The widespread use of methods of cephalometric analysis in practical orthodontics requires the adaptation of normative indicators for members of the local ethnic group. It is also important to study the relationships between cranial and odontometric parameters to understand the effects of these components on each other. The aim of the study was to establish the peculiarities of correlations between the characteristics of basal cranial structures determined by Bjork and Jarabak methods with teleradiographic parameters of the upper and lower jaws and the location of teeth in Ukrainian young men and young women with orthognathic occlusion. Teleradiography was performed in the mode of cephalometric examination of 49 young men (aged 17 to 21 years) and 76 young women (aged 16 to 20 years) who had a physiological bite as close as possible to orthognathic. Cephalometric analysis according to modifications of Jarabak J. R. – Roth-Jarabak and Bjork A. – CFT-Bjork methods, performed using OnyxCeph³™ software, 3DPro version, Image Instruments GmbH, Germany (software license № URSQ-1799). All indicators were divided into three groups according to Dmitriev M. O. (2017): the first group included metric characteristics of the skull, which are used as basic indicators in the methods of cephalometric analysis; to the second group – dental-maxillary in which the skeleton has already been formed and which surgical methods can change the length, width, angles and positions of the upper and lower jaws; to the third group – indicators that actually characterize the position of each individual tooth relative to each other, cranial structures and the profile of the soft tissues of the face. Correlation assessment was performed in the license package "Statistica 6.0" using the non-parametric Spearman method. As a result of the conducted researches in Ukrainian young men and young women with orthognathic occlusion the peculiarities of multiple correlations of characteristics of basal cranial structures determined by CFT-Bjork and Roth-Jarabak methods with teleradiographic parameters of upper and lower jaws and tooth location were established. Both the CFT-Bjork method and the Roth-Jarabak method have more reliable correlations in both young men and young women between the first and second groups (23.3 % for young men and 50.0 % for young women for CFT-Bjork and 48.4 % for young men and 41.1% for young women according to Roth-Jarabak) than between the indicators of the first and third groups (respectively 12.8 % for young men and 7.7 % for young women for CFT-Bjork and 22.5 % for young men and 12.5 % for young women for Roth-Jarabak). The expressed manifestations of sexual dimorphism of the received correlations between the indicators defined by CFT-Bjork and Roth-Jarabak methods both on quantity and force, and in some cases on a direction of correlations are established.

Annotation. Due to the fact that orthodontic treatment is primarily aimed at young people, first of all, cephalometric standards for its proper use should be obtained for this age group by conducting a study taking into account the sex and nationality of the subjects. The aim of the study was to establish the features of cephalometric parameters by the Ricketts method in Ukrainian young men and young women with orthognathic occlusion depending on the type of face and to determine the sex differences of these parameters. 49 young men and 76 young women with orthognathic occlusion in OnyxCeph³™, 3DPro version, Image Instruments GmbH, Germany (license № URSQ-1799) underwent a cephalometric study using the Ricketts method. The division into facial types was performed using the Garson index. As in previous studies, cephalometric parameters were divided into three groups. The analysis of the second (characteristics of jaws by the Ricketts method) and the third (indicators by the Ricketts method that characterize the position of the teeth) groups was performed. Statistical processing of the survey results was performed in the licensed statistical package “Statistica 6.0” using non-parametric evaluation methods. As a result of the conducted researches at young men or young women between different types of face numerous reliable and tendencies of both similar differences, and the corresponding differences of differences of cephalometric parameters according to the Ricketts method concerning the second (higher number) or third groups are established. The pronounced manifestations of sexual dimorphism of cephalometric parameters between young men and young women with the corresponding facial types are established only for the indicators of the second group. The obtained results will improve the existing methods of treatment of dental patients and minimize the likelihood of diagnostic errors and complications.

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Obtaining orthognathic occlusion in a patient as a result of treatment is a key goal of any orthodontist. However, the thorny path that both the patient and the doctor must go through involves painstaking work, which primarily begins with planning and choosing a method of orthodontic treatment, predicting and modeling its results. However, the latter is possible only if previously conducted research to determine the normative indicators for a population. The aim of the study was to construct and analyze regression models of teleradiographic parameters according to the Jarabak method in Ukrainian young men and young women with orthognathic occlusion. 49 young men and 76 young women with orthognathic occlusion underwent cephalometric analysis of lateral radiographs according to the modification of the method Jarabak J. R. – Roth-Jarabak, performed using the software OnyxCeph³™. All parameters according to the Jarabak method were divided into three groups: the first group included metric characteristics of the skull, which are used as baseline indicators; to the second group – dental-jaw in which the skeleton has already been formed and which surgical methods can change the length, width, angles and positions of the upper and lower jaws; to the third group – indicators that characterize the position of each individual tooth relative to each other, cranial structures and the profile of the soft tissues of the face. Construction of regression models of teleradiographic indicators by the Jarabak method was performed in the licensed package “Statistica 6.0” using step-by-step regression analysis. When modeling teleradiographic parameters according to the Jarabak method, which were included in the second group, depending on the indicators of the first group in young men with orthognathic occlusion, 8 out of 19 possible reliable regression models with a coefficient of determination greater than 0.5 (R2= from 0.589 to 0.950) were constructed. The constructed equations most often include the value of the angle N-S-Ar and the distances Ar-Go and N-S. In young women with orthognathic occlusion, 6 reliable regression models of the second group were constructed depending on the indicators of the first group (R2= from 0.609 to 0.971). The constructed equations most often include the value of the distances Ar-Go, S-Ar, N-S and the angle N-S-Ar. When modeling teleradiographic indicators included in the third group, depending on the indicators of the first and second groups in young men, 5 out of 8 possible reliable regression models with a coefficient of determination greater than 0.5 (R2= from 0.658 to 0.751) were constructed. The constructed equations most often include the values of the angles N-A-Pog, N-Go-Gn, S-N-B and A-N-B. In young women with orthognathic occlusion, 6 reliable regression models of the third group were constructed depending on the indicators of the first and second groups (R2= from 0.509 to 0.772). The constructed regression equations most often include the value of the angles N-A-Pog, A-N-B, S-Ar-Go, S-N-A and the ratio Go_Me:N-S. The obtained models will allow orthodontists to automatically calculate the required cephalometric parameters.