odontogenesis- part 1 Flashcards
what is the budding epithelium known as?
primary epithelial band
when mesenchyme migrate to the maxilla/mandible for tooth formation what signal is released from the epithelium?
FGF8
what does FGF8 cause the mesenchyme to do?
undergo condensation and cluster under the primary epithelial band
what week is primary epithelial band formed?
week 6
what happens in week 7?
the primary epithelial band forms the DL and VL which grow
what happens in week 8?
continued growth of DL and VL
what happens within week 9?
apoptosis of VL begins- in order to form the vestibule
what is the vestibule ?
it is the gap between the soft tissues and the teeth
what happens in week 10-11?
continued growth of DL and continued apoptosis of VL
what happens in week 12?
vestibule is formed creating the sulcus between tooth and labial/buccal surface
what are the 3 stages of tooth development?
initiation
morphogenesis (shaping)
histogenesis
what does the epithelia (ectoderm) form?
enamel and hyaline of the root
what does the ectomesenchymal cells form?
dentine
pulp
cementum
pdl
bone
what happens in the initiation stage of tooth development and what week does this occur?
the epithelial thickens around week 6
describe the bud stage of tooth development and what week it starts?
week 8
-epithelium proliferate and move into mesenchyme- enamel organ formed
-fgfs and baps released from epithelium than cause condensation of ectomesenchyme at bud
-condensed mesenchyme=dental papilla
lots of proliferation at this stage
what happens during the cap stage of tooth development?
-little morphogenesis into cap like structure
-proliferation of epithelial (periphery is quicker)
-migration of more ectomesenchymal cells which will form dental follicle
what happens at the bell stage? and at what week?
week 14
-tooth shape forming-morphogenesis
-dl shrinkage
-enamel epithelium differentiation into 4 layers- histogenesis
what does the dental papilla form?
-odontoblasts that form dentine
-pulp
what does the dental follicle form?
-cementum
-pdl
-bone
what are the 4 layers of enamel from inner to outer?
IEE
stratum intermedium
stellate reticulum
OEE
what does the IEE form?
the ADJ
what does the ADJ form?
ameloblasts to make enamel
what shape are IEE cells?
columnar
what shape are stratum intermedium cells?
flattened
what shape are stellate reticulum cells?
star shaped due to desmosomes for attachment
what is the function of stellate reticulum ?
form fluid filled space for shape and protection
what is the shape of OEE?
cuboidal
what is the purpose of OEE?
shaping of cell and for exchange
