The document discusses various theories of craniofacial growth, including remodeling, genetic, sutural dominance, and cartilaginous theories, each presenting distinct mechanisms for how growth occurs. It also introduces concepts like Enlow's 'v' principle, the counterpart principle, and neurotrophism, which highlight the interactions between different bones and surrounding tissues. Additionally, Petrovic's servosystem theory outlines the role of growth signals and feedback mechanisms in craniofacial development.

1. THEO
RIES
O
F
GRO
W
TH

2. Remodeling theory
• By Brash
• Selective bone deposition and resorption.

3. Genetic theory
• By Brodie.
• Not widly accepted.
• Growth is under the influence of genetic
control and is pre programmed.

4. Sutural Dominance Theory

6. Points against sutural theory of growth:
• Transplantation.
• Microcephaly.
• Cleft palate.

7. Cartilaginous theory
• James Scott.
• Nasal septal theory.

9. Points supporting cartilagenous theory of growth:
• Transplantation.
• Endochondral bone formation.
• Removal of nasoseptal cartilage
Deficient growth

10. Functional matrix theory
Functional cranial component
( tissues, organs, spaces, skeletal part )
skeletal unit functional matrix
(bone, cartilage tendons
periosteal capsular
micro skeletal unit macro skeletal unit

12. •Skeletal Unit:
-Macro skeletal unit
(mandible-maxilla)
-Micro skeletal unit
(Alveolar process-condyle)

13. Functional matrix
Periosteal matrices Capsular matrices
( muscles, vessels, nerves, ( neurocranial capsule &
glands ) orofacial capsule )
Acts directly on skeletal unit Acts indirectly
Produce a secondary compen- Produce a secondary
atory transformation by translation in space
Deposition & Resorption by expansion

15. Van Limborgh theory of growth
Factors
influencin
g growth
intrinsic
environm
ental
local
Habits
Muscle
force
general
Nutrition
oxygen
epigenetic
local
Adgacent
structure
(brain-eye)
general
hormones

16. Enlow's "V" Principle

17. • Enlow's V Principleis related to the bones of
the craniofacial area which have a V shape
configuration.
• We see bone resorption happening on the
outer side of the "V" of the bone and bone
deposition happens on the inner side of the
"V".
• Movement of bone happens towards the open-
end of the V.

19. Enlow's Counterpart Principle
• Enlow's Counterpart Principle states that
growth of one bone in the craniofacial area
relates to the other bones in the same region.
• Each bone and its counterpart bone both
grow to a certain extent to maintain the
balanced growth.
• An example is the growth of maxilla
corresponding to the growth of mandible.

20. Counterparts which situated in craniofacial
region:
 Nasomaxillary complex/anterior cranial fossa.
 Middle cranial fossa /breadth of ramus.
 Maxilla/mandible.
 Maxillary tuberosity/mandibulartuberosity.

22. Neurotrophism
• Neurotrophism is a non-impulse transmitting
neural function that involves axoplasmic
transport and provides for long term
interaction between neurons and innervated
tissues that homeostatically regulates the
morphological, compositional and functional
integrity of those tissues.

23. Different types of neurotrophic mechanisms are:
• Neuro-epithelial trophism
• Neuro-muscular trophism
• Neuro-visceral trophism

24. Servosystem theory
• By Alexandre Petrovic .
• stated that craniofacial growth happened
because of growth signals and feedback
mechanisms.
• Petrovich theorized a Cybernetic Model for
the Servosystem theory.

25. • According to this theory control of primary
cartilage takes a cybernetic form of a
command, whereas in contrast, control of
secondary cartilage (e.g. mandi condyle) is
comprised not only of a direct effect of cell
multiplication but also of indirect effects.

26. Command
( growth hormone, somatomedins, sex hormone, thyroxin )
In secondary cartilage In primary cartilage
direct control
Indirect control Direct control Septal cartilage
saggital positioning of maxilla
normal signal deviation signal
Lateral pterygoid Condylar
muscle activity Cartilage Regulatory
mechanism
Mandibular growth

27. • This theory explains the mode of action of the
functional appliances directed at condyle.
• The upper arch acts as a mould into which the
lower arch adjusts it self, such that optimal
occlusion is established.

28. THANK YOU