6 - Occlusion 2 Flashcards
What do you use to assess tooth contacts?
- articulating paper
- miller’s forceps
When should you mark tooth contacts?
- before prep
- removing a restoration
- after placing a restoration or crown
Define functional cusps.
- cusps that occlude with the opposing teeth in ICP
- lingual cusps of uppers
- buccal cusps of lowers
Define non-functional cusps.
- cusps that don’t occlude with the opposing teeth in ICP
- buccal cusps of uppers
- lingual cusps of lowers
Define ICP contact.
- when the lingual cusp of an upper molar contacts the fossa of a lower molar
- when the buccal cusp of a lower molar contacts the fossa of an upper molar
Define overbite.
Vertical overlap of incisors
What is the most common overbite?
Class II Div 2
Define overjet.
Relationship between upper and lower teeth in horizontal plane
Define AOB.
- anterior open bite
- lack of vertical overlap of anterior teeth when posterior teeth are in occlusion
Define posterior/lateral open bite.
Failure of contact between posterior teeth when teeth are in full occlusion
Define canine guidance.
- mandible moves laterally
- contact only between the working side canine
- no posterior contacts
- mutually protected occlusion
Define group function.
- mandible moves laterally
- multiple tooth contacts on working side
- bilateral group function seen in severe toothwear
Define protrusion.
- condyles move forwards and downwards
- only incisors ± canines contact
- no posterior contacts
Define occlusal interference.
Undesirable tooth contacts that may produce mandibular deviation during closure to ICP
What is a working side contact?
Posterior tooth contact on the working side (similar cusps contact)
What is a non-working side contact?
Posterior tooth contact on the non-working side (dissimilar cusps contact)
What is a protrusive interference?
Any posterior contact during protrusion
Why is it important to avoid posterior contacts?
- molars are designed to absorb force in the direction of the long axis
- undesirable tooth contacts prevent musculature from resting
- occlusal trauma
Define eccentric bruxism.
- side to side parafunctional grinding of teeth
- can be rhythmic, spasmodic or functional
- leads to occlusal trauma
Define centric bruxism.
- static clenching
- pressure and clamping of teeth together
- associated with physical exertion or acute nervous tension
What are the clinical signs of bruxism?
- toothwear
- fractured restorations
- tooth migration
- mobility
- muscle pain/fatigue
- headache
- earache
- TMJ symptoms
What are the different types of toothwear?
- multifactorial
- abrasion
- attrition
- erosion
- abfraction
Define abrasion.
Loss of tissue due to outside mechanical force (ie toothbrush)
Define attrition.
Loss of tissue due to tooth-tooth contacts
Define erosion.
Loss of tissue due to acid
Define abfraction.
Loss of tissue due to excess forces being applied causing fracture
