Postnatal Development Flashcards
____ tissues are poorly studied
soft
Bone develops due to…
genetics
Soft tissue develops due to…
adaptation to bone
______ plays a role in dental-alveolar complex & mandible
environment
-ex: mouth breathing can inhibit mandible growth
What type of bones undergo endochondral growth?
long bones
What way does endochondral bones grow?
from the middle outward
What does endochondral growth grow from?
cartilage precursor
What is another phrase for endochondral growth?
indirect growth
What does indirect growth grow out from?
growth centers or growth plates
What are the three facts about growth centers?
- genetically programmed
- mechanical stress (pressure/tension) has no effect
- highly organized
What are the steps of indirect/endochondral growth?
- bone collar and hyaline cartilage model
- primary ossification center
3a. blood vessels grow in
3b. secondary ossification center - articulation occurs and growth plate centers form
What is a growth plate or center?
- Where the cartilage matrix is replaced by immature bone
*genetically programmed
The mandible is a long bone: true or false.
FALSE
What type of growth does the cranial base/chondrocranium use?
cartilaginous growth
*responds to long bone growth patterns
What does the cranial base angle determine?
class I, II, or III
*related to specific malocclusion
When does the intersphenoid synchondrosis fuse?
birth
When does the spheno-ethmoidal synchondrosis fuse?
6 years
When does the spheno-occipital synchondrosis fuse?
12-15 years
What is the most important type of bone growth in dentistry?
intramembranous bone growth
(90% of craniofacial growth)
How does intramembranous bone growth work?
Replacement of connective tissue with bony tissue
Intramembranous growth will result in ________ of other structures in space
displacement
What are the steps of intramembranous bone formation?
- mesenchymal cell -> signaling factors
- osteoblasts
- ossification center
- osteoid -> calcification
- osteocytes
- lamelar or cortial bone
The bone formation occurs directly in a _________ in intramembranous ossification
vascularized mesenchyme
_________ occurs throughout life to keep the bone in balance
remodeling
What is an example of too much bone formation (apposition)?
tori
What is an example of too little bone formation (resorption)?
periodontal disease
New bone forms on the _______ aspect of the bone while bone is resorbed on the ______ aspect
external
internal
True/False: The ratio is not always proportional as some structures must increase in size during growth
True
What is the V principle of Enlow?
- 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
Placing a V on a ________ osseous structure will determine the direction of growth
growing
________ surfaces are in the center of the V
Apposition
__________ surfaces are located outside the V
Resorbing
What type of growth is direct?
intramembranous
Displacement of bone in space by resorption-apposition is called?
drift
What is the drift principle?
allows volume increase and displacement in space while maintaining the proper shape
