PECULIARITIES OF FORMATION OF THE HARD PALATE FOLDS DURING THE SECOND AND THIRD TRIMESTER OF THE INTRAUTERINE DEVELOPMENT

Abstract

A comprehensive study of anatomical-functional peculiarities of the cranial bones promotes implementation of new methods of performing radical and reconstructive-restorative surgery on the face and cranium. Objective: to determine peculiarities of formation of the hard palate folds structure in the fetal and early neonatal periods of human ontogenesis. Materials and methods. The study was conducted on 53 specimens of dead fetuses from 4 to 10 months of development and on 9 specimens of dead neonates by means of macro- and micro-section, preparing histological and topographic-anatomical sections, and morphometry. Formation of the hard palate folds during the second and third trimesters of the intrauterine development was found to consist of the following stages: epithelial thickening, penetration into the adjacent mesenchyme originating the rudiment of the fold; smoothing of the basal membrane and epithelial outgrowth over the surface with formation of the primary fold; condensation of mesenchyme cells under the fold apex; formation of fibrous stroma inside of the fold which is a peculiar core; epithelial smoothing to even thickness similar to that one embracing the areas between folds with formation of the final fold. At the end of the third trimester of the intrauterine development posterior transverse palatine folds become less marked, some of them disappear, and the anterior ones become more marked, closer and pressed one to another.