[The osteometric method for the determination of sequential localization and sex characteristics of the ribs using discriminate analysis].

The study material was ribs of the Caucasoid carcasses from the collections of the Department of Anthropology, M.V. Lomonosov Moscow State University, and the Department of Personality Identification, Russian Centre of Forensic Medical Examination. Each rib was measured as stipulated by the 13 point program of A.I. Turovtsev (1972). The results were analysed with the use of the SPSS statistical packet. Diagnostic models were calculated for the purpose of forensic medicine practice based on step-by-step discriminative analysis. It is recommended to perform expert evaluation in two stages. The aim of the first stage, is to establish the group affiliation of a concrete rib. Group 1 comprises III-V ribs, group 2--ribs VI--VIII, and group 3--ribs IX-XI. Determination of the sequential localization of I, II, and XII ribs encounters practically no difficulty due to their unique anatomical structure. The accuracy of classication of group localization of the ribs amounts to 99.6%. At the second stage, individual number of a concrete rib within a group is determined. The accuracy of classification of ribs belonging to groups 1 and 3 is 80.2% and 85.7% respectively and that of ribs in group 2 is lightly lower (41.7-69%). Sexual identity of the ribs was determined by means of multidimensional discriminative analysis. The accuracy of diagnosis is directly related to the integrity of the study material; in other words, it depends on the amount of ribs available for the analysis. It is shown that sexual identity is best established for rib VI followed by ribs VIII, II, IV, and I respectively. The main discriminative features include the total arch length, costal plane curvature, and height-width dimension. Diagnostic equations are derived for the determination of sexual identity of individual ribs for the practical purposes of forensic medical examination.