Gingiva Periodontology

basics about gingiva, gingiva structure, anatomy, aging, age changes in gingiva, with common examples and more pictures, easy, easy understanding

1. GINGIVA PRESENTED BY: SAI LAKSHMI C MDS 1 ST YEAR PERIODONTOLOGY

2. CONTENTS Introduction Oral mucosa Role of Gingiva Development of gingiva Clinical anatomy of gingiva Macroscopic features Microscopic features Gingival epithelium Gingival epithelium – connective tissue interface Gingival connective tissue Age changes

3. The periodontium consists of the investing and supporting tissues of the tooth. Periodontium- Peri = ‘around’ - odontos = ‘tooth’, i.e. structures around the tooth. Comprises: Gingiva Periodontal ligament Cementum Alveolar bone INTRODUCTION

4. The knowledge of the microscopic and macroscopic details of components of periodontium will provide a greater understanding of functional operation. A thorough understanding of the components that form the supporting structures of the teeth will provide appreciation of interactive and adaptive nature of the system as well as reference point of how the periodontium changes when pathologic, normal and excessive physiologic and inflammatory stimuli stress the components..

5. Oral mucosa – 3 zones :- Masticatory mucosa Specialized mucosa Lining mucosa

6. Oral mucosa consists of 3 zones: Masticatory mucosa - Gingiva and covering of the hard palate [25%] Specialized mucosa - The dorsum of the tongue [15%] Lining mucosa - Oral mucous membrane lining the remainder of the oral cavity [60%]

7. GINGIVA Gingiva is that part of oral mucosa which covers the alveolar processes of the jaws and surrounds the necks of teeth. -Carranza The fibrous investing tissue, covered by keratinized epithelium, which immediately surrounds a tooth and is contiguous with its periodontal ligament and with the mucosal tissues of the mouth. -AAP 1992

8. 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. -Schroeder Gingiva is the part of oral mucous membrane attached to the teeth and the alveolar processes. - Grant G in g i v a i s th a t par t of o r al m u c ou s me m b r ane t h a t c o v e r s t he alveolar processes of the cervical portions of the teeth. -Genco

9. Connects soft tissue to hard tissue, establishing a seal around the teeth Fastens to the tooth along an extensive area Provides sensation for control of biting & chewing Controls oral microbes Protects the PDL & alveolar bone Adapts to changing oral conditions & eruption Attaches firmly to the bone thus supporting the tooth Joins with the adjacent alveolar mucosa ROLE OF GINGIVA

10. Development of Gingiva l epithelium

11. A separation occurs between the attached epithelium and the tooth surface.

12. Clinical Anatomy of Gingiva

13. MACROSCOPIC FEATURES

14. MARGINAL GINGIVA Unattached Gingiva Terminal edge or border of gingiva . in 50% cases it is d emarcated by free gingival groove. It forms the soft tissue wall of the Gingival Sulcus.

15. Marginal gingiva / Gingival margin/ Margo gingivalis The terminal edge / border of the gingiva surrounding the teeth in collar-like fashion. V aries in width from 0.5 - 2.0 mm from the free gingival crest to the attached gingiva. M ore translucent appearance (than attached gingiva) Lacks stippling, and the tissue is mobile or free from the underlying tooth surface ( can be demonstrated with a periodontal probe). 1.5- 2mm coronal to CEJ

16. A shallow line or depression on the gingival surface at the junction of the free and attached gingiva. Presence of free Gingival Groove in different regions - Region % of Free Gingival Groove Right lower Premolars (44,45) 55% Right lower Canine (43) 54% Upper left Molars (26,27) 15% FREE GINGIVAL GROOVE

17. GINGIVAL SULCUS / Sulcus gingivalis The space between the free gingiva and the tooth surface “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

18. Depth of gingival sulcus : 0 – 3 mm for a clinically normal gingival sulcus. Gottlieb Orban 1933 The depth is measured using a periodontal probe . Histologic sections: 1.8 m m 1.5 mm 0.69 mm Probing depth: 2-3 mm

19. Study related to depth of sulcus in different aspects of the tooth in a healthy gingiva- Location Highest Lowest Mesio - buccal Aspect Right upper second molar (1.96 mm) lower left canine (1.14 mm) Disto - buccal aspect Left upper first molar (1.71 mm) Left lower first premolar (1.13 mm) Buccal aspect Upper right molars (1.37 mm) left lower canine (0.86 mm). Lingual & Palatal aspect Right upper second molar (1.31 mm) right lower incisors (0.79 mm)

20. ATTACHED GINGIVA Definition: It is firm & resilient gingiva, tightly bound to the underlying periosteum of alveolar bone. ( Glossary of Periodontal terms, 4 th Edition) Demarcation: It extends to the relatively loose and movable alveolar mucosa, from which it is demarcated by the mucogingival junction. c

21. Functions and clinical importance Dissipates functional and masticatory stresses. Provides a resistant barrier to plaque induced inflammation. Prevents Recession. Deepens vestibule to provide better access for tooth brushing. Improves esthetics, patient comfort and ease of hygiene.

22. WIDTH OF ATTACHED GINGIVA Definition: The distance between the mucogingival junction and the projection on the external surface of the bottom of gingival sulcus or the periodontal pocket. The width of attached gingiva varies in different individuals and on different teeth of the same individual.

23. WIDTH OF ATTACHED GINGIVA Facial: Widest in incisor region- Maxilla: 3.5 – 4.5 mm Mandible: 3.3 – 3.9 mm Most narrow adjacent to premolars- Maxilla: 1.9 mm Mandible: 1.8 mm Lingual: Wider in molar region Narrow in incisor region Increases- by age of 4 years - supraerupted teeth

24. M easuring the width of Attached Gingiva 1. Visual Method HALL WB, 1982: the width of attached gingiva is determined by subtracting the sulcus or pocket depth from total width of gingiva Total width of gingiva = from MGJ to crest of marginal gingiva 2. Roll test 3. Histochemical staining

25. Clinical Method

26. MUCOGINGIVAL JUNCTION

27. Definition: Junction between masticatory mucosa & lining mucosa (i.e. attached gingiva & alveolar mucosa) Location : on all gingival surfaces except the palatal surface in humans. Clinical Relevance: Important anatomic landmark for determining the "width" of keratinized gingiva; flap designs, gingival grafts, etc. MUCOGINGIVAL JUNCTION

28. Methods to determine Mucogingival Junction (MGJ) By stretching the lip or cheek while the pocket / sulcus is being probed : The amount of attached gingiva is considered to be insufficient when stretching of lip or cheek induces movement of free gingival margin. (Carranza 1996) Painting the mucosa with Schiller’s iodide solution: The glycogen-containing alveolar mucosa takes on a brown color, while the attached, glycogen-free gingiva remains unstained ( Fassek in 1953)

29. INTERDENTAL GINGIVA DEFINITION: The interdental gingiva is the part of gingiva that occupies the gingival embrasures, which is the interproximal space beneath the area of tooth contact. Shape : The interdental gingiva have two shapes : pyramidal & a " col " shape. “Col”: it is a valley-like depression that connects facial and lingual papilla.

30. Shape depends on: Contact point Presence or absence of recession Course of CEJ In posterior region, the teeth have contact surface rather than contact point hence the shape of papilla follows the outline of interdental contact surfaces forming a concavity- a COL

31. In the area of the col, the gingival epithelium is thin and non keratinized . If a diastema is present, the gingiva is firmly bound over the interdental bone and forms a smooth, rounded surface without interdental papilla.

32. INTERDENTAL PAPILLA The tissue that resides in the interproximal embrasure is called i nterproximal or ‘interdental papilla’. Shape : The shape of this papilla varies from triangular and knife-edge in the anterior regions due to point- sized contacts of the teeth, to broader and more square- shaped tissue in the posterior sextants due to the teeth having broad contact areas.

33. Facial Papillae Lingual Papillae

34. MACROSCOPIC FEATURES COLOUR: Attached and marginal gingiva- coral pink Alveolar mucosa- red, smooth & shiny

35. SIZE: Sum total of the bulk of -cellular and intercellular elements -and their vascular supply Alteration of size is a common feature of gingival disease.

36. CONTOUR: Marginal gingiva envelops the teeth in collar-like fashion and follows a scalloped outline on the facial and lingual surfaces. straight line - along teeth with relatively flat surfaces . accentuated - pronounced mesiodistal convexity (e.g., maxillary canines)on teeth in labial version. horizontal and thickened - in lingual version. SHAPE: Correlated with shape of the teeth & contacts/embrasures. Also depends on the presence / absence of recession & course of CEJ.

37. CONSISTENCY: Firm and resilient & tightly bound to the underlying bone SURFACE TEXTURE: Attached gingiva is stippled (orange peel appearance).This is due to the normal protuberances and depression in the gingiva.

38. The level at which the gingival margin is attached to the tooth. Continuous eruption, even after meeting their functional antagonists occurs through out life Active Eruption : Movement of teeth in the direction of occlusal plane Passive Eruption : exposure of the tooth by apical migration of Gingiva Gingival Zenith : The most apical point of marginal gingival scallop. The apico -coronal and mesio -distal dimension – 0.06 - 0.96 mm. POSITION:

39. Physiologic Pigmentation (melanin )  Melanin (non haemoglobin derived brown pigment) Prominent in blacks, diminished in albinos. As a diffuse, deep purplish discoloration or as irregularly shaped brown and light brown patches and may appear as early as 3 hours after birth.

40. MICROSCOPIC ANATOMY Histologically, gingiva is composed of : Gingival epithelium Gingival epithelium-connective tissue interface Gingival connective tissue

41. Continuous lining of stratified squamous epithelium . Function: Physical barrier to Infection Participate actively - in responding to infection - in signaling further host reactions - in integrating innate and acquired immune responses To protect deep structures Allow a selective interchange with the oral environment . GINGIVAL EPITHELIUM

42. GINGIVAL EPITHELIUM – types

43. 4 l a y e r s o f s t r a tified sq u a m o u s epitheliu m a s seen by electron microscopy:

44. 1) Stratu m Basale Basal layer - made of cell s that synthesize DNA & undergo mitosis. Basal cells show ribosomes & elements of RER indicative of a protein synthesizing activity. Found immediately adjacent to the connective tissue separated by a basement membrane. Germinative layer: having the ability to divide.

45. Structure - less zone seen under light microscope is ' basement membrane ’. 1 – 4 microns wide. Under electron microscope, Basal lamina : lamina lucida – light zone lamina densa – dark zone It takes approximately 1 month for a keratinocyte to reach the outer epithelial surface, where it is shed from the stratum corneum.

46. 2) Stratum Spinosum P rickle cell layer Large polyhedral cells with short cytoplasm processes. Show first sign of maturation. Nuclei stains less intense I ntercellular spaces of the ‘prickle’ layer are large and distended, with more prominent desmosomes

47. 3) Stratum granulosum Flatter & wider cells N uclei show signs of degeneration & pyknosis. Flattened cells, in a plane parallel to the gingival surface. Keratohyalin granules : Associated with keratin formation; are 1 μm in diameter & round in shape and appear in the cytoplasm of the cell. Protein synthesis rate progressively gets diminished as cell approaches stratum corneum.

48. 4) Stratum corneum Made up of keratinized squamae, which are larger & flatter than the granular cells. Nuclei & other organelles disappear. C lo s ely pac k ed, fl a t t ened c e lls t h a t h a v e lo s t nu c lei and most other organelles as they become keratinized. Clear, rounded bodies, representing lipid droplets appear within the cytoplasm of the cell. The cells are densely packed with tonofilaments.

49. KERATINIZED EPITHELIUM - TYPES

50. Orthokeratinized epithelium Complete keratinization  superficial horny layer No nuclei in stratum corneum layer. Well-defined stratum granulosum. Few areas of outer gingival epithelium.

51. P arakeratinized epithelium Intermediate stage of keratinization. Most prevalent surface area of the gingival epithelium. Can progress to maturity or de- differentiate under different physiologic or pathologic conditions. Stratum cornea retains PYKNOTIC NUCLEI. Keratohyalin granules are dispersed.

52. Non-keratinized epithelium Viable nuclei in superficial layer. Has neither granulosum nor corneum strata. Layers of nonkeratinized epithelium: Stratum superficiale Stratum intermedia Stratum basale

53. Keratinized epithelium Nonkeratinized epithelium Layers - basal, spinosum, granular, cornified layer. Layers -b a s a l, i nt e rm e d i at e , surface layer. Produce a cornified surface layer. Do not produce a cornified surface layer. Prickly appearance. Intercellular spaces not obvious- no prickly appearance. No nuclei- orthokeratinized contains nucleated cells Numerous to n of i lame n ts , k e ra t oh y al i n granules present. Less developed and dispersed tonofilaments; no keratohyalin granules

54. EPITHELIAL CELL CONNECTIONS: Together with intercellular protein-carbohydrate complexes, cohesion between cells is provided by numerous structures called “DESMOSOMES”. DESMOSOMES: Located between the cytoplasmic processes of adjacent cells. Two hemidesmosomes facing each other. Large number of desmosomes gives a solid cohesion between cells.

55. A D esmosome comprises the following structural components: the outer leaflets (OL) of the cell membrane of two adjoining cells, the thick inner leaflets (IL) of the cell membranes the attachment plaques (AP), which represent granular and fibrillar material in the cytoplasm.

56. TONOFILAMENTS: Cytoskeleton of keratin proteins which radiate in brush like fashion from the attachment plaques into cytoplasm of the cells. TIGHT JUNCTIONS (ZONAE OCCLUDENS): Rarely observed forms of epithelial cell connections where the membranes of the adjoining cells are believed to be fused

57. CELLS PRESENT IN GINGIVAL EPITHELIUM :

58. 90% of the total gingival cell population. Main function: KERATINOCYTES Helps in barrier action of the epithelium, while allowing a selective interchange with the oral environment.

59. M o v e f r om ba s a l t o superficia l l a y e r s o f the epi t heliu m a s t he process of differentiation occurs, forming a keratin barrier. The microfilaments present in the keratinocytes help in cell motility and maintenance of the polarity.

60. Langerh a ns cells Melanocytes Merkel's cells NON- KERATINOCYTES Inflammatory cells They together make up 10% of cell population in the oral epithelium. In light microscope - No tonofilaments & No maturation Do not possess cytokeratin filaments, hence do not have the ability to keratinize. Not arranged in layers Dendritic and appear unstained or clear Function Protective

61. Langerh a ns cells Melanocytes Merkel's cells NON- KERATINOCYTES Inflammatory cells Types of Non-keratinocytes

62. Langerhans cells Reside chiefly in suprabasal layers. Role in immune reaction as antigen -presenting cells for lymphocytes. Characterized by: Birbeck Granules. Found = normal gingiva > sulcular epithelium Absent = healthy junctional ep.

63. Melanocytes Residing in the basal layer Establishes contact with about 30-40 keratinocytes through their dendritic processes. Melanin produced by melanocytes: Melanosomes Keratinocytes release mediators essential for normal melanocytes function.

64. Merkel cells Originate from neural crest Present in Basal layer Located in deeper layers of epithelium Not dendritic cells Possess keratin , tonofilaments and desmosomes. Sensory in nature - respond to touch – Tactile perceptors

65. Inflammatory cells Nucleated cell layers Transient Lymphocytes : Most frequent Associated with Langerhans cells Polymorphonuclear leukocytes Mast cells

66. Lines the gingival sulcus. Thi n, non k e r a tin i z ed s t r a t ified squamous epithelium No rete pegs. Extends from the coronal limit of the junctional epithelium to the c r e s t o f the gin g i v al margin. Hydropic degeneration of cells. Contains K4 and K13, K19. Don’t have merkel cells. SULCULAR EPITHELIUM

67. Sulcular epithelium has the potential to keratinize: If it is reflected and exposed to the oral cavity. If the bacterial flora of the sulcus is totally eliminated. Outer epithelium loses its keratinization: When it is placed in contact with the tooth. These findings suggest that the local irritation of the sulcus prevents sulcular keratinization. Sulcular epithelium is extremely important because it act as a semi permeable membrane through which injurious bacterial products pass into gingival fluid. Permeability SE < JE.

68. Consists of a Collar-like band of stratified squamous non-keratinizing epithelium. 3 to 4 layers thick in early life, but the number increases with age to 10 or even 20 layers. Tapers from its coronal end to apical termination, located at the CEJ in healthy tissue. Length: 0.25 to 1.35 mm. JUNCTIONAL EPITHELIUM

69. Junctinal epithelium is the non - keratini z ed stratified squamous epithelium which attaches and form a collar around the cervical portion of the tooth that follows CEJ . Carranza’s clinical periodontology It provides the attachment mechanism of the epithelium to the hard tooth surface. It also provides a protective function relative to the subjacent periodontal ligament.

70. What is Junctional Epithelium? JE tapers from its coronal end, which may be 10 to 29 cells wide , to 1 or 2 cells wide at its apical termination, located at the CEJ in healthy tissue. Those cells are grouped into two strata: BASAL LAYER facing the connective tissue and  SUPRABASAL LAYER extending to the tooth surface. It provides the attachment mechanism of the epithelium to the surface of tooth hard substance. It also provides a protective function relative to the subjacent periodontal ligament.

71. What are it’s functions? JE is firmly attached to the tooth and thus forms an epithelial barrier against the plaque bacteria. It allows the access of GCF , inflammatory cells and components of the immunological host defense to the gingival margin. JE cells exhibit rapid turnover, which contributes to the host- parasite equilibrium and rapid repair of damaged tissue

72. DEVELOPMENT OF JUNCTIONAL EPITHELIUM Formation of reduced enamel epithelium Union of REE and Oral epithelium As the tooth erupts REE is converted into JE

73. 1. REE surrounds the crown of tooth from the moment enamel is properly mineralized till it erupts. 3. Migrating epithelium produces an epithelial mass between oral epithelium and REE so that tooth can erupt without bleeding. 2. 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. 4. During later phases of tooth eruption all cells of REE is replaced by the JE.

74. Cuboidal cells derived from the ameloblasts begin to flatten Align parallel to the tooth surface and take appearance of junctional epithelium Since these cells which have lost capacity to divide get exfoliated at base of the sulcus Cells from stratum intermedium which have proliferative capacity get transformed into Junctional epithelium Changes during conversion into junctional epithelium:

75. STRUCTURE OF JUNCTIONAL EPITHELIUM Anatomical aspects Junctional epithelium and interstitial cells Epithelial attachment apparatus

76. JE: ANATOMICAL FEATURES: JE forms a collar peripheral to cervical region of tooth of about 0.25 to 1.35 mm Interproximally JE of adjacent teeth fuse to form the lining of the col area Epithelial connective tissue interface is smooth (no rete pegs) JE is thickest at bottom of sulcus and tapers of f in apical direction

77. JE: MICROSCOPIC FEATURES C ollar-like band of nonkeratinised stratified squamous epithelium E xtend s from CEJ to bottom of gingival sulcus Coronally , 15-30 cells thick . A pically narrows to 1-3 cells . T wo strata- stratum basale and stratum suprabasale T wo basal lamina – External and internal

78. DAT CELL: The single layer of cell lying in contact with tooth surface ( directly attached to tooth surface). Recent studies indicate that DAT cells are capable of – Undergoing cell- division. Exclusive proliferating population of epithelial cells (DAT) in suprabasal location is a unique feature of junctional epithelium. DAT cells possess the capacity to form and renew the components of the epithelial attachment .

79. These cell layers can be grouped in two strata: The basal layer: that faces the connective tissue (External Basal Lamina) The suprabasal layer: that extends to the tooth surface – DAT CELLS (Internal basal lamina) 3 zones of junctional epithelium: Apical – germination Middle – adhesion Coronal- permeable

80. JE: Wide intercellular space may be a double-ended sword-

81. JE : Role in Anti-Microbial Defense: Junctional epithelium consists of active populations of cells and antimicrobial functions, which together form the first line of defense against microbial invasion into tissue. Even though junctional epithelial cell layers provide a barrier against bacteria, many bacterial substances, such as lipopolysaccharide, pass easily through the epithelium but have only limited access through the external basal lamina into the connective tissue ( Shwartz et al 1972).

82. JE in the Anti-Microbial Defense: Rapid turnover, as such, is an important factor in the microbial defense of JE. The area covered by the dividing cells in the junctional epithelium is at least 50 times larger than the area through which the epithelial cells desquamate into the gingival sulcus. T here is a strong funneling effect that contributes to the flow of epithelial cells (Schroder et al 1967). Rapid shedding and effective removal of bacteria adhering to epithelial cells is therefore an important part of the antimicrobial defense mechanisms at the dentogingival junction.

83. PERMEABILITY OF JUNCTIONAL EPITHELIUM The bi-directional arrows indicate that the junctional epithelium is the most permeable portion of the gingival epithelia. Because of its permeability to bacterial products and other assorted antigens, the connective tissue adjacent to the junctional epithelium tends to become infiltrated with chronic inflammatory cells, primarily lymphocytes and plasma cells.

84. PRIMARY ATTACHEMENT EPITHELIUM SECONDARY ATTACHEMENT EPITHELIUM EPITHELIUM ATTACHMENT APPARATUS Attachment of reduced enamel epithelium to the enamel of the unerupted tooth . After conversion of REE to JE the attachment is referred to as junctional epithelium. Mediated by the hemidesmosomes of DAT cells and internal basal lamina EPITHELIAL ATTACHMENT

85. Attachment of JE – ultramicroscopic mechanism defined as epithelial attachment apparatus Consists of: Hemidesmosomes – at plasma membrane of cells directly attached to the tooth Basal lamina like extracellular matrix I nternal basal lamina on the tooth surface

86. DYNAMICS (TURNOVER RATE) OF JE The turnover rate of JE cells is exceptionally rapid. In non-human primates it is about 5 days (twice that of oral epithelium). The DAT cells express a high density of transferrin receptors supporting the idea of active metabolism and high turnover. DAT cells have an important role in tissue dynamics and reparative capacity of the J E. The exi s ten c e of a div i ding populat i on of D A T ce l ls in a suprabas a l loc a tion in several layers from connective tissue is a unique feature of JE.

87. Characteristics Outer Oral epithelium Sulcular epithelium Junctional epithelium Origin Oral epithelium Oral epithelium Reduced enamel epithelium Keratinization Parakeratinized Sometimes or t h okera t i n i zed Nonkeratinized Nonkeratinized Stratification Well stratified Stratified but granulosam and corneum are absent Poorly stratified Proliferation Lesser proliferation among three Higher than OEE but lesser than JE Higher proliferation Permeability Not permeable to water soluble substances M o de r a t e l y permeable Highly permeable Intercellular Space Desmosomes& tonofilaments Narrowest More than SE& JE Narrower than JE More than JE Widest among three Least among three Retepegs Present Normally absent, appears in inflammation Normally absent, appears in inflammation

88. Ultrastructurally this interface is composed of 4 elements: B asal cell plasma membrane. Lamina lucida: 25 to 45 nm wide. Lamina densa : 40 to 60 nm thickness. Reticular layer . From the lamina densa so called anchoring fibrils project in a fan- shaped fashion into the connective tissue. EPITHELIUM-CONNECTIVE TISSUE INTERFACE

89. Various junctional complexes present in gingiva are: Tight junctions/Zonae occludens Adhesive junctions: Cell to cell Zonula adherens Desmosomes Cell to matrix Focal adhesions Hemidesmosomes Gap junctions : Intercellular pipes/channels bridge both adjacent membranes and intercellular space. Intercellular space in gap junction is approx. 3 nm. Major pathway for direct intercellular communication.

90. P redominant tissue component of gingiva : ‘ Lamina Propria’. T h e g i n gi v a l c o nn e c t i v e t i ss u e i s c o m p o s e d o f: Ground substance Gingival fibers Cells Blood vessels Nerves and, Lymphatic vessels Layers of connective tissue: Papillary Layer Reticular Layer CONNECTIVE TISSUE

91. 1) Ground substances Connective tissue cells and fibers, together with vessels and nerves are embedded in a matrix which is synthesized by fibroblast and it is made up of: Glycoproteins : it is a protein-polysaccharide molecule in which protein component is predominating. Glycoprotein mediates attachment and migration of fibroblasts. Proteoglycans: it is a protein polysaccharide molecule in which polysaccharide component is predominating. Glycosaminoglycans: are polysaccharides which can bind large amounts of water providing the characteristic resiliency of the gingiva (i.e. resist compressive force). Glucosaminoglycans also facilitate transport of: nutrients, metabolic products, cells and cytokines which are chemical messengers that modulate cellular function.

92. 2) Gingival fibers The gingival connective tissue fibers are produced by the fibroblasts and can be divided into: Collagen fibers Reticulin fibers Elastic fibers. C onnective tissue of marginal gingiva is densely collagenous containing a prominent system of collagen fiber bundle C onsists mainly of type 1 collagen.

93. FUNCTIONS OF GINGIVAL FIBRES

94. 07 / 12 / 16 COLLAGEN FIBRES Predominate in gingival connective tissue & constitute the most essential components of the periodontium The smallest unit, collagen molecule, is often referred to as “tropocollagen”.

95. 07 / 12 / 16 RETICULIN FIBRES Argyrophilic staining properties Numerous in tissue adjacent to basement membrane Occur in large no. in loose connective tissue Present at epithelium - connective tissue interface OXYTALAN FIBRES Scarse in gingiva but numerous in PDL Composed of long thin fibrils with diameter of ~ 150 Å

96. 07 / 12 / 16 ELASTIC FIBRES Only present in association with blood vessels of gingiva and PDL. Gingiva coronal to mucogingival junction (MGJ) does not contain elastic fibres except in association with blood vessels.

97. 07 / 12 / 16 Gingival fibers

98. Originates from cementum and spreads laterally into lamina propria Dentogingival Orginates from periosteum and spreads into lamina propria Alveologingival Originates from cementum near CEJ into periosteum of alveolar crest Dentoperiosteal Originates from within the free marginal and attached gingiva coronal to alveolar crest and encircles each tooth Ci r cular Originates from interproximal cementum coronal to crest and courses mesially and distally in the interdental area into cementum of adjacent teeth Transseptal

99. Originates from the periosteum of the lateral aspect of alveolar process and spreads into attached gingiva. Periosteogingival Originates from within interdental gingiva and follows a n orofacial course Interpapillary Originates within the attached gingiva interwing along dental arch between and around teeth T r an s gin g i v al Originates from cementum on distal surface of tooth spreading buccally and lingually around adjacent tooth and inserting on mesial cementum of next tooth Intercircular Originates from attached gingiva immediately subjacent to basement membrane and courses mesiodistally Intergingival Originates from cementum of the mesial surface of tooth and courses distally and inserts on the cementum of distal surface of same tooth Semicircular

100. GINGIVAL CELLS

101. Predominant connective tissue cells(65%) Spindle or stellate shaped with oval nucleus containing one or more nucleoli Function- maintains structural integrit y of connective tissue by secreting extracellular matrix . FIBROBLAST S MAST CELLS Large spherical or elliptical mononuclear cell Present in relation to blood vessels so they play a role in maintaining normal tissue stability and vascular homeostasis

102. 07 / 12 / 16 Well developed nucleus, G olgi apparatus Numerous vesicles Scarse granular endoplamic reticulum Phagocytic function Includes - Neutrophils Lymphocytes Plasma cells MACROPHAGES INFLAMMATORY CELLS

103. Blood supply to periodontium The gingiva receiv e s its blood supply mainly th r ou g h supraperiosteal blood vessels which are terminal branches of- Sublingual artery Buccal artery Facial artery Greater palatine artery Infraorbital artery Posterior superior artery

104. VESSELS OF PERIODONTAL LIGAMENT Extend s into gingiva . Anastomosis: -With capillaries in sulcular area

105. SUPRAPERIOSTEAL ARTERIOLES Facial and lingual surfaces of alveolar bone Capillaries extend along sulcular epithelium Between rete pegs of outer epithelium Occasional branches of arterioles pass through Alveolar bone PDL Over the crest of alveolar bone ARTERIOLES FROM CREST OF INTERDENTAL SEPTA Extend parallel to crest of alveolar bone Anastomosis: Vessels of PDL Capillaries in gingival crevicular areas Vessels that run over alveolar crest

106. Blood supply originating from the vessels in the periodontal ligament pass the alveolar bone crest and contribute to the blood supply of the free gingiva. The main blood supply of free gingiva is from the supraperiosteal blood vessels (SV) which, in the gingiva, anastomose with blood vessels from the alveolar bone and periodontal ligament.

107. Venous drainage Buccal, lingual, greater palatine & nasopalatine veins. Veins run into the pterygoid plexus.

108. Lymphatic drainage The lymph vessels from teeth usually run directly into ipsilateral submandibular lymph nodes. Lymph from mandibular incisors drain into submental lymph nodes . Lymphatic drainage starts in connective tissue papillae and drains into regional lymph nodes; from- - mandibular incisor-region gingiva  submental lymph nodes - maxillary palatal gingiva  deep cervical lymph nodes -maxillary buccal gingiva  submandibular lymph nodes -mandibular premolar-molar-region gingiva  submandibular lymph nodes

109. Nerve supply The nerve supply is derived from branches of Trigeminal nerve. A number of nerve endings have been identified in the gingival connective tissue, such as tactile corpuscles, temperature and pain receptors ( Krause type end bulbs).

110. REPAIR / HEALING OF GINGIVA Turnover rate is 10-12 days. It is one of the best healing tissues in the body with little or no scarring. However, the reparative capacity is lesser than that of periodontal ligament and epithelial tissue.

111. Stippling usually disappears with age. Width of the attached gingiva increases with age. Gingival epithelium: Thinning and decreased keratinization Rete pegs flatten Migration of junctional epithelium apically. Reduced oxygen consumption. Age Changes

112. Gingival connective tissue: Increased rate of conversion of soluble to insoluble collagen Increased mechanical strength of collagen Increased denaturing temperature of collagen Decreased rate of synthesis of collagen Greater collagen content. Age Changes

113. The biological width is defined as the dimension of the soft tissue, which is attached to the portion of the tooth coronal to the crest of the alveolar bone. BIOLOGIC A L WID T H- Clinical considerations

114. Biologic Width Evaluation: Clinical (discomfort when the restoration margin levels are being assessed with a periodontal probe) Radiographs (for interproximal violation but mesiofacial and distofacial line angle not seen properly) Bone sounding (probing under anesthesia)- If this distance is less than 2 mm or more at one or more locations, a diagnosis of biologic width violation can be confirmed Biologic width violation: Unpredictable bone loss Gingival recession Persistence of gingivitis

115. Conclusion Gingival tissues play a key role in the protection of tooth structures and supporting periodontal tissues against trauma and / or infection Making the gingival health, a very essential component for the success of all periodontal treatment procedures. Proper functioning of the periodontium is achieved only through structural integrity and interaction between the various tissues which are its components.

116. References Clinical Periodontology, By Carranza, 12 th Edition Clini c al P e r iod o nt ol o gy And Impla n t De n ti s t r y B y Jan Lindhe, 4 th Edition Oral Histology, Development, Structure And Function – A.R. Ten cate, 5th Edition

117. THANK YOU