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Collagen in Health and Disease
Journal of Orofacial Research, July-September 2012;2(3):153-159
153
JOFR
REVIEW ARTICLE
Collagen in Health and Disease
Simarpreet V Sandhu, Shruti Gupta, Himanta Bansal, Kartesh Singla
ABSTRACT
Collagen is the unique, triple helical protein molecule which forms
the major part of the extracellular matrix. It is the most abundant
protein in the human body, representing 30% of its dry weight
and is important to health because it characterizes the structure
of skin, connective tissues, tendons, bones and cartilage. As
collagen forms building block of body structures, any defect in
collagen results in disorders, such as osteogenesis imperfecta,
Ehlers-Dalnos syndrome, scurvy, systemic lupus erythematosus,
systemic sclerosis, Stickler syndrome, oral submucous fibrosis,
Marfan syndrome, epidermolysis bullosa, Alport syndrome. This
review discusses the role of collagen in health as well as disease.
Keywords: Collagen, Collagen disorders, Extracellular matrix,
Fibroblast, Health.
How to cite this article: Sandhu SV, Gupta S, Bansal H, Singla
K. Collagen in Health and Disease. J Orofac Res 2012;2(3):
153-159.
Source of support: Nil
Conflict of interest: None
INTRODUCTION
Collagen has been studied extensively by a large number of
research laboratories since the beginning of the 20th century.
It comprises a family of proteins present in the skin, bone,
cartilage, smooth muscle and basal lamina and provides
rigidity, elasticity and strength. Collagens are produced by
several cell types and are distinguishable by their molecular
compositions, morphologic characteristics, distribution,
functions and pathologies.1 This is the major fibrous
glycoprotein present in the extracellular matrix and in
connective tissue and helps in maintaining the structural
integrity of these tissues. It has a triple helical structure.
Collagen forms the major component of many vital tissues in
body and is essential in maintenance of structure and function
of body. Various studies have proved that mutations that modify
folding of the triple helix result in identifiable genetic
disorders.2 Therefore, this review highlights the role of
collagen in normal health and also the disorders associated
with structural and functional defects in collagen.
Structure and Types of Collagen
It is the most abundant protein in animals. In humans, collagen
encompasses one-third of the total protein, accounts for three-
quarters of the dry weight of skin and is the prevalent
constituent of the extracellular matrix. Twenty-eight different
types of collagens composed of at least 46 distinct polypeptide
chains have been recognized in vertebrates (Table 1).
Variations among collagen includes difference in assembly
of basic polypeptide chain, different length of triple helix,
interruptions in helix, difference in termination of helical
domains. This fibrous, structural protein comprises a right-
handed bundle of three parallel, left-handed polyproline
II-type helices. Common characteristic is the presence of
hydroxyproline and hydroxylysine and glycine is present at
every third position. It is supposed that glycine, because of its
small size, permits the close association of the three -chains.
The three -chains are held together by hydrogen bonds of
hydroxyproline whereas hydroxylysine permits the formation
of fibrils by binding the tropocollagen molecules to each other
and provide collagen molecule with sites of attachment for
short carbohydrate chains that are made up of glucose,
galactose or both. Collagen fiber bundles are referred to as
white fibers because of the fact that collections of collagen
fibers appear glistening white in living tissue.3,4
Microscopic Appearance
When unstained collagen fibers of connective tissue are usually
less than 10 µm in diameter and are colorless. They appear as
long, wavy, pink fibers bundles after staining with hematoxylin
and eosin. Electron micrographs of collagen fibers stained
with heavy metals display crossbanding at regular intervals of
67 nm, a characteristic property of these fibers. These fibers
are formed from parallel aggregates of thinner fibrils 10 to
300 nm in diameter and many micrometers in length.3, 4
Synthesis of Collagen
Mesenchymal cells and their derivatives (fibroblasts,
osteoblast, odontoblast, chondroblasts and cementoblasts) are
the chief producers of collagen. Other cell types synthesizing
collagen are epithelial, endothelial, muscle and Schwann cells4
(Fig. 1).
Fibroblast
Fibroblast is the most common cell of connective tissue that
produces and maintains the extracellular matrix. Fibroblasts
provide a structural framework for many tissues and play an
imperative role in wound healing. The key function of
fibroblasts is to maintain the structural integrity of connective
tissues by continuously secreting precursors of the
extracellular matrix, primarily the ground substance and a
variety of fibers. They are recognized by their association with
collagen fibers bundles. The quiescent fibroblast or fibrocyte
10.5005/jp-journals-10026-1032
Simarpreet V Sandhu et al
154 JAYPEE
Table 1: Types of collagen3-5
Molecule type Synthesizing cell Function Location in body
1. Fibril-forming; most common Fibroblasts, osteoblasts, Resists tension Dermis, tendon, ligaments,
of all collagens odontoblasts, cementoblasts capsules of organs, bone,
dentin, cementum
2. Fibril-forming Chondroblasts Resists pressure Hyaline and elastic cartilage
3. Fibril-forming; also known Fibroblasts, reticular cells, Forms structural framework of Lymphatic system, spleen, liver,
as reticular fibers. Highly smooth muscle cells, spleen, liver, lymph nodes, cardiovascular system, lung, skin
glycosylated hepatocytes smooth muscle, adipose tissue
4. Network-forming; do not Epithelial cells, muscle Forms meshwork of the lamina Basal lamina
display 67 nm periodicity cells, Schwann cells densa of the basal lamina to
and -chains retain provide support and filtration
propeptides
5. Fibril-forming Fibroblasts, mesenchymal Associated with type I collagen, Dermis, tendon, ligaments,
cells also with placental ground capsules of organs, bone,
substance cementum, placenta
6. Microfiber forming collagen — Bridging between cells and Ligaments, skin, cartilage
matrix (has binding properties
for cells, proteoglycan, a type I
collagen)
7. Network-forming; form Epidermal cells Forms anchoring fibrils that Junction of epidermis and dermis
dimers that assemble into fasten lamina densa to
anchoring fibrils underlying lamina reticularis
8. Meshwork — Tissue support, porous Basal laminae of endothelial cells
meshwork, provide compressive and smooth muscle cells and
strength Descemet’s membrane of cornea
9. Fibril-associated; decorate Epithelial cells Associates with type II collagen Cartilage
the surface of type II fibers
collagen fibers
10. Meshwork — Calcium binding Hypertrophic zone of cartilage
growth plate
11. Fibril collagen fibers — Forms core of type II fibers, Cartilage and vitreous humor
provides tensile strength
12. Fibril-associated; decorate Fibroblasts Associated with type I collagen Tendons, ligaments and
the surface of type I collagen fibers aponeuroses
fibers
13. Transmembrane protein — Cell matrix and cell adhesion Cell surfaces, focal adhesion
and intercalated disks
14. FACIT — Modulates fibril interactions
15. Endostatin forming collagen Endothelial cells Proteolytic release of Endothelial basement membrane
antiangiogenic factor
16. Cartilage and placenta — Unknown Endothelial, perineural muscle
and some epithelial basement
membrane, cartilage and placenta
17. Collagen-like protein; Epithelial cells Cell to matrix attachment Hemidesmosomes
a transmembrane protein,
formerly known as bullous
pemphigoid antigen
18. Collagen-like protein; Endothelial cells Proteolytic release of Endothelial basement membrane
cleavage of its C-terminal antiangiogenic factor
forms endostatin and
angiogenesis inhibitor
19. FACIT — Unknown Endothelial, perineural muscle
and some epithelial basement
membrane, cartilage and placenta
20. FACIT — — Cornea (chick)
21. FACIT — — Stomach, kidney
22. FACIT — — Tissue junctions
23. Membrane-associated — — Heart, retina
collagen with interrupted
triple helix
24. Fibrillar — — Bones, cornea
25. Membrane-associated — — Brain, heart, testis
collagen with interrupted
triple helix
26. FACIT — — Testis, ovary
27. Fibrillar — — Cartilage
28. Microfiber forming collagen — — Dermis, sciatic nerve
Collagen in Health and Disease
Journal of Orofacial Research, July-September 2012;2(3):153-159
155
JOFR
is smaller than the active fibroblast and is usually spindle-
shaped. It has fewer processes; a smaller, darker, elongated
nucleus; and more acidophilic cytoplasm with much less rough
endoplasmic reticulum. They have a branched cytoplasm
surrounding an elliptical, speckled nucleus having one or two
nucleoli. Active fibroblasts can be recognized by their oval,
pale- staining nucleus and greater amount of cytoplasm,
abundant rough endoplasmic reticulum, golgi apparatus,
secretory vesicles and mitochondria (Fig. 2). Fibroblasts
exhibit contractility and motility which are important during
connective tissue remodeling and formation and during wound
repair. In certain tissues, fibroblasts have significant
contractile properties and are called as myofibroblasts.3,5
Degradation of Collagen
Mechanisms involved in degradation of collagen are:
(1) Secretion by cells of enzymes that sequentially degrade
collagen and other matrix molecule extracellularly,
(2) selective ingestion of collagen fibrils by fibroblasts and
their intracellular degradation. Collagen triple helix is highly
resistant to proteolytic attack. Matrix metalloproteinases
(MMP) is a large family of proteolytic enzymes that includes:
Collagenases (MMP-1, 8, 13), gelatinases (MMP-2, 9),
metalloelastases (MMP-12), stromelysins (MMP-3, 10, 11),
matrilysin (MMP-7) that are involved in degradation of
collagen. Collagenase 1, 2 and 3 degrades type I, II, III, V
collagen, collagenase 3 can degrade type I, II, III, IV, IX, X,
XI, fibronectin and other extracellular matrix component.
Gelatinases A and B which is produced by alveolar
macrophages and stromeolysins 1, 2 and metalloelastases
degrade type I collagen and basement membrane component
(type IV) collagen, fibronectin, elastin respectively.5,6
Collagen in Health
Collagen is sometimes referred to as the body’s cement that
holds everything in place. Collagen is important to health
because it dictates the structure of skin, connective tissues,
tendons, bones and cartilage.
1. Skin health: Collagen plays an important role in skin health.
Type I and III collagen are formed in human skin in a higher
proportion relative to other types and are maintained in a
fixed proportion relative to one another in normal skin
tissue. Collagen type I constitutes approximately 70% of
Fig. 1: Synthesis of collagen
Fig. 2: Structure of fibroblast. A: Nucleus; B: Nucleolus; C: Golgi
apparatus; D: Cytoplasm; E: Intermediate/transfer vesicles; F:
Ribosomes; G: Mitochondria; H: Polyribosomes; I: Rough
endoplasmic reticulum; J: Collagen fibrils; K: Cell processes; L:
Microtubules; M: Secretory granules
Simarpreet V Sandhu et al
156 JAYPEE
collagen in the skin, with type III being 10% and trace
amounts of collagen types IV, V, VI and VII. Collagen
maintains firmness and elasticity of skin. Collagen in the
form of collagen hydrolysate keep skin hydrated. A lack
of collagen becomes obvious during the aging process as
skin begins to sag and lines and wrinkles begin to form. In
formation of scar tissue as a result of age or injury, there
is change in the abundance of types I and III collagen as
well as their proportion to one another. Type III collagen
synthesis decreases with age resulting in changes in skin
tension, elasticity and healing.7
2. Wound healing: Collagen is a key protein in connective
tissue and play an imperative role in wound healing by repair
and formation of scar. Collagen deposition and remodeling
contribute to the increased tensile strength of the wound,
which is approximately 20% of normal by 3 weeks after
injury gradually reaching a maximum of 70% of that of
normal skin. Collagen overproduction can form abnormal
scars, which impede wound healing. A chronic wound burden
among the elderly has been documented and much of this
age-related, delayed wound healing is caused by impaired
collagen synthesis and increased degradation. Increase in
fibroblasts and collagen during healing suggested that a
correlation might exist between number of fibroblasts,
quantity of collagen and tensile strength of a scar. 8
3. Bone: Bone is a complex and dynamic tissue that provides
structural support for the body, protection of internal
organs and acts as levers to which muscles are attached,
allowing movement. Out of 22 to 25% of organic
component 94 to 98% is mainly collagen type I and other
noncollagen proteins and 2 to 5% are cells. The
combination of hard mineral and flexible collagen makes
bone harder than cartilage without being brittle.
Combination of collagen mesh and water forms a strong
and slippery pad in the joint that cushions the ends of the
bones in the joint during muscle movement. 9, 10
4. Cartilage, tendon, ligaments: Collagen, in the form of
elongated fibrils, is predominantly found in fibrous tissues
such as tendon and ligament. It is a flexible and stretchy
protein that is used by the body to support tissues and thus it
plays a vital role in the maintenance of the cartilage, tendons
and ligaments. Normal tendon consists of soft and fibrous
connective tissue that is composed of densely packed
collagen fibers bundles aligned parallel to the longitudinal
tendon axis and surrounded by a tendon sheath also
consisting of extracellular matrix components. Collagen
constitutes 75% of the dry tendon weight and functions
chiefly to withstand and transmit large forces between
muscle and bone.11 Collagen also forms a major constituent
of cartilages. Cartilage collagen fibrils consist of collagen II,
the quantitatively minor collagens IX and XI. 4,5
5. Muscles: In muscle tissue, it serves as a major component
of the endomysium. Collagen constitutes 1 to 2% of
muscle tissue, and accounts for 6% of the weight of strong,
tendinous muscles. 4,6
6. Dental tissues:
a. Dentin: The mature dentin is made up of approximately
70% inorganic material, 20% organic material and 10%
water by weight. The organic phase is about 30%
collagen (mainly type I with small amounts of types III
and V) with fractional inclusions of lipids and
noncollagenous matrix proteins. Collagen type I acts
as a scaffold that accommodates a large proportion
(estimated at 56%) of the mineral in the holes and pores
of fibrils.12
b. Pulp: The extracellular compartment of the pulp or
matrix consists of collagen fibers and ground
substance. The fibers are principally types I and III
collagen. The overall collagen content of the pulp
increases with age, the ratio between types I and III
remains stable and the increased amount of
extracellular collagen organizes into fiber bundles.13
c. Cementum: Predominant collagen present in
cementum is type I collagen (forms 90% of the organic
matrix). Other collagens associated with cementum
include type III, a less crosslinked collagen found in
high concentrations during development and repair and
regeneration of mineralized tissues and type XII that
binds to type I collagen and also to noncollagenous
matrix proteins. Collagens found in trace amount in
cementum are types V, VI and XIV.14
d. Periodontal ligament: Periodontal ligament is
composed of collagen fibers bundles connecting
cementum and alveolar bone proper. The predominant
collagens of the periodontal ligament are types I, III
and XII, with individual fibrils having a relatively
smaller average diameter than tendon collagen fibrils.
The vast majority of collagen fibrils in the periodontal
ligament are arranged in definite and distinct fiber
bundles and these are termed as principal fibers. The
periodontal ligament has also the capacity to adapt to
functional changes. When the functional demand
increases, the width of the periodontal ligament can
increase by as much as 50 % and the fiber bundles also
increase markedly in thickness.14
7. Basement membrane: The epithelial basement membrane
and adjacent area is termed the epithelial basement
membrane zone. The lamina densa consisting of type IV
collagen that is coated by heparan sulfate, a glyco-
saminoglycan and anchoring fibrils, that are composed of
type VII collagen and extend from the lamina densa to the
connective tissue.15
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Journal of Orofacial Research, July-September 2012;2(3):153-159
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Collagen Disorders Categorization
Heritable/Genetic Collagen Disorders
a. Ehlers-Dalnos syndrome (Tenascin – X deficiency
syndrome/Lysyl hydroxylase deficiency syndrome):
Ehlers-Danlos syndrome (EDS) is a clinically and
genetically heterogeneous connective tissue disorder
characterized by hyperextensibility of the skin,
hypermobility of joints and tissue fragility. It was first
described by Van Meekeran in 1682 (Table 2). The exact
abnormality in biogenesis of the collagens has been
identified in four varieties and in case of EDS IV an
abnormal gene locus has been determined. In some clinical
forms of EDS a mutation in COL1A1 and COL1A2 genes
is reported which results in interferences with conversion
of procollagen to collagen. This leads to defective
crosslinking and a consequent reduction in tensile strength
of tendons. Presence of dystrophic scars and a tendency
to excessive bleeding manifested by bruises, ecchymoses
and hematomas is noticed in EDS. The oral manifestations
of EDS include the ability of 50% of these patients to
touch the tip of their nose with their tongue (Gorlin sign),
a feat that can be achieved by less than 10% of normal
people. Mucosal tears are more frequent when touched by
instruments and sutures do not hold. The gingiva is fragile
and hemorrhage may be difficult to control during surgical
procedures. Early onset generalized periodontitis is one
of the most noteworthy oral manifestations of the
syndrome resulting in the premature loss of deciduous and
permanent teeth. Hypoplasia of the enamel is commonly
seen. Premolar and molar teeth can present with deep
fissures and long cusps. The teeth seem to be fragile and
microdontia is sometimes present. Radiographic
examination often divulges pulp stones and roots that
are short and deformed. A tendency for recurrent
subluxation of the temporomandibular joint has also been
reported.16,17
b. Osteogenesis imperfecta: Comprises a heterogeneous
group of heritable disorders characterized by impairment
of collagen maturation. The disease causes either a
decrease in collagen synthesis or the production of
structurally defective collagen, hence, all tissues rich in
type I collagen may be affected. Except on rare occasions,
the disorder arises from heterozygosity for mutations in
one of two genes that guide the formation of type I
collagen: The COLIAI gene on chromosome 17 and the
COLIA2 gene on chromosome 7. The clinical features
commonly observed in patients with osteogenesis
imperfecta include abnormal bone formation, growth
deficiency, bone fragility, blue sclerae, hearing loss, skin
thinness, joint laxity and hypermobility and dentinogenesis
imperfecta. Abnormal collagenous maturation results in
bone with a thin cortex, fine trabeculation and diffuse
osteoporosis. Upon fracture, healing will occur but may
be associated with exuberant callus formation. 6,18
c. Stickler syndrome: It is a unique autosomal dominant
syndrome of premature osteoarthritis, retinal degeneration,
hearing loss and orofacial abnormalities described by
Gunnar B Stickler in 1965. The disorder (hereditary arthro-
ophthalmopathy or Stickler syndrome) is known to be caused
by mutations in the COL2A1, COL11A1 and COL11A2
procollagen genes of type 2 and 11 collagen. 19
d. Alport syndrome: Alport syndrome is a generalized
inherited disorder of basement membranes, particularly
those of glomeruli that involve type IV collagen. The
mutations occur in the gene located on the X chromosome.
Inherited defect of the classical X-linked Alport syndrome
affects the -5 chain of collagen type IV collagen gene
(COL4A5) while the -3 and -4 chain of collagen type
IV collagen gene (COL4A3 and COL4A4) are responsible
for less frequent recessive forms of Alport syndrome. It
is characterized by renal impairment, loss of hearing and
lens abnormalities, hypertension, hematuria and proteinuria.
The damage of collagen IV due to mutations causes
dysfunction of bound epithelium and results in organ
damage. 20
e. Epidermolysis bullosa: Hereditary epidermolysis bullosa
is a group of rare genetically transmitted disorders that
have several methods of inheritance with various degrees
of severity and expression. It is a multiracial disorder that
is characterized by the formation of vesicles and bullae
on the skin and mucous membranes. The vesicles may arise
spontaneously or from minor trauma. The four types of
epidermolysis bullosa are simplex, dystrophic and
junctional and hemidesmosomal. Specific mutations in the
K5 or K14 genes and genes coding for the laminin has
Table 2: Categorization of collagen disorders
Heritable/genetic collagen disorders Autoimmune collagen disorders Miscellaneous
• Ehlers-Danlos syndrome • Systemic lumpus erythematosus • Scurvy
• Osteogenesis imperfecta • Systemic sclerosis
• Stickler syndrome • Oral submucous fibrosis
• Alport syndrome
• Epidermolysis bullosa
• Marfan syndrome
Simarpreet V Sandhu et al
158 JAYPEE
been responsible for dominant simplex type and junctional
form respectively. The dystrophic type is related with
mutations in the type VII gene. The hemidesmosomal type
is characterized by mutations of genes associated with
various hemidesmosomal attachment proteins such as
plectin, type XVII collagen and 64 integrin.21,22
f. Marfan syndrome: It is the most common inherited
connective tissue disorder with a reported incidence of
one in 10,000 individual and equal distributions between
the sexes. It is caused by an autosomal dominant mutation
in the gene encoding fibrillin (FBN1, chromosome
15q15–21.3), a glycoprotein that is an integral part of the
connective tissue in the body (ligaments, blood vessel, eye
lenses). It primarily involves the skeletal, ocular and
cardiovascular systems. Typically, patients present with
tall stature, ectopia lentis, aortic root dilatation and a
positive family history. The diagnosis is made when a
patient presents with complications of the syndrome, such
as aortic dissection or with involvement of the pulmonary,
skin/integument or nervous systems. 23
Autoimmune Collagen Disorders
a. Systemic lupus erythematosus: Lupus erythematosus is
a multifactorial autoimmune collagen vascular or
connective tissue disease, which may affect the oral
mucosa in either its cutaneous and systemic forms with
varied prevalence. Common findings include fever, weight
loss, arthritis, fatigue and general malaise. A characteristic
rash, having the pattern of a butterfly, develops over the
malar area and nose. Cardiac involvement is also common
with pericarditis. Warty vegetations affecting the heart
valves (Libman-Sacks endocarditis) are also observed.
Oral lesions include ulceration, pain, erythema and
hyperkeratosis may be present. Other oral complaints are
xerostomia, stomatodynia, candidiasis, periodontal disease
and dysgeusia. 21,24
b. Systemic sclerosis (progressive systemic sclerosis;
scleroderma; hide-bound disease): Progressive systemic
sclerosis is a disorder of the connective tissue that
illustrates fibrosis of the skin, blood vessels, visceral
organs and mucosa. The exact mechanism of the fibrotic
changes is unknown, but hyperplastic changes of collagen
have been documented. The pathological findings signify
that fibroblasts are activated to produce excessive amounts
of collagen and other components of the cellular matrix.
The most apparent symptom is the involvement of the skin
together with the quality of its mobility, particularly in
the distal portions of the extremities. Cutaneous
manifestations include thickening of skin, starting with
pitting edema and over several months pitting edema is
replaced by tightening and hardening of skin. Raynaud´s
phenomenon is usually the first symptom. The oral
manifestations include classic facial skin hardening and
limited opening of the oral orifice with characteristic
furrows radiating from the mouth resulting in a classic
mask-like and appearance purse string appearance
respectively. Bone resorption at the angle of the mandible
is also a common feature. Deposition of collagen in the
lingual and esophageal submucosa, producing a firm,
hypomobile (board-like) tongue and an inelastic esophagus,
thus resulting in dysphagia.21,25
c. Oral submucous fibrosis: It is a chronic, premalignant
condition of the oral mucosa which was first described by
Schwartz 1952. Recently it is thought to be an autoimmune
disease. The presence of various autoantibodies in varying
titers is reported in several studies confirming autoimmune
basis to the disease.26 Tilakratne WM et al in 2006 reported
that although the data on various HLA types, raised
autoantibodies and the detection of immune complexes
tend to indicate an autoimmune basis for the disease
substantial number of cases and matched controls may be
required to verify these findings.27 This disease is
considered to be a consequence of disturbances in the
homeostatic equilibrium between synthesis and
degradation of extracellular matrix, wherein collagen
forms a major component, thus can be recognized as a
collagen-metabolic disorder. It is characterized by a juxta
epithelial inflammatory reaction followed by fibroelastic
change in the lamina propria and associated epithelial
atrophy. This leads to a restricted mouth opening, resulting
in trismus leading to restriction of food consumption,
difficulty in maintaining oral health, as well as impairs the
ability to speak. The fibroelastic changes are almost
entirely due to abnormal accumulation of collagen in the
subepithelial layers, resulting in dense fibrous bands in
the mouth. 28, 29
Miscellaneous
Scurvy: A deficiency of vitamin C is known as scurvy. Key
function of ascorbic acid is its involvement in the synthesis
of collagen fibers from proline via hydroxyproline. Other
metabolic reactions for which vitamin C is required are the
hydroxylation of lysine into hydroxylysine in collagen. In
individuals who suffer from a deficiency of this vitamin, the
-chains of the tropocollagen molecules are unable to form
stable helices and the tropocollagen molecules are incapable
of aggregating into fibrils. It first affects connective tissues
with a high turnover of collagen, such as the periodontal
ligament and gingiva. Avitaminosis C is associated with the
failure of wound healing or the rupture of capillaries due to
intrinsic intercellular weakness with lack of connective tissue
support of the capillary walls. Among the presenting features
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Journal of Orofacial Research, July-September 2012;2(3):153-159
159
JOFR
of scurvy, oral signs may be cardinal: Fetid odor and loosened
teeth, gingivae are boggy, ulcerated and bleed with the
interdental and marginal gingiva becoming bright red, smooth,
swollen and shiny.30
CONCLUSION
Collagens are the major structural element of all connective
tissues and are also found in the interstitial tissue of virtually
all parenchymal organs, where they contribute to the stability
of tissues and organs and maintain their structural integrity.
An inborn error of metabolism involving abnormal structure
or metabolism of collagen results in collagen disorders.
Despite the increasing knowledge about the structure and
synthesis of collagen, the genetic and molecular bases of the
collagen disorders are considered as incurable. Hence, future
research and studies are required in this field in order to
provide the best treatment modalities to the patients with
collagen disorders.
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ABOUT THE AUTHORS
Simarpreet V Sandhu (Corresponding Author)
Professor and Head, Department of Oral and Maxillofacial Pathology
Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab
India, e-mail: s_vrk@yahoo.com
Shruti Gupta
Junior Resident, Department of Oral and Maxillofacial Pathology, Genesis
Institute of Dental Sciences and Research, Ferozepur, Punjab, India
Himanta Bansal
Associate Professor, Department of Oral and Maxillofacial Pathology
Genesis Institute of Dental Sciences and Research, Ferozepur, Punjab
India
Kartesh Singla
Junior Resident, Department of Oral and Maxillofacial Pathology, Genesis
Institute of Dental Sciences and Research, Ferozepur, Punjab, India
