Tooth Development 2 Flashcards
when is this?
week 14
stellate reticulum
stratum intermedium
dental follicle
inner enamel epithelium
outer enamel epithelium
dental lamina
dental papilla
name two main things that happen in the bell stage
Odontoblasts form predentine
Cervical loop proliferation
bell stage - cervical loop proliferation
where the ? cells meet the ? cells
Signals from the ? induces ? of the ?, as these cells mature get differentiation into ?
Once ? cells mature they signal ? cells to mature and lay down ? then ?
These signal back to the ? for the ? to mature into ? and start laying down ?
outer enamel epithelial
inner enamel epithelial
dental papilla (ectomesenchyme)
proliferation
inner enamel epithelium
preameloblasts
IEE
dental papilla
predentine
dentine
IEE
pre-ameloblasts
ameloblasts
enamel
what signals from the dental papilla (ectomesenchyme) induces proliferation of the inner enamel epithelium? 4
Bone morphogenic protein
FGF
Wnt
Sonic headgehog
odontoblasts
predentine
preameloblasts
dental papilla
inner enamel epithelium
stratum intermedium
sellate reticulum
outer enamel epithelium
dental follicle
in what stage does enamel start to form?
crown stage
in what stage does predentine start to form?
bell stage
ameloblast
stratum intermedium
stellate reticulum
notice the change in shape of an ameloblast
give an overview of what happens to an ameloblast as it matures
lengthens
develops tomes process
shortens
Tooth shape determination - morphogenesis
Takes place in ? stage or ? stage
Tooth shape is determined by differential rates of ?/? through signals from the ?
Happens from the switching on of specific growth factors
late bell
early cap
cell division
maturation
dental papilla
? drives initiation of tooth development, if its not switched on no teeth will develop
PITX2
tooth shape determination happens from the switching on of which specific growth factors?
Msx1, Msx2, Dlx1, Dlx2, Barx-1 and Alx-3
what growth factor stops tooth morphogenesis?
Wnt
Reduced enamel epithelium
Formed when the 4 layers of enamel organ ? once the crown is ?
Secretes ? that facilitate the breakdown of the ? to form an ?
Interacts with ? to recruit ? that differentiate into ? and can assist connective tissue ? and bone ?
fuse
complete
proteases
connective tissue
eruption pathway
dental follicle
monocytes
osteoclasts
degradation
resorption
what are the 3 roles of reduced enamel epithelium?
protection of enamel surface from resorption and cementum formation
provide an epithelial lined pathway for eruption
forms initial junctional epithelium
understand this
what is a successional dental lamina?
formation of secondary dentition behind the primary one
where does a successional dental lamina normally form in relation to the primary tooth?
Normally goes to the lingual side of the tooth
Tooth gland lamina - if it goes to the labial side
successional dental lamina
what is hypodontia?
missing teeth
what genes are impacted in hypodontia?
msx1 and pax9
what is oligodontia?
more than 6 teeth missing
what genes are impacted in oligodontia?
msx1, pax9 and Axin2
what is anodontia?
all teeth are missing
what causes supernumery teeth?
overexpression of genes
hypodontia, oligodontia, anadontia and supernumeries are caused by developmental disruption in which stage?
initiation stage
what is microdontia?
small teeth
what is macrodontia
large teeth
microdontia and macrodontia are cause by developmental disruption in which stage?
bud stage
what is dens en dente?
enamel organ invaginates into the dental papilla
what is this an example of?
dense en dente
what is gemination?
tooth germ tries to divide so get a single root with two teeth
how can you tell clinically if its gemination or fusion?
fusion may have extra roots
in gemination there will be an extra tooth where as fusion will be a missing tooth
dense en dente, fusion and gemination are caused by developmental disruption in which stage?
cap stage
