TMJ - WK3 ( CH11 pt.1 )

Question 1

List all the structures that attach to the TMJ discs.

Answer 1

Posterior Region: inferior retrodiscal laminae ( attaches to superior neck of mandible; superior retrodiscal laminae ( attaches to tympanic plate of temporal bone; posterior to mandibular fossa)

Anterior Region: superior neck of mandible, tendon of superior head of lateral pterygoid, temporal bone.

The TMJ discs are fibrocartilage like the menisci of the knee

Question 2

Name the ligaments of the TMJ and their respective jobs.

Answer 2

Lateral Temporomandibular Ligament: stabilize the lateral side of the TMJ capsule

Stylomandibular and Sphenomandibular ligaments: help suspend the mandible form the cranium

Question 3

Describe the osteokinematic movements of the following mandible motions: protrusion, retrusion, lateral excursion, depression, elevation

Answer 3

protrusion: anterior translation
retrusion: posterior translation
lateral excursion: side to side movement of mandible, usually combined with slight rotation
depression: opening the mouth, inferior translation
elevation: closing the mouth, superior translation

Question 4

Describe the arthrokinematic movements of the following mandible motions: protrusion, retrusion, lateral excursion, depression, elevation

Answer 4

protrusion: condyle and disc translate anteriorly following the slope of the articular eminence.
retrusion: condyle and disc translate posteriorly following the slope of the articular eminence.
lateral excursion: side to side translation of disc and condyle in fossa; occurs with slight rotation in horizontal plane
depression: when the mouth begins to open the condyle rolls in the fossa anteriorly; then the disc moves and the condyle slides anteriorly; limited by the superior retrodiscal laminae
elevation: reversal of depression.

Question 5

List the muscles involved in the following motions:protrusion, retrusion, lateral excursion, depression, elevation

Answer 5

protrusion: masseter, temporalis, medial and lateral pterygoids
retrusion: temporalis; suprahyoids
lateral excursion: masseter, temporalis, medial and lateral pterygoids
depression: lateral pterygoid; suprahyoid
elevation: masseter, temporalis, medial pterygoid

Question 6

During elevation of the mandible….
(a) the superior retrodiscal laminae does what ?
(b) The superior head of the lateral pterygoid does what ?

Answer 6

(a) pull on the TMJ disc to bring it back into the fossa
(b) controls the tension in the disc and it’s position during resisted closure of the jaw.

Question 7

List the secondary muscles of mastication that belong to each group.

Answer 7

Suprahyoids: digastric,stylohyoid, mylohyoid, geniohyoid
Infrahyoids: sternothyroid, thyrohyoid, omohyoid, sternohyoid

Question 8

Walk through the steps of what happens to the TMJ disc during a full cycle of opening and closure of the mouth.

Answer 8

• during the late phase of depression, the disc is stretched and pulled anteriorly by the condyle and the increased intra-articular pressure; by activation of the inferior head of the lateral pterygoid; the superior head inactive during opening
• the sup head contracts eccentrically to ease the disc and condyle back into their space

Question 9

How does capsular fibrosis of the TMJ develop ?

Answer 9

overproduction of fibrous connective tissue
-limited and altered osteokinematics

Question 10

Describe the sequence of events involved in TMJ internal disc derangment.

Answer 10

disc can be pulled out of fossa causing pain, clicking in the jaw

Question 11

What is TMD ?

Answer 11

broad term used to describe many clinical problems associated with the TMJ joint.

Question 12

Explain how a forward head posture affects the TMJ.

Answer 12

stretches infrahyoids; mandible is depressed and retruded due to effect of infra- on suprahyoids; changes position of the condyles

Question 13

What would you do for a patient with TMJ pain who exhibits a chronic forward head posture ?

Answer 13

Postural education; manual therapy; workplace adjustment; strengthening