Tooth wear and occlusion

Question 1

What are the parts of the articulatory system

Answer 1

Temporomandibular Joints (TMJs)
Occlusion
Muscles of Mastication

Question 2

What does the study of occlusion take into consideration

Answer 2

The close interrelationship between
the articulation of the teeth and the muscles of mastication and TMJ

Question 3

What are the types of occlusion

Answer 3

Static and dynamic

Question 4

What does static occlusion involve

Answer 4

Centric Occlusion (CO)
Habitual Bite
Maximum Intercuspation (MIP)
Intercuspal Position (ICP)

All terms for teeth fitting together

Question 5

What does dynamic occlusion involve

Answer 5

Mandibular Eccentric Movements
Lateral Excursion

The sideways movement of the mandible from a centric position

Question 6

How can we mark the occlusal contacts

Answer 6

Occlusal analysis armamentarium
Articulating papers held by miller forceps

Question 7

Why are different colours of
papers used in marking occlusal contacts

Answer 7

For identifying specific tooth contacts and to allow comparisons to be made

Question 8

What holders can be used for articulating papers

Answer 8

Miller forceps
Y-type articulating holder
Fix-clip bite frame

Question 9

What is the benefit of a bite-chek articulating film

Answer 9

Bite-Chek with its easy-grip handle,
requires no forceps, simplifing
checking the occlusion.
*There is no risk of biting forceps.
*No curling, handle hold the film flat.
*Handle keeps the gloves clean.
*Thin 19 micron film marks high points
accurately.
*Available in double-sided Black/Black or
Black/Red

Question 10

Why are thin papers used to show occlusion

Answer 10

To minimise contacts artefacts and clearly indicate tooth contact detail

Thick paper will mark a large area surrounding the point of contact and result in grinding of unnecessary tooth

Question 11

Why might ICP contacts be broad and rubbing

Answer 11

There may be underlying occlusal problems

Question 12

What does a large ring on colour with a much lighter internal segment indicate in occlusion

Answer 12

The lighter section is where the actual occlusion occurs while the surrounding area is from the high pressure squeezing out extra pigment

Question 13

What are wear facets

Answer 13

A type of non-carious lesion that
occurs when teeth rub against each other too much

Question 14

What are the supporting cusps in occlusal stability

Answer 14

Mandibular buccal
Maxillary palatal cusps

Question 15

What may excess colour from articulating papers indicate

Answer 15

Premature contact due to a high point on the tooth which will be more prone to fracture and should consider altering this

Question 16

What are the non-supporting cusps

Answer 16

Mandibular lingual
Maxillary buccal

Question 17

What causes axial loading

Answer 17

Reciprocal incline contacts (tripodization)

Question 18

How many reciprocating contact areas does each centric cusp have in relation to the opposing fossa in tripodization

Answer 18

3

Question 19

Where should the occlusion from a cusp be

Answer 19

On a fossa or marginal ridge for stability

Question 20

If a cusp only has a single contact with an opposing tooth what can occur

Answer 20

Allows for unwanted tilting and overeruption

Question 21

When should tripodization be used

Answer 21

When contact point of the cusp cant be in line with the fossa so tripodization is the next best option

Question 22

What can cause a mediotrusive contact

Answer 22

The new posterior restoration has been
overcarved, resulting in a lack of contact with the mandibular buccal cusp

After a time the mandibular tooth shifts to a more stable occlusal position, which
re-establishes contact between the mandibular buccal cusp and the restoration

Although the ICP is now stable, a
mediotrusive contact has
resulted

Question 23

Why should occlusal contacts on tooth-restorative interface be avoided

Answer 23

Dental restorative materials, while durable, may not withstand the full force of occlusion over time as well as natural tooth enamel. Excessive pressure can lead to
material fracture or debonding

Question 24

What is T scan

Answer 24

A digital tool used to analyse occlusal forces.
It provides a detailed understanding
of the patient’s bite and how their
teeth come together

Question 25

How can we detect the infra-occluded restoration

Answer 25

Shimstock is used to check firmness of occlusal contacts in
comparison with those on the selected index teeth

Question 26

What is the thickness of shimstock

Answer 26

8 microns

Question 27

What is group function

Answer 27

Multiple contact relations between
the maxillary and mandibular
teeth in lateral movements (Canine
are included)

Question 28

What is canine guidance

Answer 28

The lower canines guide the mandible during lateral excursions of the jaw
This means that when the jaw moves to the side, the contact between the upper and lower canines prevents the posterior teeth from touching

Question 29

How can we check that a new crown fulfils proper occlusion

Answer 29

The shimstock is still held after restoration as it did in between the natural teeth

Question 30

When is occlusion improtant

Answer 30

Reduce Risk of Fracture/wear/ Failure
- Tooth
- Restoration

Question 31

What should be remembered when placing or adjusting restorations considering occlusion

Answer 31

The periodontal ligament able to detect materials between teeth down to half the thickness of human hair

Question 32

What is the ‘conformative’ approach

Answer 32

Consideration of the occlusal scheme is made according to the patients existing intercuspal position, and new restorations are provided in harmony with the
existing jaw relationships

Question 33

How are dental loupes beneficial in occlusion

Answer 33

The use of loupes will facilitate removal of excess and reduce the risk of damage to marginal enamel

Allows a better working posture of <25 degrees avoid bending over the oral cavity