Odontogenesis: Tooth Dev 1 Flashcards
what is histogenesis
differentiation of undid cells to make new tissues
what is mineralised dental tissues
enamel, dentine and cementum and UNMINERALISED dental tissues - dental pulp and periodontium
what is dental lamina
contributes to development of teeth
what is vestibular lamina
contributes to the vestibule of mouth, form sulcus
what is the invitation stage
first stage of tooth dev
what si the bud stage
second stage
spherical to ovoid
epi condenses poorly
what si the cap stage
3rd stage of tooth dev
tooth germ grows into cap shape
what is the bell stage
4th stage
differentiation occurs to furthest extent resemble bell
what is the crown stage
fully dev tooth
what is the external enamel epi
outer layer of cuboidal cells that limit the enamel origin
what si the stellate reticulum
of epi origin
behave like mesenchymal cells
syn collagen 1,2,3
what is stratum intermedium
2 or 3 layers of cells sitting above IEE
express alkaline phosphatase
what is inner enamel epi
columnar shaped cells rich in RNA
connected by desmosomes
what is ectomesehcyme
neural crest cells
mesodermal somites
what does the primary epi band give rise to
dental lamina
vestibular lamina
what does the vestibular lamina do
grows then breaks down
froms vestibule between teeth and lips/cheeks
tooth dev is 3 phases
initiation
morphogenesis
histogenesis
what does the epi give rise to
ectoderm
enamel
hyaline layer of root
what does the mesenchyme give rise to
ectomesenchyme
- dentine
- pulp
- cementum
- periodontium (PDL and bone)
when is the first sign of tooth development
6 weeks i.u
what happens in initiation of tooth dev
localised epi thickening in incisor and molar regions
which tissues initiates tooth dev
epi
ecotmesenchyme or nerve
tissue remobinations
why are a couple of important genes involved in tooth dev
MSX 1/2
what does the dental lamina do in germ
continues to lengthen
changes shape
what happen in tooth germ to ectomesenchyme
condensation
what are the components of tooth germ
enamel origin
dental papilla
dental follicle
what is sen at the bud stage
spherical/ovoid epi condensation
cell prolif
no morhpo/histognesis
what is seen at the cap stage
cap shaped enamel organ
poorly histodiff
little morphogen
what is seen at the early bell stage
morphs and hist diff
what is the enamel origin in the early bells stage
inner enamel epi
startup intermedium
stellate reticulum
outer enamel epi
what does the ecotmesenhcyme do int he early bell stage
dental papilla - forms odontoblast and pulp
dental follicle - forms cemetnuem, PDL and bone
what are the enamel organ component
inner enamel epi
stratum intermedium stellate reticulum
outer enamel epi
what does the inner enamel epi contain
basal lamina = ADJ
columnar cells at cusp tips
ameloblasts = enamel
what does stratum interediam contain
flattened cells
what is the role oft he stratum intermedian
syn and transport to and from IEE
what is the stellate reticulum composed of
star shaped cells
fluid filled extrcell space
what s the osmotic gradient due to in the stellate reticulum
extracellular GAG’s
what is the role of the stellate reticulum
maintain shape and protection
what is the role of the outer enamel epi
maintenance of shape and exchange
what does the outer enamel epi made of
cuboidal cells
what are the transitory structures
enamel knot
enamel niche
enamel septum
what si the enamel knot important for
signalling centre
BMP, Shh, MSX1
what si the enamel nice
2d - hole
3d - depression
what does the enamel septum do
aid change in shape from cap to bell
what is the extracellular matrix important in
morhpgensis differentiation adhesion prolif migration polarisation
what does the extracellular matrix do
express type 1,2,3 collagens
laminin
proteoglycans
what does the extracellular matrix cause changes in
fibronectin
tenascin
typ 1,2,3 collaneg
syndecan
