Enumerate theories of growth. Describe the functional matrix theory in detail.
Or
Enumerate various theories of growth. Describe in detail functional matrix concept.
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Enumerate various theories of growth and development. Describe functional matrix hypothesis in detail.
Or
Enumerate theories of growth. Describe in detail functional matrix growth theory.
Or
Name the different theories of growth and explain functional matrix theory in detail.
Or
Enumerate various theories of growth discuss in detail functional matrix theory
Or
Write short note on functional matrix theory of Moss.
Or
Write briefly on functional matrix theory.
Or
Write short note on functional matrix theory.
Answer.
Theories of Growth
Depending on the Area Where Growth Center Occur
- Genetic theory (Brodie)
- Sutural dominance theory (Sicher)
- Functional matrix theory (Melvin Moss)
- Cartilaginous theory (James Scott.
Based on Other Concepts or Hypothesis Related to Craniofacial Growth
- Von Limborgh’s compromise theory
- Cybernetic theory (Petrovic)
- Hunter and Enlow’s growth equivalent concept.
Functional Matrix Theory/Functional Matrix Hypothesis/Functional Matrix Theory of Moss
Defiition of Functional Matrix
The functional matrix hypothesis claims that the origin, form, position, growth and maintenance of all skeletal tissue and organ are always secondary, compensatory and necessary responses to chronologically and morphologically prior events or process that occurs in specially related nonskeletal tissues, organs or functional spaces (functional matrices).
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Functional Matrix Theory
The functional matrix theory is given by Melvin Moss and is truly based on work done by Van der Klaauw. The theory states that, “There is no direct genetic inflence on the size, shape or position of skeletal tissues, only the initiation of ossifiation. All skeleto-genic activity is primarily depends upon the functional matrices”.
Functional Cranial Component
- Tissue and spaces which together leads to a single function are known as functional cranial component.
- As per Moss, head leads to many of the functions, i.e. respiration, digestion, hearing, etc. Each one function is carried together by tissues and spaces in the head.
- Functional cranial component is divided into following two components, i.e. functional matrix and skeletal unit.
- Functional matrix: It performs any function.
- Skeletal unit: It protects and supports the functional matrix.
Functional matrix
- Combination of all the soft tissues which lead to a single function is known as functional matrix.
- Functional matrix is divided into periosteal matrix and capsular matrix.
Periosteal matrix
- It inflences bone directly by periodontium.
- Periosteal matrix functions by depositing bone and resorpting bone.
- Periosteal matrices are muscles, blood vessels, nerves, gland, teeth and temporalis muscle.
- The periosteal matrices create local environmental factors. These factors affect the growth.
- Periosteal matrix affects the micro-skeletal unit.
Capsular matrix
- It consists of the capsule which surrounds mass and spaces.
- Example of capsular matrix is neural mass which is present in capsule of skin and dura mater.
- The capsular matrices are neurocranial capsule and orofacial capsule.
- Neurocranial capsular matrix is formed by cerebrospinal fluid, leptomeninges and brain.
- Orofacial capsular matrix consists of functioning spaces and tissues in deglutition, respiration, etc.
- Capsular matrix gives rise to local epigenetic factor which helps in control of growth.
- Expansion of capsular matrix by volume leads to translation of whole bone. This translation of whole bone is also known as Macro-skeletal unit.
- Capsular matrix leads to the growth of complete bone.
Skeletal unit
- Combination of all skeletal tissues which is associated with single function is known as skeletal unit. It consists of bone, cartilage and tendinous tissue.
- Skeletal units are of two types, i.e. micro-skeletal unit and macro-skeletal unit.
- Micro-skeletal unit: When a bone is comprised of several contiguous skeletal units, it is known as micro-skeletal unit.
- Macro-skeletal unit: When adjoining bones are limited to function as single cranial component, e.g. entire endocranial surface of calvarium.
Micro-skeletal unit
It consists of all the parts of bone which are affected by periosteal matrix and this leads to the transformation of bone, i.e. change in size and shape of the bone.
Macro-skeletal unit
It consists of core of the bone which is affcted by the capsular matrix which leads to translation of bone, i.e. change in the position of bone.
The combination of both the skeletal units and the functional matrices, i.e. periosteal matrix and capsular matrix results in growth.
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