GINGIVA

CONTENTS Introduction Macroscopic features Microscopic features

Gingival epithelium

Oral epithelium

Sulcular epithelium

Junctional epithelium Renewal of gingival epithelium Cuticular structures Gingival crevicular fluid Gingival connective tissue Gingival fibres Blood supply, nerve supply and lymphatics Correlation of clinical & microscopic features Age changes

INTRODUCTION

ORAL MUCOSA

GINGIVA

Carranza

Gingiva is the part of the oral mucosa that covers the alveolar processes of the jaws & surrounds the necks of the teeth

MACROSCOPIC FEATURES

Schluger et al 1990

Marginal gingiva

The terminal edge / border of the gingiva

surrounding the teeth in collarlike fashion.

Free gingival groove

1 mm wide

1.5- 2mm coronal to CEJ

Incisor & premolar molar

Gingival sulcus

Shallow crevice/space around the tooth bounded

by the surface of tooth on one side & the

epithelium lining the free margin of the gingiva

on the other side

V shaped

Depth of gingival sulcus

Normal/ideal conditions: 0

Gottlieb, Orban 1933

Histologic sections:

1.8 mm (Larjava et al)

1.5 mm (Saito et al)

0.69 mm (Everts et al)

Probing depth: 2-3 mm

Attached gingiva

Firm, resilient, and tightly bound to the underlying periosteum of alveolar bone

Mucogingival junction Absent on palate

Stippling- orange peel

appearance

Width of keratinized gingivaWidth of attached gingiva

Distance between the mucogingivalJunction & the projection on the external surface of the bottom of gingival sulcus

3.5-4.5 mm : Maxilla 3.3-3.9 mm : Mandible

•1.9 mm : Maxilla•1.8 mm : Mandible

Ainamo J & Loe H 1966

Narrow Incisors Wide Molar region Range 1-9 mm

Increases with age

Roll test

Schillers iodide test

Total width of gingiva – Sulcus depth

Importance of attached gingiva

PREDISPOSING FACTORS

INADEQUATE ATTACHED GINGIVA

• Narrow zone of gingiva is considered insufficient to:

– Protect the periodontium from masticatory forces

– Dissipate the pull because of muscles of adjacent mucosa

(Friedman 1957)

• Inadequate zone of gingiva favors:

– Subgingival plaque formation (Friedman, 1962)

– Attachment loss and soft tissue recession due to decreased

resistance to apical spread of plaque associated gingival lesions

(Stern, 1976)

– Along with decreased vestibular depth it causes accumulation of

food particles during mastication and impedes oral hygiene

measures (Gottsegen, 1954)

• Bowers, 1963: Classic study on width of attached gingiva. To clarify meanings of

ADEQUATE / INADEQUATE gingiva.

• Width varied for different teeth and different individuals

• Mean width increased from deciduous to permanent dentition, but changed

little after maturity

• Ranged from 1 – 9mm

• Lowest in the premolar canine region

• Influenced by tooth malposition, frenum attachment and recession

• Recession was most common in 1st premolar-canine, maxillary 1st molar and

mandibular incisor regions

Gingiva could be maintained with <1mm present

• Ainamo and Loe, 1966:

• Band of attached gingiva moved apically with recession by unknown

mechanism

• Greatest width on maxillary and mandibular anteriors

• Lang and Loe, 1972: to determine how much of gingiva id ADEQUATE

(118 randomly selected plaque free surfaces)

Surfaces with <2mm of

keratinized gingiva Inflammation

Surfaces with > 2mm keratinized

gingiva 80% were clinically healthy

“2mm of keratinized

gingiva/1mm of attached gingiva is

adequate to maintain health”

• Maynard and Wilson, 1979 subgingival restorative

procedures require

2mm free gingiva

3mm attached gingiva

5mm keratinized

gingiva

• Miyasato et al., 1977

Study on dental students

Mid facial plaque free surface of

mandibular premolars

Minimal keratinized

gingiva 1mm

Appreciable keratinized

gingiva 2mm

25 days experimental

gingivitis

Increases in plaque, gingival

exudate and inflammation

were similar in both groups

• Dorfman et al., 1980 2 year study on 92 patients

Experimental side free gingival grafts Control side root planing and oral hygiene instructions every 3 months

Grafted areas had an increase of 4mm of attached gingiva but no difference in GI, PI and loss of attachment compared to the controls

Patient can be maintained in gingival health with excellent oral hygiene and regular periodontal care at 3 month intervals

Interdental gingiva

Occupies gingival embrasure, which is the interproximal space beneath the area of tooth contact

Determined:

Contact relationships between the teeth

Width of approximal tooth surfaces

Course of the CEJ

Pyramidal

Col shaped Cohen

MICROSCOPIC FEATURES

Stratified squamous epithelium

Central core of connective tissue

GINGIVAL EPITHELIUM

Function:

Protects deep structures

Mechanical, chemical, water, microbial barrier

Signalling function

General aspects of gingival epithelium biology

Oral/ outer epithelium

Sulcular epithelium

Junctional epithelium

Four cell layers: Stratum Basale (Basal layer) Stratum spinosum (prickle

cell layer)

Stratum granulosum (granular

layer) Stratum corneum (cornified

layer)

Principal cell: keratinocytes

Clear cells / Nonkeratinocytes:

Langerhans cells

Merkels cells

Melanocytes

Inflammatory cells

keratinocytes

Main function

PROLIFERATION

DIFFERENTATION

keratinocytes

Morphologic changes:

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 the nucleus

Schroeder 1981

Stratum Basale:

Cylindric/cuboid.

Contact with basement membrane

Mitotic cell division

Stratum germinativum

Progenitor cell compartment of

the epithelium

1 month

Basal lamina : Joins the epithelium to the

underlying connective tissue

300-400 Å

App 400 Å beneath the epithelial basal layer

Produced by the basal cells

Light microscope

Structure less zone

PAS stain positive

Permeable to fluids, barrier to particulate matter

Stratum spinosum

10-20 layers

Large, polyhedral cells

Short cytoplasmic processes resembling spines

Prickly appearance

Cohesion : Desmosomes Located between the

cytoplasmic processes of adjacent cells

Interconnections: Desmosomes Tight junctions

(Zonae occludens)

Stratum granulosum Keratohyalin granules

Very sudden keratinization of the

cytoplasm of the keratinocyte &

conversion into horny squame

Stratum corneum

Filled with keratin

Apparatus for protein synthesis & energy

production lost

Complete keratinization Orthokeratinized

Parakeratinized epithelium

Nonkeratinized epithelium

Orthokeratinized

Superficial horny layer

No nuclei in stratum corneum

Well defined stratum

granulosum

Parakeratinized

Pyknotic nuclei

Dispersed keratohyaline

granules

Absence of stratum

granulosum

Nonkeratinized

Viable nuclei

Absence of stratum granulosum

& corneum

keratinization

Immunohistochemistry, Gel electrophoresis,

Immunoblot technique

Keratin proteins different polypeptide subunits

Basal cells: K19 (40 KD)

Stratum corneum: K1 (68 KD)

Other proteins: Keratolinin Involucrin Filaggrin

In sudden transition Keratohyalin granules Filaggrin Matrix of Corneocyte

Precursors of chemical resistant structure- EnvelopePrecursors packed in keratohyaline granules

Cytoplasmic organelles: Deeper strata

Numerous mitochondria

Succinic dehydrogenase

Nicotineamide-adenine dinucleotide

Cytochrome oxidase

Active Tricarboxyliccycle

Activity towards cell surface: Pentose shunt Glucose-6-phosphatase

Ribonucleic acid (RNA)

Synthesis of keratinization proteins

Uppermost cells: Stratum spinosum

Keratinosomes/Odland bodies

Acid phosphatase:Enzyme involved in the

destruction of organelle membranes

Degree of keratinization

Nonkeratinocytes

Langerhans cells

Inflammatory cells

Melanocytes

Merkels cells

Melanocytes

Dendritic cells Basal & spinous layers Premelanosomes/melanosomes

Tyrosine

Tyrosinase

MelaninDihydroxyphenylalanine (dopa)

Melanophores/Melanophages

Langerhans cells

Dendritic cells

Suprabasal layer

Modified monocytes

Immune reaction antigen-presenting cells

g-specific granules (Birbeck’s granules)

Found: Oral epithelium & sulcular epithelium

Absent: Junctional epithelium

Merkel cells

Deeper layer

Harbor nerve endings

Tactile perceptors

Inflammatory cells

Clinical normal areas of mucosa

Lymphocytes : Most frequent

Associated with langerhans cells

Polymorphonuclear leukocytes

Mast cells

Difference between attached gingiva & alveolar mucosa

ATTACHED GINGIVA ALVEOLAR MUCOSA

Keratinized Nonkeratinized

Stippled Unstippled

Deep rete pegs Short,wide rete pegs

Thick lamina propria Thin lamina propria

Few elastic fibers Numerous elastic fibers

Indistinct submucosa Distinct submucosa

Firmly attached Movable

Squier GA, Johnson NW

Extracellular matrix

Glycoproteins, lipids, water Proteoglycans: Hyaluronan, decorin, syndecan CD 44 – cell surface

Hakkinen L Cell adhesion molecules: ICAM-1, β1 integrin family

Cawford Serves: Cell adhesion Adhesion to tooth surface & basement

membrane Diffusion of water, nutrients & toxic materials

Crest & outer surface 0.2-0.3 mm in thickness Keratinized/parakeratinized

Degree of keratinization

Age & onset of menopause

Palate > Gingiva > ventral aspect of tongue >

cheek

Oral epithelium

Keratins:

Ortho-keratinized areas• K1• K2, • K10 - K12

Highly proliferative epithelia• K6• K16

Stratification-specific cytokeratins• K5• K14

Para-keratinized areas• K19

Thin, non-keratinized stratified squamous epithelium

No rete pegs Lacks: Stratum granulosum Stratum corneum Merkels cells

Keratins: K4, K13= Esophageal-type

Cytokeratins

Sulcular epithelium

Enzymes: low degree of activity Acid phosphatase staining negative Semipermeable membrane

Potential to keratinize: It is reflected & exposed to oral cavity Bral &

Caffesse Absence of bacterial flora

Caffesse

The junctional epithelium is the epithelial component of the dentogingival unit that is in contact with the tooth surface. The innermost cells of the JE form & maintain a tight seal against the mineralized tooth surface, the so called epithelial attachment

Schroeder & Listgarten, 1977

Collar-like band of stratified squamous nonkeratinizing epithelium

Glickman

Junctional epithelium

Junctional epithelium

Gingival fibers

Dentogingival unit

Current concepts of dentogingival junction

Upto 1912 Min information regarding junction between tooth & epithelium

Attachment = CT fibers inserting into cementum & bone

GV Black 1915 Presence of subgingival space extending upto CEJ under a loose fitting gingiva

Gottlieb 1921 Presence of a firm attachment (Organic union) between gingiva & tooth = Epithelial attachment /epithelansatz

Orban 1931 during eruption REE forms epithelial attachment

Waerhaug 1952 Gingiva seperated from tooth by a capillary space forming a “Epithelial cuff”

Epithelial attachment Epithelial cuff

Orban 1956 Agreed to both concepts & gave term

“Attached epithelial cuff”

Stern 1962 Demonstrated the DGJ in rat incisors consisting of Basal Lamina & Hemidesmosomes

The above concepts were incorrect

Junctional Epithelium, a tissue capable of forming & renewing itself continuously throught life

Term JE = Anderson & Stern in 1966

Transformation of REE to junctional epithelium:

1-2 years Schroeder & Listgarten

Tencate 1966

Secondary junctional epithelium

Undifferentiated basal cells originating from oral gingival epithelium

Primary junctional epithelium

Reduced enamel epithelium

Structure of Junctional epithelium

Stratified squamous non-keratinized epithelium 3-4 layers thick 10-20 layers Tapers: from coronal end located: CEJ Length of junctional epithelium:

0.25-1.35 mm

2 strata: Basal layer Suprabasal layer

Basal cells = face gingival CT

Suprabasal cells = tooth surface

also called as DAT cells (Directly Attached to

Tooth)

Salonen 1989

Lymphocytes & macrophages

Sensory nerve fibers

Byers and Holland 1977, Maeda et

al,1994

Keratins: K19

Stratification specific: K5 & K14

Lack of expression:

Morgan et al : Junctional area is the only stratified

nonkeratinized epithelium in the oral cavity that

does not synthesize K4 or K13

Lack of K6 & K16 : Though turnover of the cells is

very high

Interconnections

Few desmosomes only Occasional gap junctions

Schroeder & Listgarten, 1977 Saito et al, 1981 Hashimoto et al, 1986

Wide fluid-filled intercellular spaces

Schroeder& Münzel-Pedrazzoli, 1970

3 Zones: Apical zone germinative characteristics

Middle zone higher density of hemidesmosomes

role in adhesion

Coronal zone numerous intercellular space

increased permeability

Epithelial attachment

Internal basal lamina

External basal laminaLamina lucida

Lamina densa

Signal transuduction

Histochemical evidence Neutral

polysaccharide

Thonard JC

Basal lamina:

Laminin: similar to endothelial & epithelial cells

Lack type IV & VII collagen, perlecan,lamina

fibroreticularis. Salonen &

Santti 1985

Dynamics of junctional epithelium

Turnover is very high protective & regeneration

Earlier thought epithelial cells facing external

basal lamina divide rapidly

Evidence DAT cells high mitotic activity

DAT cells Role in tissue dynamics & reparative

capacity of JE

Mechanism of DAT cell turnover: Daughter cells replace degenerating

cells on tooth surface Daughter cells enter exfoliation

pathway & gradually migrate coronally

between basal cells & DAT cells Epithelial cells move in coronal

direction along tooth surface

Periodontology 2000Vol 31, 2003

Structural & functional features:

Firm attachment: epithelial barrier

Immunologic host defense: Gingival fluid,

inflammatory cells

Rapid cell turnover Endocytic capacity equal to that of macrophages

and neutrophils

Cho.Garant.2000

Antimicrobial defense:

1. Quick cell exfoliation-rapid cell division

2. Funnelling effect-Rapid shedding & effective removal of bacteria adhering to epithelial cells

3. Basement membrane- barrier

4. Antimicrobial substances JE cells

5. Epithelial cells secrete chemokines

& cytokinesPeriodontology 2000Vol 31, 2003

Renewal of Gingival epithelium

Mitotic activity: 24 hr periodicity

Highest Morning

Nonkeratinized areas

Gingivitis

Lowest Evening

New cell formatio

n

Shedding of old

cells

Cell turnover time:

Palate, tongue, cheeks: 5-6 days

Gingiva: 10-12 days

Junctional epithelium: 1-6 days

Beagrie G S

Epithelial repair & regeneration

Gingivectomy & incisional wounds:

Undamaged epithelial cells from wound margin, migrates within hours of

injury

Migrate over exposed connective tissue

New hemidesmosomes are formed

1-2 days = epithelial surface is 2-3 cell thick & str basale forms

By day 5 = wound is fully covered

By day 7 = epithelium has matured & new str corneum formation

Green RJ

et al

Periodontal flaps: heals long junctional epitheliumStahl SS et al

Dental cuticular structure

A thin, acellular structure with a homogeneous matrix, sometimes enclosed within clearly demarcated, linear borders

ListgartenCoatings of developmental

origin

Formed as part of tooth development

Reduced enamel epithelium

Coronal cementum

Dental cuticle

Acquired coatings

Exogenous origin

Saliva

Bacteria

Calculus

Surface stains

Gingival crevicular fluid

Seeps through the thin sulcular epithelium

Cleanse material from the sulcus

Improve adhesion of the epithelium to the tooth

Antimicrobial properties

Antibody activity

GINGIVA

CONTENTS Introduction Macroscopic features Microscopic features

Gingival epithelium

Oral epithelium

Sulcular epithelium

Junctional epithelium Renewal of gingival epithelium Cuticular structures Gingival crevicular fluid Gingival connective tissue Gingival fibres Blood supply, nerve supply and lymphatics Correlation of clinical & microscopic features Age changes

Gingival connective tissue

Collagen fibers 60%

Fibroblast 5%

Vessels, nerves & matrix 35%

CT lamina propria

1. Papillary layer

2. Reticular layer

Cellular Extracellular

• Fibroblasts

•Mast cells

•Macrophages

•Inflammatory cells

• Fibers

•Ground substance

Cellular elements

Fibroblasts: Predominant

Mesenchymal origin

Synthesize: collagen & elastic fibers

Glycoproteins & GAG

Degradation of collagen

Role of fibroblast in maintaining tissue homeostasis

Mast cells:

Numerous, located perivascular region

Vasoactive substances:

Histamine

Heparin

Proteolytic enzymes

Macrophages:

Phagocytic function

Numerous in inflammed tissue

Circulating blood monocytes

Inflammatory cells:

Polymorphonuclear leukocytes

Lymphocytes

Plasma cells

Clinically normal gingiva : Small foci of plasma

cell & lymphocytes : base of the sulcus

Neutrophils : High numbers in gingival

connective tissue & sulcus

Recently erupted teeth in children : Area below

the junctional epithelium of healthy gingiva : T-

lymphocytes Early defense recognition system

As time elapses : B-lymphocytes & plasma cells

Specific antibodies against already recognized

antigens, always present in the sulcus of

clinically normal gingiva

Fibers

Fibers

Collagen

Reticulin Oxytalan

Elastic

Collagen fibers

Predominate

Type I collagen

Cross banding 700 Å

Fibroblast

Cementoblasts

Osteoblasts

Synthesis of collagen fibers

1/3 rd : Glycine 20% : Proline & Hydroxyproline

Synthesis of collagen fibers

Reticulin fibers

Argyrophilic staining

Adjacent to basement membrane

Blood vessels

Epithelial-connective tissue

Endothelial-connective tissue

interface

Oxytalan fibers

Scarce in gingiva

Long thin fibrils

Diameter =150 Å

Parallel to long axis of tooth

Function= not known

Elastic fibers

Blood vessels

Functions:

To brace marginal gingiva firmly against the tooth

To provide the rigidity necessary to withstand the

forces of mastication without being deflected away

from tooth surface

To unite the free marginal gingiva with the

cementum of the root & the adjacent attached

gingiva

Principal groups

Arnim S, Hargerman D. 1953

Secondary groups

Page R 1974

Principal group

Dentogingival Alveologingival DentoperiostealCircular Transeptal

Secondary

group

Periostogingival Interpapillary TransgingivalIntercircularIntergingivalSemicircular

Principal group

Dentogingival fibers

Facial, lingual & interproximal surfaces

Originate at cementum

Fanlike conformation

Interproximally : Extend towards

crest of the interdental gingiva

Provide gingival support

Alveologingival fibers

Emanate from periosteum

covering height of alveolar crest Splay coronally into

substance of the attached gingiva

Attach gingiva to bone

Dentoperiosteal fibers

Arise in cementum

Insertion

Crest of alveolar process

Lateral aspect of cortical plate

Anchor tooth to bone

Protect PDL

Circular fibers

Marginal & Interdental gingivae

Encircle each tooth

Cuff /Ring like fashion

Purse string manner

Maintain contour & position

of free marginal gingiva

Transseptal fibers

Interproximally

Horizontal bundles

Between epithelium at base of the

gingival sulcus & crest of interdental bone

Sometimes classified

as principal fibers

Support for interdental gingiva

Secure positions of adjacent teeth

Protect interproximal bone

Maintain integrity of dentition within dental arch

Secondary group

Periostogingival fibers

Most abundant of secondary fibres

Originate:

Lateral aspect of alveolar bone

Splay laterally, coronally & apically

Attach gingiva to bone

Provide support & tone

within attached gingiva

Interpapillary fibers

Within substance of interdental papilla

Coronal to transeptal fiber

Provide support for interdental gingiva

Transgingival fibers

Zigzag course around dental arch

Serpentine fashion in-and-out between the teeth

Coronal to CEJ

Maintain tissue consistency, enhance arch

alignment & provide additional support for

marginal gingiva

Intercircular fibers

Originate from cementum near the distal line

angles

Insert into mesial cementum of next distal tooth

Aid in maintaining arch integrity

Intergingival fibers

Course in a mesiodistal direction within attached

gingiva

Do not insert into any calcified structure

Provide form, support &contour of attached

gingiva

Semicircular fibers

Form a half-ring about each tooth on both oral

and facial aspects

support free marginal gingiva

Ground substance

Fills the space between fibers & cells

Amorphous

Water

Proteoglycan

Glycoprotein

Glycosaminoglycans

Dermatan sulfate (60%)

Chondroitin sulfate (30%)

Hyaluronan and Heparan sulfate (10%)

Decorin, Biglycan, Versican, Syndecan, CD-44 &

Perlecan

Glycoprotein

Fibronectin

Distributed throughout gingival connective

tissues

Localized over collagen fibers

Binds fibroblasts to fibers

Mediate cell adhesion & migration

Osteonectin, Vitronectin, Elastin & Tenascin

Present diffusely

Near the subepithelial basement membrane in

the upper connective tissue & capillary blood

vessels

Laminin

Basal laminae

Attach it to epithelial cells

Repair of gingival connective tissue

High turnover rate

Remarkably good healing and regenerative

capacity

Generally shows little evidence of scarring after

surgical procedures

Rapid reconstruction of the fibrous architecture of

tissues

Melcher 1976

Within hours

Wound site stabilized by fibrin clot formation

Heavy infiltrate of neutrophils

Within 3 days

Granulation tissue evident

Heavily infiltrate of inflammatory cells

Fibrin clot is slowly degraded

Day 7

Rich in newly formed granulation tissue

Collagen fibers align parallel along root surface

Day 14

Collagen fibers show signs of attachment to root

surface

3 weeks

Fully functional connective tissue attachment

Reformation of Sharpey’s fibers

Blood supply

Posterior superior alveolar artery

Infra orbital artery

Greater palatine artery

Inferior alveolar artery

Supraperiosteal arterioles

Arterioles from crest of interdental septa

Vessels of PDL

Supraperiosteal arterioles

Facial & lingual surfaces of alveolar bone

Capillaries extend along sulcular epithelium

Between rete pegs of outer epithelium

Occasional branches

Alveolar bone PDL

Over crest of the alveolar bone

Vessels of PDL

Extend into gingiva

Anastomose with capillaries

in sulcus area

Arterioles from crest of interdental septa

Extend parallel to crest of bone

Anastomosis

Vessels of PDL

Capillaries in gingival crevicular areas

Vessels that run over alveolar crest

Beneath the epithelium

Subepithelial plexus

Thin capillary loops

Terminal hairpin loops

Efferent & Afferent branches

Spirals

Varices

Sometimes linked by cross-communications

Beneath JE

Dentogingival plexus

Blood vessels : ~ 40µm

Mainly venules

Healthy gingiva

No capillary loops

Sulcular epithelium : Flat anastomosing plexus

Col area : Mixed pattern of anastomosing

capillaries & loops

Absence of inflammation

Regular, repetitive & layered pattern

Inflamed gingival vasculature

Irregular vascular plexus pattern

Lymphatics

Remove excess fluids, cellular and protein

debris, microorganisms & other elements

Control diffusion

Resolution of inflammatory processes

Lymphatics of connective tissue papillae

Collecting network external to periosteum

Regional lymph nodes

Lymphatics beneath JE

PDL

Accompany blood vessels

Labial & lingual gingiva of mandibular incisor

region

Submental lymph nodes

Palatal gingiva of maxilla

Deep cervical lymph nodes

Buccal gingiva of maxilla

Buccal & lingual gingiva in

mandibular premolar-molar region

Submandibular lymph nodes

Nerve supply

Maxillary & Mandibular branches of Trigeminal

nerve

Labial aspect of maxillary incisors, canines &

premolars

Superior labial branches from infraorbital nerve

Buccal gingiva in maxillary molar region

Posterior superior alveolar nerve

Palatal gingiva

Greater palatine nerve

Area of incisors

Long sphenopalatine nerve

Lingual gingiva in mandible

Lingual nerve

Labial gingiva of mandibular incisors & canines

Mental nerve

Gingiva at buccal aspect of molars

Buccal nerve

Gingival connective tissues

Most nerve fibres : Myelinated

Blood vessels

Gingival innervation : Derived from fibers arising

from nerves in the PDL & from the labial, buccal,

and palatal nerves

Nerve structures in connective tissue

Meshwork of terminal argyrophilic fibers

Meissner-type tactile corpuscles

Krause type end bulbs : Temperature receptors

Encapsulated spindles

Correlation of clinical & microscopic features

Color

Size

Contour

Shape

Consistency

Surface texture

Position

Color

Attached or marginal gingiva

Coral pink

Vascular supply

Thickness

Degree of keratinization of epithelium

Presence of pigment-containing cell

Alveolar mucosa

Red, smooth & shiny

Epithelium : Thinner

Nonkeratinized

No rete pegs

Connective tissue : Loosely arranged

Blood vessels : Numerous

Physiologic Pigmentation (Melanin)

Non-hemoglobin derived brown pigment

Skin, gingiva, oral mucous membrane

Gingiva : 60%

Hard palate : 61%

Mucous membrane : 22%

Tongue : 15%

Dummett 1946

Diffuse, deep-purplish discoloration

Irregularly shaped brown & light brown patches

As early as 3 hours after birth

Size

Cellular &

Intercellular

elements

Vascular

supply

size

Contour

Shape of the teeth

Alignment in the arch

Location & Size of proximal contact

Facial & lingual gingival embrasures

Marginal gingiva : Scalloped outline

Flat surfaces : Straight line

Pronounced mesiodistal convexity

Teeth in labial version

Contour accentuated

Teeth in lingual version

Horizontal & Thickened

Shape

Interdental gingiva

Contour of proximal tooth surfaces

Location & shape of gingival embrasures

Proximal surfaces relatively flat faciolingually

Roots are close together

Interdental bone thin mesiodistally

Gingival embrasures & interdental gingiva are narrow mesiodistally

Proximal surfaces flare away from area of contact

Mesiodistal diameter of interdental gingiva is broad

Anterior region : Pyramidal

Molar region : Flattened in buccolingual direction

Consistency

Firm & Resilient

Tightly bound to underlying bone

Exception : Movable free margin

Collagenous lamina propria

Contiguity with mucoperiosteum

Gingival fibers

Surface texture

Stippled

Orange peel

Lingual < Facial surfaces

Absent : Infancy

Appears : About 5 years

until adulthood

Disappear : Old age

Microscopically Alternate rounded protuberances & depressions

Degree of keratinization

Low magnification : Rippled surface interrupted

by irregular depressions (50 µm)

Higher magnification : Cell micropits

Adaptive specialization/ Reinforcement for

function

Reduction or loss of stippling

Gingival disease

Position

Refers to the level at which the gingival margin is attached to the tooth

JE, OE, REE : Undergo extensive alterations & remodeling

Continuous Tooth Eruption

Gottlieb & Orban, 1933

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

Anatomic crown

Clinical crown

Anatomic root

Clinical root

Active & passive eruption proceed together Gottlieb &

Orban, 1933 Attrition

Loss of tooth substance

Tooth eruption

Cementum deposited at apices and furcations of

roots

Bone formed along fundus of alveolus and at

crest of alveolar bone

Passive eruption is divided into 4 stages

Physiologic process Pathologic

process

Age changes

Gingival Epithelium Thinning of epithelium

Shklar 1966

Decreased keratinization

Glickman 1950

Shape of the Rete pegs (Conflicting results) Flattening of rete pegs

Shklar 1966 Height of epithelial ridges increased

Wentz 1952 Formation of epithelial cross ridges

Loe & Karring 1972

↑ cell density

Meyer 1956,Ryan 1974 Morphology : Do not change

Wentz 1952 Regeneration time (Conflicting results) Mitotic activity ↑

Meyer 1956,Gargiulo 1961 Constant

Ryan 1974 Mitotic activity↓

Karring and Loe 1973

Location of JE

Health: Apical termination of JE located at CEJ

Dental plaque : Etiological factor in development

of gingivitis

Suami,1971

Absence of plaque : Periodontal breakdown does

not occur : periodontal pocket will not occur

Lindhe & Nyman 1975; Axellsson &

Lindhe 1978

Continuous presence of plaque & its quantity :

Development & course of periodontal disease

Contradicting studies

Apical migration of JE can occur in absence of plaque & inflammatory cells

Skilleni 1930, Rushton 1951, Beersten et al 1982

Continuous passive eruption theory

Gottlieb and Orban 1933

Age : Gradual physiological recession of gingiva concomitantly with apical migration of epithelium

Recession : Occlusal migration of teeth

compensating for occlusal wear + Stable

location of gingival margin

In contrast Recession Mechanical trauma e.g. tooth brushing

Loe et al 1978 Extrusion of teeth

Batenhorst et al 1974

Occlusal movement of teeth does not imply apical

migration of JE

Manson 1963, Anneroth & Ericsson 1967, Loe 1967

Gingival Connective Tissue

Coarser & dense

Rate of maturation changes

Cellular elements

Rate of collagen synthesis

Soluble - Insoluble collagen

Mechanical strength

Denaturing temperature

Collagen stabilization

Conclusion

knowledge of architecture of the gingiva, how the tissue

structure develops & how it relates to function is fundamental

importance for understanding the disease process, and for

devising effective therapeutic strategies

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References