During palatal fusion, the epithelium that covers the tip of opposing palatal shelves adheres, intercalates and thins into a single-layer medial edge seam(MES). The disintegration of the MES results in the confluence of the palatal mesenchyme. Transforming growth factor(TGF)B3 is essential for palate development, especially in the late phase of palatogenesis, in which the palatal MES disintegrates and mesenchymal confluence occurs. Regulation of medial-edge epithelium(MEE) cell completion of the epithelial—mesenchymal transition(EMT) by TGFB3 has become the primary concern of the fate of MEE cells. TGFB3 activates the transcription complexes of Smad2, Smad4, phosphatidylinositol- 3-kinase, Lef1, Twist, and other transcription factors to regulate the palatal EMT program. The function of TGFB3 gene in the MES disintegration process, associated mediated signal transduction pathways, and related research progress are summarized in this paper.
