Topographic and Anatomical Peculiarities of the Lateral Region of the Head in Human Fetuses

HEAD IN HUMAN FETUSESAbstract. In order to clarify the topographical and anatomical peculiarities and variant anatomy of the structures of the lateral region of the head in the fetal period of human ontogenesis, 24 specimens of human fetuses aged from 4 to 10 months of intrauterine development were studied using a complex of morphological research methods (anthropometry, macroscopy, computer tomography, morphometry, reconstruction). We found anatomical variants of the masseter and temporal muscles in human fetuses. Thus, in a 5-month-old fetus, separate muscle bundles were found, which went from the right masseter to the right temporal muscle. In a 6-month-old fetus, the deep part of the left masseter muscle was fused to the left temporal muscle. In human fetuses, the temporal fascia in the direction of the zygomatic arch splits into two layers, between which there are accumulations of adipose tissue. In late fetuses, a formed sub-aponeurotic fi brous space was found. At the end of the fetal period, a deep fi brous space is observed between the periosteum and the inner edge of the temporal muscle. The cellular spaces of the temporal area in front are connected with the buccal fat pad, which creates the prerequisites for the spread of infl ammatory processes. The topographic and anatomical features of the temporal region of human fetuses are: weak development of the temporal muscle and small depth of the temporal fossa – in the middle part from 3.0 to 6.0 mm (depending on the age of the fetus); weakly developed tendinous part of the temporal muscle, which does not reach the temporal line of the parietal bone. The bony base of the temporal area is represented by the squamous part of the temporal bone, the greater wing of the sphenoid bone, part of the parietal and frontal bones, on the inner surface of which arterial grooves and impressions of cerebral gyri are hardly visible, and sometimes not at all clear or absent. Anatomical variants of the structure of the temporal and masticatory muscles, as well as the temporal fascia, can cause complications and errors during the diagnosis and surgical treatment of infl ammatory processes in the postnatal period of human ontogenesis.