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