growth and facial development Flashcards
replacement of the cartilage matrix by an osseous matrix
endochondral growth
long bones growth pattern
and involves growth centers or growth plates
indirect growth
where cartilage matrix is replaced by immature bone.
Genetically programmed!
growth plates or centers
the cartilaginous growth of the cranial base= chondrocranium
has the spheno-ethmoidal synchondrosis that stops growing at=
intersphenoid synch. that stops growing at=
spheno-occipital synchondrosis that stops growing at=
6
birth
12-15 years
replacement of connective tissue with bony tissue
irregular bones
intramembranous bone growth (important in dentistry!)
intramembranous bone formation:
- mesenchymal cells
[signaling factors] - osteoblasts
- ossification center (in the tissue and grow)
- creates Osteoid (unmineralized bone)
[calcification] - Osteocytes
- Lamelar or cortical bone(dense hard to resorb) is formed
the bone formation occurs directly in a vascularized mesenchyme
intramembranous ossification
new bone forms on the external aspect of the bone while bone is resorbed on the internal aspect
resorption-apposition
a bony structure will be displaced during growth.
in order to preserve the shape, parts of the bone will receive new bone and parts will resorb
V principle of Enlow
The V is placed on the growth surface
where does apposition take place
where does resorption take place
apposition on surfaces in the center
resorption surfaces outside V
what are the growth mechanisms of the cranio-facial structures:
- intramembranous (DIRECT)
- displacement of bone in space by resorption-apposition
-drift principle:^^ allows volume increase and displacement in space whiile maintaining the proper shape
what is drift principle
allows volume increase and displacement in space while maintaining the proper shape
resorption apoosition
drift principle
