Occlusion 3

Question 1

3 types of articulators to mount casts?

Answer 1

• Arcon
• Average value
• Semi adjustable

Question 2

Two angles in used in average value articulator?

Answer 2

• Bennet Angle - 15
• Condylar guidance angle - 30

Question 3

What is the advantage of semi-adjustable articulator?

Answer 3

Allows you to set the Bennet and condylar guidance angle

Question 4

What are 4 components of a facebow?

Answer 4

• Bite fork
• Reference plane locator
• Earbow
• Transfer jig

Question 5

Where would you mark the anterior reference point when using the reference plane locator with the facebow?

Answer 5

43mm apical to the upper lateral incisor
* position of the infraorbital foramen

Question 6

What is the point of a facebow record?

Answer 6

• Transfer the relationship between the maxilla to the hinge axis of rotation of the mandible to an articulator

Question 7

How do you mount the lower cast?

Answer 7

Using an interocclusal registration to mount the lower to the upper

Question 8

What are the two positions to mount the lower casts?

Answer 8

• ICP (conformative)
• RCP (reorganised)

Question 9

4 materials to use to take interocclusal registration in ICP?

Answer 9

• No material - ICP obvious to technician
• Wax - ICP not obvious to technician
• Record blocks - free end saddles ( cannot hand articulate)
• Registration paste - ICP not obvious to technician

Question 10

What is the problem if too much wax was used when recording interocclusal registration ? and how to avoid this?

Answer 10

Increase in ICP, use thin wax and ensure cusp tips are visible

Question 11

Which approach would you consider when taking ICP registration with OVD increase?

Answer 11

Reorganised

Question 12

Which approach would you consider when taking ICP registration without OVD increase?

Answer 12

conformative

Question 13

Which approach would you consider when taking RCP registration with or without OVD increase?

Answer 13

Reorganised

Question 14

Define the conformative approach?

Answer 14

the provision of restorations in harmony with the existing jaw relationships

Question 15

What are tripod contact points in occlusion?

Answer 15

When functional cusps contact the opposing teeth in 3 points achieving occlusal stability

Question 16

When do we not use the conformative approach? (4)

Answer 16

• Increasing the OVD to make space for restorations
• When teeth are significantly out of position
• When a significant change in appearance is wanted
• History of fractures of existing restorations due to occlusal failure

Question 17

Define reorganised approach

Answer 17

the provision of restorations that change the current occlusion but is well tolerated by the patient

Question 18

3 reasons to take inter-occlusal registration in RCP?

Answer 18

• To create space for restorations
• ICP is not existent or not used by the patient
• Becuase RCP is a reproducible position of the mandible independent of teeth

Question 19

3 techniques to guide the patient in RCP to take interocclusal registration?

Answer 19

• Bimanual manipulation
• Chin point guidance
• Chin point guidance with anterior jig

Question 20

When taking a registration in RCP, when would you take the registration exactly?

Answer 20

• at a slightly increased OVD just before the initial tooth contact ( when the mandible is rotating along its terminal hinge axis)

Question 21

What is another name of initial tooth contact and where does this happen in posselts envelope?

Answer 21

• a centric relation premature contact
• At any point in the retruded arch of closure

Question 22

Where is RCP in relation to ICP?

Answer 22

infero-posterior to ICP by 0.5-2mm

Question 23

What is an important component of a mutually protected occlusion?

Answer 23

Canine guidance

Question 24

6 things to check when assessing occlusion?

Answer 24

• Incisor relationship
• Molar relationiship
• Severity of tooth wear
• TMJ and Mom function
• Contacts on the working and non working side
• Guidance