Occlusion and restorative dentistry 2

Question 1

What are the two ways you can examine the occlusion?

Answer 1

Dynamic or static.

Question 2

What are two ways that you can mark tooth contacts?

Answer 2

Miller forceps or fine articulating paper.

Question 3

Why do dentists use two colours of articulating paper?

Answer 3

One for static occlusion and one in the intercuspal position.

Question 4

When should you mark tooth contacts?

Answer 4

Before- preparing a tooth and removing a restoration

After- placement of a crown or placement of a restoration.

Question 5

What are the stops called that show where the ICP stops (opposing cusps contact)?

Answer 5

Tripodised contacts.

Question 6

What is another name for non-functioning cusps?

Answer 6

Balancing cusps.

Question 7

What is another name for functional cusps?

Answer 7

Working cusps.

Question 8

What are functional cusps in ICP?

Answer 8

Cusps that occlude with the opposing teeth in the intercuspal position
The lingual cusps of the upper posterior teeth and the buccal cusps of the lower posterior teeth.

Question 9

What are non-functional cusps in ICP?

Answer 9

Cusps that do not occlude with the opposing teeth in the intercuspal position
The buccal cusps of the upper posterior teeth and the lingual cusps of the lower posterior teeth.

Question 10

What are the ICP contacts?

Answer 10

The lingual cusp of an upper molar contacts the fossa of a lower molar
The buccal cusp of a lower molar contacts the fossa of an upper molar.

Question 11

In mm, what is the normal overbite?

Answer 11

2-4mm.

Question 12

What is a class 1 ackerly classification?

Answer 12

Incisor relationship- lower incisors impinge into palatal mucosa
Signs of trauma- inflammation of palatal mucosa with the imprint of lower incisal edges.

Question 13

What is a class 2 ackerly classification?

Answer 13

Incisor relationship- lower incisors incisal edge occlude into palatal gingival crevices of maxillary teeth
Signs of trauma- labial splaying of maxillary incisors.

Question 14

What is a class 3 ackerly classification?

Answer 14

Incisor relationship- Class 2 div 2 type of incisor relationship
Signs of trauma- stripping of the gingiva in relation to palatal surfaces of an upper teeth and labial surfaces lower anterior teeth.

Question 15

What is a class 4 ackerly classification?

Answer 15

Incisor relationship- lower incisor causing progressive abrasion of palatal surfaces of maxillary teeth
Signs of trauma- abrasion of palatal surfaces of upper anterior teeth, dentine hypersensitivity.

Question 16

What is an overjet?

Answer 16

Relationship between the upper and lower teeth in a horizontal plane.

Question 17

What are the two types of crossbite?

Answer 17

Posterior and anterior.

Question 18

What is a crossbite?

Answer 18

Cross bite is a condition where one or more teeth may be abnormally malpositioned buccal or lingually or labially with reference to opposing teeth.

Question 19

What is an anterior open bite?

Answer 19

Lack of vertical overlap of anterior teeth when posterior teeth are in full occlusion.

Question 20

What is a posterior/lateral open bite?

Answer 20

Failure of contact between the posterior teeth when the teeth are in full occlusion.

Question 21

What is canine guidance?

Answer 21

When the mandible moves to the left (working side)- contact only between the canines and no posterior tooth contacts (a space). This is what is known as a mutually protected occlusion.

Question 22

Why is canine guidance preferable?

Answer 22

The canines have big long chunky roots and withstand significant forces.

Question 23

What is the GOLD STANDARD mutually protected occlusion?

Answer 23

Canine guidance
Posterior disclusion in lateral excursions
No non-working/working side contacts
No protrusive interferences.

Question 24

What is group function?

Answer 24

Mandible moves to the left (working side), multiple teeth in contact on the left
Bilateral group function frequently seen in toothwear.

Question 25

What happens to the condyle on protrusion?

Answer 25

Condyle moves forwards and downwards on articular eminence.

Question 26

Is there posterior tooth contacts in protrusion?

Answer 26

No.

Question 27

What are occlusal interferences?

Answer 27

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

Question 28

What are the three types of occlusal interference?

Answer 28

Working side
Non-working side
Protrusive.

Question 29

What is a working side contact?

Answer 29

When there is a heavy or early tooth between the maxillary and mandibular teeth on the side that the mandible is moving towards, and this contact may or may not discludes the anteriors.

Question 30

What is a non-working side contact?

Answer 30

When there is a heavy or early tooth between the maxillary and mandibular teeth on the side that the mandible is moving away from, and this contact may or may not discludes the anteriors.

Question 31

What is protrusive interference?

Answer 31

Any posterior contact during protrusion.

Question 32

Why do we avoid posterior contacts?

Answer 32

Teeth are designed to absorb heavy forces in the direction of the long axis of the tooth. Most teeth are not designed to absorb significant lateral forces generated by occlusal interferences. Musculature gets a rest as less activity if not undesirable posterior contacts. Occlusal trauma and undesirable tooth movements.

Question 33

What are the two different types of bruxism?

Answer 33

Eccentric and centric.

Question 34

What is eccentric bruxism?

Answer 34

The parafunctional grinding of the teeth. An oral habit consisting of involuntary rhythmic or spasmodic or functional gnashing, grinding or clenching of the teeth in other than chewing movements of the mandible which may lead to occlusal trauma.

Question 35

What is centric bruxism?

Answer 35

Clenching: the pressing and clamping of the jaws and teeth together. Frequently associated with acute nervous tension or physical effort.

Question 36

What are some clinical signs and symptoms of bruxism?

Answer 36

Toothwear
Fractured restorations
Tooth migration
Tooth mobility
Muscle pain and fatigue
Headache
Earache
Pain and stiffness in the TMJ and surrounding muscles.

Question 37

What are the 5 categories of tooth wear?

Answer 37

Multifactorial
Abrasion
Attrition
Erosion
Abfraction.

Question 38

What are the different grades of tooth wear?

Answer 38

0- no loss of enamel surface characteristics
1- loss of enamel surface characteristics
2- buccal, lingual and occlusal loss of enamel, exposing dentine for less than one third of the surface, incisal loss of enamel and minimal dentine exposure
3- buccal, lingual and occlusal loss of enamel, exposing dentine for more than one third of the surface, incisal loss of enamel and substantial loss of dentine
4- buccal, lingual and occlusal complete loss of enamel, pulp exposure or exposure to secondary dentine, incisal pulp exposure or exposure of secondary dentine.

Question 39

What is the basic erosive wear examination criteria?

Answer 39

0- no erosive tooth wear
1- initial loss of surface texture
2- distinct loss of hard tissue under 50% of the surface area
3- hard tissue loss over 50% of the surface area.

Question 40

What is occlusal trauma?

Answer 40

Injury resulting in tissue changes within the attachment apparatus, including periodontal ligament, supporting alveolar bone and cementum, as a result of occlusal forces.

Question 41

What is primary, secondary and fermitus occlusal trauma?

Answer 41

Primary- intact periodontium
Secondary- reduced periodontium
Fremitus- palpable or visible movement of a tooth when subjected to occlusal forces.

Question 42

What is your examination checklist for examining occlusion?

Answer 42

Incisor relationship
Guidance
Overjet/overbite
ICP contacts
Working/non-working/protrusive contacts
Pathology.