Functional Morphology of Tissues in Ontogenetic Aspect in Children with Complete Bilateral Cleft Lip and Palate. Summary of the Doctoral Thesis

Abstract

Cleft lip and palate is one of the most common congenital pathologies, causing esthetic and functional disorders in a child. Complete bilateral cleft lip and palate is a grave pathology, in its treatment multigrade plastic surgical corrections are needed, resulting in the closure of the wound and formation of scar tissue, which can negatively affect the growth of the facial and oral tissues. Nowadays the morphogenetic study of facial cleft-affected tissues is of great significance, in order to understand the etiomorphogenesis of this embrionally determined pathology and post-operation tissue remodeling potential. The development of the face and oral cavity contains the following specifically coordinated processes – tissue proliferation, differentiation, migration, programmed tissue death, synthesis and degradation of extracellular matrix, development of the basis of local protection factors. The processes mentioned in embryonic tissues are coordinated by different signal molecules and growth factors. Specific genes, external and teratogenic factors can cause the lack or excessive presence of a certain signal molecule and/or growth factor, resulting in the development of the facial cleft. The aim of the research was to study specific signaling molecules and tissue death determination in the cleft-affected tissues, as well as determination of those factors, which most essentially characterize morphopathogenesis of bilateral cleft lip and palate in the ontogenetic aspect. 46 patients were included in the research: 22 children had bilateral complete cleft lip, alveolar process and palate, 24 children – unilateral complete cleft lip, alveolar process and palate. By means of immunohistochemical method there were studied and analyzed matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-8 (MMP-8), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), tissue inhibitor of matrix metalloproteinase-4 (TIMP-4), gene protein MSX1, IRF6, PAX9, RYK, vascular endothelial growth factor (VEGF), transformating growth factor beta-3 (TGFβ3), transmembranous glycoprotein CD34 (CD34), protein gene product 9.5 (PGP 9.5), nestin, proliferation marker Ki-67 (Ki-67), osteocalcin (OC), osteopontin (OP), osteoprotegerin (OPG) and relative amount of bone morphogenetic protein 2/4 (BMP2/4) immunoreactive structures. By TUNEL method was studied the presence and distribution of apoptotic cells. All in all, in the most severe type of the cleft – bilateral cleft lip and palate there was found the presence of decreased transcription factor IRF6, MSX1 and PAX9, the growth factor TGFβ3 and VEGF, as well as the decreased cell proliferation and apoptosis in the soft tissues, but in the supporting tissues – the decreased OPN, OPG, MMP-2, TIMP-2, BMP2/4 and TGFβ3 presence. It was conclusively proved, that morphological tissue changes were more severe in patients with bilateral clefts. During repeated operations, one and the same patients we were identified an increased MSX1, MMP-9, TIMP-4, TGFβ3, Ki-67 and decreased VEGF expression.