This document discusses bone loss and patterns of bone destruction in periodontal disease. It describes the normal anatomy of alveolar bone and lists various factors that can influence bone morphology, including periodontal disease. These factors include the thickness of the interdental septa and alveolar plates. The document also lists causes of bone destruction such as plaque, trauma from occlusion, and systemic disorders like hyperparathyroidism. Finally, it discusses different patterns of bone destructive defects like horizontal bone loss, vertical defects, osseous craters, and furcation involvement.

1. Dr Jaffar Raza Syed
Bone Loss and Patterns of Bone Destruction
Normal Anatomy Of Alveolar Bone
Bone Loss and Patterns of Bone Destruction
Normal Anatomy Of Alveolar Bone
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Bone Loss and Patterns of Bone Destruction

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Various Factors Determining Bone Morphology In Periodontal Disease
(i) Normal variation in alveolar bone
(ii) Exostoses
(iii) Trauma from occlusion
(iv) Buttressing bone formation
(v) Food impaction
(vi) Aggressive periodontitis

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Various Anatomic Features That Influence Bone Destructive
Patterns In Periodontal Disease.
(i) Thickness, width and crestal angulation of the interdental septa
(ii) Thickness of facial and lingual alveolar plates
(iii) Presence of fenestration and dehiscence
(iv) Alignment of teeth
(v) Proximity with another tooth surfaces
(vi) Root and root trunk anatomy
(vii) Root position within alveolar bone

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Various Causes Of Bone Destruction
(i) Extension of gingival inflammation
(ii) Trauma from occlusion
(iii) Systemic disorders.
Various Systemic Disorders Which Cause Bone Destruction
(i) Hyperparathyroidism
(ii) Leukemia
(iii) Langerhan’s cell histiocytosis

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Changes In The Bone Could Be As Follows:
Gingival inflammation
↓
Marrow spaces
↓
Replaced by leukocytes and fluid exudates, new blood vessels and proliferating
fibroblasts
↓
Increase in osteoclasts and mononuclear cells
↓
Thinning of bone trabeculae and enlargement of the marrow spaces
↓
Destruction of the bone and reduction in bone height
↓
Replacement of fatty bone marrow with the fibrous type
(around the resorption areas)

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various mechanisms of bone destruction
According to Hausmann, the various mechanisms of bone destruction
are:
(i) Direct action of plaque products on bone progenitor cells induces
the differentiation of these cells into osteoclasts.
(ii) Plaque products act directly on bone, destroying it through a
noncellular mechanism.
(iii) Plaque products stimulate gingival cells, causing them to release
mediators, which in turn induce bone progenitor cells to
differentiate into osteoclasts.
(iv) Plaque products causes gingival cells to release agents that can
act as cofactors in bone resorption.
(v) Plaque products causes gingival cells to release agents that destroy
bone by direct chemical action, without oseoclasts.

8. Dr Jaffar Raza Syed
Various Bone Destructive Patterns In Periodontal Disease
(i) Horizontal bone loss
(ii) Vertical/angular defects
Various Bone Destructive Patterns In Periodontal Disease
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9. Dr Jaffar Raza Syed
Osseous Defects
• One walled osseous defects
• Two walled osseous defects
• Three walled osseous defects
: only one bony wall is present
: two bony walls are present
: three bony walls are present
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nt
: three bony walls are present

10. Dr Jaffar Raza Syed
(iii) Osseous craters
They are concavities in the crest of the interdental bone
confined within the facial and lingual walls
They are concavities in the crest of the interdental bone
confined within the facial and lingual walls
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11. Dr Jaffar Raza Syed
(iv) Bulbous bony contours
caused by exostoses, adaptation
found more frequently in the maxilla than mandible
caused by exostoses, adaptation to function or buttressing bone formation.
more frequently in the maxilla than mandible
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to function or buttressing bone formation.

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(v) Reversed architecture
defects are produced by loss of interdental bone
plates without loss of radicular bone
(more common in maxilla)
loss of interdental bone, including the facial and lingual
without loss of radicular bone, thereby reversing the normal
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including the facial and lingual
, thereby reversing the normal architecture

13. Dr Jaffar Raza Syed
(vi) Ledges
They are plateau-like bone margins caused by resorption of
thickened bony plates.
like bone margins caused by resorption of
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14. Dr Jaffar Raza Syed
(vii) Furcation involvement
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Bone Destruction in Periodontal Disease
• Bacteria mediated — LPS, lipoteichoic acid, lipoproteins and others.
• Host mediated — prostaglandins, leukotrienes, cytokines and others.
• Combination of both.
Diagnosis of Osseous Defects
a. Clinical examination — transgingival probing.
b. Radiographs — not very reliable, cannot reveal the extent of involvement
and presence/absence of bony walls.
c. Surgical exposure — during flap operations, it is the only reliable method
for determining the true architecture of a bony defect