Articulation And Occlusion Lecture 4

Front 1

What are the three main axises of the jaw?

Back 1

Horizontal, Vertical, Sagittal

Front 2

The horizontal axis moves in the ___ plane.

Back 2

Sagittal

Front 3

The sagittal axis is through (1/both) condyle(s)

Back 3

1

Front 4

The vertical axis is through (1/both) condyle(s)

Back 4

1

Front 5

The horizontal axis is through (1/both) condyle(s)

Back 5

both

Front 6

Which axis is also called the "terminal hinge axis"?

Back 6

horizontal

Front 7

The vertical axis moves in the ___ plane.

Back 7

horizontal

Front 8

The sagittal axis moves in the ___ plane.

Back 8

frontal

Front 9

Average patient is __ mm from each vertical axis to midsagittal plane

Back 9

55mm

Front 10

Variations in the horizontal axis can alter cusp position in (closure/working and nonworking) movements.

Back 10

closure

Front 11

Variations in the vertical axis can alter cusp position in (closure/working and nonworking) movements.

Back 11

working and nonworking

Front 12

A patient typically measures 55mm from the midsagittal plane to the ___ plane

Back 12

vertical

Front 13

What is the terms for when the condyles are in the most superior anterior position of the glenoid fossa with the disc interposed?

Back 13

Centric relation

Front 14

Centric relation is a term for when the condyles are in the most superior and (anterior/posterior) position of the glenoid fossa with the disc (relaxed/interposed)

Back 14

anterior, interposed

Front 15

What two things determine centric relation?

Back 15

1. muscles
2. articular surface of TMJ

Front 16

True or False, centric relation is a relative area

Back 16

False, it is an EXACT position

Front 17

True or False, centric relation is the most orthopedically stable position

Back 17

True

Front 18

True or False, centric relation is stable for the joint, but NOT for the muscles

Back 18

False, it is the MOST STABLE for the muscles as well

Front 19

True or False, centric relation is the most repeatable position

Back 19

True

Front 20

True or False, centric relation can easily be altered in a short amount of time

Back 20

False, it is UNchangable in the short term

Front 21

Centric relation is the limit of the mandibular movement (anteriorly/posteriorly)

Back 21

posteriorly

Front 22

The horizontal rotation axis typically measures __mm

Back 22

20-25mm

Front 23

What is centric occlusion?

Back 23

the closure in CR to first tooth contact

Front 24

What is defined as the deflection of the mandible anteriorly or laterally from the first tooth contact to centric occlusion

Back 24

centric slide

Front 25

What is the term for the maximum interdigitation of the teeth?

Back 25

intercuspal position

Front 26

True or False, intercuspal position is determined by our habits or tendencies

Back 26

True

Front 27

Centric occlusion = centric relation in __% of the population

Back 27

10%! This means in 90% of the population, CR is not maintained when we fully close our mouths

Front 28

True or False, intercuspal position can be altered

Back 28

True

Front 29

What establishes the most superior position of the mandible?

Back 29

intercuspal position

Front 30

When you are in postural position, your jaw is about __ to ___ mm below intercuspal position when the muscles of mastication are at rest

Back 30

2-4

Front 31

When your jaw is at rest, 2-4mm below intercuspal position, we call this ___ position

Back 31

postural (or rest)

Front 32

What determines postural position?

Back 32

muscles

Front 33

True or False, postural position is arbitrary

Back 33

True

Front 34

*What are the 7 requirements of optimum occlusion?

Back 34

1. Both the right and left condyles are in a supero-anterior position in fossae.

2. The articular disc is properly interposed.

3. There is even and simultaneous contact of all teeth.

4. Lighter contacts occur on the anterior teeth than on the posterior.

5. Occlusal forces are directed down long axis of teeth.

6. During laterotrusive movement, the mediotrusive side is discluded immediately.

7. During protrusive movement, all the posterior teeth are discluded immediately.

Front 35

Protrusion is GUIDED by what 2 things?

Back 35

1. teeth
2. TMJ

Front 36

Maximum protrusion is determined by the ___ of the TMJ, NOT the TMJ itself.

Back 36

ligaments

Front 37

Which specific ligament limits protrusion?

Back 37

stylomandibular

Front 38

What is the normal opening range in mm?

Back 38

40-60mm

Front 39

If I told you a patient's condyles are fully rotated with maximum anterior translation, you could assume they were doing what?

Back 39

opening their mouth as wide as they can (aka maximum opening)

Front 40

True or False, you only need 2 out of the 3 axises to be recreated on the articulator to get an accurate duplication of the cuspal movement

Back 40

False, need all 3

Front 41

The horizontal axis describes movement of both condyles (at the same time/separately) through the sagittal plane

Back 41

at the same time

Front 42

About how far can the jaw open (in mm) before the outer oblique portion of the temporomandibular causes the condyle to slide forward?

Back 42

20-25mm

Front 43

What ligament limits the horizontal axis?

Back 43

outer oblique portion of temporomandibular ligament

Front 44

Translation occurs in the (upper/lower) joint space

Back 44

upper

Front 45

Rotation occurs in the (upper/lower) joint space

Back 45

lower

Front 46

Which two axises (of the 3) describe movement through 1 condyle only?

Back 46

Vertical and sagittal (these are AXISES, not PLANES... the horizontal axis is movement through 2 condyles in the sagittal PLANE)

Front 47

Mediotrusive = working OR non-working?

Back 47

non-working

Front 48

Lateriotrusive = working OR non-working?

Back 48

working

Front 49

True or False, the rotating condyle is on the mediotrusive side

Back 49

False, either orbiting condyle on mediotrusive, OR rotating condyle on laterotrusive

Front 50

Which axises are in motion in left or right lateral excursion?

Back 50

ALL 3!

Front 51

How far down can sagittal rotation be? (think inside the TMJ)

Back 51

the bottom of the eminence

Front 52

Which axises are in motion in a protrusive movement?

Back 52

NONE of them!

Front 53

True or false, you can have centric relation if the disc is out of place... all we care about is the condyle

Back 53

False, disc must be properly interposed

Front 54

The condyle rests on the (anterior/posterior) slope of the eminence in centric relation

Back 54

posterior

Front 55

True or false, the muscle of mastication help determine CR

Back 55

True

Front 56

What does CR stand for?

Back 56

centric relation

Front 57

True or False, CR is an exact position

Back 57

True

Front 58

How can CR change over a LONG period of time?

Back 58

bone remodeling can slowly alter the position of the condyle due to changing fossa dimensions

Front 59

True or False, movement beyond CR is normal

Back 59

False, it is pathologic... aka, a car wreck or a baseball bat to the face. Or a Yugo to the face.

Front 60

Rotational movement is limited to __-___ mm

Back 60

20-25

Front 61

True or False, because our CR is relatively similar, our Posselt's Envelope of Motion is almost exactly the same from person to person

Back 61

False, varies depending on person but maintains a relatively similar shape

Front 62

What ligament limits protrusive movement?

Back 62

stylomandibular

Front 63

What ligament stops rotation?

Back 63

outer oblique portion of temporomandibular

Front 64

The maximum opening of the jaw is determined by ___.

Back 64

muscles of mastication

Front 65

The superior limit of the mandible is determined by ___

Back 65

intercuspal position

Front 66

What is represented by red 1?

Back 66

Maximum protrusion

Front 67

What is represented by red 2?

Back 67

The pt where you are protruding and your posterior teeth have slid past your anterior teeth and are now completely in front of them

Front 68

What is represented by red 3?

Back 68

The pt at which you are protruding and your posterior teeth are about to complete their slide on the anterior teeth and begin sliding down the facial of them

Front 69

What is represented by red 4?

Back 69

The end of anterior guidance (in a protrusive movement)

Front 70

What is represented by red 5?

Back 70

CR and ICR, this is rare (10%). Most of the time, ICR will be slightly higher and then CR will be a bit lower [Note: also, the beginning of anterior guidance if shifting to red 4)

Front 71

What is represented by red 6?

Back 71

When the outer oblique portion of the temporomandibular ligament is tight and changing rotation to translation

Front 72

What is represented by red 7?

Back 72

Maximum opening

Front 73

The black line between red 1 and red 7 represents what type of movement?

Back 73

When you go from protrusion to max opening, or max opening to protrusion (1 = protrusion, 7 = max opening)

Front 74

What does blue 1 indicate? (ignore the direction)

Back 74

Anterior guidance

Front 75

Which blue line (2 or 3) is rotation?

Back 75

2

Front 76

Which blue line (2 or 3) is translation?

Back 76

3

Front 77

What is indicated by the orange dot?

Back 77

Postural position... when your mouth is relaxed open

Front 78

When CR and ICR are the same (as in red 5), we call this what?

Back 78

Centric occlusion

Front 79

What is indicated by the orange dot?

Back 79

Centric relation (assuming this person is NOT one of the 10% with matching CR and ICR)

Front 80

What is indicated by 1 and 3?

Back 80

Maximum side excursion (right and left respectively)

Front 81

What is indicated by red 2?

Back 81

ICP (could be CO if person is one of the 10% with matching ICP and CR)