basic characteristics of gingiva described to ultrastructural levels for better understanding of normal gingiva

1. 1

2. GINGIVA IN HEALTH
Presented by:- Ganesh Nair
FY PG
Dept of Periodontology
and implantology
2
Guided by:-
Dr. Anita Panchal
Dr. Sachin K.
Dr. Bhaumik Nanavati
Dr. Rahul Shah
Dr. Mansi Pathak

3. Contents:-
• Definition
• Parts of GINGIVA.
• Microscopic features of gingiva
• Gingival fibres.
• Blood, lymphatic and nerve supply of gingiva.
• Clinical features of gingiva.
• Gingiva in disease
• Classificaton of gingival diseases.
• Bibliography
3

4. Definitions:-
4

5. 5

6. Parts of GINGIVA:-
• Anatomically parts:-
1.Marginal gingiva &
Gingival sulcus
2.Attached gingiva
3.Interdental gingiva
6

7. 7

8. Identification of Mucogingival junction and
significance:
 Mucogingival junction is identified by-
• visual method (VM),
• functional method (FM)/Roll test
• VM after histochemical staining method (Histochemical
method).
• Tension test.
VM FM HM 8

9. Histologic sulcus depth vs. clinical sulcus
depth
• The histologic depth of a sulcus does not need to be exactly
equal to the depth of penetration of the probe. The so-called
probing depth of a clinically normal gingival sulcus in humans
is 2 to 3 mm
• The depth of this sulcus, as determined in histologic sections,
has been reported as 1.8 mm, with variations from 0 to 6 mm,
other studies have reported 1.5 mm and 0.69 mm.
-Orban and kohler- 1924
9

10. Microscopic features of gingiva:-
• Main form of tissue in the gingiva is the stratified squamous
epithelium.
• Major Cell Type
Keratinocyte
• Other Cell Types(non keratinocyte)
Langerhans cells
Melanocytes,
Merkel cells
10

11. Keratinocyte:-
• Of ectodermal origin.
• Identification: large oval nucleus with one or more nucleolii
abundance of metabolic organelles, basophilic in light
microscopy.
• Functions:
a) protect the deep structures while allowing a selective interchange
with the oral environment.
11

12. • By proliferative and
differentiation.
1)progressive flattening of the
cell with an increasing
prevalence of tonofilaments,
2)intercellular junctions
coupled to the production of
keratohyaline granules,
3)disappearance of nucleus
12

13. Classification of gingiva on the basis of degree
of keratinization:
• A complete keratinization process leads to the production of
an orthokeratinized superficial horny layer similar to that of the
skin, with no nuclei in the stratum corneum and a well-defined
stratum granulosum.
• parakeratinized epithelia the stratum corneum retains pyknotic
nuclei, and the keratohyalin granules are dispersed, not giving
rise to a stratum granulosum
• The nonkeratinized epithelium (although cytokeratins are the
major component, as in all epithelia) has neither granulosum
nor corneum strata, whereas superficial cells have viable
nuclei
13

14. 14

15. Types of keratin:
• Immunohistochemistry, gel electrophoresis, and immunoblot
techniques have made identification of the characteristic
pattern of cytokeratins possible in each epithelial type.
• Generally, basal cells begin synthesizing lower-molecular-
weight keratins, such as K19 (40 kD), and express other
higher-molecular-weight keratins as they migrate to the
surface.
A (neutral-basic) B (acidic) Occurrence
keratin 1, keratin 2 keratin 9, keratin 10
stratum corneum,
keratinocytes
keratin 3 keratin 12 cornea
keratin 4 keratin 13 stratified epithelium
keratin 5 keratin 14, keratin 15 stratified epithelium
keratin 6 keratin 16, keratin 17 squamous epithelium
keratin 7 keratin 19 ductal epithelia
keratin 8 keratin 18, keratin 20 simple epithelium
15

16. Keratinocyte vs. Corneocyte
• Keratohyaline granules contain a histidine-rich, sulphur-poor
protein which when the cell reaches the stratum corneum
becomes modified to filaggrin.
• In the sudden transition to the horny layer, the keratohyaline
granules disappear and give rise to filaggrin, which forms the
matrix of the most differentiated epithelial cell, the corneocyte.
• thus in the fully differentiated state, the corneocytes are
mainly formed by bundles of keratin tonofilaments embedded
in an amorphous matrix of filaggrin and are surrounded by a
resistent envelope under the cell membrane.
16

17. Langerhan cells:
• Langerhans are dendritic cells located
among keratinocytes at all suprabasal
layers.
• They belong to mononuclear phagocyte
system.
• They contain elongated granules and are
considered macrophages with possible
antigenic properties.
• They contain g-specific
granules(Birbeck’sgranules).
• They are found in oral epithelium of
normal gingiva and in smaller amounts in
sulcular epithelium.
• They are absent in junctional epithelium of
normal gingiva. 17

18. Melanocytes
1. Melanocytes are dendritic cells located in the basal and
spinous layer of the gingival epithelium.
• Pre melanosome organelles.
• These contain tyrosinase which hydroxylates tyrosine into
dihydroxyphenylalanine(dopa) which in turn is converted into
melanin
• Melanin granules are phagocytosed & contained in
melanophages or melanophores.
• Lacks desmosomes
18

19. Merkel cells:
• Merkel cells located in deep layers of the epithelium(basal
layer)
• Epithelial in origin
• Harbor nerve endings.
• They have been identified as tactile preceptors.
• Small membrane bound vesicles in the cytoplasm adjacent to
nerve endings
19

20. Layers of an epithelium
• The epithelium is joined to the
underlying connective tissue by a
basal lamina 300 to 400 Å thick,
lying approximately 400 Å
beneath the epithelial basal layer.
• The four layers:
I) BASAL LAYER (STRATUM
BASALE)
II) PRICKLE CELL LAYER
(STRATUM SPINOSUM)
III) GRANULAR LAYER
(STRATUM GRANULOSUM)
IV) KERATINIZED CELL LAYER
(STRATUM CORNEUM) 20

21. Basal lamina:-
• Ultra structurally ,basement membrane is called basal lamina.
• Basal lamina is made up of a clear zone (lamina lucida) just
below the epithelial cells and a dark zone (lamina densa)
beyond the lamina lucida and adjacent to the connective
tissue
• Anchoring fibrils , which forms loops and are inserted into
the lamina densa.
• Lamina lucida is 20-40 nm wide glycoprotein layer.
21

22. • Functions of basal lamina-
a) They form selectively permeable barrier between adjacent
tissues in some cases
b) They have mechanical functions, forming anchoring
intermediaries between epithelial & connective tissues,
assisting to stabilize & orient the tissue layers
c) Changes in thickness of basal lamina is often associated with
pathological conditions as in thickening of the glomerular
membrane in glomerulo-nephritis & diabetes.
22

23. Stratum Basale:
• Cuboidal or columnar cells adjacent to basement membrane
• Ability to divide ( mitotic division)
• According to orban
a) Serrated-heavily packed with tonofilaments which are
adaptations for the attachment.
b) Non-serrated-is composed of slowly cycling stem cells which
give rise to population of cells amplified for cell division.
Hence called stratum germinativum.
• Least differentiated (contains normal cell organelles)
• Characteristic structure –tonofilament and desmosomes
23

24. Stratum Spinosum & Stratum Granulosum :
• Spinous layer:
1. They are arranged at regular intervals they give the cell
prickled appearance hence also called prickle cell layer.
2. Contains fewer cell organelles & more tonofilaments.
3. Active in protien synthesis.
4. Uppermost cell contain keratinosomes or odland bodies,
which are modified lysosomes. They contain large amount of
acid phosphotase an enzyme involved in destruction of
organelle membrane.
• Granulosum Layer
1. The presence of keratohyaline granules gives it a granular
appearance, hence named so.
2. Nuclei shows sign of degeneration & pyknosis.
3. Tonofibrils more prominent.
4. Still synthesizes protein.
24

25. Stratum Corneum:
• This layer is keratinized and the cells are larger and
flatter than granular cells.
• Nucleus and other organelles like mitochondria and
ribosomes disappear.
• Keratinized VS. Non Keratinized
• The Stratum Granulosum and Stratum Corneum are
absent in the non keratinized epithelium
• Ortho VS. Para Keratinized Epithelia
• The presence and absence of the nucleii in the Stratum
Corneum determines Ortho and Para keratinized epithelium. 25

26. Inter-cellular Junctions:-
• Types:
1. Occluding (tight) junctions (zonula occludens)
2. Adhesive junctions
a. Cell-to-cell
i. Zonula adherens
ii. Macula adherens (desmosorne)
b. Cell-to-matrix
i. Focal adhesions
ii. Hemidesmosomes
3. Communicating (gap) junctions
26

27. Occluding junctions:
• The transmembrane
adhesive proteins, which
include occludin,
members of the claudin
family, and in some
tissues, junctional
adhesion molecule
(JAM), interact
homotypically with the
same proteins on the
adjacent cell.
27

28. Adhesive junction:
• Hold cells together or anchor cells to the extracellular
matrix. In contrast to tight junction the intercellular space in
cell-cell adhesive junction is maintained at approximately 20
nm.
• Adhesive junctions are also important in cellular signaling
• In cell-cell adhesive junctions, the principal
transmembrane proteins are members of the cadherin
family.
28

29. • Cadherins are calcium
ion-dependent proteins
that interact
homotypically with
cadherins on the adjacent
cell.
• The cytoplasmic adapter
proteins are members of
catenin family.
29

30. Desmosome:
• In the Desmosome the
cadherins are desmoglein and
desmocollin. The interaction of
these transmembrane proteins
with those from the adjacent cell
results in a dense line in the
middle of the intercellular space
at the desmosome.
• The catenins are desmoplakin
and plakoglobin, which form an
electron- dense plaque on the
cytoplasmic side of the
desmosome.
30

31. Cell matrix junctions:-
• Have a structural organization similar to that of cell-cell
adhesive junctions, but they use different molecular
components and attach the cell to the extracellular matrix.
• In focal adhesions the transmembrane component is a
member of the integrin family of adhesion molecules.
• Integrins are heterodimers of different alpha and beta
subunits with specificity for various extracellular matrix
molecules.
• Eighteen known alpha subunits and 8 beta subunits occur in
24 different combinations.
• integrin binds to collagen, laminin, fibronectin, and other
extracellular matrix proteins
31

32. Hemidesmosome:
• The transmembrane adhesive
molecules present in
hemidesmosome are the
integrin alpha 6, beta 4, which
binds specifically to the basal
lamina glycoprotein laminin, and
collagen XVII (also identified as
BPI8O).
• Hemidesmosomes link the cell
to the basal lamina, and through
additional extracellular
molecules, to the rest of the
extracellular matrix.
32

33. Gap junctions:
• Transmembrane proteins of the
connexin family form aqueous
channels between the cytoplasm
of adjacent cells.
• Six connexin molecules form a
connexon, which has a central
channel approximately 2nm
diameter.
• The connexons in one cell pair
with connexons in the adjacent
cell to create a patent channel.
Small molecules such as ions and
signaling molecules can move
readily from one cell to another.
33

34. Cellular organelles variations in different
layers of epithelia:-
• Mitochondria are more numerous in deeper strata and
decrease toward the surface of the cell.
• Accordingly, histochemical demonstration of succinic
dehydrogenase, NAD, cytochrome oxidase, and other
mitochondrial enzymes reveals a more active tricarboxylic
cycle in basal and parabasal cells, where the proximity of the
blood supply facilitates energy production through aerobic
glycolysis.
34

35. Epithelium of Gingiva:-
• The epithelium covering the
gingiva may be differentiated as
follows:
1)Oral epithelium(OE), which faces
the oral cavity
2)Oral sulcular epithelium(OSE),
which faces the tooth without
being in contact with the tooth
surface
3)Junctional epithelium(JE) ,which
provides the contact between the
gingiva and the tooth
35

36. Oral Epithelium:
• It covers the oral cavity and the outer surface of marginal
gingiva and attached gingiva,
• Represents the keratinized gingiva.
• Extends from mucogingival junction to gingival margin.
• On average ,the oral oral epithelium is 0.2 to 0.3 mm in
thickness.
• The degree of gingival keratinization diminishes with age and
onset of menopause.
• Palate(most keratized), gingiva, ventral aspect of tongue
and cheek(least keratinized)
• K6 and K16, characteristic of highly proliferative epithelia,
and K5 and K14, stratification-specific cytokeratins, also are
present.
• Parakeratinized areas express K19, which is usually absent
from orthokeratinized normal epithelia.
36

37. Sulcular Epithelium:
• lines the gingival sulcus
• thin, nonkeratized stratified squamous epithelium without rete
pegs and it extends from the coronal limit of the junctional
epithelium to the crest of the gingival margin.
• it contains K4, K13 keratins.
• It also expresses K19 keratin.
• Despite these morphologic and chemical characteristic the
sulcular epithelium has the potential to keratinize if:
1)it is reflected & exposed to the oral cavity.
2)The bacterial flora of the sulcus is totally eliminated
• These findings suggest that the local irritation of the sulcus
prevents sulcular keratinization.
37

38. Junctional Epithelium:
• The junctional epithelium consists of a collar like band of
stratified squamous non keratinising epithelium.
• According to Glossary of Periodontal terms 2001 Junctional
epithelium “is a unique, non keratinizing, non differentiated
tissue which is affixed to tooth structure on one side & oral
sulcular epithelium & connective tissue on the other.”
• It is 3 to 4 layers thick in early life, but the number of layers
increases with age to 10 to 20 layers.
• It tapers from its coronal end which may be 10 to 29 cells
wide to 1 to 2 cells at its apical termination located at the
cementoenamel junction in healthy tissues.
38

39. • The length of the junctional epithelium ranges from 0.25 to
1.35 mm.
• It is formed by the confluence of the oral epithelium and the
reduced enamel epithelium during tooth eruption.
• Produces laminin and play a key role in the adhesion
mechanism
• The attachment of the junctional epithelium to the tooth
surface is reinforced by gingival fibers which brace the
marginal gingiva against the tooth surface.
• Junctional epithelium and the gingival fibers are considered a
functional unit referred to as the dentogingival unit.
• Three zones in junctional epithelium-
-Apical is for germination
-Middle is for adhesion
-coronal is permeable. 39

40. • Apical zone: - Contains fewer
hemidesmosomes and cell with
germinative characteristics.
• Middle zone:- Area of greatest
attachment having large numbers
of hemidesmosomes
• Coronal zone:- Area of greatest
permeability characterized by
numerous intercellular spaces.
Some of which directly open into
internal basal lamina. 40

41. • The junctional epithelium is the
only gingival epithelium with two
distinct basal laminas. It has a
basal lamina on each surface.
External basal lamina:
• This basal lamina mediates the
attachment of the junctional
epithelium to the connective
tissue.
Internal Basal Lamina
• This attaches the junctional
epithelium to the tooth surface.
The 2 zones of basal lamina
• Lamina lucida (electron lucent
zone) &
• The lamina densa (electron dense
zone). 41

42. • Internal Basal Lamina:
• It lacks most of the common basement membrane
components such as collagen types IV and VII, most laminin
isoforms, perlecan, and a lamina fibroreticularis (Hormia et al.,
2001).
• Laminin-5, however, appears to be expressed in the internal
basal lamina (Oksonen et al., 2001).
• External basal lamina :
• contains collagen type IV, heparan sulfate proteoglycan,
laminin, and fibronectin.
• Kobayashi et al. described a third lamina, the sublamina
lucida (120 ± 20A), between the tooth and lamina densa.
42

43. Antimicrobial activity of JE:
(1) because of rapid cell division
(2) and funnelling of junctional
epithelial cells towards the sulcus
hinder bacterial colonization.
Laterally, the (external) basement
membrane forms an effective barrier
against invading microbes
(3) Active antimicrobial substances are
produced in junctional epithelial
cells. These include defensins and
lysosomal enzymes
(4) Epithelial cells activated by
microbial substances secrete
chemokines,
43

44. Modes of attachment of Junctional
epithelium:
GOTTLIEB IN 1921
• Concluded that there is no such space. Rather, the gingiva
forms an organic union with the enamel and is firmly bound to
it, and he named it as (epithelansatz or epithelial
attachement).
ORBAN 1944
• Incorporated the views of Meyer, Becks, and Weski by
stating that, the separation of the epithelial attachment cells
from the tooth surface involved preparatory degenerative
changes in the epithelium.
44

45. WAERHAUG 1952
• He described the gingiva as being separated from the tooth
by a capillary space, forming an epithelial cuff.
• This cuff was believed to be weakly adherent to the tooth, and
could be displaced from the tooth surface and then replaced
against it without diminishing the strength of the adhesion.
STERN 1962
• First demonstrated the ultra structure of the ameloblast
enamel junction (the dentogingival junction) of rat incisor
which consists of a basal lamina and hemidesmosomes, and
that the basal lamina has components namely lamina lucida
and lamina densa
45

46. Turnover of JE cells & Development of
Gingival sulcus:
• The junctional
epithelium(JE) is formed by
the joining of the oral
epithelium(OE) and the
reduced enamel
epithelium(REE).The arrows
indicate the coronal
movement of the
regenerating epithelial cells
which multiply more rapidly
in the JE then in OE
Demetriou and Ramfjord, 1972
• The migrating daughter cells
provide a continuous
attachment to the tooth
surface. 46

47. Difference between the three epithelium:-
• There are three distinct difference between the three epithelia
in respect to the junctional epithelium:-
1. The size of the cells in the junctional epithelium is, relative to
the tissue volume i.e. larger than in the oral epithelium.
2. The intercellular space in junctional epithelium is, relative to
tissue volume i.e. wider than the oral epithelium.
3. The no. of desmosomes are smaller in the junctional
epithelium than in the oral epiuthelium
47

48. The dentogingival unit:
• The dentogingival unit comprises of
the junctional epithelium, the
connective tissue and the gingival
fibres.
• A term frequently used to describe
the dimensions of the soft tissues
that face the teeth is the biologic
width of the soft tissue attachment.
(1) the biologic width of the attachment
varied between about 2.5 mm in the
normal case and 1.8 mm in the
advanced disease case, and
(2) the most variable part of the
attachment was the length of the
epithelial attachment (junctional
epithelium).
48

49. Gingival Fluid (Sulcular Fluid)
• The gingival sulcus contains a fluid that seeps into it from the
gingival connective tissue through the thin sulcular epithelium.
• The gingival fluid is believed to:
1) cleanse material from the sulcus.
2) contain plasma proteins that may improve adhesion of the
epithelium to the tooth.
3) possess antimicrobial properties.
4) exert antibody activity to defend the gingiva.
49

50. Gingival connective tissue:-
• The major components of the gingival connective tissue are
collagen fibers (about 60% by volume), fibroblasts (5%),
vessels, nerves, and matrix (about 35%).
• The connective tissue of the gingiva is known as the lamina
propria and consists of two layers:
(1) a papillary layer subjacent to the epithelium, which
consists of papillary projections between the
epithelial rete pegs, and
(2) a reticular layer contiguous with the periosteum of the
alveolar bone.
• The components of the gingival connective tissue can be
divided into as matrix component(or ground substance) and
the fibre component.
50

51. • The ground substance fills the space between fibers and
cells, is amorphous, and has a high content of water.
• It is composed of proteoglycans, mainly hyaluronic acid and
chondroitin sulfate, and glycoproteins, mainly fibronectin,
osteonectin.
51

52. Connective tissue fibres:
• The three types of connective tissue fibers are collagen,
reticular,oxytalan and elastic.
• Collagen type I forms the bulk of the lamina propria and
provides the tensile strength to the gingival tissue.
• The elastic fiber system is composed of oxytalan, elaunin.
• Oxylatan are scare in gingiva but numerous in the PDL.
• Elastin fibers distributed among collagen fibers
52

53. Gingival fibres:
• The connective tissue of the marginal gingiva is densely
collagenous containing a prominent system of collagen fibre
bundle called the gingival fibres.
• They consist of type I collagen.
• The gingival fibers are arranged in five groups: dentogingival,
circular, transseptal, semicircular and transgingival.
53

54. Blood & Lymphatic supply:
•Three major sources of
gingival blood supply are:-
1.Supraperiosteal arterioles.
2.Vessels of PDL.
3.Arterioles
•Labial & lingual surface of gingiva
of mandibular incisors by-
Submental lymph node.
•Palatal gingiva-Deep cervical
lymph node.
•Buccal of maxillary and buccal &
lingual on mandibular molar region
–Submandibular lymph node.
54

55. Nerve supply:
• Branches of trigeminal nerve.
a) Labial aspect of maxillary incisors,canines & premolars-
Superior labial branches from infraorbital nerve.
b) Buccal gingiva of maxilla-Posterior superior alveolar nerve.
c) Palatal gingiva-Greater palatine nerve.
d) Lingual gingiva in mandible-Lingual nerve.
e) Buccal gingiva-Inferior alveolar nerve.
55

56. Clinical features of healthy gingiva:
• Colour: • Size:
56

57. • Contour: • Shape:
57

58. • Consistency: • Surface texture:
58

59. • Position:
59

60. Gingiva in disease:
• The most widely accepted classification of periodontal
diseases is that developed and presented at the 1999
International Workshop for the Classification of Periodontal
Diseases.
• This is the basis for clinicians to diagnose lesions of the
gingival and periodontal tissues and to clarify the disease
status of patients.
• Gingivitis now has the subcategories of dental plaque-induced
gingival disease and non-plaque-induced gingival disease.
• The following classification was given by Holmstrup P: Ann
Periodontol 4:20, 1999; and Mariotti A: Ann Periodontol 4:7,
1999.
60

61. • Dental Plaque-Induced Gingival Diseases
I. Gingivitis associated with dental plaque only
A. Without local contributing factors
B. With local contributing factors
II. Gingival diseases modified by systemic factors
A. Associated with endocrine system
1. Puberty-associated gingivitis
2. Menstrual cycle-associated gingivitis
3. Pregnancy associated
a. Gingivitis
b. Pyogenic granuloma
4. Diabetes mellitus-associated gingivitis
B. Associated with blood dyscrasias
1. Leukemia-associated gingivitis
2. Other 61

62. III. Gingival diseases modified by medications
A. Drug-influenced gingival diseases
1. Drug-influenced gingival enlargements
2. Drug-influenced gingivitis
a. Oral contraceptive-associated gingivitis
b. Other
IV. Gingival diseases modified by malnutrition
A. Ascorbic acid deficiency gingivitis
B. Other
62

63. • Non—Plaque-Induced Gingival Lesions
I. Gingival diseases of specific bacterial origin
A. Neisseria gonorrhoeae
B. Treponema pallidum
C. Streptococcus species
D. Other
II. Gingival diseases of viral origin
A. Herpesvirus infections
1. Primary herpetic gingivostomatitis
2. Recurrent oral herpes
3. Varicella zoster
B. Other
63

64. III. Gingival diseases of fungal origin
A. Candida species infections: generalized gingival
candidiasis
B. Linear gingival erythema
C. Histoplasmosis
D. Other
IV. Gingival lesions of genetic origin
A. Hereditary gingival fibromatosis
B. Other
64

65. V. Gingival manifestations of systemic conditions
A. Mucocutaneous lesions
1. Lichen planus
2. Pemphigoid
3. Pemphigus vulgaris
4. Erythema multiforme
5. Lupus erythematosus
6. Drug induced
7. Other
65

66. B. Allergic reactions
1. Dental restorative materials
a. Mercury
b. Nickel
c. Acrylic
d. Other
2. Reactions attributable to:
a. Toothpastes or dentifrices
b. Mouth rinses or
mouthwashes
c. Chewing gum additives
d. Foods and additives
3. Other 66

67. VI. Traumatic lesions (factitious, iatrogenic, or accidental)
A. Chemical injury
B. Physical injury
C. Thermal injury
VII. Foreign body reactions
VIII. Not otherwise specified
67

68. Bibliography:
• Carranza’s clinical periodontology 10th
edition.
• Clinical periodontology and implantology, Jan lindhe, 4th
edition.
• Orban’s Oral histology, 12th
edition
68

69. 69