Notion Press

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First Published by Notion Press 2016Copyright © Dr. Priyam Mishra 2016

All Rights Reserved.

ISBN 978-1-945400-05-6

This book has been published with all efforts taken to make the material error-free after the consent of the author. However, the author and the publisher do not assume and hereby disclaim any liability to any party for any loss, damage, or disruption caused by errors or omissions, whether such errors or omissions result from negligence, accident, or any other cause.

No part of this book may be used, reproduced in any manner whatsoever without written permission from the author, except in the case of brief quotations embodied in critical articles and reviews.

Contents

CHAPTER 1 ANATOMY OF THE PERIODONTIUM 1

GINGIVA 1

Question 1: Correlate the Normal Clinical Features of Gingiva and Its Microscopic Features 1Question 2: Development of Gingival Sulcus 18Question 3: Clinical Significance of Attached Gingiva 20Question 4: Fibroblasts 28Question 5: Microcirculation of Gingiva 30Question 6: Oxygen Consumption of Gingiva 43Question 7: Junctional Epithelium 43Question 8: Histochemistry of Gingiva 52

CEMENTUM 57

Question 1: Discuss Cementum in Health and Disease 57Question 2: Cemento-Enamel Junction 73

PERIODONTAL LIGAMENT 81

Question 1: Discuss The Development and Functions of Periodontal Ligament 81Question 2: Describe The Structure of the Periodontal Ligament and Discuss Its Functional

Adaptation and Masticatory Forces 92Question 3: Discuss in Detail the Biochemical Aspects of Normal Periodontal Connective Tissue 104Question 4: Collagen: Structure and Biological Properties 112Question 5: Hemidesmosomes 126Question 6: Pathways of Pain 129Question 7: Pain Pathways of PDL 134

ALVEOLAR BONE 135

Question 1: Discuss Alveolar Bone in Health and Disease 135Question 2: Odontogenesis 160

Contentsvi

CHAPTER 2: AGING AND THE PERIODONTIUM 165

Question 1: Age Changes and Periodontium 165

CHAPTER 3: CLASSIFICATION OF DISEASES & CONDITIONS AFFECTING THE PERIODONTIUM 169

Question 1: Dental Plaque Induced Gingival Disease 169Question 2: Non Inflammatory Destructive Periodontitis 172Question 3: Gingival Diseases Associated With Malnutrition 174Question 4: Refractory Periodontitis 175

CHAPTER 4: FUNDAMENTALS IN THE METHODS OF PERIODONTAL DISEASE EPIDEMIOLOGY 185

Question 1: What are the Various Methods of Epidemiological Surveys? 185Question 2: Reliability of Indices Used in Periodontal Disease 188Question 3: Branches of Biostatistics, Collection of Data and Sampling 197Question 4: Cohort Study 201

CHAPTER 5: GENETIC SUSCEPTIBILITY TO PERIODONTAL DISEASE 209

Question 1: Describe Genetic Risk Factors for Periodontitis 209Question 2: Gene Transcription 220Question 3: Gingival Lesions of Genetic Origin 223Question 4: Disease Modifying Genes in Relation to Peri-Implantitis 227Question 5: Clinical Implications of Genetic Studies in Periodontal Disease 231

CHAPTER 6: THE ROLE OF DENTAL CALCULUS AND OTHER LOCAL PREDISPOSING FACTORS 233

Question 1: Dental Calculus 233Question 2: Role of Proton Concentration (Ph) of Saliva in Relation to Dental Calculus 245Question 3: Describe the Role of Secondary Local Etiologic Factors Which May Predispose

to Periodontal Disease 247Question 4: Food Impaction 258

CHAPTER 7: BIOFILM AND PERIODONTAL MICROBIOLOGY 263

Question 1: Biofilm (or) Describe the Role of Dental Plaque Biofilm in Periodontal Disease 263Question 2: Discuss the Current Concepts and Controversies on Microbial Plaque 278Question 3: Microbial Specificity of Periodontal Disease 281Question 4: Facultative Anaerobes of Oral Cavity 283Question 5: Discuss the Normal Oral Flora. Give a Detailed Account of Microbiology

of Periodontal Health and Disease 285

Contents vii

Question 6: Actinobacillus Actinomycetum 299Question 7: Porphyromonas Gingivalis 310Question 8: Characteristics of Subgingival Plaque 326Question 9: Association Between Herpes Virus and Periodontal Disease

(or) Enumerate Various Viral Lesions that Affect Oral Cavity and its Effect on Periodontium 328

Question 10: Herpetic Lesions of Gingiva 339Question 11: Plaque Complex 341Question 12: Growth Dynamics of Dental Plaque 343Question 13: Capnocytophaga 346Question 14: Pre-Requisite for Initiation & Progression of Periodontal Disease 348Question 15: Discuss the Role oH.pylori as a Causative Agent for Periodontal Diseases 350Question 16: Probiotics-Oral Biofilm and Microflora 357Question 17: Lipopolysaccharides 367Question 18: Adhesins 370

CHAPTER 8: MOLECULAR BIOLOGY OF THE HOST-MICROBE INTERACTIONS IN PERIODONTAL DISEASES 379

Question 1: Macrophages 379Question 2: Phagocytosis 381Question 3: Emigration and Chemotaxis 383Question 4: Discuss The Role of Mast Cells in Inflammatory Process 386Question 5: Describe the Process of Acute Inflammation 390Question 6: Vascular Changes in Acute Inflammation 394Question 7: Chemical Mediators of Inflammation 400Question 8: Pro-Inflammatory Mediators 411Question 9: Write in Detail on Inflammation, Proinflammatory Mediators in Relation to

Periodontal Inflammation 412Question 10: Classify Leukocytes and Discuss the Role of Neutrophils in Health & Disease 414Question 11: Pmn Defects or Neutrophil Related Periodontal Diseases 417Question 12: Papillon Lefevre Syndrome 426Question 13: Apoptosis 428Question 14: Immunoglobulins 433Question 15: Discuss the Various Components of Immune System 441Question 16: Discuss the Host Microbe Interaction in Periodontal Diseases 461Question 17: Discuss Host Response in Periodontal Disease 472Question 18: Matrix Metallo Proteinases 487Question 19: Role of Cytokines in Periodontal Disease 497Question 20: Lymphokines 507Question 21: Natural Killer Cells 508

Contentsviii

Question 22: T-Cell Interaction 509Question 23: Bone Resorption in Periodontal Disease 517Question 24: Mechanism of Transendothelial Migration of Cells During Inflammation 527Question 25: Reactive Oxygen Species 533

CHAPTER 9: SMOKING AND PERIODONTAL DISEASE 545

Question 1: The Effect of Tobacco Smoking in Periodontal Health 545Question 2: Modification of Host-Bacteria Relationship in Smoking 552

CHAPTER 10: INFLUENCE OF SYSTEMIC CONDITIONS ON THE PERIODONTIUM 557

Question 1: Describe the Various Hematological Disorders and their Effects on Periodontium 557Question 2: Bleeding Disorders 576Question 3: The Role of Stress on Periodontal Disease 586Question 4: Evaluate Nutrition as a Factor in the Management and Prevention if Periodontal Disease 594Question 5: Role of Vitamins in General Health 614Question 6: Describe the Role if Minerals and Trace Elements in Periodontal Health 616Question 7: Oral Changes in Macrocytic Hypochromic Anaemia 619

CHAPTER 11: IMPACT OF PERIODONTAL INFECTION ON SYSTEMIC HEALTH 623

Question 1: Periodontal Disease and Diabetes Mellitus-A 2 Way Relationship. Elborate in Detail 623Question 2: Lab Investigation in Diabetes Mellitus 638Question 3: Functions of Insulin 643Question 4: Basal Metabolic Rate 647Question 5: Define Periodontal Medicine. Explore Association Between Periodontal Disease

and Coronary Heart Disease/Atherosclerosis 649Question 6: Advanced Glycation End Products 664Question 7: Fibrinogen 667

CHAPTER 12: DEFENSE MECHANISMS OF THE GINGIVA 669

Question 1: Defense Mechanism of Gingiva 669Question 2: Clinical Significance of Gingival Fluid 675Question 3: Discuss the Role of GCF Enzymes as a Diagnostic aid for Periodontal Diseases 684Question 4: Lactic acid Dehydrogenase 695Question 5: Discuss Secretions and Functions of Saliva 697Question 6: Describe the Composition of Saliva. Discuss in Detail the Role of Inorganic

and Organic Constituents of Saliva in Etiopathogenesis of Periodontal Disease 702Question 7: Salivary Antibodies & Antibacterial Factors 705

Contents ix

CHAPTER 13: GINGIVAL INFLAMMATION 711Question 1: Established Gingival Lesion 711

CHAPTER 14: CLINICAL FEATURES OF GINGIVITIS 713

Question 1: Causes of Gingival Bleeding 713Question 2: Gingival Disease in Menopause 715Question 3: Factors Affecting Gingival Pigmentation 716Question 4: Metal Intoxications-Periodontal Manifestations 729

CHAPTER 15: GINGIVAL ENLARGEMENT 731

Question 1: Describe the Current Concepts on the Pathogenesis of Drug Induced Gingival Enlargement 731

Question 2: Conditioned Gingival Enlargements 747Question 3: Localized Discrete Gingival Enlargements 752Question 4: Systemic Diseases Causing Gingival Enlargement 756Question 5: Idiopathic Gingival Enlargement 758

CHAPTER 16: ACUTE GINGIVAL INFECTIONS 761

Question 1: Etiopathology of Anug 761Question 2: Write about Recent Advances in Microbial Profile of Anug 766Question 3: Classify Ulcerative Lesions of Oral Cavity & Describe Clinical Features 767Question 4: Host Response & Predisposing Factors in Necrotizing Periodontal Disease 776Question 5: Differential Diagnosis of Primary Herpetic Gingivostomatitis 780Question 6: Pericoronitis 783

CHAPTER 17: GINGIVAL DISEASE IN CHILDHOOD 787

Question 1: Differences Normally Observed Between the Periodontium of an Adult and a Child 787

CHAPTER 18: DESQUAMATIVE GINGIVITIS 791

Question 1: Desquamative Gingivitis 791Question 2: Discuss Oral & Periodontal Lesions Associated With Skin Diseases 806

CHAPTER 19: THE PERIODONTAL POCKET 811

Question 1: Micro Topography of Pocket Wall 811Question 2: Histopathology of a Periodontal Pocket 813Question 3: Pathogenesis of Periodontal Pocket 817

Contentsx

CHAPTER 20: PERIODONTAL RESPONSE TO EXTERNAL FORCES 821

Question 1: Discuss the Merits of “Traumatic Occlusion by Itself Cannot Cause Periodontal Disease” 821Question 2: Lamina Dura 831Question 3: Discuss the Etiopathogenesis of Tooth Mobility and Migration in Periodontal Disease 832Question 4: Bone Factor Concept as Related to Etiology and Pathogenesis of Periodontal Diseases 841Question 5: Bone Coupling 843

CHAPTER 21: CHRONIC PERIODONTITIS 851

Question 1: Immunological Profile of Subjects with Periodontitis 851Question 2: Periodontal Disease Activity 853Question 3: Periodontal Disease is not a Continuous Destructive Process. Discuss. 857

CHAPTER 22: AGGRESSIVE PERIODONTITIS 859

Question 1: Aggressive Periodontitis or Discuss the Current Concepts of Etiology of Prepuberty Periodontitis 859

Question 2: Burn-Out Phenomenon 878

CHAPTER 23: PATHOLOGY AND MANAGEMENT OF PERIODONTAL PROBLEMS IN PATIENTS WITH HIV INFECTION 879

Question 1: Oral Thrush 879Question 2: Oral Anti-Fungal Agents 883Question 3: What is A.I.D.S? What is the Role of the Periodontist with Regard to

Precautions and Management of Periodontal Problem in A.I.D.S Cases? 892

Chapter

ANATOMY OF THE PERIODONTIUM

GINGIvA

QUESTION 1

Correlate the Normal Clinical Features of Gingiva and Its Microscopic Features

ANSWER: Gingiva is the part of oral mucosa that covers the alveolar process of the jaws and surrounds the neck of teeth and is structured to resist the forces of mastication.

MICROSCOPIC FEATURES1

The gingiva consists of stratified squamous epithelium which overlays the deeper connective tissue of the lamina propria to which it is intimately attached. Both tissues have extracellular matrix, but due to their vastly different structures and functions, these matrices differ quite significantly.

GINGIVAL EPITHELIUM1

Gingiva epithelium is not strictly a connective tissue, due to its relationship to the underlying connective tissue and functional demands but its an essential periodontal component. It is the strategic component of the host defense against bacterial assault on the periodontal tissues. Gingival epithelium adopts morphologically variant forms as different location, and these forms can be distinguished by differentiation markers. They are:

• Junctional epithelium, • Oral or outer epithelium, • Sulcular epithelium, • Pocket epithelium, as in periodontally diseased gingiva.

Panacea for Periodontology2

Parts of gingival epithelium

The epithelial structures vary in their:

• Degree of keratinization, • Number of cells, • Presence of rete pegs

There are no fibrous protein components of the epithelial extracellular matrix and the nonfibrous epithelial components include:

• Water • Variety of glycoproteins, lipids, and proteoglycans, • Extensions of intercalated cell surface molecules

The principal cell type of gingival epithelium as well as of other stratified squamous epithelia is the keratinocyte. Other cells fond in the epithelium are the clear cells or nonkeratinocytes, which include the:

• Langerhans cells, • Merkel cells • Melanocytes.

The main function of the gingiva epithelium is to protect the deep structures while allowing a selective a selective interchange with the oral environment. This is achieved by proliferation and differentiation of the kerationocytes.

Proliferation of kerationocytes takes place by mitosis in the basal layer and less frequently in the suprabasal layers, where a small proportion of cells remain as proliferative compartment while a larger number begins to migrate to the surface.

Differentiation involves a process of keratinization consisting of a sequence of biochemical & morphologic events that occur in the cells as it migrate from the basal layer to the superficial layer.

Dr. Priyam Mishra 3

The morphologic changes include:

• Progressive flattening of cells • With an increasing prevalence of tonofilaments • Intercellular junctions coupled to the production of keratohyaline granules • Disappearaance of the nucleus.

Ortho Keratinization: It is a complete keratinization process that leads to the production of an ortho keratinized superficial horny layer similar to the skin with no nuclei in the stratum corneum and a well defined stratum granulosum.

Para keratinization:The stratum corneum retains pyknotic nuclei and the keratohyaline granules are dispersed, not giving rise to a stratum granulosum.

Non Keratinized Epithelium: It has neither the granulosum nor the corneum strata and the superficial layer has viable nuclei.

LAYERS OF EPITHELIUM1

1. Stratum Basale

• Basal cells are made up of 2 populations; one is serrated and heavily packed with tonofilaments. The other is non-serrated and composed of slow cycling stem cells.

• The lateral borders of the adjacent basal cells are closely adapted/apposed and connected by desmosomes.

• Whole desmosomes link keratinocyte to each other, the hemidesmosomes attach basal epithelial cells to the basement membrane.

2. Stratum Spinosum

• Cells are irregular, polyhedral and are longer than the basal cells. • Light microscopy shows intercellular bridge and the tonofilaments, seem to course from cells to cells

via these bridges. • Tonofilaments loop lie adjacent to the attachment and do not cross over the adjacent cells. • Spinous layer shows large intercellular space in keratinizing epithelia. Hence desmosomes appear

prominent to the spinous cells exhibit a prickly appearance • Spinous layer has the highest level of protein synthesis. • Odland bodies are modified lysosomes which are chiefly found in the uppermost cells of the stratum

spinosum as dense granule. They contain increased quantities of acid phosphatase. • Keratolinin and Involucrin are the proteins which are present in the upper part of the stratum

spinosum.

3. Stratum granulosum • Cells in this layer contain basophilic keratohyaline granules. • Nuclei show signs of degeneration and Pyknosis.

4. Stratum Corneum • Made up of larger and flatter cells compared to the stratum granulosum. • All cellular organelles disappear.

Panacea for Periodontology4

Layers of epithelium

ORAL EPITHELIUM

• It faces the oral cavity and extends from the gingival margin to the mucogingival junction. • It covers the crest and outer surface of the marginal gingiva and the surface of the attached gingiva. • It is keratinized, or parakeratinized or present with a combination. • The degree of keratinization diminishes with age and onset of menopause. • Keratin polypeptides provide mechanical strength to the epitheliod sheets. • Cells are constantly being shed from the outmost layer by surface sloughing of mature kerationocytes

& they are constantly renewed from the basal layer. • Keratins K1 and K2 and K10–K12 which are specific to epidermal differentiation, are

immunohistochemically expressed with high intensity in orthokeratinized areas and with less intensity in parakeratinized areas. K6 and K16 characteristic to highly proliferative epithelia, and k5 and k14, stratification specific cytokeratins are also present parakeratinized areas express k19, which is usually absent from orthokeratinized normal epithelia.

• Glycogen can accumulate inter-radically when it is not completely degraded by any one of the glycolytic pathways. Thus its concentration in normal gingiva is inversely related to degree of keratinization and\d in inflammation.

SULCULAR EPITHELIUM

• It is a thin, non keratinized, stratified squamous epithelium without rete pegs. • Extends from the coronal limit of the functional epithelium to the crest of the gingival margin. • It lacks the granulosum and corneum strata and the intermediate layer contain more desmosomes. • The sulcular epithelium has the potential to keratinize if:

○ Exposed by refection towards oral cavity ○ Elimination of total bacterial flora from the sulcus.

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• Sulcular epithelium is very important as it may act as a semi-permeable membrane through which injurious bacterial product may part into the gingival and through which tissues fluid from the gingiva seeps into the sulcus.

• It lacks K1, K2 and K10–K12 cytokeratins. But contains K4 and K13 the so called esophageal type cytokeratins. It also expresses k19.

• Acid phosphatase staining is negative.

JUNCTIONAL EPITHELIUM

• It is a collar like band of stratified squamous, non keratinizing epithelium. • It is 3 to 4 layers thick in early life, but the number of layers increase with age to 10 to 20 layers. • It is 30–100 µm thick • These cells can be grouped into two strata: basal and suprabasal. • Length ranges from 0.25 to 1.35 mm. • It is formed by the confluence of oral epithelium and the reduced enamel epithelium during tooth

eruption. • Intercellular junctions are loose and Intercellular spaces are more distensible.

Junctional epithelium

• The Junctional epithelium is attached to tooth surface by means of internal basal lamina,and to the gingival connective tissue by means of external basal lamina.

• Similar to the sulcular epithelium, it exhibits less glycolytic enzyme activity than the oral epithelium and lacks phosphate activity.

• It expresses K19 and the stratification specific cytokeratins K5 and K14. It lacks expression of K6 and K16 which are proliferation specific keratins, although the turnover the cells is very high.

Panacea for Periodontology6

Junctional epithelium on an erupting tooth

Zones of the Junctional EpitheliumThe division of zones is based upon the following parameters:

• Hemidesmosomes • Their thickness and their density • The morphology of the cellular membrane adjacent to the tooth surface. • The cytological, aspects of the epithelium • Intercellular spaces

GINGIVAL CONNECTIVE TISSUE1

Underlying, the gingiva epithelium is the lamina propria of the gingiva, the gingival connective tissue. The gingiva is attached to tooth surfaces and alveolar bone trough fibrous attachments of the connective tissues.

• Approximately one tenth of the gingival connective tissue volume is occupied predominantly by fibroblasts (Schluger et al 1990). These cells are responsible for producing connective tissue elements in both normal and diseased gingiva (Narayanan and Page 1983).

• Besides the fibroblasts, most other cells present in the gingiva connective tissue are largely derived from blood vessels and the blood itself. These cells include:

○ endothelial cells, ○ polymorphonuclear leukocytes, ○ macrophages, ○ lymphocytes, ○ plasma cells, ○ mast cells

• In normal gingiva connective tissues, inflammatory cells are present in relatively small numbers. These cells increase in number during inflammation, however, their number during inflammation, and their proportions differ from one site to another according to the type and severity of the inflammatory reaction.

Dr. Priyam Mishra 7

• One of the most distinguishing features of the gingiva connective tissue is its rapid remodeling and high turnover rate.

○ Indeed, the turnover rates of gingiva and periodontal ligament collagens are higher than those of most other connective tissues, including skin.

○ This very high turnover rate of matrix components does not appear to decrease greatly with age (Page and Ammons 1974, Sodex 1976; Sodex and Ferrier 1988).

Gingival fibers2

The various collagen fibers of the gingiva connective tissue provide a rigid structural framework in the gingiva.

• Collagens are the most abundant biochemical components in the gingiva connective tissue, where they provide greater than 60% of the total tissue protein.

• These fibers are organized into several characteristic and architecturally distinct units that are classified into various groups based on their location, origin, and insertion (Schluger et al 1990).

1. The fibers that arise from the cementum immediately apical to the base of the epithelial attachment and spread out into the gingiva are called dentogingival fibers.

2. Those that bend apically over the alveolar crest and insert into the buccal and lingual periosteum are classified as dentoperiosteal fibres.

3. The alveologingival fibers originate from the alveolar crest, traverse coronally, and terminate in the free and papillary gingiva.

4. Those fibers that pass circumferentially around the cervical region of teeth in the free gingiva are classified as circular fibers.

5. Semicircular fibers, traverse from the cementum at the proximal root surface, extend into the free marginal gingiva, and inset into a corresponding position on the opposite site of the tooth.

6. The fibers traversing from the cementoenamel junction to the free marginal gingiva of the adjacent tooth are transgingival fibers.

7. The intergingival fibers extend along facial and lingual marginal gingiva from tooth to tooth. 8. Fibers that arise from the cemental surface just apical to the base of the epithelial attachment,

traverse the interdental bone, and insert into a comparable position on the opposite tooth; these are transseptal fibers. The transseptal fibers form a ligament between teeth and connect all the teeth in the arch, and are important for the structural integrity of the gingiva tissues.

5.

Panacea for Periodontology8

The various gingiva fiber groups mentioned above are interdependent for function and differ in how they are affected during inflammatory periodontal diseases. For example, portions of transseptal fibers remain unaffected even in advanced stages of periodontitis, and those that are destroyed appear to reform at a more apical level.The gingival collagen fibers, like those fibers of other connective tissue, are made up of heterotypic mixtures of collagen types, of which type I collagen is the major species (Barrold and Narayanan and Page 1983; Narayanan and Bartold 1996).

• Ultra structural studies using collagen type specific antibodies and electron microscopy have shown that these fibers are arranged in two patterns or organization, either as:

○ large, dense bundles of thick fibers, or ○ in a loose pattern of short thin fibers mixed with a fine reticular network (Chavrier et al 1984;

Narayanan et al 1985; Rao et al 1979).

• They contain principally type I and III collagen; type I collagen is preferentially organized into denser fibrils within the lamina propria.

• Although it is not restricted to any particular region, type III collagen appears to be localized mostly as thinner fibers and distributed in a reticular pattern near the basement membrane adjacent to the epithelial junction. (Chavrier et al 1984; Narayanan et al 1985; Romanos et al 1992; Wang et al 1980).

• Gingiva connective tissue contains only small quantities of type V collagen, which, in healthy gingiva, accounts for less than 1% of the total collagen (Narayanan and Page 1983).

• Immunostaining studies have revealed that this collagen distributes throughout the tissues in a parallel filamentous pattern and appears to coat denser fibers composed of type I and III collagens (Narayanan et al 1985; Romanos et al 1991).

• The gingival connective tissue also contains the beaded fibril-forming collagen, type VI, which is present as diffuse microfibrils throughout the lamina propria. (Romanos et al 1991).

Dr. Priyam Mishra 9

Types of gingival fibers

Name of fiber group Origin & orientation Function

Principal groups:

Dentogingival

From cementum, splay laterally into lamina propria

Provide gingival support

Alveologinigval From periosteum of the alveolar crest, splay coronally into lamina

propria

Attach gingiva to bone

Dentoperiosteal From cementum near the cementoenamel junction, into

periosteum of the alveolar crest

Anchor tooth to bone; protect periodontal Ligament

Circular Within free marginal and attached gingiva coronal to alveolar crest,

encircle each tooth (“purse string”)

Maintain contour and position of free marginal gingiva

Transseptal From interproximal cementum coronal to alveolar crest, course

mesially and distally in interdental area into cementum of adjacent tooth

Maintain relationships of adjacent teeth; protect

interproximal bone

Secondary groups: Periostogingival

From periosteum of the lateral aspect of alveolar process, splay into

attached gingiva

Attach gingiva to bone

Interpapillary Within interdental gingiva (gingival papilla), orofacial course

Provide support for interdental gingiva

Transgingival Within attached gingiva, intertwining along the dental arch between and

around the teeth

Secure alignment of teeth in arch

Intercircular From cementum on distal surface of a tooth, splaying buccally and

lingually around adjacent tooth and inserting on mesial cementum of

next tooth

Stabilize teeth in arch

Intergingival Within attached gingiva, immediately subjacent to epithelial basement membrane, course mesiodistally

Provide support and contour of attached Gingiva

Semi-circular From cementum on mesial surface of tooth, course distally, insert on

cementum of distal surface of same tooth

None intuitively obvious

Panacea for Periodontology10

A: Gingival fibers, B: Periodontal ligament fibers, C: Alveolar bone

1.Dentogingival fibers 2. Alveologingival fibers 3. Interpapillary fibers 4. Transgingival fibers 5. Circular and semicircular fibers 6. Dentoperiosteal fibers 7. Transeptal fibers 8. Periostogingival fibers 9. Intercircular fibers 10. Intergingival fibers3

BASEMENT MEMBRANE1

In the gingiva, basement membrane structures separate underlying connective tissues from the gingiva epithelium, from endothelial cells in blood vessels, and from surrounding nerves.

• Between the epithelium and tooth surface, an internal basal lamina serves as the interface through which junctional epithelium is attached to the root surface.

• These basement membranes are similar in biochemical composition to other basement membrane structures, and immunolocalization studies have revealed that type IV collagen and laminin are two major constituents (Chavrier et al 1984; Graner et al 1995, Narayanan et al 1985; Romanos et al 1991a, 1991b, Sawada et al 1990).

• However while both of these molecules are present in the external basal lamina, the internal basal lamina appears to contain only laminin, at least in rats (Graner et al 1995).

• The basal lamina of the epithelium is invested into the underlying connective tissue through anchoring fibrils containing type VII collagen.

• The attachment of epithelial cells to basement membranes and to the tooth surface is mediated via hemidesmosomes.

• The hemidesmosomes contain type XVII collagen (also called bullous permphigoid antigen-2, BAPG-2) and at least two other proteins, BAPG-1, a 230-kd noncollagenous protein, and the integrin α6β4 (Uitto et al 1996).

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