1. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 1 Chapter 20 Unit 3 Oral Pathology

2. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 2 Oral Pathology Defined as the study of oral diseases, their causes ( if known), and their effects on the body.

3. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 3 Oral Pathology Terms Antigenic –Capable of causing the production of an antibody Palpate –Feel with fingers Biopsy –Removal of a small amount of tissue surgically Etiology –Cause of the disease

4. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 4 Inflammation Process of inflammation- how body responds to disease and injury –Redness (erythemia) –Heat –Swelling (edema) –Pain

5. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 5 Inflammation Histamine –Brings about the inflammation process –Increases blood flow to the involved area Causes redness and heat –Stimulates nerve endings Causes pain –Attracts white blood vessels Destroys microorganisms and aids healing

6. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 6 Oral Lesions Lesions classified above the surface of the oral mucosa Lesions classified below the surface of the oral mucosa Lesions classified even or flat with the surface of the oral mucosa Lesions classified flat or above the surface of the oral mucosa

7. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 7 Lesions Classified Above the Surface of the Oral Mucosa Blister is a raised area, usually oval or circular in shape, that is fluid filled. –This fluid leaks from the blood vessels to underlying layers of skin following some type of trauma such as burn, friction, or disease. –This fluid also protects the damaged tissue.

8. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 8 Lesions Classified Above the Surface of the Oral Mucosa Bulla is a large (greater than one-half inch in diameter), fluid-filled blister. Papule is a small (less than one-half inch in diameter), solid, raised area of skin. –The surface of the papule may be pigmented in color and either smooth or bumpy in texture.

9. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 9 Lesions Classified Above the Surface of the Oral Mucosa Plaque is any raised or flat patch in the oral mucosa. This term is not to be confused with dental plaque. Pustule is a small, pus-containing blister. –A person may see a pustule during noninfective acne. –A pustule at the end of an eyelash follicle is a stye. Vesicles are small, fluid-filled blisters.

10. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 10 Lesions Classified Above the Surface of the Oral Mucosa Hematoma is a lesion caused by bleeding from a ruptured blood vessel, which appears as a raised bruised area due to the collection of localized, clotted blood. –Dental assistants should watch for a hematoma after oral anesthetic. –Even the best clinicians may nick a blood vessel during an injection, resulting in hematoma. –The dental assistant alerts the dentist about the condition and then applies pressure to the area to disperse the blood in the tissue, which alleviates the pressure.

11. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 11 hematoma

12. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 12 Lesions Classified Below the Surface of the Oral Mucosa Abscess is a concentrated area of pus formed as a result of infection by microorganisms. –Dental abscesses are periapical (at the end of the tooth) or periodontal, caused by microorganisms invading the membrane of the tooth.

13. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 13 Periapical Abcess

14. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 14 Lesions Classified Below the Surface of the Oral Mucosa Cyst is a fluid or semisolid fluid-filled sac. The causes of cysts are numerous. –In dentistry, cysts normally occur as a result of a duct leading from a fluid-forming gland becoming blocked. –Cysts can develop around the crown of an undeveloped tooth prior to eruption.

15. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 15 Cyst

16. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 16 Lesions Classified Below the Surface of the Oral Mucosa Erosion is the defect left from a trauma or an injury. –It may arise from a person biting the cheek. –The margins of the cheek erosion are red and painful. Ulcer is due to destruction of the mucous membrane and appears as an open sore on the tissue. –The ulcer may appear shallow or crated deeply and is normally inflamed and painful.

17. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 17 Lesions Classified Even or Flat with the Surface of the Oral Mucosa Ecchymosis is a medical term for bruising of the tissue. Macule is a spot of different texture or color on the skin. Patch is an area of skin that appears differently either in color or texture.

18. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 18 Lesions Classified Even or Flat with the Surface of the Oral Mucosa Petechiae are small spots, red or purple in color, that occur in the skin or mucosa tissue. –They are caused by localized hemorrhage.

19. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 19 Lesions Classified Even or Flat with the Surface of the Oral Mucosa Purpura is caused by bleeding within underlying tissues. –These purplish or reddish brown areas or spots of discoloration can range in size from the diameter of a pinhead up to one inch. –Small purpura normally are referred to as petechiae, and the larger ones are called ecchymoses, or bruises.

20. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 20 Lesions Classified Flat or Above the Surface of the Oral Mucosa Granuloma is associated with chronic inflammation and appears as a neoplasm or tumor that is filled with granulation tissue. –The suffix -oma refers to neoplasms or tumors.

21. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 21 Lesions Classified Flat or Above the Surface of the Oral Mucosa Neoplasm is the medical term for tumor. –This new, abnormal growth that serves no usefulness can be either malignant (life threatening) or benign (non–life threatening). Nodule is a small lump of tissue, either hard or soft, that is usually more than one- quarter inch in diameter. –A nodule may either protrude from the tissue or form beneath the surface of the tissue.

22. Copyright © 2004 by Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED. 22 The End