Bone loss and pattern of bone destruction .pptx

bone loss and pattern of bone destruction

1. BONE LOSS AND PATTERNS OF BONE DESTRUCTION DR DEEPTHI CHERIAN DEPT OF PERIODONTICS

2. Introduction Although periodontitis is an infectious disease of the gingival tissue,changes that occur in bone are crucial because the destruction of bone is responsible for tooth loss. Height and density of the alveolar bone are normally maintained by an equilibrium, regulated by local and systemic influences ,between bone formation and resorption. Resorption >formation-bone height and density reduced. Degree of bone loss not related with pocket depth or ulceration on pocket wall or presence or absence of pus.

3. Causes of bone destruction Bone destruction caused by the extension of gingival inflammation. Bone destruction caused by trauma from occlusion Bone destruction caused by systemic disorder

4. Bone destruction caused by gingival inflammation Most common cause-Extension of inflammation from the marginal ginigiva into supporting periodontal tissues.

5. Histopathology Gingival inflammation extends | Collagen fibre | Follows course of blood vessel through loosely arranged tissues around them | to alveolar bone.

6. Interproximally : Gingiva -> bone Bone -> PDL Gingiva -> PDL Facially & lingually Gingiva -> outer periosteum Periosteum -> bone Gingiva -> PDL

7. RADIUS OF ACTION

8. BONE DESTRUCTION CAUSED BY TRAUMA FROM OCCLUSION Periodontal response to the external force. TFO can occur in presence or absence of inflammation. Absence -> osteoclasts

9. When combined with inflammation, i.e. ZONE OF CO-DESTRUCTION, Aggrevate bone destruction caused by inflammion Result in Bizzare pattern

10. BONE DESTRUCTION CAUSED BY SYSTEMIC DISORDERS - Possible relationship between periodontal bone loss and systemic disorders. OSTEOPOROSIS : loss of bone mineral content and structural bone changes. Risk factors- aging,smoking,etc •OSTEOPENIA : tooth mobility and tooth loss •Hyperparathyroidism, leukopenia

11. FA CTORS DETERMINING BONE MORPHOLOGY IN PERIODONTAL DISEASE- 1)Normal variation of alveolar bone : a)thickness,width,crestal angulation of interdental septa b)thickness of facial & lingual plates c)presence of fenestrations & dehiscences d)allignement of teeth e)root anatomy and position

12. Exostoses : a)overgrowth of bone b)they can occur as small or large nodules, sharp ridges , spike-like projections.

13. TFO : a)thickening of cervical margin of alveolar bone. b)angular defects or buttressing bone.

14. BUTTRESSING BONE FORMATION - attempt to buttress the bone subjected to resorption. Central and peripheral buttressing bone formation. e)results in bulbous bone contours( lipping ).

15. FOOD IMPACTION : a)interdental bone defects occur when there is abnormal or absence of proximal contact. b)food impaction here , results in inverted bone architecture. AGGRESSIVE PERIODONTITIS : vertical or angular bone defects. Arc shaped

16. BONE LOSS PATTERN Horizontal Vertical or angular defects Osseous craters Bulbous bone contours Reverse architecture Ledges Furcation involvement

17. Horizontal bone loss a)most common pattern b)bone height reduced, but margin remains perpendicular to tooth surface.

18. Vertical bone loss a)angular defects , occur in an oblique direction leads to hollowed-out trough in the bone alongside root. b)Depending on number of walls present , angular defects were classified by Goldman and Cohen (1958) as, ( i ) Three osseous walls (ii)Two osseous walls (iii)One osseous wall (iiii)Combination

19. Osseous craters a)concavities in the crest of interdental bone confined within faciolingal walls. b)Reasons : (i)plaque accumulation and difficulty to clean. (ii)normal concavity in lower molars (iii)vascular patterns crest, a pathway for inflammation

20. B ULBOUS BONY CONTOURS : a)bony enlargement b)an adaptation to Exostoses c)adaptation to function or buttressing bone formation.

21. R EVERSED ARCHITECTURE : produced by loss of interdental bone, facial and lingual plates without concomitant loss of radicular bone.

22. L EDGES : (a)plateau-like bony margins (b)caused by resorption of thickened bony plates

23. F URCATION INVOLVEMENT : Invasion of bifurcation or trifurcation of multirooted teeth by periodontal disease. Classification - (i)Grade 1 : incipient bone loss (ii)Grade 2 : partial bone loss (iii)Grade 3 : total bone loss with through and through opening of furcation (iiii)Grade 4 : similar to grade 3,with gingival recession exposing the furcation to view.

24. Patterns of bone destruction Reverse architecture Furcation involvement