Alterations in Vascular Pattern of the Developing Palate in Normal and Spontaneous Cleft Palate Mouse Embryos

Abstract

The alterations in the vascularization of the developing palate were studied through the use of resin cast images of vascular networks in normal and spontaneous cleft lip and palate (CL/Fr) mouse embryos (crown rump [CR] Length 9-18 mm, body wt. 0.11-0.65 g). A more dense vascular plexus was observed in the oral side than in the nasal side before the reorientation of the palatal shelves. Prominent terminal dilatations of the vascular plexus were observed in the extreme medial edge of the elevating palatal shelves which may exert significant force for palatal shelf elevation. The vascular plexus showed a lateral extension. Many small spherical masses of resin were observed in the medial edge of the palatal shelves at the time of medial extension and during fusion, indicating some changes occurring in the capillary wall leading to the resin leakage. In the spontaneous cleft group, a similar vascular pattern was observed, but the greater palatine artery showed discontinuity in the premaxillary region at an early stage. At the same time, terminal dilatations were delayed and frequently absent in the contralateral shelf. After the reorientation of the palatal shelves, the vascular plexus formed an irregular lattice pattern. Dilated vasculature was apparent in the anterior nasopalatine region, indicating the persistence of a more primitive vascular structure in the spontaneous cleft embryos. However, the area where capillary dilatation occurred was different between unilateral and bilateral cleft embryos. In conclusion, blood vessels in the palatal shelves are underdeveloped and remained immature in cleft lip and palate embryos and showed different patterns in the anterior nasopalatine region between unilateral and bilateral cleft embryos. These variant vascular patterns may be due to the inadequate blood supply to the nasopalatine region from the early embryonic stages possibly resulting from the discontinuity of the greater palatine artery.

Microarray analysis of murine palatogenesis: Temporal expression of genes during normal palate development

“…Interestingly, mRNA expression fell between ED13.5 and 14.5, suggesting that annexin VIII mRNA levels are higher before palatal shelf elev-ation. A dense vascular plexus is seen in the oral side of the palatal shelves before their reorientation, with prominent terminal dilatations at the extreme medial edge of the elevating palatal shelves, suggesting a significant force for palatal shelf elevation (Amin et al 1994). A dense vascular plexus is seen in the oral side of the palatal shelves before their reorientation, with prominent terminal dilatations at the extreme medial edge of the elevating palatal shelves, suggesting a significant force for palatal shelf elevation (Amin et al 1994).…”