Download - 1. growth & development
General concepts of growth Growth Assessment Bone formation and growth
control Growth of craniofacial
complex
Growth Development
- Increase in size - increase in & number complexity -Anatomical -increase in specialization -phsiological or behavioral
Pattern
Variability
timing
Reflects proportionality overtime Allows predictability Ex: changes in overall body proportions - cephalocaudal gradient of growth
Not all tissues
grow at the same rate
Individuals are not alike in the way they grow
It is important to know if an individual is at the extreme of a normal variation or outside the normal range
The same events happen to different individual at different times ( biologic clock)
Some children grow quickly and mature early
Chronological age Vs Development age CA is not a good indicator of growth
status because of timing and variability
To determine optimum time for treatment(growth modification & surgery)
To determine the amount of growth left
To determine type of growth
“Brachy”tends to grow horizantly “Dolicho” tends to grow vertically Knowing the general pattern of growth
and the expected direction can be helpful in orthodontics diagnosis and treatment planning .
Vertical GrowthDamages Faces(Dolicocephalic)
Horizontal GrowthImproves Faces(Brachycephalic)
Bone ,teeth,sometimes cartiladge
Hyperplasia hypertrophy Mineralized ECM Interstitial growth is Impossible after
calcification Direct or surface
deposition
Everything including some cartiladge except bone and teeth
Hyperplasia Hypertrophy and
secretion of ECM occur in the surface
The sites of growth
Type of growth
Control of growth
Flat bones –intermembranous bone Ossification center Apposition of new bones at the cranial
sutures ,periosteal activity (remodelling)-pressure from the growing brain
Bone resorption from the inner surface and bone deposition in the outer surface - remodelling
Bones of the base of the skull are formed by endochondreal ossification .
Centers of ossification appears leaving some cartilage called synchondroses in between
These are the growth sites . Sphino-occipital . Intersphenoid . Sphenoethmoidal
Cranial base grows by endochondreal ossification that occurs at both margins of the synchondrosis.
Intermembranous Growth occur by : . Apposition of bone at the sutures
that connect the maxilla to the cranium
. Surface remodelling Downward and forward – anterior
maxilla is the area of resorption
Growth of the surrounding soft tissue translates the maxilla downward and forward ,opening spaces in the sutures where bone is added
Remodelling of the palatal vault moves it in the same direction as it is being translated
Bone is removed from the floor of the nose and added to the roof of the mouth
On the anterior surface ,bone is removed ,partially cancelling the forward translation ,as the vault moves downward ,the same process of bone remodelling also widen it .
Intermembranous and endochondral
Cartridge-condyle Growth sites : . Chin inactice .translated downward and forward
by growth at the mandibular condyle along the posterior border of the ramus
. The body grows longer by periosteal apposition of bone on its posterior surface
. The ramus grows higher by endochondral replacement at the condyle accompanied by surface remodelling
. growth is upward and backward
Remodelling is done by resorption in the anterior part of the ramus and deposition in the posterior part of the ramus
Overall growth direction results in a downward and forward displacement with most of growth occuring in the ramus .
Orthodontics alternative Official Site for Natural Growth Guidance.flv