Intro

Question 1

Why study occlusion?

Answer 1

Failure of routine restorations
-e.g. fractures
-fractured teeth and restorations could be due to bruxism
Over eruptions and tilting (of UR6 and UR7)
Large under contoured amalgam (on LR6)

Question 2

ICP

Answer 2

The position of the mandible when there is maximum intercuspation of the teeth

Question 3

RCP

Answer 3

First point of contact in the centric relation arch

First tooth that meets when condyles are fully seated in glenoid fossa

Question 4

Centric relations

Answer 4

Relation of the mandible to the maxilla when the condyles are seated in midmost uppermost position in the glenoid fossa
Jaw position, nothing to do with teeth
20-25mm of pure rotation when the condyles are fully seated in the glenoid fossa
A hinge movement

Question 5

Lateral excursions

Answer 5

Side to side
Working side (side the jaw is moving to)
-guidance can be canine guidance or group function
Non-working side (the side opposite to which jaw is moving)

Question 6

Protrusive excursions

Answer 6

Starting from ICP teeth are kept touching each other and mandible moved forward slowly
Teeth in contact during this movement said to be in protrusive guidance
One of main factors which determines which teeth are in protrusive guidance is the incisor classification

Question 7

Working and non-working side

Answer 7

Working side: the side the jaw is moving to
-guidance can be canine guidance/ group function
Non-working side - the side opposite **

Question 8

RCP vs ICP

Answer 8

Usually do not coincide

We can close to RCP then SLIDE to ICP

Question 9

RCP vs ICP

Answer 9

Usually do not coincide

We can close to RCP then SLIDE to ICP

Question 10

Protusive guidance - class II division 1

Answer 10

Shallow anterior guidance

Initial guidance may be on posteriors

Question 11

Protusive guidance - class II division 2

Answer 11

Very steep overbite results in steep guidance on anterior teeth

Question 12

Protrusive guidance - class III

Answer 12

Very little/ no/ negative overbite results in minimal/ no guidance on anterior teeth in protrusion
Posterior teeth will guide in protrusive movements

Question 13

Protrusive guidance - class I

Answer 13

Protrusive excursion usually on the incisors

Question 14

Protrusive guidance - anterior open bite

Answer 14

No contact between anterior teeth

Posterior teeth will guide in protrusive movements

Question 15

Non working side

Answer 15

Posterior teeth on non-working side should ideally separate in order to avoid destructive forces on inclines of teeth
Non-working side contacts (also known as interferences) can lead to failed restorations and occlusal disharmony

Question 16

Centric relation manipulation

Answer 16

Dorsum hold? **

Question 17

1. ICP contacts

Answer 17

Check contacts using shimstock +/- GHM paper (finer paper with finer ink)
Dry tooth
Tap tap tap
AND/ OR shimstock paper, try to pull it out and if it doesn’t it’s in ICP

Question 18

GHM paper

Answer 18

19 microns thick

Excellent for detailed occlusal analysis

Question 19

Shimstock foil

Answer 19

8 microns thick

Excellent for checking contact points

Question 20

4. Anterior guidance

Answer 20

Which teeth guide?
Use Shimstock +/- GHM paper - very slow movement
Posterior disclusion - are there any posterior contacts during protusive excursion?
Crossover interferences - some people can overlap the upper teeth with lower incisors

Question 21

5. Lateral excursions

Answer 21

Visually +/- GHM (Shimstock not as good)
Which teeth guide the excursion? (canine guidance or group function)
Ask px to move jaw very slowly
Any non-working side contacts?

Question 22

Routine restorations

Answer 22

Look at starting point

1. Which teeth contact in ICP, RCP and is tooth involved in guidance?
2. Complete restoration
3. Now check ICP and RCP contacts again, and protrusive / lateral excursions

Question 23

Horseshoe articulating paper

Answer 23

Too thick

Only to be used for dentures

Question 24

Regular articulating paper

Answer 24

OK for most restorations but not for detailed occlusal analysis

Question 25

2. RCP contacts

Answer 25

Manipulate to centric relation
-firmly stabilise the head
-position fingers on lower border of mandible
-thumbs on symphysis
-with very gentle touch, manipulate so that jaw hinges slowly open and closed freely
-gentle but firm guiding of condyles upward with little fingers
Note first contact with GHM paper

Question 26

3. Slide from RCP to ICP

Answer 26

Slide from RCP to ICP - large or small?