OB9 - Dynamic Occlusion

Question 1

what is occlusion?

Answer 1

The contact relationships of teeth or equivalent

Question 2

what is articulation?

Answer 2

The dynamic relationships of the teeth when in sliding contact

Question 3

what is the jaw relationship?

Answer 3

Positional relationship which the mandible bears to the maxilla

Question 4

Name all the vertical jaw relationships and dimensions? (6)

Answer 4

• rest/ postural position
• intercuspal position
• retruded contact position
• occlusal vertical dimension
• rest vertical dimension
• freeway space

Question 5

what is the rest/postural position?

Answer 5

teeth are not together/slightly apart

Question 6

What muscles hold the mandible in place? (3)

Answer 6

• masseter
• temporalis
• medial pterygoid

Question 7

what is important about the rest position?

Answer 7

it remains reproducible throughout life in both dentate and edentulous subjects

Question 8

what is the intercuspal posistion?

Answer 8

maximal intercuspation / interdigitation

Question 9

What is retruded in the glenoid fossa in the retruded contact posistion?

Answer 9

condyles

Question 10

what is the clinical significance of the RCP?

Answer 10

• symmetrical retrusion

– gives a reproducible relationship between the maxilla
and mandible

Question 11

How far can the jaw retrude?

Answer 11

1-2mm posterior to ICP

Question 12

1-2mm posterior to ICP

Answer 12

Posterior fibres of the temporalis

Question 13

what is the occlusal vertical dimension?

Answer 13

the face height with the teeth in ICP measured between two arbitatry points governed by the height of the teeth

Question 14

What instrument could you use to measure the occlusal vertical dimension?

Answer 14

willis gauge

Question 15

what is the rest /Postural Vertical Dimension?

Answer 15

he face height with mandible in rest/ postural position that is measured between two arbitrary points and should not alter significantly throughout life

Question 16

what is the freeway space?

Answer 16

the space between teeth in rest position which is the difference between RVF and OVD

Question 17

what is the value range of the freeway space?

Answer 17

2-5mm

Question 18

What anatomical guide planes are involved in protrusion of the jaw? (3)

Answer 18

• incisal guidance
• cuspal inclines
• TMJ

Question 19

what is the working side?

Answer 19

• The side to which the teeth move

Question 20

what is the guidance of the working side?

Answer 20

•canine guidance •group function

Question 21

what is the non-working side?

Answer 21

The side away from which the teeth move

Question 22

What movement does the jaw undergo in wide opening?

Answer 22

Hinge (bottom compartment) and slide (top compartment)

Question 23

Explain what the condyle does on the working side when the jaw moves to the side?

Answer 23

The condyle rotates around the vertical axis and there is lateral bodily movement (bennett movement)

Question 24

Explain what the condyle does on the non- working side when the jaw moves to the side?

Answer 24

The condyle moves downwards, forwards over the eminence and medially

Question 25

what is the balanced occlusion concept ?

Answer 25

tooth contact during excursions at both working and non- working sides and this is difficult to achieve because teeth are rarely in contact and it cannot exist in a normal dentate occlusion

Question 26

what is masticatory efficiency ?

Answer 26

Experimental tests to define the capacity to reduce the size of food particles by chewing

Question 27

What three methods can you use to measure masticatory efficiency? (3)

Answer 27

• subjective measures
• measuring maximal biting force
• swallowing threshold test index

Question 28

What affects masticatory performance?

Answer 28

number of teeth in functioning occlusion