4. GINGIVA
• The investing tissue of the periodontium is known as the GINGIVA. It is the most
peripheral portion of periodontium at large. According to the Dorland Medical
Dictionary, the word gingiva means the ‘gum of the mouth’.
5. DEFINATION
• CARRANZA: Is the part of oral mucosa that covers the alveolar
processes of jaw and surrounds the neck of teeth.
• SCHROEDER: It is a combination of epithelium and connective tissue
and is defined as that portion of oral mucous membrane, which in
complete post- eruptive dentition of a healthy young individual surrounds
and is attached to the teeth and the alveolar processes.
• GRANT: Is the part of oral mucous membrane attached to the teeth and
the alveolar processes.
• LINDHE: Is that part of masticatory mucosa covering the alveolar
processes and the cervical portions of teeth.
6. DEVELOPMENT
• Unlike, the other tissues of the periodontium which are derived from the
ectomesenchymal dental follicle, the gingiva is a derivative of mesoderm.
• According to Schroeder, the shape, topographical distribution and width of the
gingiva and functions depends on the presence and position of erupted teeth.
• He also says that, there are reasons to assume that the gingival tissues exist and
develop as a site specific portion of the oral mucous membrane prior to the eruption
of deciduous teeth. Thereafter, the gingiva although increasing size serves both
deciduous and permanent teeth.
7. • Gingiva is divided
anatomically into:
1. Marginal gingiva.
2. Attached gingiva.
3. Interdental papilla.
MACROSCOPIC FEATURES
8. • COLOUR: coral pink .(in dark
individuals due to melanin
pigmentation its darker).
Colour varies due to racial
pigmentation, vascularity degree, epithelial
keratinization and fibrous nature of the
underlying connective tissue.
9. SIZE:
• Corresponds with the sum total of the bulk of cellular and intercellular elements and their
vascular supply.
• Alteration in size is a common feature of gingival disease.
alteration
10. CONTOUR
• Depends on shape of the tooth ,their alignment in arch, location and size of the area of
proximal contact and dimensions of facial and lingual embrasures.
• Marginal gingiva envelops the teeth in collar like fashion and forms a scalloped outline.
• On pronounced mesiodistal convexity( max. canine) normal arcuate is accentuated and
gingiva is located apically farther.
• On lingual aspect its horizontal and thickened.
11. SHAPE:
• Governed by contour of proximal surface and location and shape of embrasures.
• In anteriors its pyramidal in shape and more flattened in buccolingual direction in molar
region.
.
12. CONSISTENCY:
• Is firm and resilient.
• gingival fibres contribute in firmness.
SURFACE TEXTURE:
• Similar to orange peel, referred to as
being stippled.
• Attached gingiva is stippled and
marginal gingiva is not.
• Central part of interdental papilla has
stippling while margins are smooth.
• Prominent in facial than lingual.
13. • Varies with age . Absent in infancy ;appears in about 5 yrs.
• Stippling is form of adaptive specialization or reinforcement of function.
• Feature of healthy gingiva and absence is a common sign of gingival disease..
POSITION:
• Refers to level at which the gingival margin is attached to tooth.
• When tooth erupts margin and sulcus are at the tip of the crown; as eruption progresses
they are seen closer to the root.
14. MARGINAL / UNATTACHED / FREE GINGIVA/
MARGIO GINGIVALIS
• Is the terminal edge/ border of gingiva surrounding the teeth in collar like fashion .
• After tooth eruption it lies 1.5-2mm coronal to CEJ.
• It is demarcated from adjacent attached gingiva by a shallow linear depression –’free
gingival groove’.
A. Free gingival groove- it’s a indentation that is parallel to the vestibular surface of
gingival margin at a level corresponding at CEJ. It lies opposite to the coronal margin of
junctional epithelium.
15. B. Gingival sulcus- it’s a shallow crevice
or a space around the tooth bounded by
surface of the tooth on one side and
epithelium lining the free margin of gingiva
on another side. ‘
• V’ shaped , barely permits periodontal
probe.
• Ideal condition- 0 mm depth.
• Probing depth of normal gingiva
clinically – 2 to 3mm.
• Most apical point of marginal scallop-
gingival zenith.
16. • Is a muco-periosteum which is tightly
bound to underlying alveolar bone.
• Continuous with marginal gingiva.{from
free gingival groove to mucogingival
junction}
• Firm, resilient, tightly bound to
periosteum of the alveolar bone.
• Its attached to alveolar mucosa{loose
and movable}
• Stippling is present over it.
ATTACHED GINGIVA / FUNCTIONAL MUCOSA
17. • Width of attached gingiva(distance
between mucogingival junction and
projection of the external surface of
bottom of gingival sulcus or
periodontal pocket )
18. • Greatest at incisor : 3.5-4.5 maxilla
3.3-3.9 mandible
• Narrower at posterior : 1.9 maxilla
(1st premolar) 1.8 mandible
• Increases with age and supra-erupted
teeth.
• In maxilla continuous with palatal
mucosa.
20. STUDIES ON THE WIDTH OF ATTACHED GINGIVA
The width of the attached gingiva was studied by Bowers (1963), who concluded:
The width of the attached gingiva varies with each tooth. There is great variation in the
width of attached gingiva between patients, but the pattern of variation is consistent,
varying between 1-9 mm.
There is an increase in the mean width of the attached gingiva from the deciduous
dentition to the adult dentition . The mean width of attached gingiva for individual teeth
are approximately the same for males and females. There is a greater overall width of
attached gingiva in the maxilla than the mandible . Teeth rotated labially have a narrower
zone than the corresponding tooth on the opposite side that is well aligned. High frenal
and muscle attachments are usually associated with narrow bands of attached gingiva.
Width of attached gingival is measured with the help of iodine solutions e.g. Lugol’s
solution and schiller’s solution
21. • Functions of Attached Gingiva
1. Allows proper deflection of food.
2. Braces marginal gingiva.
3. Allows proper placement of tooth.
4. Esthetic value.
5. Maintenance of gingival health.
22. • Occupies gingival embrasures in the
interproximal space between area of
tooth contact.
• Pyramidal / col shaped.
• Pyramidal: tip of papilla located
immediately below contact point.
• Col: valley like depression that
connects facial and lingual papilla.
• If diastema present- smooth and round
(no papilla present).
INTERDENTAL PAPILLA
23. GINGIVAL CREVICULAR FLUID
•The gingiva sulcus contains a fluid GINGIVAL FLUID / SULCULAR FLUID (GCF) that seeps
into it from the gingival connective tissue through the thin sulcular epithelium.
Functions of GCF: -
•Cleanses material from the sulcus.
•Contains plasma proteins that may improve adhesion of the epithelium to the tooth.
•It also possesses antimicrobial properties.
•It exerts antibody activity in defense of the gingiva.
24. Histologically gingiva is divided into:
1. Overlying epithelium.
2. Underlying core of connective tissue.
• Gingival epithelium- Consists of
lining of stratified squamous epithelium
and 3 different areas by morpho-
functional view.
1. Oral/ outer epithelium
2. Sulcular epithelium
3. Junctional epithelium
MICROSCOPIC FEATURES
25. Cell types
Other cell types
NON-
KERATINOCYTES/
CLEAR CELLS
Principal cell type
KERATINOCYTES
(merkel cells,
langerhan cells,
melanocytes,
inflammatory
cells)
26. • Functions of gingival epithelium: Main function protect deep structures.
1. Mechanical protection
2. Chemical protection
3. Microbial barrier
4. Signaling function
27. • Like all squamous epithelium it also undergoes constatnt renewal by continuous cell
reproduction in its deepest layer and shedding at superficial layers.
• Mitotic rate of gingiva : 10- 12 days
Keratinization process takes place in 2 steps:
1. Proliferation: by mitosis from basal layer to superficial layers.
2. Differentiation: progression of bio-chemical and morphologic events that occur in the cells
as the migrate to the surface.
28. • Morphologic changes:
1. Progressive flattening of cells.
2. Increase in the number of
tonofilaments.
3. Intercellular junctions coupled to the
production of keratohyaline granules.
4. Disappearance of nucleus.
• Keratinization process is controlled by
keratinocyte growth factor(KGF).
29. 1. Orthokeratinization:
Keratinization is complete.
No nuclei in stratum corneum.
Well defined stratum granulosum
Mechanical stimuli like gingival
massage increases gingival
keratinization . Therefore there is
increased tendency towards ortho
keratinizaiton in the chewing habits.
Ortho keratinized tissue when stained
with modified Mallory’s stain , it
appeared as a bright red color , the
underlying layer appearing blue
TYPES OF KERATINIZATION
30. 2. Parakeratinization:
Intermediate stage of keratinization.
St.corneum retains pyknotic nuclei
Keratohyaline granules are dispersed
not giving rise to st. granulosum
31. 3. Non keratinization:
Superficial cells have viable nuclei
No st. granulosum and st. corneum.
34. STRATUM BASALE/ STRATUM
GERMINATIVUM:
• Cylindrical or cuboidal shape cells.
• Its in contact with basement
membrane that separates the
epithelium and connective tissue.
• 2 zones are present:
Lamina lucida: immediate below basal
cells approximate 400 A◦ wide
electron lucent zone.
Lamina densa: beneath lucida is a
electron dense zone from these
anchoring fibres project into
connective tissue.
35. • Possess the ability to divide.
• As it migrates through the epithelium it
becomes flattened with its long axis
parallel to epithelial surface.
• Microfilaments helps in motility of cells
from basal layer to surface.
36. Basement membrane/ lamina:
• The interface between basal epithelial
cells and the underlying connective
tissue is a highly specialized
anatomical site termed the basement
lamina.
• It serves as a barrier to the exchange
of cells and some large molecules
across the junction.
• Ultra structurally, the epithelial-
connective tissue interface is
composed of four elements.
37. (1) The basal cell plasma membrane with
its specialized attachment devices
(hemidesmosomes).
(2) an electron lucent region 30–50 nm in
width called the lamina Lucida.
(3) an electron-dense region 30–60 nm in
width called the lamina densa.
(4) a reticular layer containing a fine band
of specialized connective tissue containing
a variety of fibrillar and nonfibrillar
proteins.
38. • The anchoring fibrils of the basement
membrane are short curving fibrils of
approximately 20–40 nm thick and
traverse the lamina densa and lamina
lucida near the hemidesmosomes.
• These fibrils appear to terminate in
the connective tissue in electron-
dense patches termed anchoring
plaques.
• Length of these fibrils are 750nm.
• The chemical composition:
constituents are type IV collagen,
laminin and the heparan sulfate
proteoglycan perlecan.
39. • STRATUM SPINOSUM:
10-20 layers of large polyhedral cells.
Adhesion between cells is provided by desmosomes
Desmosomes are located between cytoplasmic process of adjacent cells
Uppermost cells contain dense granules keratinosome or odland bodies.
40. • STRATUM GRANULOSUM:
Flattened shaped cells with distinct keratohyaline granules inside nucleus and cytoplasm.
Tonofilaments are more dense in quantity.
They contain a histidine rich protein, FILAGGRIN which is the matrix protein that
aggregates the tonofilaments (CYTOKERATINS or INTERMEDIATE FILAMENTS) to form
keratin.
41. • STRATUM CORNEUM:
Large flattened cells
Organelles and nucleus are replaced by protein called keratin.
They are filled with compacted tonofilaments and isolated lipid droplets.
42. INTERCELLULAR JUNCTIONS
When cells come into contact with one another, and some times with the
extracellular matrix, specialized junctions may form at specific sites on the
contacting cell membranes. These specialized junctions may be classified into
several different categories as follows;
•Occluding (tight) junctions ( zonula occludence).
•Adhesive junctions
Cell-to-Cell.
Zonula adherence.
Macula adherence (desmosomes).
Cell-to-matrix.
Focal adhesions.
Hemidesmosomes.
•Communicating (gap) junctions
43. OUTER EPITHELIUM
• Covers the crest and outer surface of marginal gingiva
and surface of attached gingiva.
• 0.2-0.3mm thickness
• Keratinized or para keratinized.
• K1, K2, K10-12 cytokeratins present are immunohistochemically expressed with high
intensity in orthokeratinized areas and with less intensity in parakeratinized areas.
• K6 and K16 , characteristic of highly proliferative epithelia,
and K5 and K14, stratification-specific cytokeratins , also are present
• Stippling: depression see on gingiva- area of fusion of retepegs.
44. • Boundary between oral epithelium and
connective tissue has a wavy zone.
• Connective tissue portion which
projects into epithelium is known as
connective tissue papilla and they are
seperated by epithelial ridges known
as rete pegs.
45. CELLS
Cells in epithelium are:
Keratinocytes
Non keratinocytes
Melanocytes
Merkel cells
Langerhan cells
Inflammatory cells.
46. NON KERATINOCYTES
• Often stellate and have cytoplasmic extensions of various size and appearance .
• Do not posses the cytokeratins filaments hence do not have the ability to keratinize.
• Its called as clear cells.
• Because in histo sections zone around their nuclei appear lighter than in surrounding
keratinocytes.
• Except merkel cells these clear cells lack desmosomal attachment to adjacent cells.
• These cells migrate from :
a. Neural crest
b. Bone marrow
47. NON-KERATINOCYTES IN HUMAN GINGIVAL
EPITHELIUM
a. Langerhans cells
b. Cells showing cell process and dendrites
c. Melanocytes
d. Merkel cells
48. • Are dendritic cells and originate from
neural crest cells.
• Present in basal and spinous layer.
• Produce melanin in organelles called
pre -melanasomes / melanasomes .
• Contains tyrosinase which hydrolates
tyrosine into
dihydroxyphenylalanine(dopa) that
progresses into melanin
• Melanin granule is phagocytosed and
contain within the cells of epithelium
and connective tissue called
melanophages or melanophores.
TYROSIN
D
O
P
A
MELANIN
MELANOPHAGE
/MELANOPHORE
MELANOCYTES
TYROSINASE
49. • Dendritic cells.
• Present at suprabasal levels.
• Belong to the mononuclear phagocyte
system(RES) as modified monocytes
derived from bone marrow.
• Plays an important role in immune
reaction as antigen presenting cells for
lymphocytes
• Contain g- specific granules(birbeck
granules) and has marked ATPase
activity.
• Present in oral and sulcular epithelium
but not in junctional epithelium.
LANGERHAN CELLS
50. MERKEL CELLS
• Present in deeper layers of epithelium.
(i.e at the tip of rete ridges in clusters).
• It harbours nerve endings
• Connected via desmosomes.
• Identified as tactile receptors.
51. SULCULAR EPITHELIUM
• Lines the gingival sulcus.
• Extends from coronal limit of JE to crest of gingival margin.
• Thin, non keratinized, stratified squamous squamous epithelium.
• Without rete pegs and extends from the coronol limit of junctional epithelium to the crest
of gingival margin.
• Shows many cells with hydropic degeneration.
52. • It lacks st. granulosum and st.
corneum, also K1,K2 and K10-12
cytokerations.
• Contains K4 and K13, K19.
• Don’t have merkel cells.
• Sulcular epithelium is extremely
important because it act as a semi
permeable membrane through which
injurious bacterial products pass into
gingival fluid.
• Less permeable than JE.
• No rete pegs ,formed due to
inflammation of lateral wall
53. • Provides connection between gingiva and
tooth.
• Consist of collar like band of stratified
squamous non keratinized epithelium.
• 3-4 layers thick in early life, increases with
age.
• Tapers from coronal end which may have10-
20 cells wide to 1-2 cell wide at apical
termination at CEJ in healthy tissue.
• Cells grouped in 2 strata.
1. Basal layer: facing connective tissue
2. Supra basal layer: extending to tooth surface.
• Length of JE: 0.25- 1.35mm.
• Formed by confluence of oral epithelium and
REE during tooth eruption.
JUNCTIONAL EPITHELIUM
54. • 3 zones of junctional epithelium:
1. Apical – germination
2. Middle – adhesion
3. Coronal- permeable.
• JE is highly permeable.
• Junctional epithelium is attached to tooth surface by an internal basal lamina and
attached to gingival connective tissue by an external basal lamina.
• Internal basal lamina consist of lamina densa (adj. to enamel)and lamina lucida (to which
hemidesmosomes are attached.) firm attachment to tooth.
55. • Attachment of JE to the tooth is reinforced by gingival fibres which braces the marginal
gingiva against tooth surface. For this reason JE and gingival fibres are considered as
functional unit and referred to as dento-gingival unit.
Dentogingival
unit
Gingival
fibres
Junctional
epithelium
56. UNIQUE STRUCTURAL AND FUNCTIONAL FEATURES OF JE:
• JE is firmly attached to tooth surface forming a epithelial barrier against plaque bacteria .
• Allows an access to gingival fluid, inflammatory cells,and components of immunologic
host defense to gingival margin.
• Exhibit rapid turnover which contribute to host parasite equilibrium and rapid repair of
damaged tissue.
• Has endocytic capacity similar to macrophages and neutrophils and this activity becomes
protective in nature.
57. • It’s tissue component attains final
structures in conjunction with eruption
of teeth.
I. When the enamel is fully developed,
ameloblast become reduced in height,
Produce a basal lamina and form
together with cells from outer enamel
epithelium so called reduced enamel
epithelium(REE).
• Basal lamina lies in direct contact with
epithelium and contact between them
is maintained by hemidesmosomes.
• REE surrounds the crown of tooth from
the moment enamel is properly
mineralized till the tooth erupts .
DENTO GINGIVAL EPITHELIUM
58. 2. As the erupting tooth approached oral
epithelium oral epithelium , the cells of
outer layer of REE as well of basal layer of
oral epithelium shows increased mitotic
activity and start to migrate to connective
tissue.
• Migrating epithelium produces an
epithelial mass between oral
epithelium and REE so that tooth can
erupt without bleeding.
59. 3. When tooth has penetrated in oral cavity
large portions immediately apical to incisal
area of enamel are covered by junctional
epithelium containing few layers of cell.
• Cervical region of enamel is still
covered by ameloblasts and outer
cells of REE.
60. 4. During later phases of tooth eruption all
cells of REE is replaced by JE.
• Junctional Epithelium is continuous
with oral epithelium and provides
attachment between tooth and gingiva.
• If free gingiva is excised after tooth
eruption a new junctional epithelium is
formed during healing
• New JE is formed from oral epithelium
which indicates that cells of oral
epithelium posses the ability to
differentiate into cells of JE.
61. • JE is continuously renewed through cell division in basal layer and cells migrate to base
of gingival sulcus from where they are shed.
62. • Distinct differences between oral, sulcular, junctional epithelium:
1. Size of cells in JE is relative to tissue volume, larger than in oral epithelium.
2. Intercellular spaces in JE is relative to the tissue volume comparatively wider than in oral
epithelium.
3. No of desmosomes are smaller than in oral epithelium.
63. • Cell membrane of JE harbour hemidesmosomes towards enamel as it does towards
connective tissue.
HD
64. HISTORY:
• Hypothesis was given to explain mode of attachment of epithelium to tooth surface:
1. Soft tissue were closely opposed but not organically united to surface of enamel.
2. Gottlieb: gingiva is organically united to surface of enamel. He termed it as epithelial
attachment. (drawback- did not explain how exactly it attaches.)
3. Waerhaug : in 1952 presented a concept of epithelial cuff, he concluded that gingival
tissues are closely adapted but not organically united.
4. Stern- in 1962 showed the attachment to tooth is through hemidesmosomes.supported by
schroeder and listgarten.
65. RENEWAL OF JE
• Undergo contiunous renewal.
• Balance is maintained by between new cell formation in the basal and spinous layers and
shedding of old cells at superficial layers.
• Mitotic activity- 24 hrs periodicity.
• Highest- morning
• Lowest- evening
• Higher in non keratinized and increased in gingivitis.
• Mitotic rate : buccal mucosa> hard palate> sulcular epithelium> junctional epithelium>
marginal gingiva> attached gingiva.
• Turnover rate of gingiva – 5 to 6 days.
66. GINGIVAL CONNECTIVE TISSUE
• Major component of CT are:
Collagen (60% of vol.)
Fibroblasts (5%)
Vessels, nerves and matrix (35%)
67. • Also known as lamina propria.
• Consists of 2 layers:
1. Papillary layer: subjacent to epithelium
which consists of papillary projections
between epithelial rete pegs.
2. Reticular layer: contiguous with
periosteum of alveolar bone.
• Has cellular and extra cellular
compartment composed of fibres and
ground substance.
68. • GROUND SUBSTANCE:
Fills the space between fibres and cells.
Is amorphous and have high content of water.
Composed of:
proteoglycans- hyaluronic acid and chondroitin sulphate.
Glycoproteins- fibronectin.(binds fibroblasts to fibres helping mediate cell adhesion and
migration)
Laminin- found in basal lamina ;attaches it to epithelial cells.
70. 1. Collagen fibres:
• Type 1 collagen forms the bulk of lamina propria and provides tensile strength to gingiva.
• Type 4 branches between type 1 bundle and is continuous with fibres of basement
membranes and blood vessel walls.
• Have a characteristic banding with periodicity of 700 A0 between individual dark band.
71. 2. Reticulin fibres:
• Have argyrophilic property and are numerous in tissue adjacent to basement membrane.
• Found in large number in loose CT surrounding blood vessel
• Hence found in endothelial-CT and epithelium-CT interface.
72. 3. Elastic fibres:
• Only present in association with blood vessels.
• Gingiva seen coronal to mucogingival junction has no elastic fibres except in assocation
with blood vessels.
• Alveolar mucosa may have many elastic fibres.
73. 4. Oxytalan fibres.
• Initially described by Fullmer.
• Modified type of elastic fibres.
• Scarce in gingiva but more in PDL.
• Have thin fibrils with 150 A0 dia.
74. GINGIVAL FIBRES
• Connective tissue of marginal gingiva is densely collagenous containing a prominent
system of collagen bundles called gingival fibres.
• Consist of type 1 collagen.
• Functions of GF:
1. Brace the marginal gingiva firmly against the tooth.
2. Provides rigidity necessary to withstand the forces of mastication without being deflected
away from the tooth surface.
3. Unites the free marginal gingiva with cementum and adjacent attached gingiva.
75. • Arranged in groups (acco. To Carranza)
1. Gingivodental
2. Circular
3. Transseptal
4. Dentoperiosteal (Lindhe)
76. PRINCIPAL GROUP OF FIBRES
Originates from cementum and spreads laterally into
lamina propriaDento gingival
Orginates from periosteum and spreads into lamina propriaAlveologingival
Originates from cementum near CEJ into periosteum of
alveolar crestdentoperiosteal
Circular
Originates from within the free marginal and attached
gingiva coronal to alveolar crest and encircles each
tooth
Transseptal
Originates from interproximal cementum coronal to
crest and courses mesially and distally in the
interdental area into cementum of adjacent teeth
77. SECONDARY GROUP OF FIBRES
• Originates from the periosteum of the lateral aspect of alveolar
process and spreads into attached gingiva.peristeogingival
Interpapillary
Transgingival
Intercircular
• Originates from attached gingiva immediately subjacent to basement
membrane and courses mesidistallyIntergingival
• Originates from cementum of the mesial surface of tooth and courses
distally and inserts on the cementum of distal surface of same toothSemicircular
Originates from within interdental gingiva and follows on orofacial
course
Originates within the attached gingiva interwing along dental arch
between and around teeth
Originates from cementum on distal surface of tooth spreading
buccally and lingually around adjacent tooth and inserting on mesial
cementum of next tooth
78.
79. FIBROBLASTS:
• 65% of total population.
• Are of mesenchymal origin.
• Spindle/ stellate shaped with oval nucleus
containing 1 or more nucleoli.
• Its cytoplasm has well developed rough
endoplasmic reticulum with ribosomes , golgi
complex,
• Has tonofilaments adjacent to cell membrane.
• Large no of vesicles are also found
• Major role in development, maintenance and
repair of connective tissue.
• Synthetize collagen and elastic fibres as well as
glycoproteins and glycosaminoglycans of
amorphous intercellular substance.
• Also regulates collagen degradation through
phagocytosis and secretion of collaganase.
CELLULAR ELEMENTS
80. Collagen synthesis:
• Collagen is produce by fibroblasts.
• Smallest unit of collagen is known as
tropocollagen(TC)
• TC is 3000 Ao long and diameter of 15Ao.
• Has 3 polypeptide chains interwined to form a
helix.
• Each chain contains 1000 amino acids.
• 1/3rd of it is glycine and 20% proline and
hydroxyproline.
• TC is synthetized inside the fibroblast and is
secreted into extra cellular space.
• Hence polymerisation of tropocollagen
molecule to collagen takes place in extra
cellular compartment.
81. • Tc is aggregated to protofibrils which
are subsequently aggregated parallel
to collagen fibrils (CFR).with an
overlapping of tropocollagen molecule
by 25% of their length.
• Collagen fibre are bundles of fibrils
arranged in a way that fibres exhibit a
cross banding of 100 Ao periodicity.
• They are arranged in bundles
82. MAST CELLS:
• Numerously found.
• Fixed macrophages and histiocytes
are present in CT as components of
mononuclear phagocyte system.
• Are derived from blood monocytes.
• Large no of vesicles in cytoplasm and
they contain proteolytic enzymes,
histamines and heparin, golgi complex
is well developed and microvilli.
• Produce vaso-active substance,
affects the microvascular system and
controls the flow of blood through
tissue.
83. MACROPHAGES:
• Derived from circulating blood monocytes
which migrate into the tissue.
• Phagocytic and synthetic functions.
• Numerous in inflammed tissue..
• Nucleus- various invaginations of various
size.
• Zone of electron dense chromatin
condensation along the periphery of
nucleus.
• Golgi complex well developed.
• Free ribosomes are dispersed.
• Phagasomes are present.
84. Eosinophils:
• Scarse
• Present in lamina propria.
Plasma cells and lymphocytes:
• Found near base of sulcus. Having eccentrically located spherical nucleus.
• T lymphocytes- found below JE in healthy gingiva in newly erupted teeth.
• As time elapses B lymphocytes and plasma cells appear near sulcus.
Neutrophils & leucocytes:
• High in both connective tissue and sulcus having lobulated nucleus and numerous
lysosomes.
Inflammatory cells
85. • 3 sources of blood supply:-
1. Supra periosteal arterioles-
Along facial and lingual surface of alveolar
bone .capillaries extend along sulcular
epithelium and between retepegs of external
gingival surface.
Occasionally pass through alveolar bone of
PDL.
2. Vessels of PDL-
Extends into gingiva and anastomose with
capillaries in sulcus area.
3. Arteriorles which emerge from crest of
interdental septa-
Extends parallel to crest of bone to anastomose
with vessels of PDL with capillaries in gingival
crestal areas that run over alveolar crest.
BLOOD SUPPLY
86. LYMPHATICS
Lymphatic drainage of
gingiva brings in the
lymphatics of
connective tissue
papilla.
Progresses into
collecting network
external to periosteum
of alveolar process.
Regional lymph node
(sub-maxillary lymph
node).
87. NERVE SUPPLY
• Most are myelinated and closely associated with blood vessels.
• Innervated by maxillary and mandibular branches of trigeminal nerve.
• Gingival innervation is derived from fibres arising from nerves on PDL and from labial,
buccal, palatal nerves .
Nerve endings: more in attached gingiva and less in free gingiva.
Nerve supply in CT:
• Meshwork of terminal argyrophilic fibres , some extend in epithelium.
• Meissner type tactile corpuscles.
• Krause type end bulbs which are temporary receptors and encapsulated spindles.
88. :
Palatal gingiva
• Incisors and canine- nasopalatine
nerves
• Premolars and molars- greater
palatine nerve.
Labial / buccal gingiva
• Incisors an canine- labial branch of
infra orbital nerve
• Premolars and molars- superior
alveolar nerve.
:
Lingual gingiva
• lingual nerve
Labial / buccal gingiva
• Incisors, canine,
premolars(occasionally)- mental nerve
• Premolars and molars- long buccal
nerve
89. MATRIX
• Is a medium in which connective tissue are embedded.
• Produced mainly by fibroblasts ,some by mast cells and others derived from blood.
• Main constituents of matrix are:
proteins
proteoglycans glycosaminoglycans
Hyaluronan
sulphate
Heparan suphate
glycoproteins
fibronectin
osteonectin
90. CONTINUOUS TOOTH ERUPTION
• According to the concept of continuous tooth eruption, eruption does not cease when the
teeth meet their functional antagonists, but continues throughout life.
91. ERUPTION
Is the movement of teeth in the direction of the occlusal plane
Is the exposure of the teeth by apical migration of the gingiva.
ACTIVE
PASSIVE
ERUPTION
92. • Gottlieb and Orban believe that active and passive eruption proceed together.
• Active eruption is coordinated with attrition; the teeth erupt to compensate for tooth
substance worn away by attrition.
• Attrition reduces the clinical crown and prevents it from becoming disproportionately long
in relation to the clinical root, thus avoiding excessive leverage of the periodontal tissues.
93. • Ideally, the rate of active eruption keeps pace with tooth wear, preserving the vertical
dimension of the dentition.
• As teeth erupt, cementum is deposited at the apices and furcations of the roots, and bone
is formed along the fundus of the alveolus and at the crest of the alveolar bone.
• In this way, part of the tooth substance lost by attrition is replaced by lengthening of the
root, and socket depth is maintained to support the root.
• Although originally thought to be a normal physiologic process, passive eruption is now
considered a pathologic process.
94. Passive eruption is divided into the
following 4 stages:
STAGE 1
• The teeth reach the line of occlusion. The
JE and the base of the sulcus are on the
enamel.
STAGE 2
• The JE proliferates so that part is on the
cementum and part is on the enamel.
• The base of the sulcus is still on the
enamel.
95. STAGE 3
• The entire JE is on the cementum, and
the base of the gingival sulcus is on
the cementoenamel junction.
• As the JE proliferates from the crown
onto the root, it does not remain at the
cementoenamel junction any longer
than at any other area of the root.
96. STAGE 4
• The JE has proliferated farther on the
cementum.
• The base of the sulcus is on the
cementum, a portion of which is
exposed.
• Proliferation of the JE onto the root is
accompanied by degeneration of
gingival and periodontal ligament
fibers and their detachment from the
tooth.
• The cause of this degeneration is not
understood. At present it is believed to
be the result of chronic inflammation,
and therefore a pathologic process
97. • Apposition of bone accompanies active eruption.
• The distance between the apical end of the JE and the crest of the alveolus remains
constant throughout continuous tooth eruption(1.07mm).
• Exposure of the tooth by apical migration of the gingiva is called gingival recession , or
atrophy.
98. • According to the concept of continuous eruption , the gingival sulcus may be located on
the crown, CEJ or root, depending on the age of the patient and stage of eruption.
• Therefore some root exposure with age would be considered normal and referred to as
physiologic recession.
• Again, this concept is not accepted at present. Excessive exposure is termed pathologic
recession
99. REFERENCES
• Carranza’s Clinical Periodontology, 10th Edition.
• Clinical Periodontology and Implant Dentistry, Lindhe, 5th Edition.
• Molecular and Cell Biology of the Gingiva, Periodontology 2000; Vol 24; 2000; 28-55.
• Orban’s Oral histology and Embryology 13th Edition.
• Periodontology and Periodontics, Sigurd Ramfjord 1st Edition.
