This document summarizes bone loss and patterns of bone destruction in periodontal disease. It discusses the causes of bone destruction including the extension of gingival inflammation, trauma from occlusion, and systemic disorders. It also describes factors that determine bone morphology like normal alveolar bone variation and trauma. Common patterns of bone destruction are outlined, such as horizontal bone loss, vertical defects, osseous craters, and furcation involvement. The key role of oral hygiene in maintaining periodontal health and reducing bone loss is emphasized.

1. BONE LOSS AND
PATTERNS OF BONE
DESTRUCTION
PRESENTED BY :
A.KHADEEJA (Intern)
Government Dental College and
Research Institute, Ballari.

2. Contents :
 Introduction
 Causes of bone destruction
 Factors determining bone morphology in
periodontal disease
 Bone destruction patterns in periodontal
disease
 Conclusion
 References

3. INTRODUCTION
 The height and density of the alveolar
bone are normally maintained by an
equilibrium, regulated by local and
systemic influences, between bone
formation and bone resorption.
Resorption [exceeds]
Formation [decreased] Both
Height Density

4. Periodontitis :
Infectious disease of gingiva
Destruction of bone
Tooth loss

5.  The average progression of
bone loss in untreated
periodontitis is 0.2 – 0.3mm
per year.
 Although periodontitis is an
infectious disease of the
gingival tissue, changes that
occur in bone are very
crucial because the
destruction of bone is
responsible for tooth loss.

6. CAUSES OF BONE
DESTRUCTION
 1. Extension of gingival inflammation
 2. Trauma from occlusion
 3. Systemic disorders

7. 1. BONE DESTRUCTION CAUSED BY
THE EXTENSION OF GINGIVAL
INFLAMMATION
 The extension of inflammation is from the MARGINAL
GINGIVA to the supporting periodontal tissues.
 “Periodontitis is always preceded by gingivitis, but not
all gingivitis progresses to Periodontitis”.
 The transition from gingivitis to periodontitis is
associated with the changes in the composition of
bacterial plaque.

8. *Bacterial composition in plaque :
motile organisms and spirochetes 
coccoid rods and straight rods 
*Cellular composition in infiltrated
connective tissue [ITC] :
fibroblast, lymphocyte predominant
plasma cell, blast cell predominant
*Immune reaction :
T-cell predominant  B-cell predominant

9. HISTOPATHOL
OGY
Gingival inflammation

Collagen fibre bundle

Blood vessels

Alveolar bone

Marrow spaces

Resorption

Thinning of surrounding bone &
enlargement of marrow spaces

DESTRUCTION OF BONE
[Bone height]

10. After inflammation reaches bone

spreads to the marrow spaces and replaces it
with

leukocytes, fluid exudates, new blood vessels &
proliferating fibroblasts.

Increased multinuclear osteoclast & mononuclear
phagocytes

bone surface is lined with howship lacunae

resorption proceeds from within causing

thinning of surrounding bony trabaculae.

12. RADIUS OF ACTION
 PAGE & SCHROEDER postulated a
range of effectiveness in which the
bacterial plaque can induce loss of
bone, i.e about 1.5 – 2.5mm
 Beyond 2.5mm there is no effect;

13.  Interproximal angular defects can
appear only in spaces that are wider
than 2.5mm.
 Large defects that greatly exceed a
distance of 2.5mm from the tooth
surface may be caused by the presence
of bacteria in the tissues.

14. PERIODS OF DESTRUCTION
 Periodontal destruction occurs in
episodic and intermittent manner
with periods of inactivity.
 Resulting in  loss of collagen
 loss of alveolar bone
 deepening of
periodontal pocket.

15. Various theories have been offered in this
context :
 Bursts of destructive activity are
associated with sub gingival ulceration,
and an acute inflammatory reaction,
resulting in bone loss. [Page rc et al
1982]
 Bursts of destructive activitty coincides
with the conversion of predominantly T-
lymphocyte lesion to one with
predominantly B-lymphocyte plasma cell
infiltrate. [Seymour G 1979]

16. MECHANISM OF BONE
DESTRUCTION
BONE DESTRUCTION
Role of bacteria Host associated factors
They induce differentiation Releases PGE2, IL-1,
of bone progenitor cells into IL-1, TNF-
osteoclast
Inhibit action of osteoblast.

18. BONE FORMATION IN
PERIODONTAL DISEASE
 Response of alveolar bone to inflammation
includes bone formation and resorption.
 Areas of bone formation are also found
immediately adjacent to sites of active
bone resorption in an effort to reinforce the
remaining bone [i.e., Buttressing bone
formation]
 New bone formation impairs the rate of
bone loss, compensating in some degree
for bone destroyed by inflammation.

19. 2. BONE DESTRUCTION CAUSED
BY TRAUMA FROM OCCLUSION
 When occlusal forces exceeds the
adaptive capacity of tissues, tissue
injury results.
INFLAMMATION
Presence Absence

20. Absence of inflammation
 In the absence of inflammation, tooth
mobility takes place.

21. Trauma from occlusion [persistent]

increased tension and compression of
PDL

increased osteoclasis of alveolar bone

resorption of bone and tooth structure

FUNNEL shaped widening of crestal
portion of PDL

TOOTH MOBILITY

22. Presence of inflammation
Trauma from occlusion

aggravates bone destruction
 results in
Bizzare bone pattern

23. 3. BONE DESTRUCTION CAUSED
BY SYSTEMIC DISORDERS
 Some systemic disorders also leads to
periodontitis such as,
o Osteoporosis
o Osteopenia
o Hyperparathyroidism
o Leukemia
o Langerhans cell histiocytosis.

24. FACTORS DETERMINING BONE
MORPHOLOGY IN PERIODONTAL
DISEASE
 1. Normal variation in alveolar bone
 2. Exostoses
 3. Trauma from occlusion
 4. Buttressing bone formation [Lipping]
 5. Food impaction
 6. Aggressive periodontitis

25. 1. NORMAL VARIATION IN ALVEOLAR
BONE
 The Anatomic features that substantially affect
the bone destructive pattern of periodontal
disease includes the following :
 Thickness, width, and crestal angulation of the
interdental septa
 Thickness of the facial and lingual alveolar
plate
 Presence of fenestrations and dehiscences
 Alignment of the teeth
 Root and root trunk anatomy
 Root position within the alveolar process
 Proximity with another tooth surface.

26. EXOSTOSES

27.  Exostoses are the outgrowths of bone of
varied size and shapes.
 They occur as small nodules, large
nodules, sharp ridges, spike like
projections.

28. TRAUMA FROM OCCLUSION
 It may be a factor in
determining the
dimension and shape
of bone deformities.
 It may cause thickening
of cervical margin of
alveolar bone or
change in morphology
of bone
ex : angular defects,
buttressing bone.

29. BUTTRESSING BONE
FORMATION [LIPPING]
 Buttressing bone formation occurs
during the repair phase of TFO in
an attempt to buttress bony
trabeculae weakened by
resorption.
 When it occurs within the jaw, it is
referred as central buttressing
bone formation.
 When it occurs on external
surface, it is referred to as
peripheral buttressing bone
formation [Glickman and sumlow
1965]

30. FOOD IMPACTION
 Pressure and irritation from food impaction
contribute to inverted bone architecture.
 In some cases poor proximal relationship
result from shift in tooth position because of
extensive bone destruction preceding food
impaction.

31. AGGRESSIVE PERIODONTITIS
 Vertical or angular pattern of alveolar
bone destruction is found around first
molars in aggressive periodontitis.

32. BONE DESTRUCTION PATTERNS
IN PERIODONTAL DISEASE
 Horizontal bone loss
 Vertical or angular defects
 Osseous craters
 Bulbous bone contours
 Reverse architecture
 Ledges
 Furcation involvement

33. HORIZONTAL BONE LOSS
 Most common pattern of bone loss in
periodontal disease.
 Bone is reduced in height, but bone margin
remains approximately perpendicular to tooth
surface.
 The interdental septa, facial and lingual plates
are affected

34. VERTICAL OR ANGULAR BONE
LOSS
 These are those defects that occur in
oblique direction, leaving a hollowed out
trough in bone alongside root.

35.  On the basis of number of osseous
walls, angular defects are classified as,
[Goldman & Cohen, 1958]
 One wall defect [hemiseptum]
 Two wall defect
 Three wall defect [infrabony defect]
 Combined osseous defects

37. OSSEOUS CRATERS
 Bone loss resulting in concavities on the
crest of interdental bone confined within
facial and lingual walls.

38. Reasons :
 1. Interdental area collects plaque &
difficult to clean.
 2. Normal flat or even concave
faciolingual shape of interdental septum
in lower molars may favour crater
formation.
 3. Vascular patterns from gingiva to
centre of crest may provide pathway for
inflammation.
[Sari JT et al 1968]

39. Classification :
1. One wall
2. Two wall
3. Three wall
4. Combination

40. BULBOUS BONE CONTOURS
 They are the bony enlargements caused
by exostoses, adaptation to function or
buttressing bone formation.
 Maxilla > Mandible

41. REVERSED ARCHITECTURE
 Loss of interdental bone, including facial
plates and lingual plates, without loss of
radicular bone, thereby reversing normal
architecture.
 Commonly seen in maxilla.

42. LEDGES
 They are plateau like bone margins
caused by resorption of thickened bony
plates.

43. FURCATION INVOLVEMENT
 Refers to the invasion of bifurcation &
trifurcation of multirooted teeth by
periodontal disease.

44. Grade I : Incipient bone loss
Grade II : cul-de-sac lesion
Grade III : through and through opening
Grade IV : similar to Grade III, with gingival
recession

46. CONCLUSION
The key factor in achieving a good
periodontal health lies in maintaining a
good oral hygiene. Early and prompt
diagnosis and treatment of gingival
diseases will reduce the incidence of
periodontal disease thereby, reducing
the bone destruction and avoiding tooth
loss.

47. REFERENCES :
 Carranza [Third south asia edition]
 Shantipriya Reddy [5th edition]

48. THANK YOU