Occlusion and the Periodontal Tissue

Question 1

What is the function of the periodontium?

Answer 1

To attach the teeth to the jaws
To dissipate occlusal forces

Question 2

What horizontal forces can be applied to teeth?

Answer 2

Constant force - orthodontic
Intermittent force - occclusal (jiggling) eg clasps causing rocking, bruxism
Teeth are not designed to be loaded horizontally

Question 3

What is excessive occlusal force?

Answer 3

Occlusal force that exceeds the reparative capacity of the periodontal attachment apparatus, which results in occlusal trauma and/or causes excessive tooth wear (loss)

Question 4

What is occlusal trauma?

Answer 4

Injury resulting in tissue changes within the attachment apparatus, including PDL, supporting alveolar bone and cementum, as a result of occlusal force(s)

Question 5

What determines tooth mobility?

Answer 5

Width of PDL
Height of PDL
Inflammation
Number, shape and length of roots

Question 6

When is tooth mobility significant?

Answer 6

If it is progressively increasing
If the patient is symptomatic
If it creates difficulty with restorative treatment

Question 7

How can tooth mobility be treated?

Answer 7

Control of plaque-induced inflammation
Correction of occlusal relations
Splinting

Question 8

What is primary occlusal trauma?

Answer 8

Injury resulting in tissue changes from excessive occlusal forces applied to a tooth or teeth with normal periodontal support
Normal clinical attachment levels, bone levels
Excessive occlusal forces

Question 9

What is secondary occlusal trauma?

Answer 9

Injury to the PDL which already has reduced support
Occurs when there is attachment loss, bone loss and normal/excessive occlusal force

Question 10

What is occlusal trauma?

Answer 10

Tooth mobility which is progressively increasing
May be associated with symptoms
Radiographic evidence of increased PDL width

Question 11

What is fremitus?

Answer 11

Palpable or visible movement of a tooth when subjected to occlusal forces
Put finger on tooth and get patient to bite and see if there is movement

Question 12

How is occlusal trauma diagnosed clinically?

Answer 12

Progressive tooth mobility
Fremitus
Occlusal discrepancies/disharmonies
Wear facets (caused by grinding)
Tooth migration
Tooth fracture
Thermal sensitivity
Root resorption
Cemental tear
Radiographic evidence of widened PDL

Question 13

What effect does periodontal therapy have on mobile teeth?

Answer 13

Decreased clinical attachment loss after PMPR
Increased clinical attachment loss over time
Mobile teeth do not respond as well as mobile teeth
No association drawn between mobility and occlusal forces

Question 14

What are the effects of periodontal therapy on teeth with occlusal discrepancies?

Answer 14

Deeper initial probing depths
More mobility
Poorer prognoses than those teeth without occlusal discrepancies

Question 15

How can occlusal relations be corrected?

Answer 15

Occlusal adjustment (selective grinding)
Restorations
Orthodontics

Question 16

How does occlusal therapy affect periodontal prognosis?

Answer 16

In the presence of occlusal trauma, occlusal therapy may slow the progression of periodontitis and improve the prognosis

Question 17

When is splinting carried out?

Answer 17

If mobility is due to advanced loss of attachment
If mobility is causing discomfort or difficulty chewing
If teeth need to be stabilised for debridement

Question 18

What is important to note when splinting?

Answer 18

Does not influence the rate of periodontal destruction
May create hygiene difficulties
Is a treatment of last resort

Question 19

What are the consequences of tooth migration?

Answer 19

Loss of periodontal attachment
Unfavourable occlusal forces
Unfavourable soft tissue profile

Question 20

How is tooth migration managed?

Answer 20

Treat the periodontitis
Correct occlusal relations
Either accept the position of the teeth and stabilise, or move the teeth orthodontically and stabilise

Question 21

How are vertical bone defects created?

Answer 21

If inflammation is greater than 2mm, horizontal bone loss will occur, sparing some alveolar bone

Question 22

What are the effects of excessive occlusal forces on gingival recession?

Answer 22

No correlation between mobility and gingival recession
No solid evidence on the effects of occlusal forces on non-carious cervical lesions and gingival recession