Abstract
(1) The undifferentiated neural crest cells were recognized in the early tooth germ of the mice embryos. In the bud stage the neural crest cells were scattered in the vicinity of the cell group or cell mass in the tip of the dental epithelium and in the mesonchyme adjacent to it, and in the cap stage they were recognized arround the enamel knot in the inner enamel epithelium and in the dental papilla adjacent to it. In the early bell stage the neural crest cells of the inner enamel epithelium were scattered in the place where the cell arrangements were in disorder. (2) In the early bell stage, further, the undifferentiated neural crest cells were present in close proximity to the capillaries and outside the capillary wall in the future pulp, and the undifferentiated mesenchymal cells in the dental papilla were scattered in the neighbourhood of the basement membrane. (3) The neural crest ce l l s were scattered in the locally thickened oral epithelium and in the underlying mesenchyme, in the boundaries between the dental lamina and the underlying mesenchyme. (4) Furthermore, the neural crest cells were present in the mesenchyme under the oral epithelium composed of one or two cell layers in stage forming the dental lamina, and they were present parallel to the epithelium. Besides, they were scattered in the meenchyme along the outer enamel epithelium (including the future outer enamel epithelium) on the lateral side of the dental epithelium in the bud, cap, and the bell stages.
