The periodontium attempts to accommodate to the forces exerted to the crown. This adaptive capacity varies in different persons and in the same person

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6 The periodontium attempts to accommodate to the forces exerted to the crown. This adaptive capacity varies in different persons and in the same person at different times.

7 The effect of occlusal forces on the periodontium is influenced by: Magnitude Direction Duration Frequency

8 Magnitude of force increased widening of the periodontal ligament. Changing the direction of occlusal forces reorientation of stresses within the periodontium. Constant pressure on the bone is more injurious than intermittent forces.

9 Definition: Tissue injury result when the occlusal forces exceed the adaptive capacity of the periodontal tissues. Trauma from occlusion refers to the tissue injury NOT the occlusal force.

10 Terminology: Traumatizing occlusion Occlusal trauma Occlusal overload Periodontal traumatism Note: An occlusion that produces such an injury is called as traumatic occlusion.

11 1) Depending on the onset and duration: a. Acute trauma from occlusion b. Chronic trauma from occlusion 2) Depending on the cause: a. Primary trauma from occlusion b. Secondary trauma from occlusion

12 Acute trauma: Causes: a. Sudden occlusal impact e.g. biting on olive pit b. Restorations or prosthetic appliances which alter the direction of occlusal forces Symptoms : Tooth pain, sensitivity to percussion Increasing tooth mobility In severe cases periodontal abscess

13 Chronic trauma: Develops from gradual changes in occlusion produced by: - Tooth wear - drifting movement combined with parafunctional habits create gradual changes in occlusion More difficult to treat

14 Primary Occlusal Trauma: Injury resulting from excessive occlusal forces applied to a tooth or teeth with normal support. Secondary Occlusal Trauma: Injury resulting from occlusal forces applied to a tooth or teeth with inadequate support.

15 Etiology: Increase in occlusal force Periodontal structures relatively healthy Occurs with: High filling Prosthetic replacement or failure to replace tooth/teeth Orthodontic movement of teeth into functionally unacceptable positions We do not see: Changes in clinical attachment levels Development of pockets

16 Foreign object to tooth habit in the form of pipe stem biting. Occlusal trauma limited to site of pipe stem.

17 Etiology: Adaptive capacity of tissues is impaired as a result of bone loss Previously well-tolerated forces become excessive.

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19 INJURY- REPAIR- ADAPTIVE REMODELLING Stage I Injury: Tissue injury is produced by excessive occlusal forces. Varying degrees of pressure & tension create varying degrees of changes

20 The tooth with vertical occlusal forces - has a small area of periodontal ligament pressure (1) - Increased area of periodontal ligament tension (3)

21 Horizontal occlusal force causes the tooth to - rotate about an axis (2) - demonstrates an increase in area of periodontal ligament pressure (1) - a reduced area of ligament tension (3)

22 Slight pressure : Resorption of bone Widened periodontal ligament space Blood vessels numerous & reduce in size Slight tension : Periodontal ligament fibers elongate Apposition of bone Blood vessels enlarge

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24 Radiograph of lower Molar with Traumatic Occlusion. Widened Periodontal ligament space on Mesial all the way around the apex with beginning bone loss in furcation.

25 Greater pressure: Compression of fibers Injury to fibroblasts, CT cells necrosis of ligament Resorption of bone Greater tension: Widened periodontal ligament space Tearing of ligament Hemorrhage

26 The body then attempts to repair the injury and restore the periodontium. This can occur if the forces are diminished or if the tooth drifts away from them. 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.

27 Thinned bone is reinforced with new bone, This attempt to compensate for lost bone is called buttressing bone formation

28 Periodontium is remodeled in an effort to create a structural relationship, in which the forces may no longer be injurious to the tissues Following remodeling, stabilization of resorption & formation occurs

29 Trauma from occlusion is reversible Inflammation inhibits potential for bone regeneration inflammation must be eliminated

30 Tooth mobility: Occurs during injury stage (injured PL fibers) Also occurs during repair/remodeling (widened PL space) Tooth mobility greater than normal BUT, Not considered pathologic unless tooth mobility is progressive in nature

31 Pain on chewing or percussion Tooth migration Attrition Fractured tooth Fremitus (tooth displacement created by the patient's own occlusal force)

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33 1. Increased width of the periodontal space 2. Thickened lamina dura: Lateral aspect of root Apical area Furcation areas 3. Vertical bone loss 4. Root resorption

34 1. Reduce/eliminate tooth mobility 2. Eliminate parafunctional habits 3. Prevent further tooth migration

35 Primary Occlusal Trauma: Remove the cause Soft diet for 3 weeks Selective grinding Habit control Orthodontic movement Night guard Secondary Occlusal Trauma: Treatment of Periodontal disease Splinting Selective grinding Orthodontic movement

36 1. Increasing tooth mobility 2. Progressive tooth migration 3. Premature contacts remain 4. No change in radiographs/worsening 5. Parafunctional habits remain 6. TMJ problems remain or worsen