The aim of the study was to assess the capabilities of age determination (age group) at death using classification techniques by histomorphometric characteristics of osseous and cartilaginous tissue aging.Materials and Methods. The study material was a database containing the findings of morphometric researches of osseous and cartilaginous tissue histologic specimens from 294 categorized male corpses aged 10-93 years. For data analysis and classification we used modern machine learning methods: k-NN, SVM, logistic regression, CatBoost, SGD, naive Bayes, random forest, nonlinear dimensionality reduction methods (t-SNE and uMAP), and recursive feature elimination for feature selection.Results. The used techniques (algorithms) provided effective representation of a complex data set (76 histomorphometric features), allowing to reveal the cluster structure inside the low dimensional feature space, thus fitting the classifier becomes even more reasonable. During feature selection, we estimated their importance for age group classification and studied the relationship between classification quality and the number of features inside the feature space. Data pre-processing made it possible to get rid of noise and keep most informative features, thereby accelerating a learning process and improving the classification quality. Data projection showed more well-defined cluster structure in the space of selected features. The accuracy of establishing certain groups was equal to 90%. It proves high efficiency of machine learning techniques used for forensic age diagnostics based on histomorphometric findings.

The aim of this cross-sectional study was to test the accuracy of the third molar maturity index ( I 3 M ) cut-off value (0.08) to distinguish between individuals above and below the adult age of legal responsibility (18 years) in a Russian population. A sample of 571 digital panoramic radiographs of healthy Russian minors and young adults (363 females and 208 males), aged between 14 and 24 years, was evaluated. The lower left third molars were analyzed by applying the cut-off value of 0.08 determined by Cameriere et al. (2008). Lin’s concordance correlation coefficient ( ρ c ) and Cohen’s kappa coefficient ( κ ) showed that repeatability and reproducibility are high for both intra- and interobserver errors. The I 3 M value decreased with age in both sexes. Age distribution gradually decreases as I 3 M increases in both girls and boys. In the male group, molar maturity stages 0-0.04, 0.04-0.08, 0.08-0.3, 0.3-0.5, and 0.9-1.4 were reached slightly earlier than in the female group. The results demonstrated that sensitivity is 0.96 in boys and 0.93 in girls; associated specificity values were both 0.98. The cut-off value of I 3 M is statistically robust and thus valid for forensic application in a Russian population to determine whether or not a subject has reached 18 years of age. Finally, we compared our results with those of other studies in which the same I 3 M cut-off value was tested on different populations. The method is novel as it is reliable and easily reproducible, thus ensuring a universal way of comparing the results obtained (based on a cut-off value) among many populations, in order to develop an ever-increasing database.

ИСПОЛЬЗОВАНИЕ ЛУЧЕВОЙ ДИАГНОСТИКИ ДЛЯ ОПРЕДЕЛЕНИЯ БИОЛОГИЧЕСКОГО ВОЗРАСТА ЧЕЛОВЕКА ПО МОРФОМЕТРИЧЕСКИМ ПАРАМЕТРАМ ЩИТОВИДНОГО ХРЯЩАПиголкин Ю.И., Полетаева М.П., Золотенкова Г.В.ель исследования. Изучить возрастную динамику строения щитовидного хряща (ЩХ) на рентгенограммах для оценки возможности использования по-лученных данных при судебно-медицинской идентификации личности. Материалы и методы. Исследованы 90 рентгенограмм щитовидного хряща, на которых с помощью программы графического анализа изображений были определе-ны площадь щитовидного хряща, площадь костной и хрящевой ткани. Результаты. После статистической обработки полученных данных найдена сильная прямая связь между степенью окостенения щитовидного хряща и возрастом человека (r= 0,8), что в дальнейшем позволило вывести уравнение линейной регрессии для опре-деления возраста. Среднеквадратичная величина ошибки прогнозирования составила 8,4 года.Выводы. Полученные результаты могут быть применены на практике как до-полнительный критерий определения биологического возраста человека при судебно-медицинской идентификации личности.Ключевые слова: идентификация личности, определение возраста, щитовидный хрящ, рентгенологический метод. AGE DETERMINE BY THE AGE OF THE THYROID CARTILAGE BY THE RADIOLOGICAL METHOD IN FORENSIC MEDICINEPigolkin Yu.I., Poletaeva М.P., Zolotenkova G.V.urpose. The aim of this article is radiological examination of age change of thyroid cartilage (TC). Materials and methods. 90 radiographs of TC were observed in this study. The degree, distribution and frequency of ossification of thyroid cartilage were investigated in each radiograph by the software of graphical analysis of data.Results. Radiographically detectable thyroid ossification increased with age. There was a positive correlation between degree of osseous tissue and age (correlation coefficient =0.8) and standard error was 8.4 year.Conclusions. The thyroid cartilage has age-related changes in its structure. This method for detecting of age can be used in personal identification with more accurate methods in forensic medicine.

No abstract