TMJ

Question 1

TMJ is considered a modified hinge jt because a ________ separates the jt into ________ and _________ articulations with the ________________ and _______________ .

Answer 1

Disc
Upper and lower

Mandibular condyle and mandibular fossa of the temporal bone

Question 2

The disc in the TMJ functions to:

Answer 2

Cousin the large repetitive force of mastication

Question 3

The osteology of the TMJ consists of

Answer 3

Mandibular condyle
Mandibular fossa
Articular eminence of the temporal bone

Question 4

TMJ joint classification:

Answer 4

Synovial

Question 5

The articular eminence and mandibular condyle are both _________ resulting in an ________________

Answer 5

Convex

Incongruent jt

Question 6

The articulating surfaces are covered in ____________ instead of hyaline cartilage because…..

Answer 6

Fibrocartilage

The jt must withstand repeated and high-level stress

Question 7

The incongruency of the TMJ is addressed by a …

Answer 7

Biconcave disc!

Question 8

Purpose of the articular disc in the TMJ

Answer 8

Allow for congruency through full ROM
Increase stability
Minimize loss of mobility
Reduces friction 
Decrease biomechanical stress on TMJ

Question 9

The inferior TMJ is a _______ jt that articulates…

Answer 9

Simple hinge

The mandibular condyle and inferior disc

Question 10

The superior TMJ is a __________ jt that ariculates…

Answer 10

Gliding

The articular eminence and superior disc

Question 11

The articular disc of the TMJ is attached to ________&_________ poles of condyle. This allows the condyle to…..

Answer 11

Medial and lateral

Rotate on the disc in an AP direction

Question 12

The articular disc of the TMJ attaches to ________&____________. This will restrict posterior translation of the disc.

Answer 12

Joint capsule and lateral pterygoid anteriorly

Question 13

The articular disc of the TMJ attaches to what posteriorly?

Answer 13

The bilaminar retrodiscal pad

Question 14

The posterior attachment of the articulating disc of the TMJ has 2 parts. What are they and what do they do?

Answer 14

Superior lamina- assists the disc in translating anteriorly with mandibular depression

Inferior lamina- limits forward translation

Question 15

The TMJ capsule is relatively ______ medial/laterally and is _______ & _______ anterior and posteriorly. What does this allow for

Answer 15

Firm
Thin & loose

Allows for anterior translation when mouth is open

Question 16

The TMJ is predisposed to ____________________ due to lack of _________ of the anterior capsule and the _____________ of jt surfaces

Answer 16

Anterior dislocation of the mandibular condyle

Strength
Incongruence

Question 17

Primary ligaments of the TMJ

Answer 17

Lateral (TM) ligament
Stylomandibular ligament
Sphenomandibular ligament

Question 18

What ligament stabilizes the lateral potion of the capsule and helps guide movement of condyle during opening?

Answer 18

Lateral (TM) ligament

Question 19

What TMJ ligament is weakest?

Answer 19

Stylomandibular ligament

Question 20

What TMJ ligament is a swinging hinge that suspends the mandible?

Answer 20

Sphenomandibuliar ligament

Question 21

What is the normal resting position of the TMJ and how is it maintained?

Answer 21

Lips closed, teeth several mm apart

Maintained by low activity of the temporalis muscle

Question 22

List the Osteokinematics of the TMJ

Answer 22

Depression/elevation
Protrusion/retrusion
L&R lateral excursion (deviation)

Question 23

Arthrokinematics of mandibular depression at the TMJ

Answer 23

Early phase- roll posterior (lower jt)

Late phase- glide anterior (upper jt)

Question 24

Arthrokinematics of mandibular elevation at the TMJ

Answer 24

Early phase- glide posterior (upper jt)

Late phase- roll anterior (lower jt)

Question 25

Arthrokinematics of mandibular protrusion at the TMJ

Answer 25

Anterior and slight inferior glide of condyle and disc

Question 26

Arthrokinematics of mandibular retrusion at the TMJ

Answer 26

Posterior and slight superior glide of condyle and disc

Question 27

Why is there no rotation (rolling) with protrusion and retrusion

Answer 27

Actions involve the upper jt only

Question 28

Lateral excursion of the mandible at the TMJ involves primarily _________________________ of the condyle and disc within the fossa.

Answer 28

Side to side translation

Question 29

During lateral excursion of the mandible the _________________ condyle serves as a relatively fixed pivot point

Answer 29

Ipsilateral

Question 30

Arthrokinematics of lateral excursion (deviation)

Answer 30

Contralateral condyle glides anterior and to the side of deviation Ipsilateral condyle spins

Question 31

What works on the mandible to produce mandibular depression?

Answer 31

Gravity Digastrics Suprahyoids Lateral pterygoid

Question 32

What muscles act in the mandible to produce protrusion?

Answer 32

Masseters Medial pterygoids Lateral pterygoids

Question 33

What muscles act in the mandible to produce retrusion?

Answer 33

Temporalis Masseter Digastric (assist)

Question 34

What muscles work on the mandible to produce lateral deviation?

Answer 34

Contralateral med/lat pterygoid Ipsilateral temporalis Ipsilateral masseter

Question 35

The _________ and ____________ form a functional sling around the angle of the mandible. Contracting both will create a powerful bite with a max force of _______.

Answer 35

Masseter and medial pterygoid 422 N or 95 lbs

Question 36

Interaction with the Masseter and medial pterygoid can be effective at _______________________.

Answer 36

Grinding/crushing food | Shear force

Question 37

Normal depression at the TMJ is ________, but only _______ is required for normal mastication.

Answer 37

35-50 mm 18 mm

Question 38

The ability to fit 2 knuckles between your teeth is __________. 3 knuckle are ________.

Answer 38

Functional | Normal

Question 39

Normal protrusion at TMJ is _______. A functional way to screen is to ___________________________.

Answer 39

3-6 mm See if your lower teeth surpass your upper teeth

Question 40

Normal retrusion at the TMJ is ________

Answer 40

3-4 mm

Question 41

Normal lateral deviation at the TMJ is __________

Answer 41

10-15mm

Question 42

S/Sx of temporomandibular dysfunction

Answer 42

Pain, popping, reduced bite force, reduced ROM wiyh mouth opening, headaches, tinnitus trigger points

Question 43

Factors associated with TMD

Answer 43

``` Stress/emotional Daily oral parafunctional habits Asymmetric muscle activity Skeet bruxism Chronic forward head posture C-spine pathology ```

Question 44

Describe Deviation of the mandible

Answer 44

Motion that produces an “s” curve with depression or protrusion

Question 45

Describe deflections of the mandible

Answer 45

Motion that produces a “c” curve with depression or protrusion

Question 46

Deviations and deflections at the TMJ may result from differently shaped __________________ or it may indicate ________________.

Answer 46

mandibular condyle heads Pathology

Question 47

Articular disc displacement occurs when?

Answer 47

The disc subluxes beyond articular eminence

Question 48

Disc displacement with TMJ reduction results in a __________ when? What is this called?

Answer 48

Clicking during mandibular depression and mandibular elevation Reciprocal click

Question 49

Disc displacement without reduction

Answer 49

Disc doesn’t relocate and patient will demonstrate limited mandibular motion due to mechanical obstruction (disc)

Question 50

With disc displacement in the TMJ, the later the click occurs in the opening phase, the _____________ degree of dislocation

Answer 50

Greater

Question 51

Patients coming in with TMJ complaints should also have their __________ and ____________ examined because ______________________ may affect tension in the ___________________ which can influence the function of the mandible

Answer 51

C-spine and upper quarter Head and neck position Cervical muscles