TMJ

Question 1

Characteristics of masticatory muscle disorder

Answer 1

Parafunctional activities
AM pain
Pain at end range of motion, especially opening
Limited opening but normal lateral excursion and protrusion
Pain with resisted protrusion (lateral pterygoid)
Pain with powerstroke (biting down against resistance)
= Biting down on two separators prevents compression of joint while muscles are activated
Tenderness to palpation of muscles

Question 2

Characteristics of disc displacement with reduction

Answer 2

Joint clicking/popping (high Sn, low Sp)
Not usually restricted movement
Pain with joint compression
Tenderness to palpation of preauricular area

Question 3

Characteristics of disc displacement without reduction

Answer 3

History of clicking that is now gone
Pain with jaw function
Mobility deficit in classic pattern
- Reduced opening, with deflection to affected side
- Decreased lateral glide opposite to restricted side
- Reduced protrusion, deflection to affected side
Tenderness of preauricular area (high Sn, low Sp)
Pain with joint compression

Question 4

Functional vs. Normal opening ROM for jaw

Answer 4

Functional = 25-30 mm
Normal = 40 mm

Question 5

Three parts of disc

Answer 5

Pars anterior = nerve and vascular supply, but not thickest
Paris gracilis = thinnest, intermediate, very little innovation or vascularity
**Pars posterior = thickest, has nerve and vascular supply, most common source of pain