Occlusion 1

Question 1

What muscles are involved in mandibular movement?

Answer 1

1. Muscles of Mastication
   - Involved in depression, elevation + lateral movements of the mandible
2. Suprahyoid Muscles
   - Elevate the hyoid bone or depress the mandible

Question 2

List the muscles of mastication (4)

Answer 2

1. Temporalis
2. Lateral Pteryogid
3. Medial pterygoid
4. Masseter

Question 3

Function of temporalis

Answer 3

Elevates + retracts mandible

Assists in rotation

Question 4

Function of lateral pterygoid

Answer 4

• Lateral movement + protrusion + depression

Question 5

Function of medial pterygoid

Answer 5

• Elevates mandible

- Lateral movement + protrusion

Question 6

Function of the masseter

Answer 6

• Elevates + protracts the mandible

- Assists in lateral movement

Question 7

What are the 2 main mandibular movements?

Answer 7

1. Rotation
2. Translation:
   - Lateral translation

Question 8

Occlusal vertical dimension

Answer 8

Teeth clenched together

Question 9

Resting vertical dimension

Answer 9

Resting position of TMJ

- Mouth slightly open, lips together and teeth not in contact

Question 10

What type of movements occur in rotation?

Answer 10

Hinge movements

- Rotation of the condylar heads

Question 11

Function of a facebow (2)

Answer 11

Recording relationship of maxilla to:

1. Terminal hinge axis
2. Distance between the condyles

Question 12

Translation of the condyle steps (4)

Answer 12

1. Lateral pterygoid contracts
2. Articular disc + condyle begin to move
3. Travels downwards + forwards along the incline of the articular eminence
4. May also travel laterally (laterotrusive movement)

Question 13

What does posselts envelope show? (3)

Answer 13

Border movements of the mandible in the:

1. Frontal plane
2. Sagittal plane
3. Horizontal plane

Question 14

What do the:

1. Letters
2. Lines

In Posselts Envelope relate to?

Answer 14

1. Letters
   - Tooth positions
2. lines
   - Jaw position

Question 15

What does:

ICP
E
PR
T
R
RCP

Stand for

Answer 15

ICP - Intercuspal position

E - Edge to edge

PR - Protrusion

T - Maximum opening

R - Retruded axis position

RCP - Retruded contact position

Question 16

What is ICP? (3)

Answer 16

• Comfortable bite
• Max interdigitation of teeth
• Can be called centric occlusion

Question 17

What is edge to edge? (2)

Answer 17

• Teeth slide forward from ICP guiding on palatal surfaces of anterior teeth
• Incisal edges of upper and lower incisors touch

Question 18

If edge to edge and theres space between posteriors what does this mean?

Answer 18

Anterior guidance

Question 19

If edge to edge and theres no space between posteriors

Answer 19

Grouped function

Question 20

What is protrusion?

Answer 20

• Condyle moves forwards and downwards on articular eminence

Question 21

Tooth contacts in protrusion (3)

Answer 21

• Only incisors +/- canines
• No posterior tooth contacts
• Eventually no tooth contacts

Question 22

What is maximum opening? (3)

Answer 22

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

Question 23

What is retruded axis position? (3)

Answer 23

1. No tooth contacts
2. In the most superior anterior position of the condylar head in the fossa
3. Terminal hinge axis

Question 24

What is retruded contact position?

Answer 24

First tooth contact from retruded arch of closure

Question 25

What position do we aim to make most restorations in?

Answer 25

ICP

Question 26

What 2 sides make up lateral translation?

Answer 26

1. Working side
   - The side the mandible moves to
2. Non-working side