In order to find out the peculiarities of the structure and mineral composition of bone tissue of the human maxilla in the dynamics of prenatal ontogenesis, we investigated preparations of 219 objects (embryos, prefetuses and human fetuses) from the age of 4 weeks to 10 months of intrauterine development (3.2-375.0 mm of coccygeal-parietal length) using: a set of morphological research methods (macroscopy, morphometry, microscopy, microphotography, simple and delicate preparation of the maxilla); a complex of methods for the determination of macro- and trace elements in the germs of the bone tissue of the human maxilla (turbidimetric, photometric, atomic-emission and atomic absorption analyzes of photometry of the flame); a hardware investigation of the density of maxillary bone tissue of human fetuses in the dynamics of prenatal ontogenesis has been carried out using a computed tomograph GX CB-500 № NU011250, USA to analyze the received images of standardized software i-CATVision with the definition of quantitative density indices in international units Hounsfield (MO Hu). All the obtained digital indices have been processed by methods of variation statistics, which confirms the probability of data on the peculiarities of qualitative characteristics of human maxillary tissue in the dynamics of prenatal ontogenesis and is important for prenatal diagnosis, forensic medical practice, especially for monitoring normal fetal development and early developmental defect screening. A new approach has been proposed for the first time to study the qualitative characteristics of maxillary tissue of human fetuses, which consists in the complex (simultaneous) study of the quantitative content of trace elements (K, Fe, Co, Sr, Zn), macroelements (P, Na, Ca, Mg, S) and CT-density of the bone tissue of the germ of the maxilla of the human fetuses in the dynamics of prenatal ontogenesis. Since during the ultrasound examination, the visualization of facial structures with the detection of anomalies of development or the establishment of its norm becomes possible from 11-13 weeks of pregnancy, the study focuses on the age group of 11-16 weeks of fetal development, which, at the same time, provides the proper conception of the density of bone tissue, which is ensured by the content of micro and macroelements. In this regard, using the method of statistical groupings in the study of qualitatively homogeneous aggregates, where there are no qualitative changes yet, but there are quantitative differences, grouping for a large number of observations has been conducted (group 1 - 11-16 weeks of intrauterine development, 2 groups - 17-24 weeks; group 3 - 25-29 weeks and group 4 - 30-40 weeks of intrauterine development). The features of morphogenesis of the human maxilla in the early prenatal period of ontogenesis with the definition of the age period of the onset of prerequisites for in-depth study of mineral content and CT-density of the germs of human maxillary tissue have been studied. For the first time the quantitative indices of the mineral content (macro- and microelements) in the germs of human maxillary tissue in the dynamics of the fetal period of development have been determined and the patterns of age dynamics of the mineral elements content in the germ of the bone tissue of the maxilla of human fetuses have been studied.
The CT-density of the germ of bone tissue of various anatomical parts of the maxilla (corresponding to four apices of the upper jaw: frontal, caudal, palatal and cellular) has been determined for the first time in the dynamics of the fetal period of intrauterine development using standardized software i-CATVision in MO Hu and the patterns of age dynamics of the density of the germs of bone tissue of different parts of the human upper jaw have been established. A comparison of the age dynamics of the indices of density and mineral content (micro- and macro-) of the germs of human maxillary tissue in prenatal ontogenesis with mathematical processing and statistical analysis of the data has been made for the first time. The new actual data on the features of the structure, microelement (K, Fe, Co, Sr, Zn) and macroelement (P, Na, Ca, Mg, S) content and CT-density of human maxillary tissue in the dynamics of prenatal ontogenesis have been obtained, and they have the applied significance in the theoretical and practical branches of medicine, laboratories for morphological material screening to assess the degree of maturity and predict the viability of the organism, diagnosis of deviations from normal development and their correction. Scientific results on mineral content and bone density of the maxilla of a human fetus in the dynamics of prenatal ontogenesis are recommended for use in the educational process at the departments of pediatric dentistry and jaw-facial surgery, as well as writing monographs and textbooks on these disciplines.
