sites & types of growth (orthodontics)

SITES & TYPES OF GROWTH IN CRANIOFACIAL COMPLEXDR. SARANG SURESH HOTCHANDANI (BDS)

#ORTHODONTICS

05/02/2023SARANG SURESH HOTCHANDANI 2

TO UNDERSTAND GROWTH IN ANY AREA OF BODY IT IS NECESSARY TO UNDERSTAND

Site

/Loc

atio

n

of G

row

thType of

Growth at

that Site

Mechanism of Growth

Controlling

factors in

Growth


TO UNDERSTAND GROWTH IN ANY AREA OF BODY IT IS NECESSARY TO UNDERSTAND

Site

/Loc

atio

n

of G

row

thType of

Growth at

that Site

Mechanism of Growth

Controlling

factors in

GrowthWe are Going to Learn this


CRANIOFACIAL COMPLEX CONSISTS OF;

1. Cranial Vault1. Bones of upper & outer surface of brain

2. Floor of Cranium/Brain1. Occipital bone

2. Sphenoid bone

3. Ethmoid bone

3. Naso – Maxillary Complex1. Maxilla

2. Nose

4. Mandible

CRANIAL VAULT


SITE/LOCATION OF GROWTH & REMODELING

• Primary site of growth at cranium• Sutures

• Secondary site of growth • Inner & outer surface of bony plates

• Resorption on inner surface • Deposition on outer surface


TYPE OF GROWTH AT CRANIAL VAULT

Formation • Intramembranous Ossification

Growth & Remodeling

• Surface apposition from periosteal activity

FLOOR OF CRANIUM


SITE/ LOCATION OF GROWTH & REMODELING

• In center for midline structures• Synchondroses (Growth Sites of

Cranial Base)• These are bands of cartilage which

remained after ossification of cranial base bones by endochondral ossification.

• 3 in number• Spheno-occipital synchondroses

• Inter sphenoid synchondroses

• Spheno-ethmoidal synchondroses


SITE/ LOCATION OF GROWTH & REMODELING

•Laterally;• Sutures• Surface remodeling or apposition(outer &

inner)• E.g. Growth of sphenoid sinus


DIAGRAMMATIC REPRESENTATION OF GROWTH AT THE INTERSPHENOID SYNCHONDROSES.

• Histologically looks like two sides epiphyseal plate• Area of cellular hyperplasia

in center and maturation occur in both sides.• This cartilage produce

immoveable joint while cartilage of long bone produce moveable joint.


TYPES OF GROWTH IN CRANIAL VAULT

•Endochondral ossification at center

•Surface apposition at lateral plates and sutures.

NASO MAXILLARY COMPLEX


SITE OF GROWTH IN MAXILLA

Sutures Maxillary Surface


TYPE OF GROWTH IN MAXILLA

Intr

amem

bran

ous

Appo

sitio

n at

Su

ture

s

Surf

ace

Rem

odel

ing


MAXILLA…

• Maxilla moves forward by growth of cranial base behind it.

• GROWTH PATTERN OF MAXILLA• It grows out from under the cranium

• Means, maxilla must move a considerable distance downward & forward relative to cranium & cranial base.• This occurs in two ways;

• By push from behind created by cranial base growth &

• Coz maxilla is attached to anterior part of cranial base and lengthening of cranial base pushes maxilla forward.

• By growth at sutures.


As growth of surrounding soft tissues

translates the maxilla downward and forward, opening up space at its superior and posterior

sutural attachments, new bone is added on both

sides of the sutures.


MAXILLA…

• Growth of cranial base occurs till 6th year of age & stops at 7th year.• In achondroplasia, growth of cranial base does not occur which

result mid face deficiency because maxilla is not moving forward.

• After 7 years, forward & downward movement of maxilla occurs at sutures.


MAXILLA…

• In maxilla, sutures are attached superiorly & posteriorly.

• The sutures remain the same width, & various processes ofmaxilla becomes longer.• Because bone apposition occurs on both sides of

sutures. So bones to which maxilla is attachedalso become larger.

• Part of posterior border of maxilla is free surface in thetuberosity region.• Bone is added at this surface creating additional space into which

primary and then permanent molars erupt.


MAXILLA…

• In maxilla, bone is removed from outer/anterior surface while deposited on inner surface.• So, overall growth occur by both downward and forward

translation/movement of maxilla and simultaneously surface remodeling.• In maxilla, surface remodeling of bone occur in the opposite direction to that in which

it is being translated/moved.• However it is not rule that in every bone remodeling occurs in opposite direction, just like in growth

of palate in which remodeling occurs in the same direction to which the palate is being translated.• Palate also moves downward & forward along with maxilla, but here at the same time the bone is

removed on the nasal side and deposited on the oral side, and anterior part of alveolar process is resorptive area, here resorption occur to cancel forward growth of palate caused by maxilla.

MANDIBLE


MANDIBLE

• Both, endochondral and periosteal activity occur.• Endochondral at mandibular condyle• Periosteal activity by direct surface apposition and

remodeling at all other areas of mandible.

• There is negligible role of growth of cranial base and movement of TM joint due to growth of cranial base unlike maxilla.


PATTERN OF GROWTH OF MANDIBLE

• two ways depending on frame of reference;• if cranium is reference area and considered as stable cranial base, then

• chin moves downward & forward

• from other reference area, data from vital staining;• minimal changes in the body and chin area, while, there is growth & remodeling of ramus, moving it

posteriorly

• Both ways are correct, so the overall concept of growth of mandible is, mandible is translated downward and forward and grows upward and backward in response to this translation, maintaining its contact with skull.



• So, the principal sites of growth of mandible are;• Posterior surfaces of ramus

• Condylar

• Coronoid process

• As a growth site, anterior part of mandible along with chin is inactive as growth site.• It is translated downward and forward due to growth occurring at condyle

and posterior surface of mandible.



• Body of mandible grows by periosteal apposition only on its posterior surface.

• Ramus grows upward by endochondral replacement at condyle accompanied by surface remodeling.

• Mandible grows longer by apposition of new bone on posterior surface, while resorption on anterior surface.

• In infancy, ramus is located at about the spot where the primary 1st molar will erupt.

GROWTH OF SOFT TISSUESGROWTH OF FACIAL SOFT TISSUES DOES NOT GROW IN PARALLEL TO FACIAL HARD TISSUES.


GROWTH OF LIPS

• Growth of lips is slower than growth of hard tissues of face before adolescence.

• Growth spurt of lips occur after adolescence

• Lip height is short during mixed dentition

• Lip incompetence (Lip separation at rest) is maximum during childhood and decreases during adolescence.

• Lip thickness reaches at maximum during adolescence and then decrease• For some girls, loss of thickness seems problem and want treatment.

• Lips are framed by nose above and chin below.

• Lip prominence decrease after adolescence because of growth of chin and nose at adolescence


GROWTH OF NOSE

•Growth of nasal bone is completed at about age 10.• After this age, growth only occurs in nasal

cartilage and soft tissues which growth spurt in adolescent and that’s why nose become prominent at adolescent (especially in boys).

THE ENDSARANG SURESH HOTCHANDANI (BDS)

BIBI ASEEFA DENTAL COLLEGE, SMBBMU.Larkana, Sindh, Pakistan.

[email protected] www.twitter.com/fetusdentista

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