Development of the secondary palate in the rat: a scanning electron microscopic study.

摘要: Normal palatogenesis was studied in the Sprague-Dawley rat, using fetuses of a precise, individually determined age (between 15 and 21 days pregnancy) scanning electron microscopy. Individual fetal deviated markedly from gestational by vaginal smear method. Palatal closure, ie elevation fusion anterior remodeling middle zones as well posterior zone all occurred between 16.0 17.5 age, earlier than Wistar rat fetuses. Prior to fusion, medial edges palatal shelves revealed two distinct initial surface alterations: one at maximum shelf convexity, other caudal end portion. A similar found free edge nasal septum. Subsequent oral aspects including formation fate midpalatal line, development palatine rugae, union primary palate secondary shelves, foraminae soft following closure are described detail. It is suggested that (1) cobblestone appearance cells reflects undifferentiated epithelial status rather marks future zones; (2) involves different mechanisms, furrow growth lateral foraminae; (3) portions (soft palate) may occur independently region.