This document provides an overview of gingival anatomy and histology. It discusses the 3 parts of the gingiva - marginal, attached, and interdental gingiva. Microscopically, it describes the stratified squamous epithelium and underlying connective tissue. The epithelium consists of basal, spinous, granular, and corneal layers. The connective tissue contains collagen fibers, fibroblasts, and ground substance. Gingival fibers attach the gingiva to the tooth cementum. Blood supply and innervation is also summarized.

1. Raina J P Khanam
MDS 1stYear
Dept. Of Periodontics and Implantology

2. Introduction
Anatomic classification
Microscopic features
Gingival fibres
Correlation of clinical and microscopic
features
Conclusion
Content

3. Definition of gingiva
The gingiva is the part of oral mucosa that covers the alveolar
processes of the jaws and surrounds the necks of the teeth.

4. Anatomical classification
The gingiva is divided anatomically into :-
Attached gingiva
Interdental gingiva
Marginal gingiva
MARGINAL GINGIVA
INTERDENTAL GINGIVA
ATTACHED GINGIVA

5. Marginal Gingiva
The marginal or unattached gingiva is the terminal edge
or border of the gingiva surrounding the teeth in collar like
fashion.

6. Free gingival groove
• Shallow linear depression that
demarcates marginal gingiva
from the adjacent attached
gingiva
• About 50% of cases
• Usually about 1mm wide, the
marginal gingiva forms the soft
tissue wall of the gingival sulcus
• The most apical point of the
marginal gingiva scallop is called
gingival zenith.

7. Attached gingiva
 It is continuous with marginal
gingiva.
 Firm, resilient, and tightly bound to
the underlying periosteum of
alveolar bone.
 Facial aspect of the attached gingiva
extends to the relatively loose and
moveable alveolar mucosa.
 Demarcated by the mucogingival
junction.

8.  The width of the attached
gingiva is the distance
between the mucogingival
junction and the projection
on the external surface of
the bottom of the gingival
sulcus or the periodontal
pocket.

9.  Width of attached gingiva :-
• Maxilla incisor region: 3.5- 4.5 mm (greatest)
• Mandible incisor region: 3.3 – 3.9 mm
• Maxillary premolar: 1.9 mm
• Mandibular first premolars: 1.8 mm
 The width of the attached gingiva increases with
age and in supraerupted teeth.

10. Interdental gingiva
The interdental gingiva
occupies the gingival
embrasure, which is the
interproximal space
beneath the area of
tooth contact.
The interdental gingiva
can be pyramidal or can
have a ‘col’ shape.

11.  The shape of the gingiva in a given interdental space depends on
the contact point between the two adjoining teeth and the
presence or absence of some degree of recession.
 In the pyramidal the tip of one papilla is located immediately
beneath the contact point.
 The Col presents a valley like depression that connects a facial
and lingual papilla and conforms to the shape of the
interproximal contact.

12.  The facial and lingual surfaces are tapered toward the
interproximal contact area , whereas the mesial and distal
surfaces are slightly concave.
 lateral borders and tips of the interdental papillae are formed by
the marginal gingiva of the adjoining teeth.
If a diastema is present , the gingiva is firmly bound over the
interdental bone and forms a smooth , rounded surface without
interdental papillae.

13. Gingival sulcus
Is a shallow crevice or space
around the tooth bounded
by the surface of the tooth
on the one side and the
epithelium lining the surface
of the gingiva on the other
side.
It isV shaped.
In histologic sections the
depth of this has been
reported as 1.8 mm, with
variation from 0 to 6 mm.
The so-called probing depth
of a clinically normal
gingival sulcus in humans is
2 to 3 mm.

14. Microscopic features
Gingiva is composed of overlying stratified squamous
epithelium and central core of connective tissue
• Epithelium : predominantly cellular
• Connective tissue: less cellular and composed primarily of
collagen fibers and ground substances

15. • Continuous lining of stratified squamous epithelium.
• Function:
 Participate actively in responding to infection, in signaling
further host reactions and in integrating innate and acquired
immune responses.
 To protect deep structures while allowing a selective
interchange with the oral environment.
Gingival epithelium

16.  Proliferation through mitosis occurs in the basal layer , less
frequently in the suprabasal layer and migration occurs.
 Differentiation includes keratinization in which main
morphologic changes seen are:
• Progressive flattening of the cell with increased prevalence of
tonofilaments.
• Intercellular junctions coupled to the production of
Keratohyaline granules.
• Disappearance of the nucleus

17. 1. stratum basale (basal layer)
2. stratum spinosum (prickle cell layer)
3. stratum granulosum (granular layer)
4. stratum corneum (cornified layer)
Oral epithelium is composed of four layers –
• Layers of stratified squamous epithelium as seen by electron
microscopy:

18. Stratum basale:
• Cells: cylindric or cuboid.
• Found immediately adjacent to the connective tissue
separated by a basement membrane.
• Germinative layer: having the ability to divide.
• It takes approximately 1 month for a keratinocyte to reach the
outer epithelial surface, where it is shed from the stratum
corneum.

19. Stratum spinosum:
• Prickle cell layer.
• Large polyhedral cells with short cytoplasmic processes.
• Keratinosomes or odland bodies:
Modified lysosomes.
Present in the uppermost part of the stratum
spinosum.
Contain a large amount of acid phosphatase.

20. Stratum granulosum:
• Flattened cells, in a plane parallel to the gingival surface.
• Keratohyaline granules :
Associated with keratin formation
1 μm in diameter
round in shape and appear in the cytoplasm of the cell.

21. Stratum corneum:
• Closely packed, flattened cells that have lost nuclei and
most other organelles as they become keratinized.
•The cells are densely packed with tonofilaments.
• Clear, rounded bodies probably representing lipid droplets
appear within the cytoplasm of the cell.

22. •Three types of surface keratinization can occur in the
gingival epithelium:
1. Orthokeratinization
2. Parakeratinization
3. Nonkeratinization

23. 1. ORTHOKERATINIZATION:
• Complete keratinization -
superficial horny layer.
• No nuclei in stratum corneal
layer.
•Well-defined stratum
granulosum.
• Few areas of outer gingival
epithelium.

24. 2. PARAKERATINIZATION:
• Intermediate stage of
keratinization.
• Most prevalent surface area of the
gingival epithelium.
• Stratum cornea retains PYKNOTIC
NUCLEI.
• Keratohyaline granules are
dispersed, not giving rise to a
stratum granulosum.

25. 3. NONKERATINIZATION:
•Viable nuclei in superficial layer.
• Has neither granulosum nor
corneum strata.
• Layers of nonkeratinized epithelium:
1. Stratum superficial
2. Stratum intermedia
3. Stratum basale

26. CELLS PRESENT IN GINGIVAL
EPITHELIUM:
 KERATINOCYTES
NONKERATINOCYTES/CLEAR CELLS:
1. Langerhans cells
2. Merkel cells
3. Melanocytes
4. Inflammatory cells

27. • 90% of the total gingival cell population.
• Originate from ectodermal germ layer.
• Cell organelles: nucleus, cytosol, ribosomes, Golgi
apparatus etc
• Melanosomes: Pigment bearing granules
• Proliferation and differentiation of the keratinocyte
helps in the barrier action of the epithelium.
KERATINOCYTE

28. Melanocytes
•Dendritic cells
•Located in the basal and spinous layers of the gingival epithelium.
•They synthesize melanin in organelles -premelanosomes or
melanosomes which contain tyrosinase which hydroxylates tyrosine
to dihydroxyphenylalanine (DOPA), which in turn is progressively
converted to melanin.
•Melanin granules are phagocytosed and contained within other
cells of the epithelium and connective tissue called melanophages or
melanophores.

29. Langerhans Cell
•Langerhans cells are Dendritic cells located among
keratinocytes at all suprabasal levels.
•They belong to the mononuclear phagocytes system
(reticuloendothelial system ).
•They contain elongated granules and are considered
macrophages with possible antigenic properties.

30. Merkel cells
•located in the deeper layers of the epithelium
•they harbor nerve endings
•connected to adjacent cells by desmosomes
•They have been identified as tactile preceptors

31. Structural and metabolic characteristics of
Different Areas of Gingival Epithelium
Outer (Oral) epithelium –
•Covers the crest and outer surface of the marginal gingiva
and the surface of the attached gingiva.
•On average, the oral epithelium is 0.2 to 0.3 mm in
thickness.
•It is keratinized or para keratinized or presents various
combination of these conditions.
•Palate (most keratinized), gingiva, ventral aspect of the
tongue and cheek (least keratinized).

32. Sulcular epithelium
• Lines the gingival sulcus
• It is a thin, non-keratinized stratified squamous
epithelium without rete pegs.
• it extends from the coronal limit of the JE to the crest of
gingival margin.
• It shows many cells with hydropic degeneration.

33. •The Sulcular epithelium
acts as a semi permeable
membrane
•Unlike the JE , the Sulcular
epithelium is not heavily
infiltrated by PMNs and it
appears to be less
permeable.

34. Junctional Epithelium
•Consists of a collar like band of stratified squamous non
keratinizing epithelium.
•It is 3 to 4 layers thick in early life , but the number of
layers increases with age to 10 or even 20 layers.
• Junctional Epithelium tapers from its coronal end, which
may be 10 to 29 cells wide to 1 or 2 cells wide at its apical
termination
•The length of the Junctional epithelium ranges from 0.25
to 1.35 mm.

35. •The Junctional Epithelium is formed by the confluence of the
oral epithelium and the reduced enamel epithelium during
tooth eruption.
•The Junctional Epithelium is attached to the tooth surface by
means of an internal basal lamina.
•It is attached to the gingival connective tissue by an external
basal lamina.
•The attachment of Junctional Epithelium to the tooth is
reinforced by the gingival fibers.
•For this reason ,the Junctional Epithelium and the gingival
fibers are considered a functional units referred to as the
dentogingival unit.

37. Functions of Junctional
Epithelium
1)Junctional Epithelium is firmly attached to the tooth
surface, forming an epithelial barrier against plaque
bacteria.
2) It allows access of gingival fluid, inflammatory cells, and
components of the immunologic host defense to the
gingival margin.
3) Junctional Epithelial cells exhibit rapid turnover, which
contributes to the host- parasite equilibrium and rapid
repair of damaged tissue.

38. Gingival ConnectiveTissue
The major components of the gingival connective tissue are
collagen fibers – approx 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.
2) a reticular layer contiguous with the periosteum of the
alveolar bone.

39. Connective tissue has a cellular and an extracellular
compartment composed of fibers and ground substance.
The ground substance fills the space between fibers and cells,
is amorphous, and has a high content of water.
Ground substance is composed of proteogylcans, mainly
hyaluronic acid and Chondroitin sulfate, and glycoprotein,
mainly fibronectin.
Fibronectin binds fibroblasts to the fibers and many other
components of the intercellular matrix , helping mediate cell
adhesion and migration.
Laminin , another glycoprotein found in the basal lamina
serves to attach it to epithelial cells.

40.  3 types of connective tissue fibers are collagen, reticular and
elastic.
Collagen type I forms the bulk of the lamina propria and
provides the tensile strength to the gingival tissue.
Type IV collagen (argyrophillic reticulum fiber) branches
between the collagen type I bundle and is continuous with fibers
of the basement membrane and blood vessel walls.
The elastic fiber system is composed of oxytalan, elaunin, and
elastin fibers distributed among collagen fibers.

41. Gingival fibers
•The connective tissue of the
marginal gingiva is densely
collagenous, containing a
prominent system of collagen
fibers bundles called the
gingival fibers.
•They consists of type I
collagen

42. Functions
1)To brace the marginal gingiva firmly against the tooth.
2)To provide the rigidity necessary to withstand the forces of
mastication without being deflected away from the tooth
surface.
3)To unite the free marginal gingiva with the Cementum of
the root and the adjacent attached gingiva.

43. Gingival fibers
1. Gingivodental fibers (GDF)
Are those on the facial, lingual and interproximal surfaces.
embedded in the Cementum.
On the facial and lingual surfaces, the project from the
cementum in a fan-like conformation externally to the
periosteum of alveolar bone.
Interproximally, the Gingivodental fibers extend toward the
crest of the interdental gingiva.

44. 2. Circular fibers (CF)
 are fiber bundles which run their course in the free gingiva.
 encircle the tooth in a ring like fashion.

45. 3. Trans-septal fibers (TF)
The trans-septal fibers run straight across the interdental
septum and are embedded in the Cementum of adjacent
teeth.

46. Cellular Elements
Fibroblast –major element
mesenchymal origin and play a major role in the development,
maintenance , and repair of gingival connective tissue.
Fibroblast synthesize collagen and elastic fibers ,as well as the
glycoproteins and glycosaminoglycans of the amorphous
intercellular substance.
It regulate collagen degradation through phagocytosis and
secretion of Collagenases.

47. Other cells
•Mast cell are numerous in connective tissue.
•Fixed macrophages and histiocytes are present in the gingival
connective tissue as components of the mononuclear
phagocytes system.
•Adipose cells and eosinophils
•plasma cells and lymphocytes near the base of the sulcus.
•Neutrophils

48. Blood supply, Lymphatic, and Nerves
3 sources of blood supply to the gingiva:-
1) Supraperiosteal arterioles – along the facial and lingual surfaces
of the alveolar bone, from which capillaries extend along the
Sulcular epithelium and between the rete pegs of the external
gingival surface.
2) Vessels of the periodontal ligament – which extend into the
gingiva and anastomose with capillaries in the sulcus area.
3) Arterioles which emerges from the crest of their interdental septa.

50. Lymphatic drainage
From mandibular incisor gingiva -
sub mental lymph node.
From maxillary palatal gingiva -
deep cervical lymph nodes.
Buccal gingiva of maxilla and
Buccal & lingual gingiva in the
mandibular premolar-molar -
submandibular lymph nodes.

51. Nerve supply
Branches of the trigeminal nerve provide sensory and
proprioceptive functions.
Within the gingival connective tissues, most nerve fibers
are myelinated.
Gingival innervations is derived from fibers arising from
nerves in the periodontal ligament and from the labial,
buccal, and palatal nerves.

52. Correlation of clinical and microscopic
features
1. Color
Attached and marginal gingiva is “coral pink ˮ
The color depends upon:
 the vascular supply
 the thickness and degree of keratinization of the epithelium
the presence of pigment containing cell

53. 2. Size
The size of the gingiva corresponds with the sum total of
the bulk of cellular and intercellular elements and their
vascular supply
Alteration of size denotes gingival disease

54. 3. Contour
•Varies considerably and depends on the
shape of the teeth and their alignment in the arch
the location and size of the area of proximal contact
the dimensions of the facial and lingual gingival embrasures

55. The marginal gingiva envelops the teeth in collar like fashion
and follows a scalloped outline on the facial and lingual surfaces
It forms a straight line along teeth with relatively flat surfaces.
On teeth in lingual version - the gingiva is horizontal and
thickened

56. 4. Shape
The shape of the interdental gingiva is governed by the contour
of the proximal tooth surfaces and the location and shape of
gingival embrasures .
When the proximal surfaces of the crowns are relatively flat
faciolingually ,the roots are close together , the interdental bone
is thin mesiodistally, and the gingival embrasures and interdental
gingiva are narrow mesiodistally.

57. The height of the interdental gingiva varies with the
location of the proximal contact.
In the anterior region of the dentition, the interdental
papilla is pyramidal in form, whereas the papilla is more
flattened in a buccolingual direction in the molar region.

58. 5. Consistency
The gingiva is firm and resilient and , with the exception of
the movable free margin, tightly bound to the underlying
bone .
The collagenous nature of the lamina propria determine the
firmness of the attached gingiva.
The gingiva fibers contribute to the firmness of the gingival
margin.

59. 6. SurfaceTexture
•The gingiva presents a textured surface similar to an orange
peel and is referred to as being stippled.
•The attached gingiva is stippled ; the marginal gingiva is
not.
•The central portion of the interdental papilla is usually
stippled , but the marginal borders are smooth.
• Stippling varies with age.
• It is absent in infancy , appears in some children at about 5
yrs of age , increases until adulthood ,and frequently begins
to disappear in old age.

60. • Microscopically ,stippling is produced by alternate rounded
protuberances and depressions in the gingival surface.
•The papillary layer of the connective tissue projects into the
elevations.
•The elevated and depressed areas are covered by stratified
squamous epithelium.

61. 7. Position
•The position of the gingiva refers to the level at which the
gingival margin is attached to the tooth.
•When the tooth erupts into the oral cavity ,the margin and
sulcus are at the tip of the crown; as eruption progress ,they are
seen closer to the root.
• Active eruption – movement of the teeth in the direction of
the occlusal plane.
• Passive eruption – exposure of the teeth by apical migration
of the gingiva.

62. Stages of passive eruption (Gottlieb
and Orban)
Stage 1: Base of the gingival sulcus and JE are on the enamel.
Stage 2: Base of the gingival sulcus is on the enamel and the
part of the JE is on the root.
Stage 3: Base of the gingival sulcus is at the cementoenamel
line.
Stage 4: Base of the gingival sulcus and the JE are on the
root.

63. Exposure of the tooth via the apical migration of the gingiva
is called gingival recession or atrophy.