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Bone loss & patterns of bone loss



    INDIAN DENTAL ACADEMY
        Leader in Continuing Dental Education
           www.indiandentalacademy.com
              www.indiandentalacademy.com
Periodontitis is always preceded by the
gingivitis , but not all gingivitis progresses
to periodontitis
The transition of gingivitis to peridontitis is
associated with changes in the plaque
T lymphocytes are predominant in the
gingivitis, as the lesion becomes B
lymphocytic it becomes more destructive

        www.indiandentalacademy.com
The recurrent episodes of acute destruction
over time may be lead to progressive bone
loss in marginal periodontitis
Pathway of inflammation
 Inflammation           bone        PDL




       www.indiandentalacademy.com
Radius of action
 Locally produced bone
  resorption factors have
  to be present in the
  proximity of bone
  surface to be able to
  exert their action
 Range of 1.5mm-
  2.5mm within bacterial
  plaque can induce loss
  of bone
 Interproximal angular
  defects can appear only
  in spaces that are wider
  than 2.5mm
             www.indiandentalacademy.com
 Large  defects far exceeding 2.5mm from the
  tooth surface may be caused by presence of
  bacteria in the tissues
Rate of bone loss
8 % --- 0.1 mm –1mm/yr
 81% --- 0.05mm-0.5mm/yr

 11% --- 0.05-0.09mm/yr



          www.indiandentalacademy.com
Mechanisms of bone destruction
      Plaque                     bone progenitor cells

                    noncellular
                    mechanism

Gingival cells                     osteoclasts

        mediators

                       Bone resorption
                www.indiandentalacademy.com
Plaque          direct action   bone resorption

PGE2,IL-1 & TNF, IL-6          bone
                         resorption
NSAIDs such as flubiprofen , ibuprofen
inhibit PGE2, slowing bone loss.


         www.indiandentalacademy.com
Bone destruction caused by systemic
disases
 Bone  factor concept ---systemic component is
  present in all forms of periodontitis. Nature of
  systemic component influences the severity of
  disease.
 Osteoporosis
 Hyperparathyroidism, leukemia.



         www.indiandentalacademy.com
Factors that determine the bone morphology
in the alveolar bone
 Anatomic   factors
    Thickness   , width, & crest angulation of interdental
     septa
    Thickness of facial & lingual alveolar bone

    Presence of fenestration, dehiscence or both

    Alignment of teeth

    Root position within the alveolar process

    Proximity with another tooth surface


        www.indiandentalacademy.com
   Exostoses

   Lipping – Bone
    formation occurs in an
    attempt to buttress
    bony trabeculae
    weakened by
    resorption. When it
    occurs within the jaw it
    is called central
    buttressing bone
    formation.when it
    occurs in the external
    surface , it is reffred as
    peripheral buttressing
    bone formation.
                  www.indiandentalacademy.com
   TFO --- funnel shaped
    widening of crestal
    portion of PDL, with
    resorption of alveolar
    bone.Angular shape
    bony crest represent
    adaptation of PDL
    tissues to “cushion”
    increased occlusal
    force.



          www.indiandentalacademy.com
 Food impaction --- it
  is complicating factor
  rather than cause of
  bone defect
 JP



Bone destruction
patterns
   Horizontal bone loss
      Most common pattern
      Bone margin remains

       perpendicular to the
       tooth surface          Horizontal bone loss
            www.indiandentalacademy.com
   Angular or vertical
    defects

      They occur in an
       oblique direction
       leaving an hollowed
       trough in the bone
       along side the root
      Base of the defect
       located apical to
       surronding bone
      They accompany
       infrabony defects
      They classified on
       number of osseous
       walls present
            One wall
            Two wall
              www.indiandentalacademy.com
             Three wall
www.indiandentalacademy.com
 The number of walls in the apical portion of the defect
  may be greater than that in its occlusal portion,
  combined osseous defects
 Surgical exposure is the only sure way to determine the
  configuration of osseous walls
 Vertical defects increases with age

 Intrabony defects are more frequently found on the
  mesial surfaces of upper & lower molars
 About 60% of persons with interdental angular defects
  have only a single defect



         www.indiandentalacademy.com
www.indiandentalacademy.com
Osseous craters
 These  are the concavities in the crest of the
  interdental bone confined within the facial &
  lingual walls
 They form about 1/3 of all defects & 2/3 of
  mandibular defects
 They are twice as common in posterior
  segments as in anterior segments

          www.indiandentalacademy.com
   Reasons for high
    frequency of
    interdental craters
      Interdental area collects
       plaque & is difficult to
       clean
      Vascular patterns from

       the gingiva to the centre
       of the crest may provide
       a pathway of
       inflammation


           www.indiandentalacademy.com
Bulbous bone contours

 bony enlargements
  caused by exotoses,
  buttressing bone
  formation.
 Found more frequently
  in the maxilla than in
  the mandible
Reversed architecture
   More common in the
    maxilla

                              Reversed architecture
           www.indiandentalacademy.com
Ledges
 Plateu like bone margins caused by resorption
  of thickened bony plates
F.I.



         www.indiandentalacademy.com

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Bone loss & patterns of bone loss / /certified fixed orthodontic courses by Indian dental academy

  • 1. Bone loss & patterns of bone loss INDIAN DENTAL ACADEMY Leader in Continuing Dental Education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. Periodontitis is always preceded by the gingivitis , but not all gingivitis progresses to periodontitis The transition of gingivitis to peridontitis is associated with changes in the plaque T lymphocytes are predominant in the gingivitis, as the lesion becomes B lymphocytic it becomes more destructive www.indiandentalacademy.com
  • 3. The recurrent episodes of acute destruction over time may be lead to progressive bone loss in marginal periodontitis Pathway of inflammation  Inflammation bone PDL www.indiandentalacademy.com
  • 4. Radius of action  Locally produced bone resorption factors have to be present in the proximity of bone surface to be able to exert their action  Range of 1.5mm- 2.5mm within bacterial plaque can induce loss of bone  Interproximal angular defects can appear only in spaces that are wider than 2.5mm www.indiandentalacademy.com
  • 5.  Large defects far exceeding 2.5mm from the tooth surface may be caused by presence of bacteria in the tissues Rate of bone loss 8 % --- 0.1 mm –1mm/yr  81% --- 0.05mm-0.5mm/yr  11% --- 0.05-0.09mm/yr www.indiandentalacademy.com
  • 6. Mechanisms of bone destruction  Plaque bone progenitor cells noncellular mechanism Gingival cells osteoclasts mediators Bone resorption www.indiandentalacademy.com
  • 7. Plaque direct action bone resorption PGE2,IL-1 & TNF, IL-6 bone resorption NSAIDs such as flubiprofen , ibuprofen inhibit PGE2, slowing bone loss. www.indiandentalacademy.com
  • 8. Bone destruction caused by systemic disases  Bone factor concept ---systemic component is present in all forms of periodontitis. Nature of systemic component influences the severity of disease.  Osteoporosis  Hyperparathyroidism, leukemia. www.indiandentalacademy.com
  • 9. Factors that determine the bone morphology in the alveolar bone  Anatomic factors  Thickness , width, & crest angulation of interdental septa  Thickness of facial & lingual alveolar bone  Presence of fenestration, dehiscence or both  Alignment of teeth  Root position within the alveolar process  Proximity with another tooth surface www.indiandentalacademy.com
  • 10. Exostoses  Lipping – Bone formation occurs in an attempt to buttress bony trabeculae weakened by resorption. When it occurs within the jaw it is called central buttressing bone formation.when it occurs in the external surface , it is reffred as peripheral buttressing bone formation. www.indiandentalacademy.com
  • 11. TFO --- funnel shaped widening of crestal portion of PDL, with resorption of alveolar bone.Angular shape bony crest represent adaptation of PDL tissues to “cushion” increased occlusal force. www.indiandentalacademy.com
  • 12.  Food impaction --- it is complicating factor rather than cause of bone defect  JP Bone destruction patterns  Horizontal bone loss  Most common pattern  Bone margin remains perpendicular to the tooth surface Horizontal bone loss www.indiandentalacademy.com
  • 13. Angular or vertical defects  They occur in an oblique direction leaving an hollowed trough in the bone along side the root  Base of the defect located apical to surronding bone  They accompany infrabony defects  They classified on number of osseous walls present  One wall  Two wall  www.indiandentalacademy.com Three wall
  • 15.  The number of walls in the apical portion of the defect may be greater than that in its occlusal portion, combined osseous defects  Surgical exposure is the only sure way to determine the configuration of osseous walls  Vertical defects increases with age  Intrabony defects are more frequently found on the mesial surfaces of upper & lower molars  About 60% of persons with interdental angular defects have only a single defect www.indiandentalacademy.com
  • 17. Osseous craters  These are the concavities in the crest of the interdental bone confined within the facial & lingual walls  They form about 1/3 of all defects & 2/3 of mandibular defects  They are twice as common in posterior segments as in anterior segments www.indiandentalacademy.com
  • 18. Reasons for high frequency of interdental craters  Interdental area collects plaque & is difficult to clean  Vascular patterns from the gingiva to the centre of the crest may provide a pathway of inflammation www.indiandentalacademy.com
  • 19. Bulbous bone contours  bony enlargements caused by exotoses, buttressing bone formation.  Found more frequently in the maxilla than in the mandible Reversed architecture  More common in the maxilla Reversed architecture www.indiandentalacademy.com
  • 20. Ledges  Plateu like bone margins caused by resorption of thickened bony plates F.I. www.indiandentalacademy.com