1. Periodontal Response to External Forces
Logien Al Ghazal
24/11/2015

2. ADAPTIVE CAPACITY OF THE PERIODONTIUM TO OCCLUSAL FORCES

3. The effect of occlusal forces on the Periodontium is influenced by:
Magnitude
Direction
Duration
Frequency of the forces.

4. Magnitude
The periodontium tries to accommodate to the forces exerted on the crown.
This adaptive capacity varies in different persons and in the same person at different times.
When the magnitude of occlusal forces is increased:
Widening of the periodontal ligament space
Increase in the number and width of periodontal ligament fibers (PDL)
Increase in the density of alveolar bone.
Excessive occlusal forces may also disrupt the function of the masticatory musculature:
Painful spasms
Injure the temporomandibular joints
Excessive tooth wear.

5. Changing the direction of occlusal forces causes a reorientation
of the stresses and strains within the periodontium.
The principal fibers of the PDL
occlusal forces along the long axis of the tooth

6. The response of alveolar bone is also affected by:
The duration
and frequency of occlusal forces.
3. Frequency of the forces
Constant pressure on the bone is more injurious than intermittent forces.
The more frequent the application of an intermittent force, the more injurious the force to the periodontium. .

7. TRAUMA FROM OCCLUSION
(T.F.O) OR
OCCLUSAL TRAUMA.

8. Definition :Trauma from occlusion:
The resultant injury when occlusal forces exceed the adaptive capacity of the tissues.
Thus trauma from occlusion = the tissue injury.
An occlusion that produces such injury is called a traumatic occlusion .
Types of trauma from occlusion
Acute
Chronic

9. Types of trauma from occlusion

10. Acute trauma from occlusion
Results from an abrupt occlusal impact.
such as that produced by biting on a hard object (e.g., an olive pit).
Restorations or prosthetic appliances that interfere with or alter the direction of occlusal forces on the teeth may induce acute trauma.
Symptoms:
Tooth pain, sensitivity to percussion, increased tooth mobility. Necrosis accompanied by periodontal abscess formation or persist as a symptom-free chronic condition.
Acute trauma can also produce cementum tears
If the force is dissipated the injury heals and the symptoms subside.

11. Chronic trauma from occlusion
More common.
Develops from gradual changes in occlusion produced by tooth wear.
Causes may be:
Drifting movement
Extrusion of teeth,
combined with parafunctional habits such as bruxism and clenching.
The criterion that determines whether an occlusion is traumatic
is whether it produces periodontal injury, not how the
teeth occlude.
Malocclusion is not necessary to produce trauma; periodontal injury may occur when the occlusion appears normal.
Occlusal disharmony, functional imbalance, and occlusal dystrophy:
These terms refer to the occlusion's effect on the periodontium,
not to the position of the teeth.

12. Primary and Secondary Trauma from Occlusion

13. Primary trauma from occlusion:
When trauma from occlusion is the result of alterations in occlusal forces. (Healthy peridontium).
Secondary trauma from occlusion:
When it results from reduced ability of the tissues to resist the occlusal forces.

14. Primary trauma from occlusion

15. Secondary trauma from occlusion

16. Primary trauma from occlusion
Trauma from occlusion is considered the primary etiologic factor in
periodontal destruction and if the only local alteration
to which a tooth is subjected is from occlusion.
Causes:
The insertion of a high filling.
The insertion of a prosthetic replacement that creates excessive forces on abutment and antagonistic teeth.
The drifting movement or extrusion of teeth into spaces created by unreplaced missing teeth.
The orthodontic movement of teeth into functionally unacceptable positions.

17. Secondary trauma from occlusion
Occurs when the adaptive capacity of the tissues to withstand occlusal forces is impaired by bone loss resulting from marginal inflammation.
The periodontium becomes more vulnerable to injury, and previously
well-tolerated occlusal forces become traumatic.

18. TISSUE RESPONSE TO INCREASED
OCCLUSAL FORCES

19. Stages of Tissue Response:
Tissue response occurs in three stages:
Injury.
Repair.
Adaptive remodeling of the periodontium.

20. Stage I: Injury.
Tissue injury is produced by excessive occlusal forces.
Forces are diminished or if the tooth drifts away from them. The body then attempts to repair the injury and restore the periodontium.
Ligament is widened at the expense of the bone, resulting
in angular bone defects without periodontal pockets,
and the tooth becomes loose.
The areas of the periodontium most susceptible are the furcations.

21. (increase in areas of resorption and a decrease
The injury phase
(increase in areas of resorption and a decrease
in bone formation)
pressure
Resorption bone
Wide PDL
+pressure
Vascular change
necrosis
++pressure
Thrombosis,necrosis
Undermining bone

22. Stage II: Repair:
Repair is constantly occurring in the normal periodontium.
The damaged tissues are removed, and new connective
tissue cells and fibers, bone, and cementum are formed in an attempt to restore the injured periodontium
Forces remain traumatic only as long as the damage produced exceeds the reparative capacity of the tissues.

23. The repair phase demonstrates
(decreased resorption and increased bone formation)
Repair –reinforce new bone formation
Peripheral Butterssing
Facial bony plate
Lingual bony plate
Central Butterssing
Center of the jaw

24. Stage III: Adaptive Remodeling of the Periodontium.
If the repair process cannot keep pace with the destruction caused by the occlusion, the periodontium is remodeled in an effort to create a structural relationship in which the forces are no longer injurious to the tissues.
This results in a thickened periodontal ligament, which is funnel shaped at the crest, and angular defects in the bone, with no pocket formation.
The involved teeth become loose. Increased vascularization has also
been reported.
After adaptive remodeling of the periodontium, resorption
and formation return to normal.

25. EFFECTS OF INSUFFICIENT OCCLUSAL FORCE
Insufficient occlusal force may also be injurious to the
supporting periodontal tissues.
Insufficient stimulation causes thinning of the periodontal ligament, atrophy of the fibers, osteoporosis of the alveolar bone, and reduction in bone height.
Hypofunction can result from an open-bite relationship, an absence of functional antagonists, or unilateral chewing habits that neglect one side of the mouth.

26. REVERSIBILITY OF TRAUMATIC LESIONS

27. Trauma from occlusion is reversible.
When trauma is artificially induced in experimental animals, the teeth move away or intrude into the jaw.
When the impact of the artificially created force is relieved, the tissues undergo repair.
Some clinicians report the disappearance of pulpal symptoms after correction of excessive occlusal forces.

28. INFLUENCE OF TRAUMA FROM OCCLUSION ON PROGRESSION
OF MARGINAL PERIODONTITIS

29. The effect of forces is a combination of changes produced by pressure and tension on both sides of the tooth.
With an increase in the width of the ligament and increased tooth mobility can be noticed.
It has been proven that trauma from occlusion does not cause
pockets or glngivitiS, nor does it increase gingival fluid flow.
When inflammation extends into the supporting periodontal tissues (i.e., when gingivitis becomes periodontitis), plaque-induced inflammation enters the zone influenced by occlusion, which
Glickman has called the zone o f co-destruction.

30. It is important to eliminate the marginal inflammatory component
in cases of trauma from occlusion because the presence of inflammation affects bone regeneration after the removal of the
traumatizing contacts.
Trauma from occlusion may constitute an additional risk factor for the progression and severity of the disease.
An understanding of the effect of trauma from occlusion on the
periodontium is useful in the clinical management of periodontal
problems.

31. Clinical and Radiographic Signs of Trauma from
Occlusion Alone

32. The most common clinical sign of trauma to the periodontium
is increased tooth mobility.
Other causes of increased tooth mobility include some systemic causes (e.g., pregnancy).
The destruction of surrounding alveolar bone, such as occurs in osteomyelitis or jaw tumors, may also increase tooth mobility.
Trauma from occlusion also tends to change the shape of the alveolar crest.

33. The change in shape consists of a widening of the marginal periodontal ligament space, a narrowing of the interproximal alveolar bone, and a shelf-like thickening of the alveolar margin.
Therefore although trauma from occlusion does not alter
the inflammatory process, it changes the architecture of
the area around the inflamed site.
The presence of inflammation, the changes in the shape of the alveolar crest may be conducive to angular bone loss, and existing pockets may become intrabony.

34. Radiographic signs of trauma from occlusion may include
the following:
Increased width of the periodontal space.
2. A "vertical" rather than "horizontal" destruction of
the interdental septum.
3. Radiolucence and condensation of the alveolar bone.
4. Root resorption.

35. PATHOLOGIC TOOTH MIGRATION

36. Pathologic migration:
Refers to tooth displacement that results when the balance among the factors that maintain physiologic tooth position is disturbed by periodontal disease.
Most frequently in the anterior region, but posterior teeth may also be affected.
Usually accompanied by mobility and rotation.
Pathologic migration in the occlusal or incisal direction is
termed extrusion.

37. Pathogenesis
Two major factors play a role in maintaining the normal
position of the teeth:
The health and normal height of the periodontium
The forces exerted on the teeth.
The following factors are important in relation to the forces of occlusion:
Tooth morphologic features and cuspal inclination.
The presence of a full complement of teeth.
Aphysiologic tendency toward mesial migration.
The nature and location of contact point relationships.
Proximal, incisal, and occlusal attrition.
The axial inclination of the teeth.
Thus pathologic migration occurs under conditions that weaken the periodontal support, increase or modify the forces exerted on the teeth, or both.

38. Weakened Periodontal Support:
The inflammatory destruction of the periodontium in periodontitis
creates an imbalance between the forces maintaining the
tooth in position.
The tooth with weakened support is unable to maintain its normal position in the arch and moves away from the opposing force unless it is restrained by proximal contact.
Forces that are acceptable to an intact periodontium become injurious when periodontal support is reduced.
Abnormally located proximal contacts convert the normal anterior component of force to a wedging force that moves the tooth occlusally or incisally.
Pathologic migration is also an early sign of localized aggressive periodontitis.

39. Changes in the Forces Exerted on the Teeth.
Changes in the magnitude, direction, or frequency of the forces exerted on the teeth can induce pathologic migration of a tooth or group of teeth.
Unreplaced missing teeth.
Drifting differs from pathologic migration in that it does not result from destruction of the periodontal tissues.
Creates conditions that lead to periodontal disease.
Drifting generally occurs in a mesial direction, combined with tilting or extrusion beyond the occlusal plane.
Pressure from the tongue

40. Failure to replace first molars.
In extreme cases it consists of the following:
1. The second and third molars tilt, resulting in a decrease
in vertical dimension.
2. The premolars move distally, and the mandibular incisors tilt or drift lingually. While drifting distally, the mandibular premolars lose their intercuspating relationship with the maxillary teeth and may tilt
distally.
3. Anterior overbite is increased. The mandibular incisors strike the maxillary incisors near the gingiva or traumatize the gingiva.
4. The maxillary incisors are pushed labially and laterally
5. The anterior teeth extrude because the incisal apposition
has largely disappeared.
6. Diastemata are created by the separation of the anterior
teeth

41. The disturbed proximal contact relationships lead:
Food impaction.
Gingival inflammation.
Pocket formation.
Bone loss and tooth mobility.