Periodontal Considerations 2 Flashcards
Function of the peridontium (2)
- To attach teeth to jaws
2. To dissipate occlusal forces
What do loads dissipated along the long axis of teeth lead to? (3)
- Tension
- Compression
- Viscous forces
What are the 2 type of horizontal forces?
- CONSTANT
- Caused by orthodontics - INTERMITTENT
- Occlusal (jiggling)
- Less helpful, might be induced by parafunctional habits
Name some examples of parafunctional habits that can cause intermittent horizontal forces (2)
- Abnormal tooth contact
2. Arm on a clasp from a denture
Define excessive occlusal force
- Occlusal force that exceeds reparative capacity of the periodontal attachment apparatus
- Lead to occlusal trauma and/or causes excessive tooth wear (loss)
Define occlusal trauma
Injury resulting in tissue changes within the attachment apparatus, including PDL, supporting alveolar bone + cementum as a result of occlusal forces
Occlusal trauma may occur in an intact periodontium or in a reduced periodontium caused by periodontal disease
What is tooth mobility influenced by (4)
- Width of PDL
- Height of PDL
- Inflammation
- Number, shape and length of roots
Tx to reduce tooth mobility (3)
- Control of plaque-induced inflammation
- Correction of occlusal relations
- Splinting
Define primary occlusal trauma (2)
- Injury resulting in tissue changes from excessive occlusal forces applied to a tooth with normal periodontal support
- It occurs in the presence of normal clinical attachment levels, normal bone levels and excessive occlusal forces
What is the response of the healthy periodontium to primary occlusal trauma (4)
- 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 before physiological
- If demand is reduced, PDL width should return to normal
What happens if the excessive loading demand is more than the adaptive capacity of the PDL? (3)
- PDL width may continue to increase
- PDL width + tooth mobility fail to reach a stable phase
- This failure of adaptation may be regarded as pathological
Histological changes on the pressure side when theres excessive occlusal loading? (7)
PRESSURE
- Increased vascularisation +permeability
- Hyalinsation/necrosis of the PDL
- Haemorrhage
- Bone resorption
- Thrombosis
RARER:
6. Root resorption
- Cemental tears
Histological changes on the tension side when theres excessive occlusal loading? (2)
- Elongation of the PDL fibres
- Apposition of alveolar bone + cementum
As a result of sustained occlusal trauma the density of the alveolar bone decreases, while the width of the pDL space increases
- Leads to increased tooth mobility
- Radiographic widening of the pDL space
What happens to bone under areas of pressure?
Bone resorbs (dissolves) away
Less alveolar bone, more widening of PDL space
What happens to bone under areas of tension?
More bone formation
Generally end up with a wider PDL space (which is a physiological adaption on the PDL)