TMD [Guest Lecture]

Question 1

Define temporomandibular disorders (TMD)

Answer 1

Characterized by

• pain in the preauricular area, TMJ, or mm of mastication
• limitations/deviations in mandibular ROM
• TMJ sounds during jaw function

Question 2

Describe the range of TMD sx

Answer 2

Clicking, deviation, fatigue w/o pain and distability to severe pain with severe disability

Question 3

Describe the causes of repitive stress in TMD

Answer 3

Restriction (joint/soft tissue)

Compensation (mm imbalance, poor sequencing)

Behavior (posture, grinding, clenching)

Question 4

Describe the role of teeth in TMD

Answer 4

Teeth control and decelerate motion

Loss of teeth increased PROM and decreased the amount of control over jaw motion

Question 5

List the potential pain generators in TMD

Answer 5

• Inflammation of the ligaments/capsule
• Internal derangement of ligament or disc
• Joint arthritis
• Muscles (imbalance, over/under pull can cause mm pain)
• Central sensitization

Question 6

Structure: Where translation occurs

Answer 6

Superior TMJ Cavity

Question 7

Structure: Where rotation occurs

Answer 7

Inferior TMJ Cavity

Question 8

Structure: portion of disc containg the superior head of the lateral pterygoid

Answer 8

Anterior portion of disc

Question 9

Structure: Portion of disc that attached to the condylar head via medial and lateral collateral ligaments

Answer 9

Medial and lateral disc

Question 10

Structure: limited posterior displacement during jaw opening

Answer 10

Temporomandibular or lateral ligament

Question 11

Structure: resists excessive medial/lateral displacement of disc

Answer 11

Collateral ligaments

Question 12

Structure: suspending mandible and preventing excessive protrusion

Answer 12

accessory ligaments (stylomandibular and sphenomandibular)

Question 13

Movement: Loud click on opening

Answer 13

Disc reduction

Question 14

Movement: Smaller click on closing

Answer 14

Disc dislocation

Question 15

Term: clicking with opening or closing of the jaw

Answer 15

reciprocal clicks

Question 16

Condition: no audible sound with full anterior displacement w/o reduction

Answer 16

Locked joint

Question 17

Condition: Presents with reciprocal clicks

Answer 17

Anterior disc displacement WITH reduction

Question 18

Condition

• Hx of reciprocal clicks that have now stopped
• Often have limited opening range or “closed lock”

Answer 18

Anterior disc displacement WITHOUT reduction

Question 19

Condition:

• Unable to close mouth or “open lock”
• Rare but can occur after prolonged dental procedures
• Lateral pterygoid becomes overstretched

Answer 19

Posterior disc displacement

Question 20

Describe the kinematics of jaw depression/opening

Answer 20

The first 25 mm of motion is accomplished by ROTATION

The second 25-35 mm of motion is accompished by TRANSLATION

Question 21

Describe the kinematics of protrusion and retrusion

Answer 21

Pro = anterior and inferior disc translation

Re = posterior disc translation

Question 22

Describe the kinematics of lateral deviation

Answer 22

Rotation and horizontal translation of the contralateral condyle

Question 23

Describe the goal for lengthened mm in regards to posture control

Answer 23

You don’t need to change the length (won’t be able to shorten it) or stregnth, rather you need to SHIFT the length tension curve to a functional range so it can be more efficient in the inner range

Question 24

Muscle:

Bilateral = elevation

Bilateral superficial fibers = protrustion

Bilateral deep fibers = retraction

Unilateral = ipsilateral deviation

Answer 24

Masseter

Question 25

Muscle:

Bilateral = elevation and retraction

Unilateral = ipsilateral lateral deviation

Answer 25

Temporalis

Question 26

Muscle:

Bilateral = elevation and protrustion

Unilateral = contralateral lateral deviation

Answer 26

Medial Pterygoid

Question 27

Muscle:

Bilateral = protrusion

Unilateral = contralateral lateral deviation

Answer 27

Lateral Pterygoid

Question 28

Muscle: depression of the mandible during mouth opening

Answer 28

Inferior head of lateral pterygoid

Question 29

Muscle: contracts eccentriclaly during mouth closing to monitor disc position and avoid displacement

Answer 29

superior head of lateral pterygoid

Question 30

Muscle: responsible for swallowing

Answer 30

Hyoid muscles

Question 31

Muscle: Important for speech, swallowing, and tongue movement

Answer 31

Infrahyoid muscles

Question 32

List the Ideal Exercise Prescription for TMJ

Answer 32

• Postural control exercises for the kinetic chain
• Low threshold postural training
• Work on improving movement patterns
• Work on isometrics to recruit slow motor units
• Stretching