MORPHOGENESIS PECULIARITIES OF THE SUPRAHYOID REGION IN THE PREFETAL PERIOD OF HUMAN OTOGENESIS

Abstract

Elucidation of the features of morphogenesis and topographic changes of suprahyoidregion (SHR) of the neck and its structures in the dynamics of human intrauterinedevelopment (IUD) remains a relevant area of morphological research. Refined,comprehensive data on gender, age and constitutional features of the structure andtopography of organs and structures of the SHR of the neck during the prenatal periodof human ontogenesis will make it possible to develop new criteria for the interpretationof medical diagnostic imaging data, the degree of fetal viability, improve existing anddevelop new methods of surgical correction of congenital neck defects.Purpose of the work: to clarify the morphometric features of the suprahyoid region ofthe neck in the prefetal period of human ontogenesis.Material and methods. Thirty preparations of human prefetuses of 14.0-80.0 mm parietococcygeal length (PCL) (7-12th weeks of IUD) were studied using a complexof modern methods of morphological research: anthropometry, morphometry, threedimensional reconstruction and statistical analysis. The morphometric parametersof SHR were determined: width (distance between the inner surfaces of the condylarprocesses of the mandible), anteroposterior length (distance from the anterior surfaceof the hyoid bone to the lower edge of the mental symphysis), lateral length (length ofthe lateral border of the SHR – distance from the inner surface of the angle of mandibleto the lower edge of the mental symphysis), the anterior angle of the SHR (the anglebetween the lateral borders of the SHR).Results. On the basis of the obtained digital indicators of the main morphometricparameters of human SHR in the dynamics of the prenatal period of IUD the criticalperiods of development of the region were clarified and mathematical functions thatdescribe the normal course of organogenesis of SHR were created, which can be usefulfor creating diagnostic algorithms for the norm when carrying out prenatal diagnosticsand monitoring the state of the fetus. It has been established that the 9-10th week of IUDis a critical period in the development of SHR, since during this time, intensive growthprocesses occur, which are manifested by a sharp change in the size of the organ, andthis can lead to the appearance of variants of the structure and possible congenitaldefects of the SHR and the dental-maxillary apparatus in general.Conclusions.1. At the 10th week of the prefetal period of IUD, there is an accelerated increase in theanteroposterior size of the LAP (y = -6.3851 + 1.041 * x; r = 0.9374; p = 0.00001).2. At the 11th week of the prefetal period of IUD, there is an accelerated increase in thelateral length of the SHR (y = -6.1289 + 1.1277 * x; r = 0.8891; p = 0.00001).3. During the clarification of the regularities of the dynamics of changes in the widthof the SHR, it has been found that at the beginning of the prefetal period of the IUD,the growth rates of the indicator are slow, but from the 9th week of IUD, its acceleratedgrowth is observed (y = -4.5904 + 1.1074 * x; r = 0.8662; p = 0.00001).4. Features of the change in the value of the anterior angle of SHR in the prefetal periodof human ontogenesis demonstrate a general tendency towards its decrease during thisperiod of development – from 90.18±0.55° (7th week) to 82.12±1.17° (12th week), butafter a sharp decrease in this angle until the end of the 8th week of the development(79.32±1.03°), its intensive growth begins during the 9th week and until the end of theprefetal period (y = 93, 8224 – 0.9577 * x; r = -0.4140; p = 0.0229).