This document discusses trauma from occlusion (TFO), which occurs when occlusal forces exceed the adaptive capacity of the periodontium tissues, causing injury. It describes how the magnitude, direction, and duration of occlusal forces can impact the periodontium. TFO can be acute or chronic, and primary (due to increased forces) or secondary (reduced tissue resistance). The stages of tissue response include initial injury, increased repair activity, and eventual adaptive remodeling if forces are reduced. TFO influences the progression of marginal periodontitis by altering the shape of bone defects and making existing pockets more intrabony. Clinical features include increased mobility while radiographic features show widened periodontal ligament spaces and angular bone loss.

1. Trauma from Occlusion
Dr Saif Khan
Department of Periodontics and Community Dentistry,
AMU, Aligarh

2. Adaptive capacity of Periodontium- Occlusal Force
Magnitude Direction Duration

3. Periodontium changes- Magnitude of Occlusal force
PDL space
widening
Increase in no and
width of PDL fibres
Increase in alveolar
density

4. Periodontium changes- Direction of Occlusal force
Reorientation of stresses & Strain
Lateral (Horizontal)
Forces
Torque
(Rotational)
forces
More likely to
injure
Periodontium

5. Response of Alveolar bone to Occlusal force
Duration Frequency
Constant pressure on the bone is more injurious than
intermittent forces.

6. Trauma from occlusion (TFO)
• When occlusal forces exceed the adaptive capacity of the tissues-
Tissue injury results.
• The Resultant injury in Periodontium is called Trauma from Occlusion
(TFO)
• The occlusion that produces such injury is called Traumatic occlusion
• Excessive occlusal force
• Disrupts function of Masticatory musculature
• Painful spasm
• TMJ injury

7. TFO can be;
• Acute TFO
• Abrupt occlusal impact
• Tooth pain
• Sensitivity to percussion
• Increased tooth mobility
• Chronic TFO
• More Common- greater clinical significance
• Gradual changes in occlusion- tooth wear, drifting & extrusion of
teeth
• Parafunctional Habits- Bruxism & Clenching

8. TFO can also be classified as;
• Primary TFO
• Increase in the Occlusal force produces periodontal injury
• Insertion of High filling
• Prosthetic replacement causing excessive force on
abutments and antagonist teeth
• Drifting or extrusion of teeth in edentulous space
• Orthodontic movement into functionally unacceptable
position

9. • Secondary TFO
• Reduced ability to resists the occlusal force
• Adaptive capacity of tissues to bear occlusal forces is lost due to
marginal inflammation
• Reduced Periodontal attachment area
• Alters the Leverage on the remaining tissues
• Systemic disorders can reduce tissue resistance and previously
tolerable forces become excessive

10. A- Primary TFO B & C- Secondary TFO

11. Stages of tissue response to increased Occlusal force
• Stage I :
• Tissue injury is produced by excessive occlusal force
• Slight excessive pressure stimulates resorption of alveolar bone- Widening of
Periodontal ligament space
• Leads to formation of Angular Bone defects without Periodontal Pockets
• Tooth become Mobile
• Furcations are most susceptible to injury
• Injury to periodontium produces temporary decrease in mitotic activity, rate
of proliferation and differentiation of fibroblasts, collagen and bone formation
are also depressed- which are reversed after dissipation of traumatic forces

12. • Stage II:
• Continuous process- increased reparative activity
• Damaged tissues are removed and new connective tissue cells, fibres, bone
and cementum are formed
• Forces remain traumatic as long as damage exceeds the reparative capacity of
the tissues
• Buttressing bone formation is important reparative process associated with
TFO
• Central Buttressing bone – Endosteal cells deposit new bone
• Peripheral Buttressing bone on facial and lingual alveolar plate produces
shelf like thickening of alveolar margin called lipping
• Cartilage like material, Crystals formation from RBCs are seen aftermath of
TFO in PDL space

13. Buttressing Bone Formation

14. • Stage III; Adaptive remodelling of the Periodontium
• If repair cannot keep pace with destruction by occlusal force
• Periodontium is remodeled to create a structural relationship where the
occlusal forces are no longer injurious to the tissues;
• Thickened Periodontal ligament- Funnel Shaped at crest
• Angular defect in bone with no pocket formation
• Tooth Mobility
• Injury Phase: Increased bone resorption and decreased bone formation
• Repair phase: Decrease bone resorption and increased bone formation

16. Influence of Trauma of Occlusion on Marginal Periodontitis
• TFO does not cause pocket or
gingivitis nor it increases gingival
fluid flow
• As long as inflammation is
confined in gingiva it is not
affected by occlusal forces
• However when gingivitis
becomes periodontitis then
occlusal force comes into play
leading to formation of Zone of
Co-destruction

17. • Marginal gingiva is unaffected by TFO because its blood supply is
not affected even when periodontal vessels are obliterated by
excessive occlusal force
• When TFO is eliminated a substantial reversal of bone loss occur,
except in the presence of periodontitis- as inflammation inhibits
regeneration
• TFO changes the shape of alveolar crest;
• PDL space widening,
• narrowing of interproximal bone,
• shelflike thickening of alveolar margin

18. TFO changes the architecture of
the area around the inflamed
sites
In absence of inflammation, the
response to TFO is limited to
adaptation to increased force
However in presence of
inflammation (periodontitis) TFO
alters the shape of alveolar
crest leading to angular bone
loss and making existing pocket
intrabony
TFO alters the pathway of
extension of inflammation

19. TFO
• Clinical features;
• Most common is increased tooth mobility due to advanced bone loss
and periodontal inflammation
• Wear facets
• Pain in TMJ
• Pain on mastication
• Positive fremitus test

20. Radiographic features:
• Increased width of PDL
space with thickening of
lamina dura
• Angular/vertical interdental
alveolar bone loss
• Radiolucency or
condensation of alveolar
bone
• Root Resorption