Occlusion and the periodontal tissues Flashcards
what is the function of the periodontium
To attach the teeth to the jaws
To dissipate occlusal forces
What are the horizontal forces on the perio
Constant - Orthodontic
Intermittent – Occlusal (Jiggling)
What is meant by excessive occlusal force
occlusal force that exceeds the reparative capacity of the periodontal attachment apparatus, which results in occlusal trauma and/or causes excessive tooth wear
What is meant by occlusal truama
a term used to describe injury resulting in tissue changes within the attachment apparatus, including periodontal ligament, supporting alveolar bone and cementum, as a result of occlusal force
When can occlusal trauma occur
in an intact periodontium or in a reduced periodontium caused by periodontal disease
What effects tooth mobility
Width of PDL
Height of PDL
Inflammation (prescnece or abscence)
Number, shape and length of roots
What happens if there occlusal force with normal alveolar bone levels
There is not a lot of movement as the fulcrum is higher for the mobility at the coronal level
What happens if there is occlusal force on reduced bone levels
There is increased tooth mobility as the fulcrum is much lower at the apical level
What does tooth mobilty indicate
does not, necessarily, represent a pathological state of affairs, but may:
Indicate successful adaptation of the periodontium to functional demands and/or reflect the nature of the remaining attachment
It could be a adaptive reaction response to long or severe occlusal trauma
when can tooth mobilty not be accepted
When it is progressively increasing
It gives rise to other symptoms
Creates difficulty with restorative treatment
What therapy would you use to reduce tooth mobility
Control of plaque-induced inflammation.
Correction of occlusal relations.
Splinting
What is primary occlusal trauma
Injury resulting in tissue changes from excessive occlusal forces applied to a tooth or teeth with normal periodontal support. It occurs in the presence of normal clinical attachment levels, normal bone levels, and excessive occlusal force
What happens in the healthy periodontium in response to occlusal truama/force
PDL width increases until forces can be adequately dissipated, the PDL width should then stabilise
Tooth mobility will be increased as a result
This can be regarded as successful adaptation to increased demand and therefore physiological
If demand is subsequently reduced, PDL width should return to normal
In healthy periodontium what happens if the occlusal force is to great or the adaptive capacity is not enough
If the demand of occlusal forces is too great or the adaptive capacity of the PDL reduced, PDL width may continue to increase
PDL width and tooth mobility fail to reach a stable phase
This failure of adaptation may be regarded as pathological
What is the histological basis of the changes in healthy periodontium to occlusal forces
zones of tension and pressure within the adjacent periodontium.
location and severity of the lesions vary based on the magnitude and direction of applied forces.
on the pressure side, these changes may include increased vascularization and permeability, hyalinization/necrosis of the periodontal ligament, hemorrhage, thrombosis, bone resorption, and in some instances, root resorption and cemental tears.
on the side of tension, these changes may include elongation of the periodontal ligament fibers and apposition of alveolar bone and cementum.
Collectively, the histologic changes reflect an adaptive response within the periodontium to occlusal trauma.
As a result of sustained occlusal trauma, the density of the alveolar bone decreases while the width of the periodontal ligament space increases,
leads to increased tooth mobility
As a result of bone resorption the periodontal ligament space gradually increases in size on both sides of the teeth as well as in the periapical region. When the effect of the force applied has been compensated for by the increased width of the periodontal ligament space
What is secondary occlusal trauma
injury resulting in tissue changes from normal or excessive occlusal forces
applied to a tooth or teeth with reduced periodontal support.
It occurs in the presence of attachment loss, boneloss, and normal/excessive occlusal force
Basically if theres already reduced periodontium
What is fermitus
palpable or visible movement of a tooth when subjected to occlusal forces
What is the clinical diagnosis of occlusal trauma
progressive tooth mobility
fremitus
occlusal discrepancies/disharmonies
wear facets (caused by tooth grinding)
tooth migration
tooth fracture
thermal sensitivity
root resorption
cemental tear
widening of the periodontal ligament space upon radiographic examination
Why is there tooth migration in occulsal truama/excessive force
The exessive occlusal force on teeth with already perio will spread them apart like a ‘fan’
Loss of periodontal attachment
Unfavourable occlusal forces
Unfavourable soft tissue profile
Does occlusion and periodontitis have an association with vertical bone defects
No
What happended in the Fan and Caton J Clin Periodontol study on animals
In the beagle dog model, when occlusal trauma was superimposed on periodontitis, there was an accelerated loss of connective tissue attachment.
In the Rat model loss of connective tissue attachment at the onset of experimental periodontitiswas increased when inflammation was combined with occlusal trauma
what was the conclusion of Fan and Caton J Clin Periodontol
without plaque‐inducedinflammation, occlusal traumadoesnot cause irreversible bone loss or loss of connective tissueattachmenti.e.periodontitis
How would you manage tooth migration
Treat the periodontitis
Correct occlusal relations
Either:
(a) Accept the position of the teeth and stabilise or
(b) Move the teeth orthodontically and stabilise
What are abnormal occlusal contacts associated with
significantly deeper probing depths, greater clinical attachment loss and increasedassignment to a less favourable prognosis
