Moss Functional Matrix Hypothesis

FUNCTIONAL MATRIX
HYPOTHESIS
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INTRODUCTION
• Given by MELVIN MOSS
• Department of anatomy at Columbia
(1948-1951)
• Worked on the concept put by VAN DER
KLAUVW –FUNCTIONAL CRANIAL
COMPONENT
• Carried out various lab studies and
experiments

• In the year 1960 first paper was published in
the American journal of physical
anthropology-MOSS AND YOUNG
• In the year 1981 when MOSS gave the
classical statement

• THE ORIGIN,GROWTH AND
MAINTENANCE OF ALL SKELETAL
TISSUES AND ORGANS ARE ALWAYS
SECONDARY,COMPENSATORY AND
OBLIGATORY TO TEMPORALLY AND
OPERATIONAL PRIOR EVENTS OR
PROCESSES THAT OCCUR IN
SPECIFICALLY RELATED NON-
SKELETAL TISSUES,ORGANS OR
FUNCTIONAL SPACES

• MOSS said that head and neck region consist
of number of functions
1.Digestion
2.Respiration
3.Speech
4.Olfaction
5.Balance
6.Vision

• Each of these function is completely carried
out by
FUNCTIONAL CRANIAL
COMPONENT

Brought about by two processes-
• Transformation-change and size
-osseous depositon and
resorption
-direct response to primary
morphogenetic demand of
specifically related
functional matrix
Basic concept of growth

• Translation-change in the spatial relation
-passive
-without osseous deposition
and resorption

TRANSFORMATION
AND TRANSLATION

Skeletal unit
• Composed of –bone, cartilage and tendinous
tissue
MACROSKELETAL UNIT-
adjoining portions of number of neighbouring
bones carrying out a single function
eg-endocrainal surface of calvaria

Macro skeletal unit

MICROSKELETAL UNIT
bones consisting of number of small skeletal
units
MAXILLA-orbital
-pneumatic
-palatal
-basal
MANDIBLE-coronoid
-angular
-alveolar
-basal

FUNCTIONAL MATRICES
• This consist of soft tissue-
muscle,gland,nerve,vessels,fat and teeth as
well as non skeletal cartilages
DIVIDE INTO TWO TYPES-
• Periosteal matrices
• Capsular matrices

PERIOSTEAL MATRICES
• All non skeletal functional units adjacent to
skeletal unit form the periostel matrices
• They act by bringing transformation of the related
skeletal units
• Best explanation – coronoid process and
temporalis muscle

• Removal,denervation,postinfectively-
decrease in the size or total disappearance
• Functional hypertrophy/hyperactivity-
increase in size and change in shape

• Hence in simple terms it can be stated-
Coronoid process does not grow itself first and
thus provide a platform upon which the
temporalis muscle can alter its function but it
is the opposite which is true

CAPSULAR MATRICES
FOUR CAPSULES ARE PRESENT-
• NEURO CRANIAL
• ORO FACIAL
• OTIC
• ORBITAL

• Each of these capsules is an envelop
containing functional cranial component
• Sandwitched between two covering layers
• Capsules expands due to volumetric increase
of capsular matrix
• This results in the translative movement of the
embedded bones

NEUROCRAINAL CAPSULE
• Sandwiched between-skin and dura mater
• Consists of-5 layers of scalp
-bone
-two layer dura mater

TWO IMPORTANT POINTS
1.Volume of the neural mass is important
whether or not it contains “normal” amount
brain tissue.
2.Expansion of this closed capsular matrix
volume is primary event in expansion of the
capsule.

• The volumetric increase cause compensatory
expansion of surrounding capsule which is
brought about by mitotic activity.
• Later the calvarial functional cranial
component as a whole are passively and
secondarily translated
• In hydrocephaly-passive,nonperiosteal
translative growth is produced.

ORO FACIAL MATRIX
• Surround and protect oronasopharyngeal
space.
• Surrounded by skin and mucous membrane
on either side.
• Originates by process of enclosure.
• Volumetric growth of these spaces is the
primary morphogenetic event in facial skull
growth

Orofacial Capsule

• Primary function is maintaining airway this is
accomplished by “AIRWAY
MAINTENANCE SYSTEM”
• Growth of functional spaces-increase in the
size of capsule
• Followed by passive movement of functional
cranial component

MANDIBULAR GROWTH
• This can be used to explain integrated
activity of periosteal and capsular matrices
in facial growth.
This is done by-
1 longitudinal series of lateral ceph
representing mandibular growth are taken.
2 two assumptions are made.

Two superimpositions are done-
1. Anterior cranial base
- represents the total growth change
-interosseous growth
- capsular+periosteal matrix

2. Mental foramen keeping ant cranial base parallel
-represent change in shape and size
-intraosseous growth
-periosteal matrix

• IN AJO-MAY 1972, MOSS STATED THAT
INVESTIGATIONS ARE STILL GOING TO
FIND OUT VARIOUS MEANS AND
PROCESS BY WHICH MORPHOGENETIC
STIMULI ARE TRANSMITTED TO THEIR
SKELETAL UNIT ,MODE OF
TRANSMISSION,ITS RECEPTION AND
TRANSLATION.

Functional Matrix Hypothesis
Revisited

Functional cranial component
Skeletal unit Functional matrices
Macroskeletal
Eg-endocranial
surface Of calvaria
Microskeletal
Eg-coronoid,
angular
Periosteal
Eg-teeth and
muscles
Capsular
Eg-orofacial,
neurocranial

0ppositions by various authors-
-- MOORRREES 1972
-- JOHNSTON 1976
-- KOSKI 1977
-- WAYNE WATSON 1982

Functional matrix hypothesis-
revisited
This has been possible because of advances
in biomechanical,bioengineeringand
computer sciences

CONSTRAINTS OF FMH
1. METHODICAL CONSTRAINTS
macroscopic measurement technique and
arbitary reference planes are now beeen
replaced by continuum mechanics
technique like -FEM

2. HIERARCHIAL CONSTRAINTS
Earlier versions did not extended “downward” or
“upwards”
ie . Suspended between two levels

REVISED STATEMENT-
The developmental origin of all crainal elements
and all their subsequent change in shape, size
and location ,as well as their maintenance in
being ,are always without exception
secondary ,comensatory and mechanically
obligatory response to the temporally and
operrationally priop demand of their related
cephalic non-skeletal cells,tissues, organs and
operational volumes.

MECHANOTRANSDUCTION
CELL ARE IRRITATED
MECHANORECEPTION
MECHANOTRANSDUCTION

OSSEOUS
MECHANOTRANSDUCTION
• UNIQUE IN FOUR WAYS-
1.Most of mechanosensing cells are
cytological specialized,but bone cells are
not.
2.One loading stimulus evoke 3 adaptation.
3.Osseous signal transmission is aneural.
4.Responses are confined within “bone
organ”

TYPES OF
MECHANOTRASNDUCTIVE
PROCESSES
1. IONIC-brought about transport of ions through
plasma membrane resulting in creation of
electrical signal.
2. Stretch activated channels
loading S-A get activated passage of certain
sized ions
3. Electrical processes
• Electromechanical
• Electro kinetic
• Electric field strength

Mechanical process-
Extracellular collagen
intracellular
nuclear membrane

BONE AS OSSEOUS
CONNECTED CELLULAR
NETWORK
Osteocytes have cytoplasmic processes
which are oriented three dimensionally
GAP JUNCTION- are found where plasma
membrane of pair of markedly overlapping
cannicular process meet

GAP JUNCYIONS CONNECT-
Osteons and interstitial regions
Superficial osteocytes to periosteal and
endosteal osteoblasts
Lateral connection of osteoblast
Periosteal osteoblast with preosteoblastic
cells,which are interconnected

Flow of information
Stimulus intercellular output/response
signal
Initial output hidden final output
layer
Signals summation output

ATTRIBUTES OF CCN
i. DEVELOPMENTAL-
unstrained,organised,self
adapting,epigenetically regulated.
ii. OPERATIONALLY-stable,dynamic
system,oscillatory behaviour.
iii. STRUCTURALLY- variation in
organization permit discrete processing
of different signals.

Loading
Static Dynamic
Mechanosensing
Mechanoreception (Input)
Mechanotransduction
Ionic / electrical
S –A-
channels
Electro-
mechanical
Electro-
kinetic
Field
strength
Mechanical
Macromolecular
lever
Skeletal unit cell signal
CCN
Response (output)
Deposition
Resorption
Maintainancewww.indiandentalacademy.com

• Initial version – epigenetic factors
• Current – genomic regulation of growth

• Emergence- appearance of complex higher
levels by self organisation at
lower levels.
This can be explained by the concept of
CAUSATION

CAUSATION
THERE IS CONTINUING
CONTROVERSY CONCERNING THE
ROLE OF GENOMIC AND NON
GENOMIC PROCESSES IN THE
REGULATION OF GROWTH .THIS IS
RESOLVED BY SEVERAL TYPES OF
CAUSATION.

CLASSISAL CATEGORISATION
OF
CAUSATION
• MATERIAL(what is acted upon?)
• FORMAL(set of rules?)
• EFFICIENT(immediate preceding event?)
• FINAL

MATERIAL FORMAL EFFICIENT FINAL
Cellular and
extracellular
substance
Genomic
regulation
Epigenetic
event
Sufficient
Genetics Epigenetics

AN ODONTOGENIC
EXAMPLE
Rigid genomic control of odontogenesis
 a. Temporally sequential
b. Spatially restricted
 Epigenetic regulation of odontogenesis
a.experiments on polyphydont chiclid
fish.

THE GENOMIC THESIS
In simple terms states that –
It is the genome of an individual which
determines the overall phenotype

APPLICATION OF GENOMIC
THESIS IN OROFACIAL
BIOLOGY
• 10%-of the genome is related to the phenotypic
ontogenesis
CRANIOFACIAL DEVELOPMENT IS
CONTROLED BY TWO PROCESSES-
1.Regulatory gene activity.
2.Activity of the regulatory molecules.

ORTHODONTIC
IMPLICATIONS
POOR CORDINATION
OF FORM AND SIZE OF STRUCTURES
(TEETH AND JAWS) BY REGULATORY
GENES RESULT IN MALOCCLUSION
AND DENTOFACIAL DEFORMITIES

THE EPIGENETIC
ANTITHESIS
Refers to to the entire series of interaction
among cells and cell products which lead
to morphogenesis and differentiation
THESE INCLUDE-
1. All extrinsic,extraorganismal,
macroenvironment factors
2. All intrinsic,intraorganismal,
microenviromental factors

EPIGENETIC PROCESS
OF LOADNIG
Many different mechanism are capable of
modifying phenotype.
1.Loads may act at –cellular level
tissue level
2.Loads may be – dynamic
static
3.To be effective load may increase,decrease
or remain constant,

Epigenetic mechanism at cellular level-
Deformation of extracellular matrix
Altering the cell shape
Epigenetic regulation at higher level-
Regulation of the periosteal matrices.

DIALETICAL ANALYSIS
THESIS ANTITHESIS
(GENOMIC) (EPIGENETIC)
RESOLVING THESIS

COMPLEXITY AND SELF
ORGANISATION
COMPLEX ADAPTIVE SYSTEM
“ensemble”of several tissue and organs.
CAS processes genomic and epigenetic
information in parallel manner.
Minor changes in epigenetic input result in
huge fluctuation in morphogenetis output.

Ontogeny is a nonlinear process.
Spontaneous self organizing ontogenic
processes and mechanism can create
phenotypic variability under constant genetic
and other extra organisimal epigenetis
condition.

“Enviromental factors play a decisive role in
all ontogenetics processes.But it is the
organism itself that ,as an integrated system
,dictates the nature of each and a very
developmental response.
The living organism self organizes on the basis
of its own internal structuring,in continuous
interaction with the environment in which it
finds itself”
Latham-’95

THIS COMPLEXITY THEORY
REQUIRES A COMPREHENSIVE
PRESENTATION FOR BETTER
UNDERSTANDING AND EXPLANATION
WHICH ACCORDING TO MOSS WILL BE
REVIEWED SUBSEQUENTLY

BIBLIOGRAPHY
Contemporary orthodontics-WILLIAM
PROFFIT
Principles and practice of Orthodontics -
T.M.GRABER
Primary role of functional matrix in facial
growth-Moss AJO-june 1969
The doctrine of functional matrices-James
Scott AJO july1969

The capsular matrix-Moss AJO november
1969
 Twenty years of functional cranial
analysis-Moss AJO may 1972
Genetics,epigenetics and causation-Moss
AJO october 1981
Functional matrix hypothesis revisited-
Moss AJO july-oct 1997

THANK
YOU

Moss Functional Matrix Hypothesis

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