An aesthetically pleasing face is one of the main goals of orthodontic treatment. However, in the case of severe pathology, in order to achieve the harmony of the complex of soft and hard tissues of the face, it is necessary to carry out not only orthodontic but also surgical intervention, i.e. orthognathic surgery. A cephalometric analysis for orthognathic surgery (COGS) is an effective element necessary for planning such treatment. The purpose of the study is to establish the peculiarities of cephalometric parameters that characterize the position of individual teeth relative to cranial structures according to the COGS method in Ukrainian young men and young women with an orthognathic bite, depending on the type of face. 46 young men (aged 17 to 21) and 72 young women (aged 16 to 20) who belonged in three generations to residents of Ukraine of the Caucasian race and had an orthognathic bite, underwent cephalometry according to the COGS method. OnyxCeph³™ software, version 3DPro, Image Instruments GmbH, Germany, was used for cephalometric analysis of indicators characterizing the position of individual teeth relative to cranial structures. According to the value of Garson's morphological index, the type of face was determined. Statistical processing of the obtained results was carried out in the license package “Statistica 6.0” using non-parametric estimation methods. Between young women with different types of face, the following reliable or trends of differences in linear and angular indicators, which characterize the position of individual teeth relative to cranial structures according to the COGS method, were established: in young women with a very wide face type, smaller values of the distances 1u-NF, 1l-MP, 6u-NF and the OP-HP angle (compared to medium and narrow face types), as well as the 6l-MP distance (compared only to the medium face type); young women with an average face type have larger values of the 6l-MP distance (compared to narrow face types), as well as the OP-HP angle (compared to wide and narrow face types). Between young men with different types of faces, there are practically no reliable or trends of differences in linear and angular indicators that characterize the position of individual teeth relative to cranial structures according to the COGS method. Manifestations of sexual dimorphism of linear and angular indicators, which characterize the position of individual teeth relative to cranial structures according to the COGS method, have been established: in young men, the values of most linear dimensions are higher in representatives with very wide, wide and narrow face types; young women with different types of faces have larger values of the OP-HP angle. The obtained results will allow dentists to provide the necessary assistance to the patient at a modern level, taking into account not only the age, sex and ethnic characteristics of a person, but also the type of his face.

The key to successful orthodontic treatment is the use of a delicate, modern, accurate and scientifically sound method of intervention planning. In addition, it is critical that this method takes into account as many variables as possible that may affect the final result. Given these criteria, the most appropriate for planning orthodontic treatment is cephalometric analysis of lateral teleradiograms, which, however, requires preliminary clinical trials to adapt it to the local population. The aim of the study was to establish the features of cephalometric parameters of the upper and lower jaws, determined according to the COGS method, in Ukrainian young men and young women with orthognathic occlusion depending on the type of face. According to the COGS method, cephalometry was performed for 46 young men (aged 17 to 21) and 72 young women (aged 16 to 20) who belonged in three generations to Caucasian residents of Ukraine and had an orthognathic bite. OnyxCeph³™ software, 3DPro version, Image Instruments GmbH, Germany was used for cephalometric analysis of the upper and lower jaws. Determination of the type of face of young men and young women was carried out according to the values of the morphological index of Garson. Statistical processing of the obtained results was performed in the license package "Statistica 6.0" using non-parametric evaluation methods. The following significant or tendencies of differences between linear and angular parameters of the upper and lower jaws were found between young women with different face types: in young women with a very wide face type – lower values of ANS-Me distance and N-A-Pog, MP-HP angles (compared to other types face) and Ar-Go-Gn (compared to medium and narrow face types), as well as larger values of the distances N-B and N-Pog (compared to other face types); in young women with medium face type – smaller the values of the distances N-A (compared to other face types), N-B and N-Pog (compared to wide and narrow face types), Go-Pog (compared to very wide face type), A-B (compared to a wide face type), as well as larger values of the distance B-Pog and angles MP-HP and Ar-Go-Gn (compared to a wide face type); representatives with a narrow face type have higher values of the distances N-ANS (compared to other face types), B-Pog (compared to very wide and wide face types), PNS-N (compared to a wide face type). The following significant or tendencies of differences between linear and angular indicators of the upper and lower jaws were found between young men with different face types: representatives with very wide face type have higher values of N-B, N-Pog, ANS-PNS distances (compared to average face type), Ar-Go (compared to wide and medium face types), A-B (compared to medium and narrow face types) and N-A (compared to narrow face types), as well as smaller MP-HP angle values (compared to other face types); representatives with a narrow face type have larger values of PNS-N (compared to other face types) and N-ANS (compared to very wide and wide face types), as well as smaller values of N-A-Pog angle (compared to average face type); representatives with medium face type have only smaller values of the ANS-PNS distance (compared to wide face type). Young men with different face types also have larger upper linear dimensions of the upper and lower jaws than in young women with different face types; and in young women mainly with narrow and medium face types – angular indicators of the upper and lower jaws.

Annotation. Increased attention to the methods of cephalometric analysis by dentists in Ukraine requires a more detailed acquaintance with them to understand both the advantages and disadvantages of each of them. The purpose of the study is to analyze the literature on the possibilities, prospects and problems of using the methods of cephalometric analysis by Burstone, Tweed and Kim in Ukraine. The analysis of the most relevant scientometric databases for the last 10 years has shown that it is impossible to speak unequivocally about the predominance of one method over another. However, according to international researchers, for the effective implementation of a certain cephalometric method of analysis of lateral teleradiograms, it is necessary to conduct a study on the local population, taking into account such features as age, sex, facial features, which has not yet been done in Ukraine.

Annotation. Cephalometric techniques for the analysis of lateral teleroentgenograms, for successful use in orthodontist practice, require a preliminary clinical study, which should include as many healthy individuals as possible from the local population for which this technique will be applied. The purpose of the study is to build and analyze regression models of radio-radiographic parameters used in COGS-methodology in Ukrainian young men with an orthognathic bite with a wide face type. 22 Ukrainian young men with an orthognathic bite and a wide face type underwent a cephalometric study using the COGS method. For the correct modeling of cephalometric characteristics, the division of teleroentgenometric indicators into three groups proposed by M. O. Dmitriev (2016, 2017) was used: the first group is the metric characteristics of the skull, which usually do not change during surgical and orthodontic treatment; the second group – indicators of the maxillofacial system, which can be used to change the width, length, angles and position of the upper and lower jaws with the help of orthognathic surgery; 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. Construction of regression models of cephalometric indicators according to the COGS method was carried out in the “Statistica 6.0” license package. It was established that only 4 reliable regression models of teleroentgenometric indicators with a coefficient of determination greater than 0.6 were built using the COGS method for Ukrainian young men with a wide face, which were included in the second and third groups depending on the indicators of the first group (R²= from 0.626 to 0.780 ), as well as 11 reliable models of indicators were built out of 19 possible, which were included in the third group depending on the indicators of the first and second groups (R²= from 0.626 to 0.970). The analysis of the constructed regression equations showed that most often the models of indicators that were included in the second and third groups, depending on the indicators of the first group, include the value of the distances P-PTV (17.64 %) and N-Se (11.76 %) and the value of the angles H (17.64 %) and N-S-Ba (11.76 %); and to the indicator models that were included in the third group depending on the indicators of the first and second groups – the value of the distances ANS-Me (15.00 %), A-B and N-Pog (7.50 % each) and the value of the angles Ar-Go-Gn, H and N-A -Pog (7.50 % each). Further research will make it possible to develop a computer program that will enable dentists to automatically calculate individual normative teleroentgenometric indicators.

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