F matrix theory

• Growth is a general term implying an
increase in magnitude. Development is a
maturational process.It is important for us
to know and understand this biologic
process of growth &development because at
some point of time we manipulate growth
by intervening the course of the control
process of growth by giving func- appliance
& orthopedic devices. Morphogenesis- ie
growth control process tends to achieve awww.indiandentalacademy.com

balance between growing parts. But as
development progress balance can never
be actually achieved because itself creates
ongoing.This process starts at childhood,
to adult-hood & goes on till old age,but the
process is slowed down as age increases
www.indiandentalacademy.com

• Facial growth operates with two basic kinds
of growth movement-
a) remodeling
b) displacement
• The process of remodeling is placed by the
composite of soft tissue relating to each of
the bones.
• Displacement: As bone enlarges it is carried
away from other bones. This creates space
with in which bony enlargement takes place
called “Displacement” also called
translation.

VARIOUS GROWTH THEORIES
THAT HAVE BEEN PROPOSED
• Genetic control theory (Bordie 1941)
• Cartilage directed growth theory (Scott 1953)
• Sutural theory
• functional matrix theory (Moss 1960)
• Servo system theory (Petrovic 1974)

• Functional matrix theory(Moss 1960)
proffit
Moss says if neither bone nor cartilage
were determinant for growth of craniofacial
skeleton,the control would lie in the
adjacent soft tissues.He theorizes that
growth of the face occurs as a response to
functional needs & is mediated by the soft
tissues in which it is embedded. HE
theorizes that growth of the maxilla &
mandible occurs due to enlargement of
nasal& oral cavities

• FMT (Graber & Petrovic)
Regional & local factors play a role in cranio
facial morphogenesis. It says that the
growth of bone & cartilage seems to be a
compensatory response to FM growth.the
functional matrix include muscles,
nerves,glands, teeth,blood vessels etc.
The growth of functional matrix is primary;
the growth of skeletal unit is secondary

FUNCTIONAL CRANIAL
ANALYSIS
Composed of two parts
• a functional matrix
• a skeletal unit
Skeletal unit - micro skeletal unit
- macro skeletal unit
Functional matrix - periosteal matrices
- capsular matrices

PERIOSTEAL MATRICES
• For eg-functional cranial component
consisting of temporalis muscle &the
coronoid process.
• Experimental removal of the temporalis
muscle results in an actual diminution of
coronoid process size &shape.
• Also hypertrophy or hyperactivity of the
temporalis muscle produced increased size
of coronoid processwww.indiandentalacademy.com

CAPSULAR MATRICES
Functional matrices plus skeletal units are
organized in the form of cranial capsules.
2 cranial capsules -neuro cranial capsule &
oro facial capsules .
The expansion of the neurocranial capsule
is always proportional to the increase in
neural mass

ORO FACIAL MATRICES
• All functional cranial component of the
facial skull arise, grow and are maintained
with in the oro facial capsule. This capsule
surronds & protects the oro-nasopharyngeal
functioning spaces.It is the volumetric
growth of these spaces which is the primary
morphogenetic event in facial skull growth

• For the demonstration of the integrated
activity of periosteal & capsular matrices in
facial growth, mandibular growth is taken
• it is a combination of the morphologic
effects of both capsular & periosteal
matrices. Capsular growth causes an
expansion of the capsule as a whole.the
enclosed macro skeletal unit is passively &
secondarily translated in space to
successively new positions.the periosteal
matrices related to these mandibular
microskeletal units also respond to this
volumetric expansion

GENETIC, EPIGENETIC
&CAUSATION
• Combination of genomic &epigenetic factors is
a necessary cause of cranio facial growth
• Biologically causation is produced by
1.a set of cells & X”tra cellularsubstance{material
2 a program encoded in the genome [format
3 an immediately antecedent, epigenetic
event[efficient]
4 some consequent use {final}www.indiandentalacademy.com

EPIGENETIC HYPOTHESIS
• The term epigenetic is used to describe the
sum of all bio mechanics, bio electrical, bio
chemical & bio physical parameters
produced by functioning cells ,tissues,
organs &organisms
• these factors are thought to act on the
genome to regulate all developmental
process

FM HYPOTHESIS -REVISITED I
• Mechano transduction is a process of cell signal
transfer
• Biologic network theory explains the net work
of bone cells & how they interact to the signals.
• There are several mechano transductive process-
mechanoelectrical & mechanochemical which
ever used,bone adaptation requires the subsequent
intercellular transmission of the transduced
signals. www.indiandentalacademy.com

• Mechano sensing processes enable a cell to
sense and to respond to extrinsic loadings
by using the processes of mechano
reception and of the mechano transduction.
Mechano transduction transmits the extra
cellular physical stimulus into a receptor
cell where as the mechano reception
transforms the stimulus’s energetic and/or
informational content into an intracellular
signal.
• Osseous mechano transduction
• ionic or electrical process
• mechanical processwww.indiandentalacademy.com

THE ROLE OF AN OSSEOUS
CONNECTED CELLULAR NETWORK -
FMH REVISITED 2
• All bone cells except osteoclasts, are
extensively inter connected by gap
junctions that form an osseous CCN
• Gap Junctions are found where the plasma
membrane of a pair of markedly
overlapping canalicular process meet.They
also connect superficial osteocytes to
periosteal & endosteal osteoblasts .

• Mechano transductively activated bone cells eg
osteocytes, can intiate membrane action potentials
capable of transmission through interconnecting gap
junctions
• In net work theory the cells are arranged into
“layers”,an intial input, a final output & a more
intermediate or “hidden”layers.Each cell in any
layer may simultaneously receive several
“weighted” inputs (stimuli)
• When an intra cellular signal is generated it is
transmitted identically to all the hidden layer cells to
which each intial layer cell is connected by Gap
junction.

• The similar processes of weighted signal
summation, comparison & transmission occur in the
intermediate layers until the final layer cells are
reached . The out put of these anatomically
superficial cells determines the site, rate, direction,
magnitude and duration of the specific adaptive
response; ie deposition, resorption andor
maintenance,of each cohort of osteoblast
• CCN show oscillation. Gap junctions, permitting
bidirectional flow of information, are the cytological
basis for the oscillatory behavior of CCN

A skeletal CCN displays the
following attributes
• Developmentally, it is an untrained self-
organised &self-adapting and epigenetically
regulated system.
• Operationally,it is a stable, dyanamic
system that exhibits oscillatory behavior
permitting feedback
• Structurally, an osseous CCN is non
modular

FMH REVISITED-3 THE GENOMIC
THESIS
• According to this theory,the whole series of
operations to be carried out, the order and site of
synthesis and their co-ordination are all written
down in the nucleic acid message
• this thesis holds that from the moment of
fertilization,the genome contains all information
necessary to regulate - 1. The intra nuclear
formation &transcription of RNA . 2.With out any
external factor regulate intracellular &intercellular
activities of cell tissues and organs & all phenotypic
features are expressed by DNAwww.indiandentalacademy.com

EPIGENETIC ANTI THESIS AND THE
RESOLVING SYNTHESIS
• The epigenetic anti thesis,detailing both processes &
mechanisms,integrative,seeking to clarify the causal
chain between genome and phenotype. Its goal is to
identify & describe comprehensively the series of
initiating biological processes and their related
underlying(biochemical,biophysical)responsive
mechanisms that are effective at each hierarchical
level of increasing structural &operational
complexity.
FMH Revisited 4

EPIGENETIC PROCESSES
AND MECHANISMS
• Loading
• Extra cellular matrix deformation
• Cellshape changes

A RESOLVING SYNTHESIS BETWEEN
GENETIC & EPIGENETIC THEORIES
• Individually both are necessary causes, but
neither are sufficient causes alone. Together
they provide both the necessary and
sufficient causes for the control of
morphogenesis.Nevertheless,epigenetic
processes and events are the immediately
proximate causes of development, and as
such they are the primary agencies.

CONCLUSION

F matrix theory

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F matrix theory