ABSTRACT
OBJECTIVE: The aim: To determine the peculiarities of the morphometric parameters of suprahyoid region of the human prefetuses. PATIENTS AND METHODS: Materials and methods: Thirty specimens of human prefetuses of 14.0-80.0 mm parietococcygeal length (PCL) (7-12 weeks of IUD) were studied using a complex of modern methods of morphological research. RESULTS: Results: On the basis of obtained digital indicators of the main morphometric parameters of human SHR in the dynamics of the prenatal period of IUD the critical periods of development of the region were clarified and mathematical functions that describe the normal course of organogenesis of SHR were created, which can be useful for creating diagnostic algorithms for the norm when carrying out prenatal diagnostics and monitoring the state of the fetus. It has been established that the 9-10th week of IUD is a critical period in the development of SHR, since during this time, intensive growth processes occur, which are manifested by a sharp change in the size of the organ, and this can lead to the appearance of variants of the structure and possible congenital defects of the SHR and the dental-maxillary apparatus in general. CONCLUSION: Conclusions: 1.Age-depended dynamics of changes in the anterior angle of the SHR shows an almost linear decrease in the angle by the end of the 9th week of IUD almost to 76°, after which it increases to almost 90° by the end of the 10th week. From the 11th week of the IUD, the anterior angle decreases again to 77 °, but begins to increase at the 12th week and by the end of the prefeal period. 2.The lateral length of SHR increases almost uniformly until the 9th week of IUD, during which its growth rate slows down. Starting from the end of the 10th week of IUD, this morphometric parameter begins to grow rapidly until the end of the prenatal period of ontogenesis. The growth rate of the lateral length of the SHR is described by the function: L lat = 1.1025 + 0.0015 x + 0.001 x2. 3.The width of the SHR from the 10th week of IUD begins to grow rapidly until the end of the prenatal period of development. The growth rate of the width of SHR is described by the function: W = 1.1025 + 0.0015 x + 0.001 x2. 4.Analysis of the age dynamics of the area of SHR demonstrates the exponential dependence on the age of the prefetuses, which is described by a mathematical function: A = 1,2452exp(0,0424x). Meanwhile, there is a slight slowdown in its growth rate at the 10th week of IUD with subsequent recovery of growth by the end of the prenatal period of ontogenesis. 5.The 9-10th week of IUD is a critical period in the development of SHR, since during this time, intensive growth processes occur, which are manifested by a sharp change in the size of the mandible.
