BONE LOSS&PATTERNS OF BONE DESTRUCTION BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Most common cause Periodontitis is always preceded by gingivitis Not all gingivitis progress to periodontitis

BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Advancedcases: no.of motile organism&spirochetes se where as coccoid rods &straight rods se Fibroblast&lymphocyte se in stage I gingivitis No. of plasma cells&blast cells ses gradually T-lymphocyte predominate(contained gingivitis)

BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd…. Extension of inflammation supporting tissue modified pathologic potential plaque Resistance of the host Degree of fibrosis of gingiva Width of attached gingiva Fibrogenesis&osteogenesis

BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd…. HISTOPATHOLOGY Inflammation extends through collagen fibers Loosely arranged tissue around alveolar bone Inflammatory infiltrate concentrated in the marginal periodontium&results crestal resorption/loss of attachment

BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd….

BONE DISTRUCTION DUE TO GINGIVAL INFLAMMATION Contd…. inflammation bone marrow spaces replaces by leucocyte+fluid exudate,new blood vessels&proliferating fibroblast multinuclear osteoclast&mononuclear phagocytosis &bone surface (hawship lacunae)

RADIUS OF ACTION Locally produced bone resorption factors may have to be present in the proximity of the bone surface to be able to exert their action(Grant&Cho) Plaque can induce bone loss within 1.5-2.5mm beyond 2.5mm there is no effect(Waerhaug’s measurement) I/P angular defects can appear in spaces wider than 2.5mm

RATE OF BONE LOSS Acc to Loe&co-workers 8% severe periodontal diseases,yearly loss of attachment 0.1-1mm 81%moderate periodontitis,CAL 0.05-0.5mm 11%mild Periodontitis, 0.05-0.09mm

PERIOD OF DESTRUCTION Loss of collagen&alv bone with deepening of periodontal pocket Theories… Bursts of destructive activity associated with subgingival ulceration Brusts of distructive activity coincide with conversion of T B lymphocyte-plasma cells Period of exacerbation associated with *increaseof loose,unattached,motile,gm-ve,anaerobic pocket flora.Periods of remission coincide with the formation of *dense,unattached,nonmotile,gm-positive flora with a tendency to mineralize. 4.Tissue invasion by one/several bacterial species is followed by an advanced local host defence

MECHANISM OF BONE DESTRUCTION Bacterial & Host mediated factor Bacterial plaque bone progenitor cells mediators gingival cells osteoclasts Host induced factor(prostaglandin&their precursors,IL-1alpha&beeta,TNF-alpha)inducing bone resorption(in vitro) NSAID such as ibuprofen inhibit PGE-2 production slowing bone loss

BONE FORMATION IN PERIODONTAL DISEASE Areas of bone formation are also found immediately adjacent to active bone resorption The response of alveolar bone to inflammation includes bone formation &resorption New bone formation retards the rate of bone loss,compensating in some degree for the bone destroyed by inflammation

BONE DESTRUCTION CAUSED BY TRAUMA FROM OCCLUSION TFO caused destruction in the +ce/-ce of inflammation In the absence of inflammation: se compression &tension of the PDL& se osteoclasis of alv bone to necrosis of PDL &bone & resorption of bone & tooth st. Persistent TFO funnel shaped widening of the crestal portion of the PDL with resorption of the adjacent bone With inflammation TFO aggravates the bone destruction & causes bizarre bone patterns

BONE DESTRUCTION CAUSED BY SYSTEMIC DISORDER Bone factor in periodontal disease: systemic influence on the response of alv bone (Irving Glickman 1950) Bone factor is not in current use The possible relationship between periodontal bone loss&osteoporosis,osteopenia,hyperparathyroidism, leukemia or langerhans’cell histiocytosis

FACTORS DETERMINING BONE MORPHOLOGY IN PERIODONTAL DISEASE Normal variation in Alveolar bone Exostoses Trauma from occlusion Buttressing Bone formation(Lipping) Food Impaction Aggressive Periodontitis

BONE DESTRUCTION PATTERNS IN P.DISEASES Horizontal bone loss Osseous defects Vertical/Angular defects

VERTICAL/ANGULAR DEFECTS

BONE DESTRUCTION PATTERNS IN P.DISEASES Contd Osseous Craters o.c. Bulbous Bone Contours Reverse Architecture

BONE DESTRUCTION PATTERNS IN P.DISEASES Contd Ledges Furcation Involvements

MCO-1 Which of the following is related with advanced stage of periodontal diseases Fibroblast and lymphocyte predominate No.of plasma cells and blast cells decreases gradually in C.T. No.of motile organism and spirochete decreases No.of coccoid rods and straight rods decreases

MCQ-2 On interproximal surface of tooth ,the pathways of inflammation from gingiva to supporting structures in periodontitis is (a) Bone to gingiva (b)Periodontal ligament to bone (c)Gingiva to periodontal ligament (d) Periosteum to bone

MCQ-3 Which is one of the following have better prognosis of periodontal regeneration (a)One walled defect (b)Two walled defects (c)Three walled defects (d)Horizontal defects

MCQ-4 According to Waerhaug’s concept the bacterial plaque can induce loss of bone in a range of (a)1.0-1.5mm (b)1.5-2.5mm (c)2.5-3.5mm (d)3.5-4.5mm

MCQ-5 What are the changes can be observed in the periodontal ligament due trauma from occlusion Widening of periodontal ligament Thinning of periodontal ligament Necrosis of periodontal ligament Shortening of periodontal ligament