Occlusion

Question 1

What is occlusion?

Answer 1

When the upper and lower teeth come into contact

Question 2

What are the 2 main types of occlusion?

Answer 2

Static occlusion

Dynamic occlusion

Question 3

What is static occlusion?

Answer 3

Contacts between teeth when the mandible is closed and is stationary

Question 4

What is dynamic occlusion?

Answer 4

Contacts between teeth when the mandible is moving relative to the maxilla

Question 5

What is ICP and what occlusion does it relate to?

Answer 5

Intercusp position

Relates to static occlusion

Question 6

What is ICP?

Answer 6

When teeth fit together in maximum intercuspation

Question 7

What bite is ,ost easily recorded?

Answer 7

ICP

Question 8

Overjet vs overbite?

Answer 8

Overjet = horizontal overlap
Overbite = vertical overlap

Question 9

Describe class 1 occlusion?

Answer 9

Ideal position of the molars

mesio-buccal cusp of the maxillary first permanent molar occludes with the mesio-buccal groove of the mandibular first permanent molar.

Mandibular incisor edges over/just in front of the Cingular of the maxillary incisors

Question 10

What is class 2 occlusion?

Answer 10

Mand. Incisal edges behind the Cingular of max incisors

MB cusp of max 1 molar anterior to the MB groove on mand 1st molar

Question 11

What is class 2 division 1 occlusion?

Answer 11

Characterised by proclaimed layers, and central incisors

Question 12

What is class 2 division 2 occlusion?

Answer 12

Characterised by proclaimed lateral incisors and retroclined central incisors

Question 13

What is class 3 occlusion?

Answer 13

Mandibular incisal edges are anterior to the cingulum of the maxillary incisors or in reverse relationship to the incisors, edges

MB cusp of max 1st molar sits posterior to the MB of the mandibular 1st molar

Question 14

Answer 14

Question 15

What is malocclusion?

Answer 15

When the teeth are not occluding in an ideal position

Question 16

Why is this class 1 malocclusion?

Answer 16

There is crowding

Question 17

What are the functional cusps?

Answer 17

Palatal cusps of the maxillary posterior teeth

Buccal cusps of the mandibular posterior teeth

Question 18

What is the role of functional cusps?

Answer 18

Maintain vertical dimension of occlusion

They transmit occlusal forces axilally

They may be involved in interference

Question 19

What is dynamic occlusion?

Answer 19

Contacts between teeth when the mandible is moving relative to the maxilla

Mandible is moved by the muscles attached to the mandible

Movement of the mandible is influenced by 2 guidance systems

Question 20

What 2 guidance systems influence movement of the mandible?

Answer 20

Posterior and anterior determinants

Question 21

What are the posterior determinants?

Answer 21

Anything to do with TMJ

Question 22

What are the 2 TMJ systems?

Answer 22

The TMJ joint

TMJ ligament and joint capsule

Question 23

What are the 2 main movements of the TMJ?

Answer 23

Rotation

Translation

Question 24

What is the translation movement of the TMJ?

Answer 24

Movement of the head of the condyle downwards and forwards along the distal face of the articular eminence of the glenoid fossa on the intra-articular disc

Question 25

What are the anterior determinants?

Answer 25

The guidance by teeth e,g, molars

Question 26

What is the working side?

Answer 26

Is the side of the mandible towards which the mandible is moving during lateral excursion The side to which the mandible moves

Question 27

Is canine guidance involved in dynamic occlusion?

Answer 27

Yes

Question 28

During lateral excursions, what teeth are preferable for guidance?

Answer 28

Teeth towards the front of the mouth, I.e. premolars as opposed to molars

Question 29

What are the 2 types of guidance during lateral excursion?

Answer 29

Group or canine

Question 30

What occurs on the non-working side during lateral excursion?

Answer 30

Disocclusion/excursion

Question 31

What is mutually protected occlusion?

Answer 31

A dynamic occlusal relationship in which the posterior teeth contact in maximum intercuspation, but not in lateral or protrusive movements Anterior teeth protect the posterior teeth during excursion movements The posterior teeth protect the anterior teeth in maximum intercuspation

Question 32

What is christensen’s phenomenon?

Answer 32

The triangular space between the maxillary and mandibular posterior teeth bilaterally during protrusion This gap is caused by the incline of the articulation eminence

Question 33

What causes the christensen’s phenomenon?

Answer 33

The gap is caused by the incline of the articulation eminence

Question 34

When can occlusal interference occur?

Answer 34

Any occlusal contacts during mandibular excursion

Question 35

What is occlusal interference?

Answer 35

Amy occlusal contact(s) during mandibular excursions that may interfere with the smooth movement and guidance of the mandible in relation to the maxilla

Question 36

What can cause restorations to fail over time?

Answer 36

An interference from posterior teeth on the non working side during lateral excursion may cause restoration to fail over time