Expression Of Btbd7 In The Developingtooth Of Postnatal Mice

Objective:To research in different periods of SD rats after birth early development of’s epithelial root sheath cells especially Hertwig root Btbd7 gene expression and the significance, to discuss its role in the process.Materials and Methods:Selection after the birth of 5,8,11,15,19 days of SD rats, take contains the equivalent of mandibular first molar of mandible, take out the tooth germ, made from tooth germ specimens, routine paraffin section, HE stain, histological observation on root development.Immunohistochemical SABC method, testing Btbd7 genes expressed in different period of tooth germ.Results:HE staining observed 5 days after birth, to develop dental crowns, radicle in tooth surface visible double deck structure of HERS, but at the moment of HERS and into glaze has no obvious demarcation;Root formation begins at 8 days after birth, the crowns of enamel hard edges to form, into glaze in crown edge and down to the double layer epithelial structure ehrs, boundary between the two is obvious; 11 d after birth, on the edge of the crown and root bifurcation with root dentine formation, these areas of ehrs, break first, and most of HERS, remains intact; 15 d after birth, root to form, the majority of HERS to failure;Continue to form after the birth of 19 d, root, only in the root root tip remains of a small group of ehrs, a complete rupture of ehrs distribute in the root surface or was encased in a newly formed cells of bone.Immunohistochemical display in the SD rats after the birth of the fifth day, Btbd7 gene positive signal mainly locate in the tooth germ, the intermediary organization cells, staining is located in the cytoplasm;And Hertwig’s epithelial root sheath cells into glaze, star, the reticular layer of cells, and dental follicle cells staining negative; 8 days after birth, positive staining in the epithelial root sheath cells, epithelial root sheath surrounding the dental papilla cells and odontoblasts and glaze in the cytoplasm of cells, and in have no expression of bone cells into; 11th day after birth, Hertwig’s epithelial root sheath cells still express positive, dyeing in discontinuous in the root of bone surface close to the root surface epithelial root sheath cells; 15 days, Btbd7 gene positive signal in ert w H I g s epithelial root sheath cells, epithelial root sheath surrounding the dental papilla cells and in odontoblasts.Conclusion:Btbd7 gene in the late stage of tooth development, formation and mineralization related to participate in the crown enamel glaze and middle layer cells differentiation and function, and the roots in Hertwig’s epithelial root sheath after fracture is expression, and its part to maintain on the surface of cementum, and participate in the growth of root and root branch form of differentiation...