UCSF Growth and Development Flashcards
Describe difference between growth control Sites vs Centers
Site: Location at which growth occurs
Center: Location at which independent (genetically controlled) growth occurs
**All centers are sites, but not all sites are centers
T/F, Sutures and Synchondroses are growth centers
False, the sutural theory was disproven.
- Sutures transplanted to another site do not continue to grow
- Sutures respond to outside influences
Are sutures growth sites or growth centers or both
They are growth sites only
T/F, Condylar cartilage does not have innate growth potential and nasal septum cartilage has some innate growth potential.
True
Growth at the condyle is similar to sutures of maxilla, growth is reactive
What is the functional matrix theory of growth described by Moss?
Functional needs lead to enlargement of structures and cavities.
Name the two methods of bone formation
Intramembranous ossification
Endochondral ossification
Intramembranous ossification mainly occurs in what bones?
flat bones of the skull
bone is formed from mesenchyme tissue
Endochondral ossification occurs in what bones?
Long bones such as limbs
Bone is formed from cartilage
Primary ossification centers are responsible for the formation of what?
Diaphyses of long bones, short bones, and certain parts of irregular bones
Secondary ossification centers are responsible for the formation of what?
Epiphyses of long bones and extremities of irregular and flat bones
What separates the diaphyses and epiphyses?
Growing zone of cartilage called the eiphyseal plate.
These are fused together when a child reaches skeletal maturity and cartilage is replaced by bone
Where are osteoclasts derived from?
Bone Marrow (hematopoetic)
Where are Fibroblasts and Osteoblasts derived from?
Mesenchymal cells
By what method of bone formation are the bones in the cranial vault formed?
Intramembranous
By what method of bone formation is the mandible formed?
Both Intramembranous and Endochondral
Condyle is endochondral
By what method of bone formation is the maxilla formed?
Intramembranous
By what method of bone formation is the Cranial base formed?
Endochondral
Growth at synchondrosis, formed initially in cartilage and then endochondral ossificataion
Which develops from secondary cartilage?
a. midpalatal suture
b. vomer
c. condylar head
d. cornu of hyoid bone
Condylar head
Which bones of the skull are formed by intramembranous ossification?
Frontal and Parietal bones
Temporal is formed partially by endochondral and partially by intramembranous
What has sutural growth, endochondral growth, and remodeling?
Neurocranium and midface
No mandible, no sutural?
Describe Meckel’s cartilage in relation to ossification of the mandible
Lateral to the mandible intramembranous ossification
How does the maxilla grow?
By intramembranous ossification entirely.
Apposition at sutures that connect maxilla to the cranium and cranial base
By surface remodeling
Define undermining resorption
Occurs when capillary pressure is exceeded and results in hyalinization (pressure necrosis, sterile necrosis, avascular area of PDL)
Four types of Bone
Woven
Lamellar
Composite
Bundle