occlusion 3 Flashcards
arcon articulator
articulating condyle on lower - anatomically correct
average value articulators
- Bennet Angle set at 15o
- Condylar Guidance Angle set at 30o
semi-adjustable articulator
Allows you to set the Bennet and Condylar Guidance Angles

types of articulator used for diagnostic casts
Diagnostic casts are most effectively mounted on a semi-adjustable articulator with a retruded record
- see the full range of mandibular movements for occlusal diagnosis and evaluation
depends what you are doing – if not advanced re-org, average value should be fine
to mount maxillary cast need
facebow transfer
tools needed to do facebow transfer
On the clinic you will be presented with a box of components that are joined together to construct the facebow instrument
- reference plane locator
- bite forck
- registration paste
- transfer jig assembly
- ear bow
- marker
https://www.youtube.com/watch?time_continue=475&v=m91NcwEwE1M&feature=emb_logo

first step in facebow tranfer
Mark the anterior reference point
- Mark the anterior reference point on the patient’s right side using the Reference Plane Locator and Marker.
- This is 43mm apical to the incisal edge of the anterior teeth (12 ideally)
- It is the approximate position of the infraorbital foramen (1st bony reference)

2nd step in facebow transfer
Bite registration using the bite fork
- Bite registration paste applied to bite fork.
- Bite fork arm to the right and locating notch facing up
- Firmly seat to record cusp tips of maxillary teeth.
- You can use rigid wax or bite registration paste.
- Do not engage undercuts.
- Check that it is parallel with the patients’ coronal and horizontal planes
- Align the dental midline with the locating notch
- Indentations of maxillary teeth clearly visible to allow accurate repositioning and then mounting of the maxillary cast*
- Just want cusp tips, incisal edges – allows accurate positioning of maxillary cast

earbow
measures intercondylar distance
how to assemble the earbow and transfer jig
want numbers facing you
loosen the centre wheel to allow the earbow to open/close
attach the vertical shaft to the measuring bow with clamp marked 2 on the pt right and tighten with the finger screw on earbow
make sure fingers screws 1 and 2 are loose

how to assemble the facebow on the pt
Assemble the facebow on the patient by sliding the bitefork arm through clamp marked #2
Fit the measuring bow’s earpieces tightly into the patient’s ear.
- Tighten the centre wheel on the bow.
Raise or lower the bow so that the pointer aligns precisely with the anterior reference point. – marked at start
- If you are aligned with the reference point, tighten clamps #1 and #2. Be careful not to alter the bow while tightening the clamps.

before removing the facebow ensure
the bow is parallel to the interpupillary line and floor
Make sure that the #1 and #2 clamps are secure.
- Facebow registration complete

how to remove the facebow
- Loosen the finger screw on the measuring bow, slide open the bow, and remove the facebow from the patient.
- Detach the measuring bow from the transfer jig by loosening the finger screw.
- Disinfect
what does the facebow record
- The relationship of the maxilla to the hinge axis of rotation of the mandible
- We can now mount the maxillary cast in an equivalent relationship on the articulator
mounting lower casts needss
An interocclusal registration can be used to mount the mandibular cast in relation to maxillary cast already mounted on the articulator using the facebow transfer
2 choices of interocclusal registration to mount lower cast
Intercuspal Position (ICP)
- Conformative Approach
Retruded Contact Position (RCP)
- Reorganised Approach
ICP registration when not obvious to technician
wax wafer
silicone paste
ICP registration when there is free end saddles (casts cannot be hand articulated)
request record block
ICP registration when there are plenty of tooth contacts (ICP obvious to technician)
hand articulate
- multiple tooth contacts when the pt bites together
do not use material can make it work

wax wafer for interocclusal registration
- When there are enough teeth and the bite in ICP is obvious you don’t need wax.
- If too much wax is used and the lower cast is mounted like this the OVD will be increased and the restoration will be high in the bite when placed – now reorganised as confirmative bite changed
- When using wax you must ensure it is thin and cusp tips are visible

registration paste for bite registration
- When ICP will not be obvious to the technician
- Silicone paste that sets quickly
- A small amount is needed
- Too thick and it will increase the OVD
- Occlusal contacts must be visible through the material

registration postion options decided when
before embarking on treatment you must decide whether to place restorations in the existing occlusal scheme (conformative approach) or to change it deliberately (the reorganized approach).
- If the entire occlusal scheme is to be reorganized to create a new and stable position, the final restorations are made in the new ICP that coincides with RCP and may involve a change in the vertical dimension

NOT simple registration option
RCP registration WITH or WITHOUT OVD increase
ICP registration WITH OVD increase
REORGANISED APPROACH
simple registration option
ICP registration WITHOUT OVD increase
conformative approach












