L26. Toothwear and Occlusion Flashcards
What is occlusion the study of?
Upper and lower teeth when they are closed together
Where are the teeth in the “rest position”? What is this determined by?
Slightly apart
Determined by neuro-muscular memory
What does ICP stand for and what does it mean?
Inter-cuspal position - when the teeth are fully occluded
In anterior ICP, where do the lower teeth’s incisal edge/canine tip rest?
Against the cingulum of upper teeth
Name 2 materials which can be placed between the teeth to check occlusion.
Shimstock
Dental tinfoil
Should the shimstock be removable when the teeth are fully occluded?
No
Name the material which marks teeth to check occlusion
Articulating paper
Give the 2 patterns of direction our jaw moves in when we eat.
Down, right diagonally down, up
Down, left diagonally down, up
Give 3 ways to check for a balanced occlusion
- Even and bilateral ICP
- Anterior teeth contact evenly when the mandible protrudes
- There is contact between teeth in the same arch and opposing arches
What is it called when the teeth don’t meet like in ICP?
RCP (retracted cuspal position)
What is frictional keratosis? Give an example of this
A type of white patch in the mouth. eg. white line from teeth grinding on cheek - linea abla
What is translation?
The movement of the jaw downwards and forwards.
What is canine guidance?
When the mandible is moved from side to side, the canines stop any lateral movement.
What is the other guidance type to canine guidance?
Group function - when the mandible swings laterally, if a few teeth tough, it is group function.
Name the apparatus dental casts can be placed in to represent mandibular movement.
Articulator
Name the 3 types of toothwear.
Attrition
Abrasion
Erosion
Describe dental attrition.
Loss of surface due to contact from occluding surfaces eg. grinding/bruxism.
What does bruxism result in on the teeth?
Wear facets.
What are wear facets caused by?
Parafunction - purposeless bruxism
What is erosion?
The loss of tooth by acid rather than bacteria. Can be caused by bulimia
What is abrasion and what causes it?
Abnormal rubbing from a non-dental product eg a toothbrush.
What is toothwear often caused by?
A combination of erosion, abrasion and attrition.
Give 2 suggestions as to how to restore toothwear, with cons of each.
Composite - stains over time
Porcelain - May be rejected by the gingivae
Give 3 examples of why a restoration could fail.
- Secondary (recurrent) caries
- Restoration or tooth fracture
- Pulp death
How can gingivitis be caused by crowns?
Poorly-fitting crown margins
Which 3 parts does an intra and extra-oral exam include?
Static and functional occlusion
signs of tooth wear
evaluation of restorations
