Stages in crown development. A. Dental lamina stage. Localized bands of proliferating cells in the basal layer of the stratified oral epithelium, peripheral to
the developing tongue, form two (one per jaw) horseshoe-shaped epithelial ridges, or dental laminae, over the mesenchyme of the future mandibular and
maxillary arches. B. Bud stage. Stimulated by local clusters of neural crest–derived mesenchyme cells, proliferation increases in the base of each dental
lamina at the 10 sites of future deciduous teeth. These epithelial tooth buds enlarge and bulge into the underlying mesenchyme. C. Early cap stage. With
further proliferation, the deep bud surfaces invaginate and widen to form solid caps over mesenchymal clusters. In the cap's core, the cell density
decreases as internal cells become stellate and the interstices accumulate tissue fluid. The peripheral cells, which contact the basal lamina, form a simple
Source: Chapter 15. Digestive Tract, Histology & Cell Biology: Examination & Board Review, 5e
epithelial shell and continue to divide, increasing the cap's size. A stalk of dental lamina connects each cap to the oral epithelium. The mesenchyme under
Citation:and
Paulsen
DF. Histology
& Cell
Examination
Board
Review,
5e; 2010within
Available
http://mhmedical.com/
Accessed:
31,
the cap proliferates
condenses,
indenting
the Biology:
cap's base.
D. Late &
cap
stage.
Mesenchyme
the at:
indentation
forms the dental
papilla,July
further
2017
indenting the cap's base. The epithelial cells over the papilla (inner enamel epithelium) become columnar, whereas those forming the rest of the shell
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McGraw-Hill
Education.
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(outer enamel
epithelium)
remain
low cuboidal.
The stellate
cellsreserved
and fluid inside the shell make up the stellate reticulum. Between the stellate reticulum
and the inner enamel epithelium lies a layer of epithelial cells called the stratum intermedium. Together, the inner and outer epithelia, stratum intermedium,