Occlusion 3 Flashcards
What type of articulators are there
arcon
average value
semi adjustable
What is the angles used on an average value articulator
bennet angle is set at 15 degrees
the condylar guidance angle is set at 30
What is a semi-adjustable articulator
it allows you to set the bennet and condylar guidance angles
What do face bow transfers allow
the transfer of the maxillary cast onto the articulator
How do we mount the mandibular cast in relation to the face bow transferred maxillary cast
inter occlusal reg
What are the components of the face bow
bite fork
transfer jig assembly
earbow
reference plane locator
What are the steps of doing a face bow transfer
- mark the anterior ref points
- bite registration using bite fork
- assemble ear bow and transfer jig
How do we mark the anterior reference point
on the patient’s RHS using the reference plane locator and marker
Where is the anterior reference point
43mm apical to the incisor edge to the anterior teeth (12 ideally)
What does the anterior reference point approximate
position of infraorbital foramen
How is the bite registrations taken
bite registration paste is applied to the bite fork
the bite fork arm to the right and locating notch faces up
firmly seat to record the cusp tips of the maxillary teeth
do not engage undercuts
check that it is parallel with patients coronal and horizontal planes
How do we align the bite fork
align the dental midline with the locating notch
What should we able to see in the bite reg
indentations of maxillary teeth clearly visible to allow accurate repositioning and then mounting of the maxillary cast
How do we assemble the ear bow and the jig
loosen the centre wheel to allow the ear bow to open and close
attach the vertical shaft to the measuring bow with clamp marked 2 on the patient’s right and tighten the finger screw on the ear bow
How do we assemble the face bow on the patient
by sliding the bite fork arm through the clap marked 2
fit the measuring bow’s earpieces tightly into 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
if you are aligned with the reference point, tighten the clamps 1 and 2
be careful not to alter the bow while tightening the clamps
How do we remove the face bow
ensure bow is parallel to the inter pupillary line and floor
make sure the 1 and 2 clamps are secure
loosen the finger screw on the measuring bow, slide open the bow and remove the face bow from the patient
detach the measuring bow from the transfer jig by loosening the finger screw
disinfect
What have we recorded so far
the relationship of the maxilla to the hinge axis of rotation of the mandible
now we can mount the maxillary cast in an equivalent relationship on the articulator
What are the two choices of inter occlusal reg that can be sued to mount the lower cast
ICP (confirmative approach)
RCP (reorganized approach)
When we can we use no material for ICP reg
When the intercuspal is obvious
there is multiple tooth contacts when the px bites together
When can we use wax or paste for ICP reg
when ICP is not obvious to the technician
When do we use a record block for ICP reg
when there’s free end saddles and the casts cannot be hand articulated
What can happen if too much wax is used
the OVD is increased and the restoration will be high in bite when placed
when using wax ensure it is thin and cusp tips are visible
What is the registration paste
silicone paste sets quickly small amount is needed too thick and it will increase the OVD occlusal contacts must be visible through the material
What are the registration position options
RCP registration WITH or WITHOUT OVD increase (reorganized approach)
ICP registration WITH OVD increase (reorganized approach)
ICP registration WITHOUT OVD increase (confirmative approach)
