of dental mineralization. Analysis of variance revealed no significant differences in dental maturity scores in each age group among the males in both studies; similar results were seen in the females. Paired t-tests showed no statistical significance overall between chronological and estimated ages for the males in our sample (p = 0.181), whereas the females showed significant differences (p < 0.001). Our results show that smaller samples may be used when assessing dental maturity curves for forensic age estimation.