Chapter Two

1. Chapter Two Vocabulary-please study and learn on your own

2. Injury • Injury - an alteration in the environment that causes tissue damage • Physical injury can affect teeth, soft tissue, and bone. • Chemical injury can occur from the application of caustic materials to oral tissues. • Microorganisms can cause injury by invading oral tissues • Nutritional deficiencies can render oral tissues more susceptible to injury from other source.

3. Natural Defenses Against Injury • Skin • Mucosa • Enzymes in saliva • Tears • Flushing action

4. Inflammation • Nonspecific response to injury • Local or systemic • Acute or chronic • Acute inflammation - short, lasting only a few days • Chronic inflammation - lasts weeks, months or indefinitely

5. Inflammatory Response • Dynamic process which is continually changing • Transitional stages exist during which the response is changing from one type of inflammation to the next • Acute may be superimposed over a chronic inflammatory response • Repair occurs only if source of injury is removed

6. “itis” • “itis” combined with the name of the tissue denotes inflammation of that tissue • Gingivitis • Periodontitis - Pericoronitis

7. Microscopic and Clinical • Clinical signs of inflammation…classic signs • Fever • ↑ # white blood cells (leukocytosis) • Enlargement of lymph nodes (lymphadenopathy)

8. Sequence of Microscopic Events • Injury to tissue • Constriction of the microcirculation • Dilation of the microcirculation • Increase in permeability of the microcirculation • Exudate leaves the microcirculation • Increased blood viscosity • Decreased blood flow through the microcirculation • Margination and pavementing of white blood cells • White blood cells escape the microcirculation and enter tissue • White blood cells ingest foreign substances

9. Hyperemia • Responsible for two clinical signs of inflammation • Erythema • Heat --↑permeablility of microcirculation→ exudate

10. Exudate • Serous - composed of plasma fluids • Purulent - (suppuration) contains tissue debris and many white blood cells in addition to plasma fluids and proteins • Fistula - a passage for drainage

11. Cells involved in the acute inflammatory response Emigration and chemotaxis of WBC’s (leukocytes) • Neutrophils (PMN’s) - 1st to arrive • Monocytes or macrophage - 2nd • Lymphocytes • Plasma cells • Eosinophils • Mast cells

12. Neutrophils • 60-70 percent of WBC • Main function is phagocytosis • Multilobed nucleus

13. Monocytes • Macrophage - responds to chemotactic factors • Is capable of phagocytosis • mobile

14. Chemical Mediators • Can start or amplify response • Kinin System- ↑ permeability of local blood vessels & induces pain • Clotting Mechanism • Clotting – important to repair • Complement System • Sequential cascade of plasma proteins • Cause mast cells to release histamine • Other components cause cytolysis

15. Other Chemical Mediators • Prostaglandins • ↑ vascular dilation and permeability Tissue pain, redness, changes in connective tissues Lysosomal enzymes endotoxin

16. NSAIDS • Aspirin • Ibuprofen • Naproxen • Celecoxib • Prednisone - steroid

17. Systemic Manifestations • Fever • Leukocytosis-↑WBC’s • Lymphadenopathy - enlarged palpable lymph nodes • ↑ in the # of cells = hyperplasia • Enlargement of individual cells = hypertrophy

18. Regeneration and Repair • Regeneration - damage is slight and inflamed area returns completely to normal • Repair - damage is too great for return to normal…final defense mechanism

19. Microscopic events in repair • Day of injury - Clot forms - One day after injury - neutrophils emigrate and phagocytosis begins - Two days after injury – macrophages -granulation tissue formation

20. Seven days • Fibrin • Surface remains red • If source of the injury has been completely removed the inflammatory and immune response in nearly complete

21. Types of Repair • Primary Intention-clean edges of lesion joined with sutures and have very little granulation • Secondary Intention-tissue has been lost, cannot be joined. Scar tissue forms and normal tissue function is decreased • Tertiary intention-infection occurs in a site that was healing by primary intention…the infection causes tissue damage and secondary intention healing begins • Bone tissue repair - osteoblasts form bone

22. Injuries to Teeth • Group one - explain different injuries to teeth • Attrition • Bruxism • Abrasion • Abfraction • Erosion

23. Injuries to Oral Soft tissues • Group two: explain injuries to soft tissues • Aspirin burn • Phenol burn • Electric burn • Other burns

24. Lesions • From self-induced injuries – habits of patient Examples: Chronic lip, cheek, or tongue biting; scratching with fingernail • May range from ulceration to epithelial hyperplasia and hyperkeratosis • --hyperplasia= an enlargement of a tissue or organ resulting from an increase in the number of normal cells • --hyperkeratosis = excessively thickened layer of the stratum corneum composed of orthokeratin (hyperorthokeratosis) or parakeratin (hyperparakeratosis)

25. Hyperkeratosis • Excessively thickened layer of the stratum corneum composed of orthokeratin (hyperorthokeratosis) or parakeratin (hyperparakeratosis). • Thickened keratin layer (para - nuclei present, ortho - no visible nuclei)   organized connective tissue layer -  possible to have inflammatory reaction in connective tissue due to irritation -  normal maturation of epithelial cells   no evidence of dysplasia

27. Lesions Associated with cocaine use • See figure 2-26, page 54 • May be keratotic, ulcerative, or exophytic reactive lesions. • Exophytic - an outwardly growing lesion

28. Hematoma • A large ecchymosis or bruise caused by the escape of blood into the tissues • Hematomas are blue on the skin and red on the mucous membranes • As hematomas resolve they may turn brown, green, or yellow • Ecchymosis - large reddish-blue areas caused by the escape of blood into the tissues, commonly referred to as a bruise. Does not blanch on diascopy

29. Traumatic Ulcer • Can be caused by removing a dry cotton roll, tooth brushing • If persistent may result in traumatic granuloma • Granuloma - a tumor-like mass of inflammatory tissue consisting of a central collection of macrophages, often with multinucleated giant cells, surrounded by lymphocytes

30. Frictional Keratosis • A thickening of the keratin caused by rubbing friction) • Not associated with malignancy • Identification of the trauma is a key element in the diagnosis • May take a while for the “callous” to disappear

31. Linea Alba

32. Nicotine Stomatitis • A diffuse change of the palatal and/or buccal mucosa caused by a combination of hyperkeratosis and acanthosis, frequently containing multiple small dimpled nodules • Observed in heavy smokers, especially pipe smokers

33. Nicotine Stomatitis

34. Tobacco Pouch Keratosis • Altered mucosa that resembles a "pouch" due to the chronically stretched tissue in the area of the placement of smokeless tobacco

35. Traumatic Neuroma • Lesion caused by injury to a peripheral nerve • Nerve tissue is encased in sheath composed of Schwann cells and their fibers • When sheath is injured the proximal end of the nerve proliferates into a mass of nerve and Schwann cells mixed with dense fibrous scar tissue

36. Amalgam Tattoo • Oral soft tissue discolorations due to amalgam • Most common pigmentation of the oral cavity

37. Melanosis • Disorder of increased melanin pigmentation that develops without preceding inflammatory disease • Characterized by abnormal deposits of melanin (especially in the skin)

38. Solar Cheilitis • Also called Actinic Cheilitis (see Figures 40:1 & 40:2 in atlas) • Clinical lesion of the lower lip caused by excessive solar radiation damage • Older, fair-skinned men with outdoor occupations are typically affected • Considered a precancerous condition • Clinicians should warn the patient of the likelihood of disease progression

39. MucoceleMucous Retention CystMucous Retention Phenomenon • Forms when minor salivary gland duct is disrupted and mucous salivary gland secretion enters the adjacent connective tissue • Most common on lower lip • Size may decrease over time • Minor salivary glands • See pages 97 & 100 in atlas

40. Ranula • A mucocele-like lesion that forms unilaterally in the floor of the mouth • Rana=frog • Treated by surgery and cause of obstruction is removed • Associated with the ducts of the sublingual and submandibular glands

41. Objective • Describe the difference between a mucocele and a ranula

42. Necrotizing Sialometaplasia • Benign condition of the minor salivary glands characterized by moderately painful swelling an ulceration in the affected area • Thought to result from blockage of the blood supply to the area

43. Sialolith • A salivary calculus • There are many causes of salivary gland enlargement unrelated to neoplasms. Sarcoidosis, mumps, malnutrition, iodine therapy and hepatic cirrhosis, to name a few, are well-recognized causes for major salivary gland enlargement. The probable autoimmune conditions -- Mikulicz's disease and Sjogren's syndrome are additional significant causes of salivary gland disease. • Probably the most common and the one most relevant to the dental practitioner is sialadenitis (inflamation) secondary to duct obstruction. Although major salivary gland ducts are obstructed by strictures, scar formation and tumor involvement, the presence of an occluding sialolith represents the most frequent etiology.

44. Sialolith

45. Objective • Define sialolithiasis • The presence of salivary gland or duct stones

46. Sialadenitis • Inflammation involving the salivary glands • Causes: trauma, surgery, infection, mumps • Acute sialadenitis - relatively short duration - caused by trauma • Chronic sialadenitis - long, slow course

47. Glandular Odontogenic Cyst (Sialo-Odontogenic Cyst) • Usually anterior mandible with slow locally destructive progressive enlargement • Usually painless     • Usually in middle-aged adults

48. Glandular Odontogenic Cyst (Sialo-Odontogenic Cyst) • well-defined unilocular or multilocular radiolucency with scalloped borders

49. Pyogenic Granuloma • Fast-growing reactive proliferation of endothelial cells commonly on the gingiva and usually in response to chronic irritation.

50. Granuloma • A tumor-like mass of inflammatory tissue consisting of a central collection of macrophages, often with multinucleated giant cells, surrounded by lymphocytes