TMJ and Cervical Muscle actions

Question 1

What are the actions of the Medial Pterygoid

Answer 1

CHEWING
-Bilateral Protrusion (Due to attatchement to mandible, shortening would pull forward = protrude
- Elevation of the mandible (due to distal attachment on the mandible)
- Lateral movement toward opposite side (due to diagonal orientation that pulls from inside, one side to another (unilateral)

Question 2

What are the actions of the lateral pterygoid

Answer 2

RELATED TO DISC MOVEMENT
- Bilateral protrusion because it inserts on ramus of mandible so pulls it forward
- Lateral movement because frontal plane/diagonal orientation
- Superior head does forced closure b/c connected to condyle
- Does initiate depression/open
-Muscle most associated with disc

Question 3

What are the actions of the temporalis muscle

Answer 3

GUIDES BITING
- Retrusion because of orientation muscle fibers behind mandible to pull backwards
- Elevation bc superior to inferior fibers that connect on mandible
- Some lateral movement

Question 4

What are the actions of the Masseter

Answer 4

BIG CLENCH AND GRIND, BITING
- Strong Elevation b/c of main attachment to the lower mandible
- Retrusion b/c of deep attachment
- Protrusion BL because of Inserts posteriorly so when shortened, it will move forward

Question 5

Suprahyoids

Answer 5

SWALLOW
Mandibular depression because of attachment beneath the mandible

Question 6

Infrahyoid

Answer 6

Also depression but more so swallowing
Consider digastric also below chin to help with retrusion and swallowing.

Question 7

What TMJ muscles cause protrusion

Answer 7

Masseter, Lateral pterygoid, medial pterygoid

Question 8

What muscle is most related to the TMJ disc/joint itself

Answer 8

Lateral pterygoid (superior head)

Question 9

What muscles cause elevation/closing of the mouth

Answer 9

Temporalis, Medial pterygoid, lateral pterygoid Masseter

Question 10

What muscles causes depression/opening of the mouth

Answer 10

Suprahyoid, infrahyoid, lateral pterygoid because it moves the condyle

Question 11

What muscles cause retrusion

Answer 11

Temporalis, Masseter

Question 12

What muscles cause lateral excursion

Answer 12

Medial, lateral pterygoids, masseter, and temporalis

Question 13

What is the main clencher/biter muscle

Answer 13

Masseter

Question 14

What muscle guides the biting motion

Answer 14

Temporalis

Question 15

What muscles assist with swallowing

Answer 15

The suprahyoid and infrahyoid and, digastric

Question 16

Sternocleidomastoid

Answer 16

Flexion
Side bend to the ipsilateral side (shorten and pull towards side its on)
Rotate opposite (twist to shorten)

Question 17

Scalene muscles

Answer 17

Accessory breathing muscle by elevating 1st and 2nd rib

same muscle actions as SCM (anterior mainly)

Question 18

Longus colli (dont confuse with the colli/cervicis brothers)

Answer 18

Deep neck flexor, also include longus capitis, longus cervicis, rectus, capitis (THE LONGUS BROTHERS and one rectus)

Question 19

Cervical extensors

Answer 19

The 4 (colli/cervicis) brothers, multifidi, and trapezius