Lecture 1 - Periodontal Anatomy - PDF

Lecture 1 Periodontium: Anatomic Characteristics and Host Response Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. Outline  Periodontal anatomy  Characteristics of a healthy periodontal tissue  Characteristics of a diseased perio...

Lecture 1 Periodontium: Anatomic Characteristics and Host Response Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. Outline  Periodontal anatomy  Characteristics of a healthy periodontal tissue  Characteristics of a diseased periodontal tissue  Host response to periodontal diseases Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 2  Anatomic Characteristics of the Periodontium  The periodontium is defined as the tissues that surround, support, and attach to the teeth.  These tissues include the gingiva, periodontal ligament, cementum, and alveolar bone. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 3 The periodontal ligament attaches to the cementum of the tooth; the root to the alveolar bone of the socket. The collagen fibers of the ligament are grouped into bundles. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 4  Gingiva  Gingiva is described as coral pink, pink, or pale pink. Color is darker when melanin pigmentation is present.  Gingiva is distinguished from the oral mucosa at the mucogingival junction. more loose This line indicates the transition from the loosely attached oral mucosa to the gingiva, which is more firmly attached to the bone by collagen fibers. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 5 What color do you see? document colour: pink (normal) Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 6 What color do you see? colour: red (disease; inflammed) Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 7  What color do you see? colour: pink with melanin pigmentation (normal) can vary between each person Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 8  attached gingiva: firm, more pale, more keratinized Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 9 Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 10  Gingiva (Cont.)  Attached gingiva extends coronally from the mucogingival junction. Width varies from individual to individual and from tooth to tooth.  A thin band of attached gingiva is usually present in the posterior regions.  Palatal attached gingiva blends into the palatal gingiva without demarcation. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 11 Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 12  Gingiva (Cont.)  Frenum and muscle attachments are present in the gingiva. Those located coronally in the attached gingiva are associated with narrow widths of attached gingiva.  Gingiva is keratinized or parakeratinized and is commonly stippled. Nonstippled gingiva is also observed in healthy mouths. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 13  labial frenum more proiment is called diastema causing space between teeth which labial frenum might need surgery Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 14 Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 15  Stippling Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 16  Stippling Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 17  Gingiva (Cont.)  Degree of keratinization varies throughout the mouth. Palatal gingiva is the most keratinized. Cheek mucosa is the least keratinized. NOT keratinized  The tongue is covered with keratinized epithelium. specialized mucosa with taste buds Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 18  Gingiva (Cont.)  The edge of the gingiva next to the teeth, which is referred to as the margin, is 0.5 to 2 mm coronal to the normal health sulcus cementoenamel junction of the teeth. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 19  Gingiva (Cont.)  The free gingiva surrounds the tooth and creates a cuff or collar of gingiva that extends coronally approximately 1.5 mm.  The surface of the free gingiva next to the tooth forms the gingival wall of the sulcus. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 20  Gingiva (Cont.)  The free gingiva surrounds the tooth and creates a cuff or collar of gingiva that extends coronally approximately 1.5 mm.  The surface of the free gingiva next to the tooth forms the gingival wall of the sulcus. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 21 Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 22  Gingiva (Cont.)  The free gingiva is distinguished from the attached gingiva by a free gingival groove. This groove varies from tooth to tooth.  The free gingiva on buccal and lingual surfaces is described as knife edged. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 23 Knife Edge? Rolled? Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 24  Gingiva (Cont.)  The papillae, also called interdental gingivae, are gingivae that fill the embrasures. Embrasures are the proximal spaces below the contact areas of the teeth.  When the papilla is broad, often between posterior teeth, a nonkeratinized area called the col is present. The col is not usually present between anterior teeth.  When adjacent teeth do not contact each other, the papillae and col are absent. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 25  Col Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 26  Gingiva (Cont.)  The gingival epithelium is joined to the underlying connective tissue by a basal lamina.  The fibrils join the basal lamina to the connective tissue.  The connection between the free and attached gingiva and the underlying connective tissue occurs in ridges of epithelium called rete pegs. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 27  Epithelium  The surface tissue of the oral cavity is made up of stratified squamous epithelium. The function of the epithelium is to protect the underlying structures.  The epithelium consists mainly of keratinocytes cells, but it also contains islets of Langerhans, Merkel cells, and melanocytes. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 28  Epithelium (Cont.)  Keratinization occurs as the keratinocyte cells migrate from the basal layer to the surface. The cells flatten, develop keratohyalin granules, and produce a superficial layer in which no cell nuclei are present.  When epithelium shows signs of being keratinized, but the cells retain their nuclei, the epithelium is called parakeratinized epithelium.  If no signs of keratinization are present in the epithelial surface, then the epithelium is considered nonkeratinized. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 29  Epithelium (Cont.) Islets of Langerhans, Merkel cells, and Melanocytes  Islets of Langerhans are part of the phagocytic system. -Immunity  Merkel cells contain nerve endings and are associated with tactile sensitivity. -Sensory  Melanocytes are located in the basal layers of the epithelium and contain substances that convert to melanin. -Pigmentation Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 30  Epithelium (Cont.)  Melanin is phagocytized and remains in the cells of the epithelium, giving a pigmented appearance to the epithelium.  The following figure demonstrates an example of normal gingiva with extensive melanin pigmentation. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 31  Oral or Outer Epithelium outer is made up of epithelium for protection  Oral Epithelium, also called the outer gingival epithelium, is made up of the attached gingiva, the papillae, and the outer surface of the free gingiva. The outer gingival epithelium covers the crest of the gingiva, the free gingiva, and the attached gingiva. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 32  Oral or Outer Epithelium (Cont.)  Rete pegs project into the connective tissue below. The function of rete pegs is protective, and the epithelium is typically parakeratinized. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 33  Sulcular Epithelium inside of gingival sulcus is non keratinized  Sulcular epithelium is the nonkeratinized, or parakeratinized, epithelium that extends from the outer epithelium into the gingival sulcus. Sulcular epithelium may be parakeratinized near the opening to the oral cavity. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 34  Sulcular Epithelium (Cont.)  Sulcular epithelium is found from the height of the gingiva along the inner surface of the sulcus, extending to the junctional epithelium. It forms the gingival wall of the sulcus. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 35  Sulcular Epithelium (Cont.)  Healthy sulcus epithelium is smooth and intact with no rete pegs projecting into the connective tissue.  Gingival crevicular fluid, which is made up of the GCF components of the serum and other cells, is secreted through the sulcular epithelium into the sulcus. different from saliva Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 36  Sulcular Epithelium (Cont.) never write 0.5; round up to 1mm  A healthy sulcus is generally 1 to 3 mm deep. Measuring with a periodontal probe determines the depth.  Probe measurements are subject to variation including: Probe insertion pressure Ability of the probe tip to penetrate tissue Accuracy of the clinician reading the probe measurements Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 37  Sulcular Epithelium (Cont.)  Gingival crevicular fluid, also referred to as sulcular fluid or gingival fluid, flows from the underlying connective tissue into the sulcus.  Gingival fluid: Cleanses the sulcus. Improves epithelial cell adherence to the tooth surface. Has antimicrobial and immune properties. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 38  Junctional Epithelium pdl is never exposed, covered by the epithelium  Junctional epithelium separates the periodontal ligament from the oral environment. It is made up of nonkeratinized stratified squamous epithelial cells that adhere to the tooth structure. Its function is to protect the attachment of the tooth to the surrounding tissues. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 39  Junctional Epithelium (Cont.)  Junctional epithelium forms a layer that is 15 or 20 cells thick at the coronal end and narrowing to a few cells at the apical termination. Length in a healthy state ranges from 0.25 to 1.35 mm.  Fibers from the connective tissue aid the attachment of the junctional epithelium to the root surface. This attachment is called the dentogingival unit. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 40 Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 41  Gingival Connective Tissue  The connective tissue beneath the gingiva is called the lamina propria. The lamina propria is made up of two layers: 1. Papillary layer, which is beneath the epithelium Consists of papillary projections between the rete pegs. 2. Reticular layer, which extends to the periosteum closer to the bone Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 42  Gingival Connective Tissue (Cont.)  Approximately 60% of the lamina propria is made up of connective tissue that is composed of collagen fibrils that form fiber bundles. Other elements of the lamina propria include cells such as fibroblasts, undifferentiated mesenchymal cells, mast cells, and macrophages, as well as blood vessels and nerves. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 43  Gingival Connective Tissue (Cont.)  The fiber bundles are known as the gingival ligament.  Five principal fiber groups and six minor fiber groups make up the gingival ligament.  The gingival fiber bundles provide the most coronal connective tissue attachment for the teeth. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 44  Periodontal Ligament  The periodontal ligament provides a cushion in the space between the surface of the tooth and the bone. The periodontal ligament is a connective tissue primarily filled with fiber bundles and cells.  The cells in the ligament generate a pericementum (periodontal membrane) on the cemental surface of the root and a periosteum (membrane) on the bone. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 45  Periodontal Ligament (Cont.)  Unusual formations of cementum, called cementicles, can also occur in the periodontal ligament. These develop from calcified material in the periodontal ligament or from displaced bits of cementum or bone. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 46  Periodontal Ligament (Cont.)  Functions of the periodontal ligament include: Tooth anchorage Fibrous tissue development and maintenance Calcified tissue development and maintenance Nutritive and metabolite transport Sensory functions, including touch, pressure, pain, and proprioception (displacement sensitivity) Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 47  Fiber Bundles  Fiber bundles in the periodontal ligament are made up of collagen and spread throughout the periodontal ligament.  Fiber bundle functions include: Attaching the tooth to the bone Transmitting occlusal forces to the bone Resisting occlusal forces (“shock absorber”) Protecting the vessels and nerves from injury Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 48  Fiber Bundles (Cont.) Fiber Bundles Table 2-1  The five principal fiber bundles are: Dentogingival radiate from cementum into free gingiva & attached gingiva Alveologingival radiate from periosteum into attached gingiva Dentoperiosteal course from cementum near CEJ, across to alveolar crest Circular encircle entire tooth coronal to alveolar crest Transseptal span interdental space, with ends inserted into the cementum  The fiber bundles are attached to the cementum with brushlike fibers called Sharpey’s fibers. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 49  Fiber Bundles (Cont.)  Secondary gingival fiber groups include: Periostogingival Interpapillary Transgingival Intercircular Semicircular Intergingival  These fiber bundles are small collagen fibers that run in all directions in the periodontal ligament. help the primary fibers Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 50  Physiologic Mesial Migration or Drift  Physiologic mesial migration is normal tooth movement. It allows the dentition to retain balance.  The cells of the periodontal ligament mediate the changes needed in the bone and cementum to permit movement.  Gradual remodeling of the alveolar bone includes: Bone resorption by osteoclasts in response to pressure (push) along the mesial surfaces Bone deposition by osteoblasts in areas of tension (pull) along the distal surfaces too much mobility, teeth flared out due to mesial migration Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 51  Cementum  Cementum is a calcified structure that covers the root surfaces of the teeth. Cementoblasts form cementum. Cementoblasts encased in cementum are called cementocytes. cementum have cells (and the pulp)  Cementum is thinner at the cementoenamel junction and thickens as it progresses to the apex.  Functions of cementum include anchoring the teeth, maintaining occlusal relationships, and occlusion wears providing a seal for the dentinal tubules. anchors the tooth becuase of the fibers Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 52  Cementum (Cont.)  Cementum contains Sharpey’s fibers. Sharpey’s fibers are the embedded portions of the fiber bundles that attach to the roots of the teeth. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 53  Cementum (Cont.)  Hydroxyapatite makes up approximately 50% of the inorganic components of cementum. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 54  Alveolar Process  The alveolar process is an extension of the bone of the body of the mandible and maxilla. very dense (lining of the  The lamina dura lines the sockets of the teeth. socket) - very calcified The socket walls may also be referred to as the cribriform plate. preferrated Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 55  Alveolar Process (Cont.)  Radiographically, the lamina dura appears as a radiopaque line around the roots of the teeth. cannot see the separation of dentin and cementum because of the same opaqueness Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 56  Alveolar Process (Cont.)  The alveolar process is composed of: Alveolar bone, which makes up the cribriform plate encompassing the alveoli and adjacent cancellous bone Compact bone, which makes up the facial and lingual cortical plates of bone Trabecular and cancellous bone between the cortical plates and surrounding the alveoli Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 57  Alveolar Process (Cont.)  The crest of the alveolar process follows the cementoenamel junction of the teeth. It is 2 to 3 mm apical to the cementoenamel junction and 0.5 to 1.5 mm apical to the epithelial attachment to the tooth in the state of periodontal health. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 58  Alveoli  The alveoli are the tooth sockets.  They are lined by the cribriform plate, which has thousands of pores through which the tooth and the periodontal ligament are supplied with nerves and blood vessels.  The bone lining the alveoli contains Sharpey’s fibers. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 59  Compact Bone thick bone  Compact bone makes up the cortical plates on the facial and lingual sides of the jaws.  The alignment of the teeth, angulation of the roots to the bone, and occlusal forces determine the height and thickness of the compact bone. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 60  Cancellous Bone  Cancellous bone lies between the cortical plates and the alveolar bone, connecting them. spongey bone (softer than It is also known as spongiosum. compact bone) - like swiss cheese  Less cancellous bone is found in the mandible than in the maxilla. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 61  Variations in Normal Structure Three variations of the normal bone structure that are nonpathologic and are of importance to periodontal health include: 1. Dehiscence where is goes down Resorbed area of bone over the facial surface of the root Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 62  Variations in Normal Structure (Cont.) like a hole in the bone 2. Fenestration where the root is exposed An opening, or window, in the bone covering the facial surface of a root or a boneless window between two adjacent roots that almost touch between the root - means the teeth is too close (roots are almost touching) can cause some problem Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 63  Variations in Normal Structure (Cont.) 3. Root proximity Occurs when: Teeth erupt with roots that are very close together. Teeth are poorly aligned. Multirooted teeth are unusually and widely spread out. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 64  Attachment Apparatus  The periodontal ligament, cementum, and alveolar bone are referred to as the attachment apparatus. main attachment where it’s occuring Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 65  Blood Supply  Branches of the inferior and superior alveolar arteries provide blood supply to the periodontium. Superior alveolar artery supplies the maxilla. Inferior alveolar artery supplies the mandible.  Branches of these vessels extend into the central alveolar bone, over the periosteum, and terminate in the periodontal ligament.  Other branches lay along the surface of the alveolar bone, terminating in capillary loops in the gingival connective tissue next to the epithelium. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 66  Nerve Supply 5th cranial nerve: Trigeminal nerve  Nerve supply is from the trigeminal nerve.  Branches of the nerves terminate in the periodontal ligament, the connective tissue, and on the surface of the alveolar bone.  Nerve endings receive stimuli for pain (nociceptors) and position and pressure (proprioceptors). maxillary, mandible, ?? Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 67  Clinical Condition of the Periodontal Tissues  Assessing gingival structures determines the clinical signs of health or disease of periodontal tissues.  Descriptions include the color, size, shape (or contour), texture, and consistency of the gingiva. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 68  Color  Healthy gingiva is light pink or coral pink. The vascular supply, the thickness and degree of keratinization, and the presence of melanin produce variations in color.  The mucogingival junction should be a clearly demarcated line.  The alveolar mucosa should be bright red and shiny. It should blend without demarcation into the vestibule or floor of the mouth. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 69  Color (Cont.) can be localized  Melanin is the product of melanocytes in the gingiva. Melanin is observed more often in Black and Asian individuals than in people of Caucasian descent.  Melanin pigmentation is a normal variation in the color of the gingiva. smoking, hormonal changes, jaundice, carotenemia (excessive Vitamin E), pink tooth, erythroblastosis fetalis, purpura (decrease in platelets) can cause pigmentation/change the colour Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 70  Texture  Healthy free gingiva should be smooth. and shiny  Attached gingiva should be stippled, resembling an orange peel. can be present anywhere but more prominent on attach gingiva Stippled gingiva should have a matte appearance when dried. absence of stipping doesn’t mean disease, check for stipping need to dry area with gauze still inflammed Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 71  Texture (Cont.)  Stippling reflects protuberances of connective tissue into the epithelium, called rete pegs. connective tissue is called papillae Both stippled and nonstippled gingiva are keratinized.  Stippling varies with age. Stippling appears in children at approximately 5 years of age, increases in adulthood, and becomes less pronounced in the older adult. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 72  it can be slightly Size swollen, doesn’t have to increase in size  The presence or absence of swelling or other enlargement determines the gingival size.  Inflamed gingiva swells and appears shiny, and stippling is lost. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 73  Shape or Contour scalloped - the pattern is follows  Marginal gingiva follows a scalloped line around the crowns of the teeth and lies flat to the tooth. Is referred to as knife edged.  Papillae should fill the interdental spaces. papillary region The shape, size, and position of the teeth and the relationship of the tooth contact areas influence the scalloped pattern - knife edged margin contour. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 74  “Shapes” of PAPILLA knife edge - is touching the tooth  Knife-edged, pointed  Edematous enlargement - slight jetting out  Blunt(ed) not pointed, more flat (gone down) - not the margin  Bulbous enlargement - bulbing out enlargement These are adjectives (clues) to describe the papilla - Will help you determine the health or disease of the gingiva…. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 75  spacing (slightly blunted) papillae is edematous Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 76  Consistency  Consistency, or tone, of healthy attached gingiva is firm and resilient when gently touched with the back of an instrument.  Free gingiva should also be firm in texture, not soft or spongy. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 77  Sulcus Depth  Normal sulcus depth, when measured by a periodontal probe, is 1 to 3 mm. should be soft  The sulcular epithelium is intact in the healthy state, not ulcerated, and should not bleed on gentle probing. bleeding flossing or brushing (not normal) - too hard, no proper technique OR result of unhealthy gingiva amount of recession measurement from CEJ to gingival margin Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 78 facial (3 readings) and lingual (3 readings) (use calibrated probe) to measure recession Healthy? reduced periodontium (more recession (not normal) common in gingiva, sometimes in bone) Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 79  Aging and the Healthy Periodontium root carries can only happen when the root is exposed (common in older patients) - board exam  Age-related changes that occur in the periodontium recession can occur due to many factors but include: mainly periodontal disease (common amongst older patients) but old age does NOT cause Thinning gingiva recession - periodontal disease is more common in seniors Decreased keratinization of the epithelium Flattening of the rete pegs More dense connective tissue Periodontal ligament with a more irregular structure Thickened cementum Alveolar bone with a less regular surface Less orderly insertion of collagen fiber tissue looks more pale in older patients Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 80  Host Response  The immune system is responsible for the body’s reaction, which is called the host response. Immunology is the study of the immune system and the host response.  Development of disease in the periodontium depends on two factors: 1. Microbial assault from dental plaque biofilms 2. Host response not everyone gets a disease - two people who have the same growth will not receive the same response - main factor is host response Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 81  Host Response (Cont.)  When microbes assault, the cells in the host form an inflammatory reaction. infection can cause inflammation  Inflammation is protective in that it leads to the destruction of bacteria; however, it can also lead to tissue alteration and destruction in the host periodontal tissues.ifdestruction reaction in the body is excessive it can lead to tissue (periodontal disease) Inflammation may lead to irreversible changes in the periodontium, which is known as periodontal disease. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 82  Host Response (Cont.)  The inflammatory response includes: Inflammatory cells Antibody reactions Antigen reactions Complement reactions Hypersensitivity (allergic) reactions Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 83  Inflammatory Cells WBC  Inflammatory cells migrate to areas of the body when signaled by stimuli such as microbial influences. chemotaxis - when there is an infection, the immune cells will come to the area and it will act This process is called chemotaxis.  In periodontal diseases, the inflammatory cells are attracted to the gingiva, connective tissue, periodontal ligament, and bone. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 84  Inflammatory Cells (Cont.)  The function of the inflammatory cells is to: Ingest and neutralize bacteria, which is called phagocytize. phagotcytosis - engulfing Secrete products that affect the permeability of blood vessels. Cause cell disintegration, which is referred to as lysis. Cause destruction of alveolar bone by inducing osteoclastic activity. destroying cells - osteoclasts Divide to increase their numbers in a process called blastogenesis. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 85  Lymphocytes  Lymphocytes recognize and react to foreign molecules. Foreign molecules are termed antigens.  Macrophages gather up antigens and present them to the lymphocytes for their destruction. destruction of bacteria  Lymphocytes retain a memory of a specific antigen and will recognize it months or years later. will heal faster Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 86  Polymorphonuclear Leukocytes  Polymorphonuclear leukocytes (PMNs), also called neutrophils, are attracted to periodontal lesions, particularly acute lesions, through chemotaxis. PMNs make up approximately 70% of the leukocytes.  PMNs phagocytize (digest) microorganisms, and they contain destructive substances that are extremely important in periodontal infections. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 87  Polymorphonuclear Leukocytes (Cont.)  PMNs contain granules that are filled with enzymes such as collagenase or elastase.  These enzymes are released and cause tissue destruction when the PMN cells degranulate.  Abnormalities in PMNs can lead to more severe periodontal disease if the cells are unable to perform their functions or lack specific granules. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 88  Mast Cells  Mast cells mediate the inflammatory response.  Their stimulation results in increased vascular permeability, which advances the inflammatory response. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 89  Macrophages  Macrophages are scavenger cells. They engulf and digest bacteria.  Macrophages produce enzymes and other substances that play a significant role in collagen destruction, which leads to the loss of periodontal tissues. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 90  Auxiliary Cells  Many auxiliary cells, such as basophils, eosinophils, and platelets, become involved in the immune response. They react to cytokines, which are released by the lymphoid cells and phagocytes.  Basophils contain histamine. Histamine mediates hypersensitivity (allergic) reactions but may also enhance collagen destruction and bone resorption.  Eosinophils and platelets also produce a variety of mediating substances. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 91  Effector Molecules  The human body responds to tumor cells, bacteria, or their products by producing antibodies, which are also called immunoglobulins.  The process involves the following: 1. Antigens are recognized. 2. Effector molecules are stimulated. Many effector molecules are present in the immune system. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 92  Antibody innate and acquired  Antibody production involves the following: 1. Macrophages process the antigen. 2. Macrophages then present the fragments to T cells, which interact with B cells. 3. B cells differentiate into plasma cells, which produce the antibodies.  Antibodies are found in the blood, tissue fluids such as gingival fluid, and secretions. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 93  Antibody (Cont.)  Antibody responses play an important role in periodontal diseases.  The extent of the antibody response is positively related to the severity of the disease. The antibody response diminishes when the disease is treated. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 94  Cytokines  Cytokines are substances produced by stimulated immune cells.  They assist in the development and regulation of immune effector cells, such as increasing the number of T cells to multiply their effects; they cause cell-to- cell communication and are, themselves, effector molecules.  Cytokines have effects on all cells of the immune system and play a major role in both the pathogenesis of disease and healing. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 95  Hypersensitivity (Allergic) Reactions  Hypersensitivity (allergic) reactions are responses to foreign bacteria, viruses, or other substances.  Four types of hypersensitivity reactions are: 1. Type I—anaphylactic 2. Type II—cytotoxic autoimmune diseases 3. Type III—immune complex-mediated 4. Type IV—cell-mediated (delayed) Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 96  Hypersensitivity (Allergic) Reactions (Cont.)  Types I, II, and III are immediate reactions and occur within minutes or hours. Types I, II, and III are the more likely hypersensitivity reactions that affect the periodontal tissues.  Type IV reactions are delayed and can occur days later or beyond. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 97  Anaphylactic Reaction—Type I  In type I (anaphylactic) reactions, histamine is released.  The response can be generalized or localized. Generalized reaction can be life threatening (e.g., food or drug allergies). Localized reaction can result in increased tissue destruction (e.g., the periodontium).  Histamine is found in higher concentrations in chronically inflamed gingiva. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 98  Cytotoxic Reaction—Type II  In type II (cytotoxic) reactions, antibodies react directly to antigens. Type II reactions result in the breakdown of tissue or blood cells.  Cytotoxic reactions are not observed in gingival or periodontal diseases, but these reactions may be observed in areas where antibodies react directly with epithelial cell membranes, such as in pemphigus. immune related disease Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 99  Immune Complex-Mediated (Arthus) Reaction—Type III  In type III (immune complex-mediated) (Arthus) reactions, high levels of antigen persist in an area without being eliminated.  This type of reaction occurs around small blood vessels, activates complement, and can cause extensive localized tissue damage.  An example of a type III reaction is the response observed in skin tests for tuberculosis. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 100  Cell-Mediated or Delayed Reaction—Type IV  In type IV (cell-mediated) reactions, the reaction of antigens with the surface of T lymphocytes are related to this type of hypersensitivity.  Once sensitized to an antigen, these lymphocytes can undergo blastogenesis (transformation), resulting in mitotic division and greatly increasing the number of immunocompetent (reactive) cells sensitized to the specific antigen. delayed reaction to certain chemicals  These reactions explain why, on a second exposure to an allergic agent such as a beesting, the reaction can be greatly increased and possibly become life threatening. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 101  Other Protective Responses in the Oral Environment  Oral epithelium acts as a barrier to mechanical and microbial assault.  The presence and amount of gingival fluid and saliva affect the interface between the surface of the tissues and the host.  Oral epithelium and saliva play a protective role in the host. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 102  Gingival or Sulcular Fluid  Gingival or sulcular fluid increases with normal physiologic functions, such as mastication of foods, toothbrushing, increases in female sex hormones, and smoking, as well as after periodontal surgery.  Sulcular epithelium permits the migration of molecules into the gingival sulcus, resulting in fluid containing enzymes, cellular elements, electrolytes, and compounds such as glucose.  Leukocytes, white blood cells (primarily PMNs), make up approximately 92% of the cellular content of the fluid. Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 103  Saliva  Saliva provides protective influences that include: Lubrication Physical protection Cleansing Buffering reduce acidity Remineralization of teeth Antibacterial actions Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 104  Saliva (Cont.)  An increased incidence of both caries and periodontal diseases is also observed in individuals who have xerostomia (reduced salivary function). Copyright © 2014, 2007, 2001, 1996 by Saunders, an imprint of Elsevier Inc. 105