The “blind age assessment”: applicability of Greulich & Pyle, Demirjian and Mincer aging methods on a population of unknown ethnic origin

Purpose: Age estimation is one of the most crucial issues in case of unknown deceased as well as in the living and is very frequently of radiological interest. Three methods for age estimation have been designated as the most reliable among the others: Greulich and Pyle, Demirjian and Mincer. The literature provides several studies concerning their applicability in different geographic contexts. However, not always can ancestry be ascertained, for example, in the case of badly preserved corpses. In these cases, age assessment must be performed without the corrections suggested by the literature for different ethnic groups. One may therefore wonder how reliable the result of age assessment performed without knowing the racial group to which the subject belongs may be. This study aimed at testing the applicability of the Greulich and Pyle Atlas, the Demirjian and the Mincer methods on a mixed population to compare skeletal and dental methods of age estimation. Materials and methods: X-ray films of 167 subjects aged between 4 and 31 years from more than 18 countries were recruited. One hundred and nine orthopantomographs (OPG) of children aged between 4 and 15.5 years were evaluated by Demirjian's method; whenever the highest Demirjian score was reached (31 cases), the Mincer method was applied. The skeletal maturation of 54 subjects aged between 7 and 19 years was determined by the Greulich and Pyle method. Results: The lowest average variance from chronological age was shown by the Greulich and Pyle method, followed by Demirjian. The Mincer method showed very high mean variances. Conclusions: Mean variances from the different methods do not significantly differ from data reported in the literature and demonstrate that the reliability of Demirjian, and Greulich and Pyle as they stand may be applied satisfactorily to remains or individuals of unknown ethnic origin.