Periodontics › Aetiology
Trauma from Occlusion
High-yield revision notes with linked practice questions, written for dental students and candidates preparing for the ADC and other licensing examinations.
High-yield notes
Most common type of trauma from occlusion is the chronic TFO.
Primary trauma from occlusion occurs if trauma from occlusion is considered the primary etiologic factor in periodontal destruction.
In primary TFO, supracrestal gingival fibers are not affected and therefore prevent apical migration of the junctional epithelium.
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. This reduces the periodontal attachment area and alters the leverage on the remaining tissues.
If jiggling forces are exerted, the areas of pressure and tension may coexist in the same area, hence it is the most harmful type of force
Slightly excessive pressure stimulates resorption of the alveolar bone, with a resultant widening of the periodontal ligament space.
Slightly excessive tension causes elongation of the periodontal ligament fibers and apposition of alveolar bone.
The areas of the periodontium most susceptible to injury from excessive occlusal forces are the furcations
Trauma from occlusion is reversible.
The presence of inflammation in the periodontium as a result of plaque accumulation may impair the reversibility of traumatic lesions.
The marginal gingiva is unaffected by trauma from occlusion because its blood supply is not affected, even when the vessels of the periodontal ligament are obliterated by excessive occlusal forces.
Trauma from occlusion does not cause pockets or gingivitis nor does it increase gingival fluid flow.
Supragingival plaque can become subgingival if the tooth is tilted orthodontically or migrates into an edentulous area, resulting in the transformation of a suprabony pocket into an intrabony pocket.
Inflammation, in the presence of TFO may proceed to the periodontal ligament rather than to the bone. Resulting bone loss would be angular, and pockets could become intrabony.
Practice questions
Select an option to check your answer. Answers are shown below each question.
The effect of occlusal forces on the periodontium is influenced by the
- AMagnitude and Direction
- BDuration
- Cfrequency of the forces
- Dall of the above
The most dangerous type of force to the periodontium is
- AVertical force
- BOcclusal force
- CJiggling force
- DHorizontal force
When occlusal forces is very high but is within the range of adaptive capacity of the periodontal tissues,
- ATrauma from occlusion results
- BOcclusal trauma results
- CWidening of periodontal ligament occurs
- DPeriodontal necrosis occurs
When trauma from occlusion is the result of reduced ability of the tissues to resist the occlusal forces, it is known as
- AAcute trauma from occlusion
- BChronic trauma from occlusion
- CPrimary trauma from occlusion
- DSecondary trauma from occlusion
TFO associated with parafunctional habits are most likely to be
- AAcute trauma from occlusion
- BChronic trauma from occlusion
- CPrimary trauma from occlusion
- DSecondary trauma from occlusion
Lipping is seen in which stage of TFO?
- AStage of injury
- BStage of repair
- CStage of adaptive remodeling
- DAll stages show lipping
Not a feature of TFO
- AAngular bone loss
- BFunnel shaped widening of the ligament
- CAbsence of tooth mobility
- DAbsence of pocket formation
Repair phase of trauma from occlusion shows
- Aincrease in areas of resorption and a decrease in bone formation
- Bdecreased resorption and increased bone formation
- Cresorption and formation are balanced
- Dinconsistent pattern of resorption and formation.
Insufficient occlusal force may cause
- Aosteoporosis of the alveolar bone
- Breduction in bone height
- Cthinning of the periodontal ligament with atrophy of the fibers
- Dall of the above
The most common clinical sign of trauma to the periodontium is
- AIncreased pocket depth
- BBleeding on probing
- CIncreased tooth mobility
- DEdema of the gingiva
All are signs of periodontal trauma except
- APain
- BMobility
- CHypersensitivity
- DBleeding
Mobility of teeth due to occlusal trauma can be tested by
- APercussion of tooth
- BDigital palpation
- CShimmock paper
- DBite marking paper
The load on the tooth that is most destructive to the periodontium ``` ```
- AVertical
- BOblique
- CHorizontal
- DApical
Tissue changes occurring in teeth no longer in function ``` ```
- AWidening of PDL
- BIncreased trabeculation
- CCemental atrophy
- DAll
In ''Jiggling ''type of trauma, the occlusal force causes
- Afunnel shaped destruction of the socket wall
- Bdistinct pressure and tension sides within the periodontal ligament
- CNo change in the socket wall
- DHas no effect on periodontal ligament space
TFO doesn't affect ``` ```
- AAlveolar bone and enamel
- BCementum and enamel
- CGingiva and epithelial attachment
- DPDL and cementum
These notes are compiled from standard periodontology texts for study purposes. They are a revision aid, not a substitute for your own reading or current clinical guidelines. If you spot an error, please leave a comment.