Comparative analysis of the applicability of the skeletal age determination methods of Greulich-Pyle and Thiemann-Nitz for forensic age estimation in living subjects

Evaluation of hand ossification is a main pillar of radiological age diagnosis in living subjects. In the present study, we comparatively assessed the Greulich-Pyle and Thiemann-Nitz methods for accuracy of age estimation and degree of acceleration in the respective reference populations. For this, the skeletal age of 649 hand X-rays from German subjects aged 1-18 years was determined by both methods. Accuracy of the age estimates was determined based on regression and measures of certainty. In terms of accuracy, both methods seem to be equally well suited for forensic age diagnostics. The degree of acceleration in the reference populations for the two methods was calculated as the mean difference between the estimated skeletal age and the actual age of a test subject. Compared to the Greulich-Pyle population, the Thiemann-Nitz population was accelerated by 0.44 years in both male and female subjects. When an expert opinion is required and one cannot exclude the possibility that the investigated subject may come from a population with a high acceleration status, the Thiemann-Nitz method should preferably be used to prevent overestimation of age.