3 - Growth and Development (complete) Flashcards
Growth Vs. Development
growth is the anatomical change in number and/or size of cells/tissues/organs
Development is the behavioral change of complexity, differentiation, and organization
The head makes up what percent of the bodies cephalocaudal measurement at 3 months in utero, birth, and adult hood
3 months = 50%
birth = 30%
adult = 12%
How does the growth of the cranium and face go
cranium grows first, then mandible, then maxilla.
infants have larger craniums, smaller faces, Adults have smaller craniums, and larger faces
How does the growth of the mandible compare to the maxilla
the mandible grows later and larger than the maxilla
How does the rate of growth of the following compare lymphoid neural maxillary mandible somatic genital
lymphoid - peaks at 10, decreases to adulthood
neural - finished growing at 6-7
maxillary - gradually grows up to 20 years
mandible - S-curve, grows when young and at puberty
somatic - S-curve, grows when young and at puberty
genital - begins at puberty
What does the growth of the mandible correlate with
puberty
Which is better to tell whether there was an acceleration or deceleration of growth. Distance curves or Velocity curves
Velocity curves, shows height gain per year over time.
Why do we use growth charts for kids
to determine whether there is an unexpected change in growth patterns
What is individual variability, and how does it change with increasing age
individual variability is the difference in timing of growth spurts, puberty, and menarche. it decreases with increased age
When does menarche typically occur
1-1.5 years after peak growth
how do growth patterns look for early and late maturers when using biological age instead of chronological age
when using biological age (onset of menarche) growth patterns look very similar and become more predictable
How does growth of facial width, length and height occur
facial width is completed when puberty begins
facial length growth is greatest at puberty and rapidly declines into adulthood
facial height grows at a steady rate into adulthood
how does the mandible condyloid and coronoid processes and zygomatic arch grow
mandible grows by bone apposition to the surface (addition of bone to the surface)
zygomatic arch grows by apposition of bone to the surface and internal resorption
How does soft tissue grow, how does hard tissue grow
soft tissue grows via interstitial growth
hard tissue grows via direction appositional (periosteum) growth (addition of new bone to the surface)
What is the difference between modeling and remodeling
modeling is the formation of new bone (either endochondral or intramembranous)
Remodeling is the achievement of final bone shape through apposition and resorption
What is endochondral ossification and where in the head does it occur
calcification of a plate of cartilage into bone at centers of ossification
it occurs at the base of the cranium and in the mandibular condyle
What is intramembranous ossification and where in the head does it happen
bone forms directly in the mesenchyme without the formation of cartilage
it occurs in cranial vault, maxilla, and the mandible except for the mandibular condyle
What is cortical shift
deposition of bone on the periosteal surface and resorption of bone on the enosteal surface = bone relocation
What are primary and secondary displacement
primary = movement of a bone due to bone growth secondary = movement of a bone from displacement of other bones and soft tissue (nasomaxillary complex)
What makes up the cranial vault, cranial base, and face
cranial vault = bone covering the upper and outer surface of the brain
Cranial base = bony floor of the brain (between vault and face)
Face = nasomaxillary complex and mandible
How does the cranial vault grow
by intramembranous ossification, that is stimulated by the growing brain. apposition of bones at the sutures, and remodeling on the inner and outer bone surfaces
How does the cranial base grow
initially via endochondrial ossification
what are the three synchondroses found in the cranial base
spheno-occipital
inter-spheno
spheno-ethmoid
What are the steps of growth of the nasomaxillary complex
- passive growth, being pushed by the growing cranial base (occurs until about 6)
- active growth via apposition of bone at the sutures between maxilla and cranium (after age 6)
- surface remodeling, anterior surface undergoes resorption
- bone addition to the maxillary tuberosity for erupting molars
What is an example of when bone is added in the direction of the movement
the palate, it moves down and forward, and bone is being deposited on the oral side, and resorbed on the nasal side
what is an example of when bone is resorbed in the direction of movement
the anterior maxilla, it moves down and forward, and bone is being removed on the anterior maxilla and in the alveolar process
what determines if maxillary width increase is possible
as long as the midpalatal suture is patent growth can occur
How does the mandible grow
endochondral ossification on the mandibular condyle
appositional growth and remodeling on the mandibular body
Where does most of the growth of the mandible occur
the posterior surface of the ramus. The mental part of the mandible doesn’t move, it just grows backwards and upwards
What is the difference between a growth site and a growth center
growth site is anywhere that bone growth occurs, but there is no innate growth potential. it grows due to external influences
growth centers are places with genetically controlled growth potential
(all growth centers are growth sites, but not all growth sites are growth centers)
is condylar cartilage a growth center
nope
