Craniofacial Growth I Flashcards
(45 cards)
What are the 4 characteristics of growth?
- Quantitative
- Proportional
- Sprouts (or jumps)
- Decelerated
What is the definition of growth?
- Hypertrophy/hyperplasia
It is a change in size/weight resulting from an increase in number or size of cells
What is growth measured in?
Centimeters or Kilograms
Growth leads to? (2)
- Development (differentiation)
- Maturation (stabilization)
Define development/differentiation? (2)
- tissue differentiation to achieve somatic and functional characteristics
- changes in shape and structure from embryo to adult, from lower to higher stage
Define maturation (stabilizations)?
Stabilization of the
adult condition achieved thanks to the growth and development.
What are the growth influence factors? (4)
- cephalocaudal trend
- different growth rhythms in each type of tissue
- foreseeable nature
- individual variability
Growth factors: What is cephalocaudal trend? (3)
- Proximal growth before distal
- Medial growth before lateral
- Dorsal growth before ventral
Growth factors: What are the Different growth rhythms in each kind of tissue? (2)
• The reproductive organs are the last to develop.
• The brain and head are the ones that suffer
development the soonest
Growth factors: what is foreseeable nature?
There are events and changes that happen in a foreseeable order that cannot be altered
Growth factors: What is individual variability? (2)
•There exists a reasonable variation among the
normality. That is why growth charts have been
created.
•This growth charts define the child position in
relation to the group and enables to follow the
child´s growth through time.
What are the different types of growth? (2)
- Intramembranous ossification
- endochondral ossification
Intramembranous ossification and pressure?
Areas WITHOUT pressure
Endochondral ossification and pressire?
Areas WITH pressure
What is intramembranous ossification?
It forms directly from sheet-like layers of fibrous
connective tissue
What are the steps of intramembranous ossification? (3)
Step 1: Mesenchymal cells differentiate to osteoblasts
that secrete organic matrix bone.
Step 2: Bone forms between blood vessels randomly
forming a trabeculae.
Step 3: Trabeculae thickens at the periphery to form
plates of compact bone
All the bones in the skull and clavicle are formed in this way…?
Intramembranous ossification
What is endochondral ossification?
- Mesenchymal tissue transforms to cartilage in the same shape of bone.
- Cartilage is broken down, reorganized and mineralized to form bone
What are the steps of endochondral ossification? (3)
Step 1: Chondroblasts form hyaline cartilage. This is surrounded by perichondrium,
which becomes bone forming periosteum.
Step 2: Cartilage calcifies in the center of the diaphysis. Chondrocytes die due to
calcification. The ends of the bone still have healthy chondrocytes so the bone
model enlarges.
Step 3: Primary ossification bud expands. Blood vessels, osteoblasts and osteoclasts
reach the epiphysis.
The condyle and the nasal septum are formed this way…?
Endochondral ossification
What is involved with differential growth? (2)
- remodelling
- displacement
What is bone remodelling?
bone deposition and resorption
Bone remodelling responds to ____?
Functional demands
What changes does bone remodelling produce? (4)
- size
- shape
- proportion
- relationship of bone with adjacent structure