Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Restorative Dentistry > Occlusion > Flashcards

Occlusion Flashcards

1
Q

What type of joint is the TMJ?

A

Sinovial hinge joint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe how the TMJ achieves rotational movement/hinge movements?

A

This type of movement occurs during small mouth opening (up to 20mm)
Condyle and disc remains within the articular fossa.
The condyle rotates through the terminal hinge axis- this is an imaginary horizontal line through the rotational centres of the condyles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When taking a facebow, what are you measuring?

A

Recording the relationship of the maxilla to the terminal hinge axis of the condyles.

Allows us to mount the maxillary casts on an articulator to accurately reproduce what is in the mouth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe translation of the condyle?

A

Translation movement occurs when you start to open your mouth wider than 20mm.

Lateral pterygoids contract.
Condyle and the doc start to move anteriorly and downwards towards the articular eminence, until the condyle is over the articular eminence.
May also travel laterally.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a border movement?

A

When the mandible moves through the outer range of motion, reproducible movements occur, these are called border movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Posselt’s envelope?

A

Extremes of mandibular movement- border movements of the mandible in the sagittal plane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the components that make up Posselt’s envelope?

A

ICP- Intercuspal position
E- Edge to edge
Pr- Protrusion
T- maximum opening
R- retruded axis position
RCP- Retruded contact position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is ICP?

A

Intercuspal position- tooth position, regardless of condylar position.

Comfortable bite, maximum interdigitation of the teeth in the sagittal plane.

Rotational movement

Posterior teeth- lower buccal cusp and upper palatal cusp occlude with opposing fossae and marginal ridges of opposing teeth.

Anterior teeth- Lower incisal edge should occlude with the cingulum of upper teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is edge to edge?

A

Tooth position- incisal edges of upper and lower teeth touch as the lower teeth slide forwards from ICP, guiding on palatal surfaces of anterior teeth.

Condyle moving downwards and forwards until it is over the articular eminence- translational movement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is protrusion?

A

Condyle moved forwards and downwards on articular eminence.
Only incisors and canines touch
No posterior contacts
Eventually no tooth contacts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is maximum opening?

A

No tooth contacts
Mouth wide open
Full translation of the condyle over the articular eminence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the retruded axis position?

A

No tooth contacts
Most superior anterior position of the condylar head in the mandibular fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the retruded contact position?

A

First tooth contact when the mandible is in the retruded axis position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do you get the patient into RCP?

A

Get the patient to relax their jaw, tongue to the roof of the mouth and guide their condyle into the position that you have the initial posterior contact of the teeth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the ICP-RCP slide?

A

Ice is approximately 1mm anterior to RCP in 90% of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is lateral translation?

A

Also known as Bennet movement

Lateral pterygoid on the non-working side contracts, which causes the mandible to move towards the working side.

Bony wall in the Glenoid Fossa will stop the working side condyle from moving any further to the working side.

if the mandible moves towards the working side, it is the condyle on the non-working side that will move forwards and towards the working side.
Left condyle moves laterally and posteriorly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the Bennet Angle?

A

The path of the non working condyle in the horizontal plane during lateral excursion of the mandible.

18
Q

What can you use to mark tooth contacts?

A

Miller’s forceps
Articulating paper

19
Q

In terms of static occlusion, what would you want to look for in a a patient before considering what to restore?

A

Incisor relationship
Molar relationship
Overjet/Overbite
Crossbones
Open bites
Individual tooth contacts
RCP-ICP slide

20
Q

What is a functional cusp?

A

Cusps that occlude with the opposing teeth in the intercuspal position.
Upper palatal cusps and lower buccal cusps

21
Q

What is a non-functional cusp?

A

Cusps that do not occlude with the opposing teeth in the intercuspal position

Upper buccal cusps and lower lingual cusps

22
Q

Describe the teeth contacts when in ICP?

A

Upper palatal cusp and lower lingual cusp occlude with the opposing fossae of the upper molar

23
Q

What problems may be encountered in static occlusion, with regards to restoring teeth?

A

Incisor classification
Deep overbite
Anterior open bite
Posterior open bite
Large overjet
Crossbite

24
Q

What is canine guidance?

A

Mandible moves to the working side and the only tooth contact is on the upper and lower canines.
No posterior tooth contacts- posterior discussion in lateral excursions
No non-working/working side contacts

Also known as mutually protected occlusion- this is the gold standard.

25
Q

What is group function?

A

Mandible moves tot he working side and multiple teeth contact on the working side.

Frequently seen in toothwear.

26
Q

What is occlusal interference?

A

Undesirable tooth contacts that may produce mandibular deviation during closure to ICP or may hinder smooth passage to and from ICP.

27
Q

What are the 3 types of occlusal interference?

A

Working side contact- Mandible moves to the left and there is a contact posteriorly on the left side- similar cusp contact.

Non working side contact- mandible moves towards the left but there is contact posteriorly on the right side- dissimilar cusps contact.

Protrusion- when the mandible protrudes there is posterior contact- there should only be contact on incisors and canines.

28
Q

Why do we want to avoid posterior contacts?

A

Most teeth are not designed to absorb significant levels of force which are generated by occlusal interferences- especially molar teeth.

Occlusal trauma results and undesirable tooth movements.

29
Q

On an average value articulator, what is the Bennet angle and condylar guidance angle set at?

A

Bennet angle- 15 degrees
Condylar guidance angle- 30 degrees

30
Q

What is an advantage of a semi-adjustable articulator compared to an average value?

A

You can set the Bennet and condylar guidance angle to whatever you want.

31
Q

What are the components of a facebow?

A

Earbow
Reference plane locator
Bite fork
Transfer jig

32
Q

Describe the process of taking a facebow registration?

A

Mark the anterior deference point on the patient’s right side- 43mm apical to the incisal edge of 12- approximate position of the infraorbital foramen.

Bite registration paste or wax onto the bite fork and register the occlusion here- ensure dental midline is in line with the locating notch and do not engage undercuts.

Assemble the transfer jig into the ear bow.
Ear bow into patient’ ears
Tighten the centre wheel
Raise or lower the bow so that th pointer aligns precisely with the anterior reference point.
Bow should be parallel to the inter pupillary line.
Remove the facebow from the patient.
Detach and measuring bow from the transfer jig and disinfect.

Must then take an interocclusal record in order to be able to mount the lower cast (if the teeth cannot be hand articulated)
- can use conformative approach (ICP) or reorganised approach (RCP).

33
Q

What is the purpose of the ear bow?

A

Measures the intercondylar distance between the two condyles.

34
Q

What options are there for registering the occlusion in ICP?

A

No material- plenty of tooth contacts, ICP is obvious to the technician.
Wax- ICP is not obvious to the technician
Paste- ICP is not obvious tot he patient
Record block- free end saddles, casts cannot be hand articulated.

35
Q

What happens if you use too much wax or the wax is too hard when you record the occlusion?

A

The casts will be mounted in a way that increases the OVD and the restoration will be high in the bite when placed.

36
Q

What is the conformative approach?

A

The provision of restorations in harmony with the existing jaw relationships.

The occlusion of the new restoration is provided in such a way that the occlusal contacts of the other teeth remain unaltered.

37
Q

Under what circumstances would we NOT use the conformative approach?

A

An increase in vertical height is needed to make space for restorations- i.e. toothwear cases.

Tooth/teeth significantly out of position (i.e. over-erupted, tilted or rotated).

A significant change in appearance is wanted

There is a history of occlusally related failure or fracture of existing restorations.

38
Q

What is the reorganised approach?

A

Plan to provide new restorations to a different occlusion- the occlusion is defined before the work is started.

39
Q

Why might you want to do the re-organised approach?

A

ICP is non-existent or no use

You need space to place restorations

RAP is reproducible position of the mandible independent of teeth

40
Q

What techniques are used to get the patient into RCP?

A

Bimanual manipulation

Chin point guidance

Chin point guidance with anterior jig

The first initial contact in RCP can be anywhere on the retruded arc of closure- between R and RCP

41
Q

What materials can you use to register the occlusion in RCP?

A

Wax
Paste
Record block

Register just before the teeth contact in RCP- this will slightly increase the OVD.

Restorative Dentistry (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions