TMJ and Cervical Muscle actions, and other points Flashcards
What are the actions of the Medial Pterygoid
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)
What are the actions of the lateral pterygoid
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
What are the actions of the temporalis muscle
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
What are the actions of the Masseter
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
Suprahyoids
SWALLOW
Mandibular depression because of attachment beneath the mandible
Infrahyoid
Also depression but more so swallowing
Consider digastric also below chin to help with retrusion and swallowing.
What TMJ muscles cause protrusion
Masseter, Lateral pterygoid, medial pterygoid
What muscle is most related to the TMJ disc/joint itself
Lateral pterygoid (superior head)
What muscles cause elevation/closing of the mouth
Temporalis, Medial pterygoid, lateral pterygoid Masseter
What muscles causes depression/opening of the mouth
Suprahyoid, infrahyoid, lateral pterygoid because it moves the condyle
What muscles cause retrusion
Temporalis, Masseter
What muscles cause lateral excursion
Medial, lateral pterygoids, masseter, and temporalis
What is the main clencher/biter muscle
Masseter
What muscle guides the biting motion
Temporalis
What muscles assist with swallowing
The suprahyoid and infrahyoid and, digastric
Sternocleidomastoid
Flexion
Side bend to the ipsilateral side (shorten and pull towards side its on)
Rotate opposite (twist to shorten)
Tightens with forward head
Scalene muscles
Accessory breathing muscle by elevating 1st and 2nd rib
same muscle actions as SCM (anterior mainly)
Longus colli (dont confuse with the colli/cervicis brothers)
Deep neck flexor, also include longus capitis, longus cervicis, rectus, capitis (THE LONGUS BROTHERS and one rectus)
Cervical extensors
The 4 (colli/cervicis/capitis) brothers, multifidi, and trapezius,
Which TMJ glide for restriction
Inferior glide (causes distraction) to improve sx
Which TMJ glide compresses
Superior glide (more diagnostic)
Resting position
Slightly open
Norms
Open 30- 55mm
Protrusion more than 7 mm
Retrusion 3-4 mm
Lateral excursion 10-15 mm
Bite down test
Pain on same side as bite down = muscle
Opposite sided pain = joint
BITE DOWN STRESSES OPPOSITE SIDE SO IF BITE DOWN IS ON R SIDE AND YOU HAVE L SIDE PAIN > JOINT ON LEFT SIDE
Pterygoids individually vs together
Individual they do unilaterl exrcusion to other side cause slanted orientation pulls in
Together does protrusion
Must differentiate
Trigeminal nerve/nuclesus issues vs cervical
Bruxism
Clenching or grinding teet
Muscles of mastication
- Masseter
- Temporal
- Medial pterygoid
Biomechanics with opening (depression)
Anterior roll and translation of mandibular condyle
Disc goes opposite direction*
Biomechanics of closing (elevation)
Posterior roll and glide
Makes sense directionally when you do it
Disc does opposite*
Pain referalls
Make sense based on location
Masseter is exception with pain referral to many locations including eyebrow
Pain in ear or in front of ear
think TMJ, retrodiscal tissue, disc
Pain in jaw, temple
Referred
Lateral pterygoid can only be reached
Intra orally
Painful resisted testing
Think myalgia, muscle, myofascial pain
Arthralgia
Joint related pain
vs DJD
same but with imaging and prior history
Muscle interventions
Always soft tissue work
Joint interventions
Mobs, stretching, modalities, controlled opening, lifestyle changes
Disc replacement with reduction
Includes ipsilateral deviation that returns to midline (reduction)
Wobbly painful clicking
2 Clicks*
one for when it displaces
second for when it gets back in place
Without reduction
Clicks went away
Ipsilateral deviation that remains (does not return to midline upon opening)
So ipsilateral deviation on the R side would have a positive bite stick test on the L side because the L side stressed R sided joint and muscles on the L side
