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Bell Stage of Morphogenesis
This tooth germ is further developed than those seen in the preceding images. The cells in the cervical loop area (A) proliferate causing the rim of the cap to grow deeper into the connective tissue. This transforms the shape of the dental organ from a cap to a bell. The tooth germ in this section is considered to be in the early bell stage. Note the increase in intercellular material in the stellate reticulum (B) and the elongation of the IDE (D) cells into columnar cells.
A dense strand of cells (C) crosses the stellate reticulum from the dental lamina to the central region of the inner dental epithelium - the enamel septum. The enamel septum is another transitory structure with no known significance. In the dental organ, a condensation of epithelial cells covers the inner surface of the columnar, IDE cells. The layer is called the stratum intermedium (E) - intermediate in position between the stellate reticulum and the IDE cells.
Legend
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A - cervical loop |
E - stratum intermedium |
