Applicability of Greulich and Pyle method for age assessment in forensic practice on an Italian sample

The main importance in age estimation lies in the assessment of criminal liability and protection of unaccompanied minor immigrants, when their age is unknown. Under Italian law, persons are not criminally responsible before they reach the age of 14. The age of 18 is important when deciding whether juvenile or adult law must be applied. In the case of unaccompanied minors, it is important to assess age in order to establish special protective measures, and correct age estimation may prevent a person over 18 from benefiting from measures reserved for minors.

Since the Greulich and Pyle method is one of the most frequently used in age estimation, the aim of this study was to assess the reproducibility and accuracy of the method on a large Italian sample of teenagers, to ascertain the applicability of the Atlas at the critical age thresholds of 14 and 18 years.

This retrospective study examined posteroanterior X-ray projections of hand and wrist from 484 Italian-Caucasian young people (125 females, 359 males) between 11 and 19 years old. All radiographic images were taken from trauma patients hospitalized in the Azienda Ospedaliero Universitaria Ospedali Riuniti of Ancona (Italy) between 2006 and 2007. Two physicians analyzed all radiographic images separately. The blind method was used.

In the case of an estimated age of 14 years old, the true age ranged from 12.2 to 15.9 years (median, 14.3 years, interquartile range, 1.0 years) for males, and 12.6 to 15.7 years (median, 14.2 years, interquartile range, 1.7 years) for females. In the case of an estimated age of 18 years, the true age ranged from 15.6 to 19.7 years (median, 17.7 years, interquartile range, 1.4 years) for males, and from 16.2 to 20.0 years (median, 18.7 years, interquartile range, 1.8 years) for females.

Our study shows that although the GPM is a reproducible and repeatable method, there is a wide margin of error in the estimation of chronological age, mainly in the critical estimated ages of 14 and 18 years old in both males and females.