Occlusion 2 Flashcards
What is used to mark tooth contacts?
- millers forceps
- fine articulating paper
Why is it a good idea to have 2 colours of articulating paper?
- one for static contacts
- one for contacts when moving
what is the function of millers forceps?
used to hold articulating paper on occlusal surfaces
when should you mark tooth contacts?
Before:
- preparing a tooth
- removing a restoration
After:
- placement of a crown (check guidance is correct)
- placement of a restoration (check you havent altered occlusion & margins aren’t on a direct occlusal contact)
In terms of ICP contacts, what are functional cusps?
cusps that occlude with the opposing teeth in the intercuspal position
- lingual cusps of the upper posterior teeth
- buccal cusps of lower posterior teeth
In terms of ICP contacts, what are non-functional cusps?
cusps that do not occlude with the opposing teeth in the intercuspal position
- buccal cusps of the upper posterior teeth
- lingual cusps of lower posterior teeth
In terms of ICP contacts, what is a fossa?
Depression or co concavity on tooth surface
- functional cusp of a tooth contacts the fossa of the opposing tooth
What is meant by Class II div 1 incisor relationship?
increased overjet
What is meant by Class II div 2 incisor relationship?
overbite is increased
What is an overbite?
Increased vertical overlap of the incisors
what is the normal range for an overbite?
2-4mm
What does a large overbite make the patient more susceptible to?
Trauma
What is a crossbite?
One or more teeth may be abnormally malpositioned buccal or lingually or labially with reference to opposing teeth
What is a mutually protected occlusion?
when mandible moves to the left (working side), contact ONLY between canines, NO posterior tooth contacts (a space)
How would you check for a mutually protected occlusion?
- place articulating paper
- get patient to move jaw to left or right (working side)
- remove articulating paper & look for marked line left on canine
What is group function (occlusion)?
Mandible moves to left (working side), multiple teeth in contact on the left
In which patients is bilateral group function frequently seen?
Toothwear patients !
Explain the movement of protrusion?
- condyle moves forwards and downwards on articular eminence
- only the incisors ± canines touch
- no posterior tooth contacts
What are occlusal interferences?
Undesirable tooth contacts that may produce mandibular deviation during closer to ICP or may hinder smooth passage to and form ICP
What are the different types of occlusal interference?
- working side
- non-working side
- protrusive
What is a working side occlusal interference?
When mandible moves to working side, there is an undesirable posterior contact between molars (similar cusps contacting)
What is a non-working side contact occlusal interference?
Mandible moves to working side and there is an undesirable contact on the non-working side (dissimilar cusps contact)
What is a protrusive interference?
any posterior contact during protrusion
Why do we want to avoid posterior contacts?
- Occlusal interferences cause significant lateral forces
- musculature is always activated (can cause TMJ pain, hypertrophy of muscles)
- can cause occlusal trauma
What is meant by eccentric bruxism?
- parafunctional grinding of teeth (side to side)
- oral habit consisting of gnashing, grinding or clenching
- leads to occlusal trauma
What is meant by centric bruxism?
Clenching
- pressing and clamping of the jaws and teeth together
what are the clinical signs and symptoms of bruxism?
- toothwear
- fractures restorations
- tooth migration
- tooth mobility
- muscle pain and fatigue
- headache
- earache
- pain and stiffness in the TMJ and surrounding muscles
What are the different types of toothwear?
- abrasion
- attrition
- erosion
- abfraction
What is occlusal trauma?
Injury resulting in tissue changes within the attachment apparatus, including periodontal ligament, supporting alveolar bone and cementum as a result of occlusal forces
What is fremitus?
palpable or visible movement of a tooth when subjected to occlusal forces
What are the examination of an occlusion checklist steps?
- incisor relationship
- guidance
- overjet/overbite
- ICP contacts
- working/non-working/protrusive contacts
- pathology
