The validity of the age assessment method based on the "Radiographic Atlas of Skeletal Development of the Hand and Wrist" by Greulich and Pyle (1st edition 1950) has been frequently questioned. The purpose of this study was to examine the reliability of this widely used method and to compare it to various dental and other skeletal age assessment methods. Forty-seven Finnish children of known ages below 16 years, who perished in Thailand in the Southeast Asian Tsunami on 26 December 2004 were examined. Every victim repatriated to Finland underwent a complete forensic autopsy including CT-scan, toxicological screening, and diatom analysis in order to establish the cause of death, as well as DNA testing and dental examination for the verification of the identification established in Thailand. Age assessment was performed by dental and skeletal methods. The average difference between the age assessment values obtained by the Greulich and Pyle method, and the chronological age was 9.7 months. In addition to the Greulich and Pyle method, an alternate skeletal method, Tanner and Whitehouse 2, resulted in an average age difference of 10.3 months. Dental age assessment methods were based either on the eruption (Nyström method, 8 cases, average age difference 5.6 months), or the development of the crown and roots (Demirjian method, 33 cases, average age difference 5.2 months and ABFO method, 7 cases, average differences 12.6 months). Dental methods proved to be most accurate in childhood until the teeth-with the exception of wisdom teeth-have erupted and root development is completed. In adolescence, however, the validity of skeletal methods improves considerably.

In Finland, forensic age assessment is strictly regulated by legislation. According to the Aliens Act (301/2004) and the amendment of the Act (549/2010), the police authorities, the frontier guard authorities, and the immigration authorities have the right to refer asylum seekers to the University of Helsinki, Department of Forensic Medicine, for age assessment. These assessments are especially performed to solve if the person is of major age, the cutoff being 18 completed years. The forensic age assessment is largely based on dental development, since the special permit of the Radiation and Nuclear Safety Authority (STUK) to the Department of Forensic Medicine of the University of Helsinki, allowing the use of ionizing radiation for non-medical purposes, includes dental and hand X-rays. Forensic age assessment is always performed by two forensic odontologists. In 2015, the total number of forensic age assessment examinations was 149, and the countries of origin of the asylum seekers were most commonly Iraq, Afghanistan, and Somalia. The current legislation on forensic age assessment has been well received and approved. Radiological and other examinations can be performed in different parts of Finland, but the forensic odontologist at the University of Helsinki is always involved in the process and ensures joint quality standards for the forensic age assessment.