Accuracy of age estimation and assessment of the 18-year threshold based on second and third molar maturity in Koreans and Japanese

Humanitarian forensic action in East Asia: where are we now? A concise review

Humanitarian forensic action (HFA) is practiced in many parts of the world. In recent years, with the development of forensic humanitarian methods and applications and the increasing inclusion or even prioritization of HFA by organizations and institutions, research in this field has evidenced greater depth and diversity, although perspectives from the humanities and some disciplines remain limited. In-depth inquiries into this topic and an analysis of regional humanitarian data reveal the existence of ideological and cultural foundations for HFA in East Asia. At the same time, given past occurrences of natural disasters and large-scale wars in this region, the need and motivation for advancing this field and developing HFA is considerable. Currently, because of a lack of practical experience of HFA in East Asia, research on this relevant topic in the region focuses on the development of humanitarian forensic applications. Consequently, studies reporting on social surveys, psychological care and other methods are limited. It is to be hoped that East Asian countries will improve their practical HFA applications, while simultaneously carrying out social surveys and social scientific research on all aspects of HFA.

Key Points

The current development of humanitarian forensic action is described in the field of different scientific disciplines and humanitarian applications in East Asia.The base of humanism of humanitarian forensic action in East Asia, and the necessity and feasibility of developing humanitarian forensic action are summarized.Lmitations of improving humanitarian forensic action in East Asia and ways to improve are presented.

Validation of London Atlas for forensic age estimation in Koreans by comparing with Lee's and Willems' methods

This cross-sectional study aimed to evaluate the applicability of the London Atlas for age estimation in the Korean population by comparing with Lee's and Willems' methods. Dental ages of 475 orthopantomographs from Korean individuals aged 4-15 years (mean 10.32 ± 3.31 years) were estimated using the London Atlas, Lee's and Willems' methods. Correlation between dental and chronological age was determined using Pearson's correlation coefficient, and the statistical difference between dental and chronological age was analyzed using a paired t-test. The bias (mean differences), mean absolute error, and root mean square error between dental and chronological age, stratified by age groups and estimation methods, were calculated. Differences in bias and absolute error between sexes were scrutinized using an independent-samples t-test. Age estimates of the three tested methods were combined and compared to those of each individual method. The London Atlas and Willems methods resulted in overestimations, whereas the Lee method led to an underestimation on the entire sample. The overall accuracy was observed in the order of Lee's method, the London Atlas, and Willems' method. The London Atlas demonstrated superior consistency of estimation performance across age groups and no significant differences in estimation performance between sexes. The combination of estimates from the London Atlas and Lee's method resulted in an enhancement in bias and accuracy. We conclude that the London Atlas, due to its bias and accuracy comparable to Lee's and Willems' methods, is applicable for forensic practice in the Korean population.

Evaluation of Third Molar Maturity Index by Cone Beam Computed Tomography in Legal Age Estimation: A Preliminary Study

ABSTRACT

This retrospective study aimed to evaluate the accuracy and applicability of the third molar maturity index (I 3M ) for discriminating Turkish minors from adults, and its relationship with chronological age using cone beam computed tomography (CBCT). A total of 122 CBCT scans of Turkish individuals (55 boys and 67 girls) aged 13 to 23 years were evaluated using the I 3M cutoff value. Chronological age gradually decreased as the I 3M value increased. The overall accuracy was 95.9%. The sensitivity and specificity of this test were 93.5% and 97.4%, respectively. Positive predictive value was 95.6%. The intraclass correlation coefficient values of the I 3M for the intraobserver and interobserver agreements were 0.998 and 0.996, respectively. This study showed relatively higher reproducibility of measurements on CBCT scans than on panoramic radiographs in the literature. Cone beam computed tomography may be advantageous and preferred over panoramic radiographs in distinguishing the legal age threshold of 18 years according to Cameriere's method when a more extensive investigation is needed to support the solution of challenging and uncertain cases in forensic medicine.

Evaluation of four criteria in assessing third molar maturity for age estimation in Koreans

Third molar maturity is one of the major criteria for estimating human age. This study aimed to determine the most suitable third molar maturity criteria for age estimation in Koreans. The correlation between chronological age and the Demirjian, Köhler, Liversidge, and Thevissen criteria was evaluated using 900 panoramic radiographs of patients aged 15-23 years. The four criteria were applied separately to measure third molar maturity on the same radiograph. The concordance rates between third molars within the same jaw and between jaws were calculated and tested using a paired t-test. Regression was performed to observe the relationship between age and the evaluated stages for each tested criterion. The Demirjian standard showed the lowest root mean square error (1.29 years for males, 1.30 years for females) and highest adjusted R ² (0.753 for males, 0.739 for females) values; however, the differences of the values derived from other criteria were minute. In addition, the symmetry (within the same jaw) and asymmetry (between the upper and lower jaws) of third molar development, which was confirmed in previous Korean studies, was observed only in the Demirjian and Liversidge criteria. Based on the results, we can conclude that all four tested criteria are suitable for age estimation in Koreans. However, the Demirjian and Liversidge criteria can be recommended from the perspective of accurate reflection of the developmental patterns. Further research is necessary to determine whether the results of this study are consistently observed in other populations.

Validation of data mining models by comparing with conventional methods for dental age estimation in Korean juveniles and young adults

Teeth are known to be the most accurate age indicators of human body and are frequently applied in forensic age estimation. We aimed to validate data mining-based dental age estimation, by comparing the accuracy of the estimation and classification performance of 18-year thresholds with conventional methods and with data mining-based age estimation. A total of 2657 panoramic radiographs were collected from Koreans and Japanese populations aged 15 to 23 years. They were subdivided into a training and internal test set of 900 radiographs each from Koreans, and an external test set of 857 radiographs from Japanese. We compared the accuracy and classification performance of the test sets from conventional methods with those from the data mining models. The accuracy of the conventional method with the internal test set was slightly higher than that of the data mining models, with a slight difference (mean absolute error < 0.21 years, root mean square error < 0.24 years). The classification performance of the 18-year threshold was also similar between the conventional method and the data mining models. Thus, conventional methods can be replaced by data mining models in forensic age estimation using second and third molar maturity of Korean juveniles and young adults.

Estimating the 18-Year Threshold with Third Molars Radiographs in the Southern Italy Population: Accuracy and Reproducibility of Demirjian Method

The estimation of the age of the majority of living subjects is widely required nowadays due to the presence of unidentifiable individuals, without documents and general information, involved in migration or legal procedures. Dental age estimation (DAE) is a valid method for investigating the age of subjects. The aim of this study was to evaluate the accuracy of the Demirjian method in a limited age group (16-24 years) in differentiating between older and younger than 18 years. From an initial sample of 17,594 radiographs, 460 were selected meeting the inclusion criteria. Two dentists provided the age estimate according to the Demirjian method, with a simplified approach based on the development of the third molars. The presence of a developmental stage of H for at least one third molar allowed to establish the major age if the other third molars, inferior or superior, have reached a stage equal or superior to F, with an accuracy of 90.2% and a predictive positive value of 91.6%. Thirty-three patients showed the development of at least one third molar (Stage H) before the age of 18 years while six patients showed the development of all four third molars with root completion (stage H) before the age of 18 years. When all third molars reached stage H an individual was over 18 years old in 97.4% of cases. In presence of one third molar on stage H and a stage equal or superior to F for the other third molars the probability of being of major age was 91.6%.