The original articles are used to create this PPT.

1. FUNCTIONAL MATRIX THEORY-
Revisited
PRESENTED BY : DR. ADITI JAIN
1ST YEAR PG
Santosh Dental College
Department of Orthodontics and Dentofacial Orthopedics

2. History: of Functional Matrix Theory
 Given By: MELVIN L. MOSS. (American
Orthodontist)- 1962
 Concept of “ Form follows Function” : C. J. Van
der Klaauw (Dutch Zoologist) -1948-52.
 Article: Melvin L. Moss & Richard W. Young :
A functional approach to craniology in
American journal of physical anthropology-
1960.
 In the year 1981, Moss gave the classical
statement Melvin L. Moss(1923-2006)

3. Definition
“The origin, form, growth and maintenance
of all skeletal tissue and organs are always
secondary, compensatory and obligatory
responses to chronological and
morphological prior events or processes that
occur in specifically related non-skeletal
tissues, organs or functional spaces
(functional matrices).”

4. Explanation:
 The theory considers the head and not the skull as the
composite area.
 Head and neck region performs various functions : Digestion,
respiration, speech, olfaction, balance, vision.
 Each of these functions is completely carried out by
“Functional Cranial Component”.
Totality of skeletal structure + Soft tissue + Functioning space =
Functional Cranial Component.

5. Functional Cranial Component
Functional Matrix Skeletal Unit
Periosteal
Matrix
Capsular
Matrix
Neurocranial
Capsule
Orofacial
Capsule
Micro-
skeletal Unit
Macro-
skeletal Unit
Otic Capsule
Orbital
Capsule

6. Basic Concept of Growth
Transformation:
 It is a change in shape and size.
 Osseous deposition and resorpti
on.
 It is a direct response to primary
morphogenic demand
of specifically related function
matrix.
Translation:
 Change in spatial relation.
 It is without osseous
deposition and resorption.
 It is Passive.

7. Periosteal Matrix Transformation Micro- Skeletal Unit
Capsular Matrix Translation Macro- Skeletal Unit
Directly; Actively
Indirectly; Passively

8. Skeletal Unit
 When a bone is made up of
several contiguous skeletal
units they are termed as micro
skeletal units.
 The maxilla and mandible is
made of number of micro
skeletal units.
Micro- Skeletal Unit
All the skeletal tissue associated with single function are called as skeletal unit
The skeletal unit made up of bones, cartilage, tendinous tissue.

9. Macro Skeletal Unit
 When adjoining portions of a
number of neighboring bone
are united to function as
single cranial component, is
termed as macro skeletal unit
 Example:- endocranial
system of calvarium maxilla &
mandible.

10. Periosteal Matrix
 All non skeletal functional units adjacent to
skeletal unit form the periosteal matrices.
 They act by bringing transformation of the related
skeletal units.
 Alteration in periosteal matrices functional
demands produce secondary, compensatory
transformations of the size and or shape of the
skeletal units.
 Such transformations are brought about by
interrelated process of bone deposition and bone
resorption.

11. Capsular Matrix
 Defined as the organ and space that occupy
broader anatomical complex.
 This class of matrix are those masses and
spaces that are surrounded by capsules. All
the functional cranial components
(functional matrices together with the
skeletal units) organize in the form of cranial
capsules.
 Each of these capsules is an envelop
containing functional cranial component.

12. Neurocranial Matrix
 Sandwiched between skin and dura
matter.
 Consists of:
• 5 layers of scalp
• Bone
• 2 layers of dura matter.
 Volume of the neural mass is
important whether or not it
contains “normal” amount brain

13. Expansion of the enclosed
capsular matrix volume
Capsule enlarges
The whole of the included and
functional components are carried
outwards in a totally passive
manner.

14. Microcephaly
Hydrocephal
y

15. Orofacial Capsule
 Surround and protect oronasopharyngeal
space.
 Surrounded by skin and mucous
membrane on either side.
 Originates by process of enclosure.
 Primary function is maintaining airway this
is accomplished by “AIRWAY
MAINTENANCE SYSTEM”.

16. Volumetric growth of these spaces is the primary
morphogenetic event in facial skull growth.
Growth of functional spaces-increase in the size of
capsule.
The whole of the included and enclosed functional
components are translated to a new position in space.
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

18. Drawback OPPOSITION
BY VARIOUS
AUTHORS
 MOSS 1972
 JOHNSTON 1976
 KOSKI 1977
 WAYNE WATSON 1982
No clarification
on as to how
functional needs
are transmitted
to tissues.

19. FMH: Revisited
1. The role of Mechanotransduction.
2. The Role of an Osseous Connected Cellular Network.
3. The Genomic Thesis.
4. The Epigenetic Antithesis and the Resolving Synthesis.
5. Orofacial Capsular Matrices Defined.

20. Basis of Revision
The developmental origin of all cranial elements
and all their subsequent change in shape, size and
location ,as well as their maintenance in being ,are
always without exception secondary
,compensatory and mechanically obligatory
response to the operationally prior demand of
their related cephalic non-skeletal cells, tissues,
organs and operational volumes.

21. Constraints
 Macroscopic measurements use
the techniques of point
mechanics and arbitrary
reference frames.
 Roentgenographic
cephalometry permitted only
method specific descriptions
that cannot be structurally
detailed. This constraint was
removed by continuum
 This version’s descriptions did
not extend “downward” to
processes at the cellular,
subcellular or molecular
structural domains or extend
“upwards” to the multicellular
process by which bone tissues
respond to lower level signals.
 Lower attributes ≠ Higher attributes
Methodologic Constraints Hierarchical Constraints

22. The Role of Mechanotransduction
Cells are irritated.
Mechanosensing
Mechanoreception: It transmits an extracellular physical stimulus into a
receptor cell.

23. Osseous Mechanotransduction
Unique in 4 ways:
1. Most of mechanosensing cells are cytologically 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” independently.

24. Types of Mechanotransductive Processes
1.Ionic Or Electrical
Processes
Subsequent intercellular
trasport of the created
ionic or electrical signals
through a plasma
membrane.
•Electromechanical
•Electro kinetic
•Electric field strength(1-10
Stretch Activated
Channels
Loading (1k-3k ue)
S-A get activated
passage of certain
sized ions (K+, Na+,
Ca2+)
2.Mechanical Processes
Extracellular Collagen
Intracellular Nuclear Membrane
Integrin

25. Mechanical
Process
Stretch Activated
Channels
Ionic / electrical
Process
MECHANICAL PROCESSES

26. The role of an Osseous Connected Cellular
Matrix
 Osteocytes have cytoplasmic processes which are oriented 3-Dimmensionally. Present laterally and vertically.
 All bone cells except osteoclast are interconnected with Gap Junctions.
 Gap Junctions are found where plasma membrane of a pair of markedly overlapping canalicular process meet.
Superficial Osteoblast
Periosteal and
endosteal Osteoblast
Periosteal and
endosteal Osteoblast
Superficial Osteoblast
Periosteoblastic Cell Periosteoblastic Cell
B
I
D
I
R
E
C
T
I
O
N
A
L

27. The Network Theory
Initial Cell Stimuli (weighted input)
Summation
Intercellular signal (mechanotransduction)
Hidden Layer Cells (Adjacent osteocytes)
Final Layer cells (osteoblast)
Bone Responses - Output
The CCN’s shows
oscillation i.e.
iterative reciprocal
signaling
(feedback)
between layers.

28. Attributes Of CCN’s
1. Developmentally, it is an untrained self-organized, self-
adapting and epigenetically regulated system.
2. Operationally, it is a stable, dynamic system that exhibits
oscillatory behavior permitting feedback.
3. Structurally, an osseous CCN is nonmodular, i.e., the
variations in its organization permit discrete processing of
differential signals.
 It is this attribute that permits the triad of histologic
responses to a unitary loading event.

29. The Genomic Thesis
 The initial version of the functional matrix hypothesis
(FMH), claiming epigenetic control of morphogenesis,
was based on macroscopic experimental, comparative,
and clinical data.
 Recently revised, it now extends hierarchically from
gross to microscopic levels and identifies some
epigenetic mechanisms capable of regulating genomic
expression.
The genomic thesis holds that the genome, from the
moment of fertilization, contains all the information
necessary to regulate.

30. Orthodontic Implications
 Rigid Genomic control of
odontogenesis:-
a. Temporally sequential
b. Spatially restricted
 Epigenetic regulation of
odontogenesis
a. Experiments on polyphyodont
chiclid fish.
Poor co-ordination of
form and size of
structures(teeth and
jaws) by regulatory
genes result in
malocclusion and
dentofacial deformities.

31. The Genomic Thesis In orofacial Biology
 The Genomic Thesis claims that prenatal craniofacial development is
controlled by two inter related processes:
1. Initial regulatory (Homeobox) gene activity.
2. Activity of the regulatory molecular groups: growth factor families and
steroid/thyroid family.
 It is claimed that regulatory molecules can
1. “alter the manner in which homeobox genes coordinate cell migration
and subsequent cell interactions that regulate growth”.
2. And be involved in the “genetic variations causing, or contributing to, the
abnormal development of relatively common craniofacial malformations”.

32. Critical Definitions
 Epigenetics: All of the extrinsic factors impinging on vital structures and intrinsic events
occurring inside and outside of a cell.
 Hierarchy: The structural and functional complexity is increasing “upwards”.
Atoms Molecules Cells Tissue Organ Organism.
 Emergence: The integrated activities of all the attributes in a given hierarchical level self
organize to produce the next higher level of complexity.
“Bones do not Grow, they are Grown”
 Causation: How the attributes of a given biological structural level “cause” (control,
regulate, determine) the attributes of the next higher level.

33. Classification Of Causation
Principle Causes of ontogenesis
Intrinsic / Prior
(Molecular Level)
Extrinsic / Proximate
(Regulate)
Material
With , What?
Cellular &
intercellular
Formal
By what rules?
Genomic Code
Efficient
How?
Epigenetic
Factors
Final
Why?
Development
Creation of new state
Sufficient

34. Drawback of genomic Thesis
The genomic thesis passes directly from molecules
to morphogenesis: directly from DNA molecules
to adult morphology, ignoring the roles of the
many epigenetic processes and mechanism.
The epigenetic antithesis is integrative & details
the processes and mechanisms seeking to clarify
the casual chain between genome & phenotype.
Reductionist and Molecular

35. The Epigenetic Antithesis & the
Resolving Synthesis
 Process : Series of action or operation that lead towards
a particular result.
 Mechanism : Fundamental physical or chemical
process(es) involved in, or responsible for an action,
reaction or other natural phenomenon.
 Epigenetics: The entire series of interactions among cell
and cell products which leads to morphogenesis and
differentiation.

36. Loading
 Chains of intracellular molecular levers begin deformation.
 Epigenetic Cell signaling processes.
 Extracellular matrix deformation.
 Cell shape Changes.
 Other processes and mechanisms. (DNA methylation)
Epigenetic Regulation of functional matrices.

37. A resolving Synthesis
 The morphogenesis is regulated by the
activity of both epigenetic and genomic
processes and mechanisms.
Complex Adaptive system(CAS)
Epigenetic Input
(Minor Change)
Morphological output
(High Fluctuation)
Complexity Theory

38. Loading
At cellular/tissue level
Static
(Muscle Contraction)
Dynamic
(Gravity)
Mechanosensing
Mechanoreception
Mechanotransduction
Ionic/ Electrical Mechanical Process
S-A Channels Electromechanical Electrokinetic Field Strength Macromolecular Lever
Skeletal Unit Cell Signal
Connected Cellular Network
Bone Response

39. Orofacial Capsular Matrices Defined
Carbonated hydroxyapatite + protein + water = Human Enamel
Timothy G. Bromage
95% 3-4% 1-2% Hard and tough food
Following Perturbations exists- Purpose = Hard & tough food Soft Diet
• Enamel is 2mm thick and more on molars.
• Molar HSB’s originate at the Enamel Dentine Junction, dispersing into a zone of parallel
rods.
• Enamel Prism discontinuity serves to resist the propagation of cracks.
• Dentine side of DEJ itself is graded too.
• Enamel Crystallites are hexagonal offering resistance to strain in bulk enamel.
• Ameloblast secretory behavior renders incremental lines.

40. Functional matrix of nasal Cavity: Air
 Obligatory Nasal breathing is to promote normal
facial growth and function.
 The diet (chewing hard and tough food) causes
stresses and strains called as Bernoulli’s forces
which are the primary cause of nasal cavity
development.
 Perturbations exist due to breathing through
mouth which has led to current suboptimal
health of the human industrialized population.

41. In the words of
Sir Arthur Keith “Civilization
is antievolutionary in it’s
effects; it works against the
laws and conditions which
regulate the earlier stages of
man’s ascent.”

42. References
 Dubbeldam JL. An annotated bibliography of C.J. van der Klaauw with notes on the impact of his work. Acta
Biotheor. 2007;55(1):1-22. doi: 10.1007/s10441-007-9006-9. Epub 2007 Mar 9. PMID: 17347784; PMCID:
PMC2781101.
 Melvin L. Moss,Twenty years of functional cranial analysis, American Journal of Orthodontics,
Volume 61, Issue 5,1972,Pages 479-485,ISSN 0002-9416,https://doi.org/10.1016/0002-
9416(72)90152-2.(https://www.sciencedirect.com/science/article/pii/0002941672901522)
 Moss ML, Young RW. A functional approach to craniology. Am J Phys Anthropolgy. 1960
Dec;18(4):281-92. doi: 10.1002/ajpa.1330180406. PMID: 13773136.
 The functional matrix revisited 1. The role of mechanotransduction AJODO –1997 ; 112 :8-
11.
 The functional matrix revisited 2. The role of an osseous connected cellular network
AJODO -1997; 112:221-6
 The functional matrix revisited.3 .The genomic thesis AJODO-1997;112:338-42
 The functional matrix revisited.4 .The epigenetic antithesis AJODO-1997;112:410-7