MORPHOGENETIC TRANSFORMATION DYNAMICS OF HUMAN MAXILLOFACIAL APPARATUS IN THE FIRST

EMBRYOGENESIS TRIMESTER

Barsukov A.N., Dyachenko E.A., Pisariev A.A.

Department of Histology and Embryology (Head Prof. E. Yu. Shapovalova)

Crimean State Medical University named after S.I. Georgievsky

^{Studied histological sections of maxillo-facial apparatus human embryos and fetuses aged from 4 to 12 weeks. Сomplex application of morphological, histochemical and cariometric methods allowed to determine the age dynamics of morphogenetic transformations and the formation of interstitial interactions during the histogenesis of its main parts.}

^{Separation of the visceral head parts is determined on the}

^{21-day-old embryo development when bilaterally located rudiments first gill arch and the frontal process of restricting stomodeum are visible. Their basis is compounded by mesenchyme covered by one layer of epithelial ectodermal origin. On the fifth week, 4 pairs of visceral arches already became isolated. In the thickness of the mesenchyme of the first two pairs are defined basis of gill arteries and signs of differentiation toward the young connective tissue. The rudiments of the upper and lower jaws are isolated. Stomodeum communicates with the pharyngeal gut. The pair of medial and lateral nasal processes delimit the nasal fossa. On the sixth week of embryogenesis distal ends of the mandibular processes becomes closer to each other, Meckel's cartilage appears in their proximal parts. Maxillary processes with the frontal, lateral and medial nasal processes forms the upper jaw and upper lip to the end of the seventh week of development.}

^{During the 6-7th weeks there are isolated osteogenic islands, which increases in subsequent stages in size and merge together to form their skeletal framework in both jaws (at the bottom somewhat earlier). Determined the rudiments of chewing and facial muscles, mesenchyme differentiates into a loose connective tissue of the lips, cheeks and gums. In this subepithelial mesenchymocites transformed into cells of fibroblastic differon more rapidly. At the 8th week, there is a formation of enamel organs and alveolar processes. Palatal plate, which defines the osteogenic islands located bilaterally along the tongue, begin to change their position on the horizontal and a 9-week fetuses, grow together with each other, form the hard palate, resulting in oral cavity separated from the bow. During the 10th week, branches of the mandible developed, formed by hyaline cartilage on 11-12-week begins to replace by bone tissue, while the 12-week fetuses have the rudiments of designated heads of temporomandibular joint. Meckel's cartilage begin to replace by the connective tissue.}

^{Described morphogenetic changes in the structural components of the maxillofacial apparatus accompanied by regular gradual complication of the synthesis of biologically active substances and modification of cariometric indicators together reflects the quality and quantity of their restructuring.}

^{Based on our histological, histochemical and cariometric characteristics revealed the most pronounced morphological changes in the development process of human maxillofacial apparatus at the cellular, tissue and organ levels occurring the periods of separation in the gill apparatus (4th week of embryogenesis), convergence and accretion of the maxillary processes and palatal plates (5-8 weeks) and the formation of tooth rudiments (7-8 weeks), which are critical in terms of possible developmental abnormalities in the facial area.}

^{В оргкомитет Интернет-конференции}

^«Европейская наука XXI века^{», Польша,}

^{07-15.05.2011}

^{Прошу включить мои тезисы в программу конференции и выслать счет для оплаты публикации в сборнике конференции.}

^{Ассистент кафедры общей гигиены и экологии кафедры}

^{Крымского государственного медицинского университета}

^{ПИСАРЕВ Анатолий Аркадьевич}

^{Украина, АР Крым, г.Симферополь, ул. Гаспринского, 5а, кВ.6, 95017.}