24- Joints and TMJ

Question 1

What does the articulatory system consist of?

Answer 1

1. The hinge (TMJ)
2. The motors (Muscles)
3. The contacts

Question 2

What are the 3 zones of the fibrous disc?

Answer 2

PB = posterior border
IZ= Intermediate border
AB = Anterior border

Question 3

What are the three layers that lie behind the fibrous disc

Answer 3

1. Superior retrodiscal lamina (elastic)
2. Retrodiscal fat pad
3. Inferior retrodiscal lamina (collagen)

Question 4

What is the major muscle in TMD?

Answer 4

Lateral pterygoid as its superior portion is attached to the head of the condyle and the articular disc

Question 5

Where is the temporalis origination and insertion?

Answer 5

Originates from the articular eminence and inserts onto the coronoid process of the mandible

Question 6

Which muscle elevates and retracts the mandible?

Answer 6

Temporalis

Question 7

Which muscle Elevates and protrudes the mandible?

Answer 7

Lateral pterygoid

Question 8

Which muscles depress the mandible?

Answer 8

Gravity

• digastric
• geniohyoid
• mylohyoid

Question 9

What are the 3 different types of definitions of centric relation?

Answer 9

1. anatomical
2. geometrical
3. physiological

Question 10

What is the anatomical definition of centric relation?

Answer 10

position of the condylar head when fully seated in the glenoid fossa

Question 11

What is the geometrical definition of centric relation?

Answer 11

by means of posselts envelope, anywhere between R and RCP, (mandible just rotating)

Question 12

What is the physiological definition of centric relation?

Answer 12

Position where the muscles are doing the least amount of work

Question 13

What does RCP stand for?

Answer 13

Retruded contact position

Question 14

What does ICP stand for?

Answer 14

Intercuspal position

Question 15

What does E stand for?

Answer 15

Edge to edge position of incisors

Question 16

What does Pr stand for?

Answer 16

Maximum protrusion

Question 17

What does T stand for?

Answer 17

Maximum translation of condylar head/maximum mandibular opening

Question 18

What does R stand for?

Answer 18

Maximum mandibular opening with the condylar heads still in glenoid cavity

Question 19

What type of things would you record on the occlusion record?

Answer 19

• Skeletal base relationship
• Angle relationship
• First tooth that touches central relation
• difference in RCP and ICP
• canine guidance? group function?

Question 20

What are the 3 main categories of temporomandibular disorders?

Answer 20

1. Myalgia/myofascial pain
2. Disc displacement
3. Joint degeneration

Question 21

What is myalgia/myofascial pain?

Answer 21

Report of pain or ache in the jaw, temples, face, preauricular area or inside the ear. PLUS this pain can be felt on palpation of one of the major muscles of mastication

Question 22

What are the 2 types of disc displacement?

Answer 22

1. With reduction

2. Without reduction

Question 23

What does disc displacement with reduction mean?

Answer 23

• The disc is displaced anteriorly but reduces back into place making a clicking sound

Question 24

What does disc displacement without reduction mean?

Answer 24

Disc is displaced anteriorly but does not return back to normal

Question 25

What is joint degeneration?

Answer 25

Degenerative disorders of the join in which joint form and structure are abnormal e.g. arthrosis

Question 26

What type of model of illness is TMD described as?

Answer 26

Biopsychosocial model of illness

Question 27

What is bruxism

Answer 27

A parafunction which involves grinding/clenching of the teeth

Question 28

What are the 2 types of bruxism?

Answer 28

Wake bruxism | Sleep bruxism

Question 29

What is wake bruxism?

Answer 29

Habit in response to anxiety

Question 30

How do we identify sleep bruxism?

Answer 30

- sleep study - third party witness - cheek ridging - tooth wear - tongue scalloping - ask patient questions

Question 31

What can we do about sleep bruxism?

Answer 31

- stablisation - splint - CBT - Physiotherapy - warm compress - soft bite guard - ibuprofen - NTI device - Anterior repositioning splint - Arthrocentesis

Question 32

What are the 3 main splints to consider?

Answer 32

1. stabilisation splint 2. B splint 3. Anterior repositioning splint

Question 33

What are some more mild splints?

Answer 33

- soft splint | - local occlusal interference splint

Question 34

What does a stabalisation splint do?

Answer 34

help patients with masticatory muscle pain by reducing: -pain intensity -muscle tenderness and allowing mouth opening to increase

Question 35

What are some key features of a stabilisation splint?

Answer 35

- made in centric relation (when muscles doing least amount of work - created in ideal occlusion - made from hard acrylic (less likely to be chewed)

Question 36

What is needed to make a stabilisation splint?

Answer 36

1. Alginate impression 2. Centric relation jaw registration 3. Facebow record

Question 37

What is a B-splint?

Answer 37

A smaller splint with localised pressure covering the anterior 6 teeth

Question 38

What splint covers only the anterior 6 teeth?

Answer 38

A B-splint

Question 39

What is an anterior repositioning splint?

Answer 39

A splint which creates more space in the joint capsule therefore allowing the disc to move and gradually moves back into place due to elastic fibres

Question 40

In what TMD is an anterior repositioning splint used?

Answer 40

Disc displacement WITH reduction

Question 41

How long does an anterior repositioning splint need to be worn for?

Answer 41

24/7 for 3 months

Question 42

What does CBT stand for?

Answer 42

Cognitive Behaviour Therapy

Question 43

What is CBT?

Answer 43

It is a way of talking about: - how you think about yourself, the world and other people - how what you do affects your thoughts

Question 44

How can CBT help

Answer 44

Helps "how you think" (COGNITIVE) and "what you do (BEHAVIOUR) and helps you focus on the here and now problems to improve your current state of mind

Question 45

What is Arthocentesis?

Answer 45

A clinical procedure of removing arthritic waste products from joint capsule to help disc move more smoothly (removing synovial fluid from synovial joint)

Question 46

What patients is arthrocentesis used on?

Answer 46

Patients with disc displacement WITHOUT reduction

Question 47

What treatment is given to patients with disc displacement with reduction?

Answer 47

Anterior repositioning splint

Question 48

What treatment is given to patients with disc displacement without reduction?

Answer 48

Arthrocentesis