Reliability of Schmeling’s stages of ossification of medial clavicular epiphyses and its validity to assess 18 years of age in living subjects

Nowadays, due to the global increase in migration movements, forensic age estimation of living young adults has become an important focus of interest. Minors often have no identification documents providing their correct birth dates. Establishing the age of majority is therefore fundamental in order to determine whether juvenile penal systems or penal systems in force for adults are to be applied. Radiological examination of the clavicles is one of the methods recommended by the Study Group on Forensic Age Diagnostics. In this retrospective study, a sample of chest radiographs of 274 subjects, aged between 12 and 25 years, was studied according to Schmeling’s method in order to examine the ossification of both medial clavicular epiphyses. All stage classifications were evaluated by five examiners. Intra- and inter-examiner reliability was analysed by Cohen’s K statistic. Intra-examiner agreement was insufficient for two of the experts. Inter-examiner agreement, among the other three operators, was moderate (K = 0.509). Study of reliability highlighted difficulties in interpretation, the need to select qualified personnel and choice of the best radiographic image in order to reduce any anatomic overlaps. Although ossification of the medial clavicular epiphyses is recommended to assess whether an individual has already reached the age of majority or not, these results suggested that it is very difficult to clearly identify the five stages of ossification by using conventional chest radiography.