CRANIOMETRICAL CHARACTERISTICS OF THE HUMAN FETAL SKULL

Abstract

The purpose of the study – to ascertain the regularities of the age-related dynamics ofmorphometric changes of the skull in the fetal period of human ontogenesis.Material and methods. 59 specimens and 12 computed tomography (CT) scans of theskulls of human fetuses aged from 4 to 10 months of intrauterine development (IUD)were studied. A complex of morphological research methods was applied, which includedanthropometry, morphometry, three- dimensional reconstruction and statistical analysis.The results. It has been established that the longitudinal and transverse dimensions, thecircumference of the cerebral part of the skull grow almost uniformly before birth, but bythe 5th month of the IUD, a more accelerated growth is observed, due to which the scatterdiagram has the appearance of a logarithmic dependence. A somewhat uneven growth ofthese morphometric indicators is also observed in the age-related changes in the width andupper height of the face. The growth of the facial angle during the fetal period was revealed,which can be explained by the development of the mandible («pushing» it forward). At the same time, the basilar angle slightly decreases during the fetal period of development,which can be explained by the increase in the brain volume. The basilar angle increaseswith the age of the fetus, but somewhat unevenly in leptins, i. e., until the beginning of the6th month, it almost does not change, during the 6th-7th months it increases intensively,and then slows down again until the end of the fetal period of IUD. In euryons, there isa uniform growth of the basilar angle throughout the fruiting period of development, andmore intensively than in the average morphotype – mesens. Analysis of the correlation offetal age, cranial index, and basilar angle size showed even more significant anatomicalvariability. Thus, if in dolicho- and mesomorphs the basilar angle grows almost uniformlyduring the fetal period, then in brachymorphs it first intensively decreases until the 6thmonth of development, and then begins to grow until the newborn period. It should be notedthat a similar feature is observed in the dynamics of age-related changes in the facial angle,in addition to slowing down its growth from the 8th month in dolichomorphs.Conclusions. 1. Regression analysis of the correlation of age, morphotype indicators, andbasilar and facial angles made it possible to establish patterns of individual morphometricvariability of the skull in the dynamics of the fetal period of prenatal human development,as well as to identify critical periods of morphogenesis of the brain and facial parts ofthe skull, which are 6-7 months in leptins, the 6th month – for brachymorphs and the 8thmonth – for dolichomorphs. 2. The size of the basilar angle of the skull is an importantdiagnostic and prognostic indicator in combination with indices that characterize themorphotype of the individual, for monitoring the normal development of the skull andbrain of the fetus.