Occlusion - considerations 2

Question 1

What are the 3 planes of the face?

Answer 1

Sagital (side on)
Cronal (front on)
Axial (Horizontal/cross-section) view from above

Question 2

What does the TMJ contain?

Answer 2

The condyle head (ball)
Articular disc
Inferior and superior synovial cavities

Question 3

What type of tissue is the articular disc made of?

Answer 3

Fibrous tissue

Question 4

What are the superior and inferior synovial cavities filled with?

Answer 4

Synovial fluid

Question 5

What muscle has a direct attachment with the joint and is involved in its movement?

Answer 5

Superior head of the lateral pterygoid

Question 6

In more extensive movements of the joint what happens?

Answer 6

Translation of the condyle

Where the condyle moves past the articular eminence.

Question 7

What can happen if the condyle gets stuck past the articular eminence?

Answer 7

TMJ problems

Question 8

What is masseter hypertrophy associated with?

Answer 8

Parafunction habits patients

Those who clench and grind etc

Question 9

What causes protrusion of the mandible?

Answer 9

Bi-lateral contraction of the lateral pterygoid

Question 10

What is the inferior head of the LP involved in? and superior head?

Answer 10

Lateral movement and depression of the mandible.

Superior - elevation

Question 11

How would you check the lateral pterygoid clinically?

Answer 11

Resistance to opening

Question 12

What is Posselts envelope?

Answer 12

It describes the dynamic border movements of the mandible.

Question 13

What are the stages in Posselts envelope?

Answer 13

ICP - E - Pr - T - R - RCP -

Question 14

What is the freeway space and why is it important?

Answer 14

It’s the space between the maxilla and mandible at rest. Should be approx 2-3mm.
IT is important to consider this freeway space when constructing and designing dentures.

Question 15

What does T stand for in Posselts envelope?

Answer 15

Maximum opening of the jaw.

Condyle has undergone translation, with the head passing the articular eminence.

Question 16

What is RCP and why is it important to understand?

Answer 16

Retruded contact position.

Important in reorganising occlusion (reproducible contact position)

Question 17

What is canine guidance?

Answer 17

Canine guidance is where during lateral extrusion of the mandible only the canines are in contact on the working side, while the rest of the mouth are discluded.
ideal occlusion - want to replicate when making RPD

Question 18

What is group function and in what kind of patients might you see this?

Answer 18

When two or more teeth including posterior teeth come into contact during lateral extrusion of the mandible.
See this in tooth wear patients

Question 19

What are undesirable contacts and what can they cause?

Answer 19

These are contacts on the non-working side of the mouth.

These contacts can cause shooting pains

Question 20

How would you re-organise the occlusion to fix undesirable contacts?

Answer 20

Move ICP to RCP

Question 21

How would you clinically go about re-arranging a patient’s undesirable occlusion?

Answer 21

Take an alginate impression.
Record the condyle relationship with a facebow.
Mount casts using facebow.
Take jaw registration in RCP and mount lower with upper.