Optimal Occlusion

Question 1

Because these muscles have the capability of providing heavy forces, the potential for damage to occur at the two temporomandibular joints (TMJs) and the teeth is ____ (high/low)

Answer 1

high

Question 2

T/F. Centric relation (CR) is the position of the mandible when the condyles are in an orthopedically stable postion.

Answer 2

True.

Question 3

Define the most orthopedically stable joint.

Answer 3

When the condyles are located in their most superoanterior position in the articular fossae, fully seated and resting against the posterior slopes of the articular eminences.

Question 4

The optimal joint relationship is achieved only when the ___ ___ are properly interposed between the condyles and the articular fossae.

Answer 4

articular discs

Question 5

T/F. In the musculoskeletally stable (MS) position, the articular surfaces and tissues of the joints are aligned such that forces applied by the musculature do not create any damage.

Answer 5

True.

Question 6

How is the musculoskeletally stable joint position maintained?

Answer 6

when it is in harmony with a stable occlusal position

Question 7

___ (more/less) teeth contacts provide more stabilization of the mandible, and ___ (increase/decrease) the forces to each tooth.

Answer 7

More; decrease

Question 8

With optimal functional tooth contact, CO coincides with ___.

Answer 8

MI

Question 9

Optimal functional tooth contacts must have __ and __ contact of all teeth during mandibular closure.

Answer 9

even; simultaneous

Question 10

T/F. Osseous tissues tolerate pressure forces.

Answer 10

False, they do NOT tolerate pressure forces. If a forces is applied to bone, bony tissue will resorb.

Question 11

What helps the teeth control the forces they are constantly receiving?

Answer 11

Periodontal ligaments (PDL)

Question 12

The PDL is present between the ___ and the ___ ___ to control these forces.

Answer 12

roots; alveolar bone

Question 13

When cusp tips contact ___ (flat/inclined) surfaces, the resultant force is directed ____ (horizontally/vertically) through the long axes of the teeth. This type of force is accepted well by the ___ ___.

Answer 13

flat; vertically; periodontal ligament

Question 14

When the opposing teeth contact on ____, the direction of the force is not through the __ __ of the teeth. ____ forces are created that cause compression and elongation of the PDL.

Answer 14

inclines; long axes; Tipping

Question 15

The process of directing occlusal forces through the long axis of the tooth is known as __ __.

Answer 15

axial loading

Question 16

What two methods achieve axial loading?

Answer 16

cusp tip to flat surface and tripodization

Question 17

Tooth contacts on cusp tips or flat surfaces that are ____ to the long axis of the tooth result in forces directed down that axis.

Answer 17

perpendicular

Question 18

____ requires that each cusp contacting an opposing fossa be developed such that it produces ___ contracts surrounding the actual cusp tip.

Answer 18

Tripodization; three

Question 19

The amount of force that can be generated between the teeth depends on the distance from the ___ joint (fulcrum) and the muscle force vectors (masseter/medial pterygoid).

Answer 19

temporomandibular joint

Question 20

More force can be generated on the ____ (anterior/posterior) teeth than on the ____ (anterior/posterior) teeth.

Answer 20

posterior; anterior (nut scenario)

Question 21

In maximal intercuspal position, ___ (anterior/posterior) teeth come into contact and act as stops to minimize ____ (horizontal/vertical) load on anterior teeth.

Answer 21

posterior; horizontal

Question 22

The ___ (anterior/posterior) teeth guide excursive movements of the mandible so that no posterior teeth contacts occur during lateral or protrusive excursions.

Answer 22

anterior

Question 23

Which tooth is best suited to accept horizontal forces?

Answer 23

canines

Question 24

Which tooth has the longest and largest roots and therefore the best crown/root ratio?

Answer 24

canines

Question 25

___ (more/fewer) muscles are active when canines contact during eccentric movements than when posterior teeth contact.

Answer 25

Fewer.

Lower levels of muscular activity decrease forces to the dental and joint structures.

Question 26

In group function, several teeth on the ____ (working/non-working) side contact during laterotrusive movement.

Answer 26

working

Question 27

T/F. Heavy occlusal contacts on the anterior teeth occur when posterior tooth support is lost. The maxillary anterior teeth cannot accept mandibular closing forces. This often leads to labial displacement or flaring of the maxillary anteriors.

Answer 27

True.

Question 28

What are the seven effects of tooth loss?

Answer 28

1. supraeruption
2. tilting
3. loss of contact
4. Loss of posterior tooth support
5. loss of vertical dimension
6. flaring of anterior teeth
7. non-working interferences

Question 29

T/F. Occlusal treatment goals should direct occlusal forces along the long axes of teeth (stable posterior contacts).

Answer 29

True.

Question 30

T/F. In MI, all mandibular teeth should contact their maxillary opponents at the same time with the same intensity (CO=MI).

Answer 30

True.

Question 31

T/F. Occlusal treatment goals should furnish a smooth protrusive path guided by anterior teeth without any interference from the occlusal contacts between the posterior teeth.

Answer 31

True.

Question 32

T/F. Working side contacts, whether canine protected or group function, should not be prevented from contacting my non-working side interference.

Answer 32

True.