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Functional matrix Hypothesis- Revisited

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Functional matrix Hypothesis- Revisited

  1. 1. FUNCTIONAL MATRIX HYPOTHESIS- REVISITED PRESENTED BY SUSNA PAUL
  2. 2. CONTENTS • FUNCTIONAL MATRIX THEORY- ORIGINAL • FUNCTIONAL MATRIX HYPOTHESIS- REVISITED  ROLE OF MECHANOTRANSDUCTION  ROLE OF AN OSSEOUS CONNECTED CELLULAR NETWORK  GENOMIC THESIS  EPIGENETIC ANTITHESIS & RESOLVING SYNTHESIS • REFERENCES
  3. 3. FUNCTIONAL MATRIX THEORY(1960s) • The concept of this theory was introduced first by Vander Klaaw (1948-52). • Melvin L. Moss developed the functional matrix hypothesis.
  4. 4. The craniofacial skeleton develops initially and later grows in direct response to the extrinsic epigenetic environment.. BONES DO NOT GROW ,THEY ARE GROWN
  5. 5. DEFINITION The origin, form, position, growth and maintenance of all skeletal tissues and organs are always secondary, compensatory and necessary responses to chronologically and morphologically prior events or processes that occur in specifically related nonskeletal tissues, organs or functioning spaces (functional matrices).
  6. 6. Explanation The FMH considers the head, not the skull as a composite area of individual encapsulate areas.. Totality of skeletal structure+ soft tissue+ functioning space Functional Cranial Component
  7. 7. FUNCTIONAL CRANIAL COMPONENT SKELETAL UNIT FUNCTIONAL MATRIX MICRO MACRO PERIOSTEAL CAPSULAR
  8. 8. SKELETAL UNIT MICRO SKELETAL • Skeletal units may be composed variably of bone, cartilage or tendinous tissues. • When a bone consists of a number of skeletal units, we call them micro skeletal units..
  9. 9. MACRO SKELETAL • When adjoining portions of a number of neighboring bones are united to function as a single cranial component, we term this as a macro-skeletal unit. • eg: endocranial surface of the calvaria
  10. 10. THE FUNCTIONAL MATRIX THE PERIOSTEAL MATRIX This corresponds to the immediate local environment, which acts directly.. Egs: muscles, blood vessels, nerves, glands, teeth..
  11. 11. • The periosteal matrices stimulation causes direct growth of the microskeletal units. • Effect on the size and/or shape of the skeletal unit by osseous deposition and resorption. TRANSFORMATION
  12. 12. THE CAPSULAR MATRIX Defined as the organ and spaces that occupy a broader anatomical complex. Each capsule is an envelope - contain a series of FCC - skeletal unit and the related functional matrices.. Sandwiched between two covering layers
  13. 13. OROFACIAL CAPSULE In this, the cover consists of skin and mucous membrane. The orofacial capsule surrounds and protects the orofacial functional matrix..
  14. 14. The volumetric expansion of the orophoryngeal functioning spaces Increase in the size of the capsule The whole of the included and enclosed functional components, are translated to a new position in space.
  15. 15. NEUROCRANIAL CAPSULE • In this, the cover consists of skin and duramater. • The neuro-cranial capsule surrounds and protects the neurocranial functional matrix..
  16. 16. The expansion of the enclosed capsular matrix volume. The capsule enlarges The whole of the included and enclosed functional components, are carried outward in a totally passive manner.
  17. 17. • Thus the capsular matrices acts indirectly on the macroskeletal units and are carried outward in a passive manner. • The location in space of the skeletal unit is changed, not by osseous deposition and resorption. TRANSLATION
  18. 18. FUNCTIONAL CRANIAL COMPLEX GROWTH TRANSLATION TRANSFORMATION CAPSULAR MATRIX PERIOSTEAL MATRIX MACROSKELETON MICROSKELETON SKELETAL UNITFUNCTIONAL MATRIX
  19. 19. CONSTRAINTS OF THE FMH 1. Methodologic constraint: Macroscopic measurements which 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..
  20. 20. 2. Hierarchical constraint: 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.
  21. 21. 1.Mechanotransduction occurs in single bone cells. 2.Bone cells are computational elements that function multicellularly as a connected cellular network. .
  22. 22. MECHANO TRANSDUCTION All vital cells are irritable and respond to alterations in their external environment. 1. Mechanoreception 2. Mechanotransduction
  23. 23. Osseous Mechanotransduction
  24. 24. 1.Unlike other mechanosensory cells ,bone cell are not specialized for such stimuli 2.These cells shows aneural transmission of signals. 3. Bone loading stimulus evoke three adaptational responses. 4. The changes brought about by stimuli are confined to a single bone to which the signal is transduced.
  25. 25. Translates the information content of a periosteal functional matrix stimulus into a skeletal unit cell signal
  26. 26. MECHANOTRANSDUCTION Ionic / electrical Mechanical
  27. 27. Stretch Activated channel Activation of plasma membrane stretch activated ion channels Intra cellular electric events
  28. 28. Electromechanical Involves the osteocytic plasma membrane. it contains voltage activated ion channels and transmembrane ion flow..
  29. 29. Electrokinetic Bound and unbound electrical charges, associated with the bone fluids. Electrical effects in the fluid filled bone are electrokinetic i.e. streaming potential.
  30. 30. MECHANICAL PROCESS This is an alternate means by which functional matrix may regulate the lower cell bone cell.
  31. 31. The physical continuity of the transmembrane molecule integrin
  32. 32. MECHANORECEPTION MECHANOTRANSDUCTION IONIC MECHANICAL STRETCH ACTIVATED CHANNELS INTEGRIN ELECTRIC EVENTS ELECTROMECHANICAL ELECTROKINETIC
  33. 33. CONNECTED CELLULAR NETWORK All bone cells, expect osteoclasts are extensively interconnected by gap junctions. Present laterally and vertically. . Superficial osteoblast Superficial osteoblast Periosteal and endosteal osteoblasts Periosteal and endosteal osteoblasts Preosteoblastic cellPreosteoblastic cell CONNECTED CELLULAR NETWORK
  34. 34. • Network theory Initial layer cells –stimuli (loading) summation Intracellular signal (mechanotransduction) Hidden layer cells (adj. Osteocytes) Final layer cells (osteoblasts) output
  35. 35. The CCNs show oscillation, i.e. reciprocal signaling (feedback) between layers. Gap junctions are electrical synapses that permit bi-directional signal traffic
  36. 36. ionic transport through the bone cell plasma membrane intercellular transmission are computed by the operation of an osseous connected cellular network bone responses
  37. 37. • explanatory chain extending from the epigenetic event of skeletal muscle contraction, hierarchically downward (through the cellular and molecular levels to the bone cell genome and then) upwards again through histologic levels to the event of gross bone form adaptational changes.
  38. 38. The revised FMH consist of the presentation of, a thesis and an anti-thesis and of a resolving synthesis.
  39. 39. GENOMIC THESIS • The genomic thesis holds that the genome, from the moment of fertilization, contains all the information necessary to regulate..
  40. 40. • Genomic thesis claims that prenatal cranio facial 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.
  41. 41. EPIGENETIC ANTITHESIS 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.
  42. 42. The epigenetic antithesis detailing the processes and mechanisms seeking to clarify the casual chain between genome & phenotype. • Process  Series of action or operation that had towards a particular result. • Mechanism  Fundamental physical or chemical process(es) involved in, or responsible for an action, reaction or other nailed phenomenon
  43. 43. Epigenetics refers to the entire series of interactions among cells and cell products, which leads to morphogenesis and differentiation..
  44. 44. A RESOLVING SYNTHESIS • Morphogenesis is regulated (controlled, caused) by the activity of both genomic and epigenetic processes and mechanisms.
  45. 45. REFERENCES • The functional matrix revisited.1. The role of mechanotransduction. AJODO –1997 ; 112 :8-11. • The functional matrix revisted 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

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