Palatogenesis Flashcards
when does formation of palate occur
week 6-12
what is the primary palate
limit off orals nd nasal cav
from fused medical nasa prominences (inter-max segment)
when does ossification centres palate around the perp plate
week 8
what ossification takes places mostly at palate
intramembranous ossifiction
what happens in intramebarnous ossify
mesenchyme cells osteoblasts osteoid mineral depo ostebalst osteocytes
what si the role of the secondary palate
sep nasal and oral cav
imp for mast - bolus form, sensation, speech
what do the mesenchymal cells do
matrix form
prolif
differentiate
everything at right place and time
when does beginngin of palatal shelves form
week 6
what si the relation of tongue when pal shelves forming
very constricted area palatal shelves have t grow down sides of tongue never stick to tongue epi doesn’t allow
at week 7 what are the palatal shells like
lateral are vertically orientated due to tongue obstruction
what happens to tongue at week 8
tongue withdraws backwards
when tongue drops what happens
lateral platal shelves flip into hoiontal orientation then fuse making secondary palate
what is the most common cleft palate
whole
or back
fuses from front to back
what is the overall palatal shelf elevation process
initially develop medial and downward then rapidly elevate and fuse
how does palatal shelf elevation come about
extrinsic forces to palate - tongue
intrinsic forces of palate
what are the extrinsic forces to the palate affecting palatal shelf elevation
tongue withdrawal
- head lift from cardiac plate
- meckels cart grow
- other factors
what dos meckels cart grow
grow forward to mandible allowing room for tongue to drop
what re the inricsic factors infleuenicig the palatal shelf elevation
hydration of ECM
- hyaluoronan GAG
- binds 10x water
- accumulates before elevation
what are some ‘other’ intrinsic factors
mesenchymal cells - shorten and contract
forces directed by collagen
when do the palatal shelves seem to be completely fused
week 12
what si the fusion of the palatal shelves like
epi adhesion
- sticky surface glycoprotein
- specific doesn’t fuse tongue
how does epi beween plates go away
enzymatic epi degeneration
- epi-mesnchyme transition
- apoptosis
- migration to edges
what fusion rebels can occur
cleft palate
epi remnants - cell rests = cysts = pani
are palatal clefts common
one of most common congenital abnormalities (1:25000)
is cleft palate more often seen male or female
in females due to fusion process starting week later
what are some risk factors to fusion problems
smoking alcohol abuse drugs viruses folic acid def
how is HA made
3 diff enzymes
- HA synthase 1, 2, 3
(1 and 2) large molecular weight (3) smaller
what is remodelling of face done by
surface depo
resorption
