Occlusion 3 Flashcards
What are the different types of articulator we can mount a cast on?
- Arcon
- Average value
- Semi-adjustable
Whats the difference between an average value and a semi-adjustable?
AVERAGE
- Bennets angle set at 15
- Condylar guidance angle set at 30
SEMI-ADJUSTABLE
- Allows you to set the bennet + condylar guidance angles
Where do we mark the anterior reference point for the face-bow? (3)
- Mark on patients right side using reference plane locator + marker
- 43mm apical to the incisal edge of the anterior teeth (12 ideally)
- Approximate position of the infraorbital foramen
What relationship does a face-bow record?
Relationship of the maxilla to the hinge axis rotation of the mandible
Next step after using face-bow?
Mount the maxillary cast in an equivalent relationship on the RCON articulator
What do we need to mount the lower cast?
We will need an inter-occlusal regi to mount mandibular cast in relation to maxillary cast already mounted on the articulator using the face-bow transfer
What are the 2 choices of inter-occlusal registration we can use for mounting a lower cast?
- ICP position
- Maximum intercuspation
- Comfortable bite - RCP
- Reorganised approach
What is an interocclusal regi?
How the teeth meet together
How do we record ICP regi if the ICP is:
NOT obvious to tech
Wax wafer or paste
How do we record ICP regi if the ICP is:
Obvious to tech
No material needed between teeth to accurately mount the casts
Plenty of tooth contacts
How do we record ICP regi if the ICP:
Has a Free End Saddle
Record block needed
- Casts cant be hand articulated
Contraindication for using too much wax in wax wafer/registration paste (3)
- OVD will be increased
- Restoration will be high in the bite when placed
- When using wax must ensure it is thin + cusp tips are visible
What are our registration position options? (2)
RCP
ICP
RCP recrganised approach
RCP regi with/without OVD increase
NOT SIMPLE
ICP reorganised approach
ICP regi with OVD increase
NOT SIMPLE
Conformed approach
ICP regi without OVD increase
SIMPLE
What is the conformative approach defined as?
The provision of restorations in harmony with the existing jaw relationships
Means occlusal contacts of the other teeth should remain unaltered from the new restorations occlusion
When do we NOT use the conformative approach? (4)
- An increase in vertical height is needed to make space for restorations
- Tooth/teeth significantly out of position
- Overerupted
- Tilted
- Rotated - A significant change in appearance is wanted
- Toothwear
- Short teeth - Hx of occlusal related failure/fracture of existing restorations
- Something may be wrong with occlusion so change existing occlusal scheme
Does the reorganised approach change the occlusion?
Provides restorations which change the occlusion but are well tolerated by the patient
When would we want to use the reorganised approach? (2)
- ICP is non-existent or no use
2. You need space to place restorations
How do we find the retruded contact position?
- Patient guided into a terminal hinge closure to detect where initial tooth contact occurs (RCP)
Techniques used to find RCP (3)
- Bimanual manipulation
- Chin point guidance
- Chin point guidance with anterior jig
What materials can be used to register RCP registration?
- Wax
- Paste
- Record block
When restoring anterior teeth:
What do we do about guidance?
- Copy the existing guidance
- Simple
- Conformative
- Most often - Change guidance
- Not simple
- Reorganised
- Less often
Occlusal analysis checklist (9)
- TMJ function + MOM activity
- Incisor relationship
- Molar relationship
- Xbites
- Guidance
- Wear facets/severity of tooth wear
- Resto fractures
- Occlusal contacts
- Working/non working side contacts
