Rest: Occlusal Interferences

Front 1

anterior protected articulation
canine protected articulation

Back 1

a form of mutually protected articulation in which the vertical and horizontal overlap of the anterior teeth disengages the posterior teeth in all mandibular excursive movements

Front 2

occlusal interference

Back 2

any tooth contact that inhibits the remaining occluding surfaces from achieving stable and harmonious contacts

Front 3

types of occlusal interferences

Back 3

- centric
- protrusive
- working side
- non-working side

Front 4

centric slide:
what is it?
what % of the pop. does it occur in?
what does it result in?

Back 4

- movement of the mandible while in centric relation, from the intial occlusal contact into maximum intercuspation
- anterior movement of the mandible from centric relation to maximum intercuspal position
- premature contact between mesial inclines of max teeth and distal inclines of mand. teeth
- occurs in 90-95% of the pop.
- results in muscular tension, bruxism, and TMJ dysfunction if overloaded

Front 5

protrusive interference

Back 5

- anterior movement of the mandible from max intercuspation towards the incisal edges
-occurs when distal facing inclines of max posterior teeth contact mesial facing inclines of mand. posterior teeth during a protrusive movement

Front 6

working side interference

Back 6

- occurs when there is contact between max. and mand. posterior teeth on the same side of the arch in the direction the mandible moved causing disclusion of teeth
- occurs between max. lingual facing cusp inclines and mand. buccal facing cusp inclines on the working side

Front 7

non-working side interference

Back 7

- occlusal contact between max. and mand. teeth on the side opposite the direction the mand. has moved
- results when there is contact between max. buccal facing cusp inclines and mand. lingual facing cusp inclines on the non-working side

Front 8

which type of interference is the most destructive?

Back 8

non-working side interference

Front 9

vertical determinants determine what?

Back 9

cusp height and fossa depth

Front 10

1. gradual eminentia slope requires ______ cusps
2. steep eminentia slope requires ______ cusps

Back 10

1. short
2. longer

Front 11

1. deep vertical overlap permits _______ cusps
2. minimum vertical overlap requires ______ cusps

Back 11

1. longer
2. shorter

Front 12

1. pronounced horizontal overlap requires ______ cusps
2. minimum horizontal overlap permits ______ cusps

Back 12

1. shorter
2. longer

Front 13

1. excessive immediate side-shift requires ______ cusps
2. gradual immediate side shift permits ______ cusps

Back 13

1. shorter
2. longer

Front 14

how may short cusps be increased in length?

Back 14

by increasing effects of anterior guidance:
1. reducing horizontal overlap
2. increasing vertical overlap

Front 15

types of occlusion

Back 15

- bilaterally balanced
- unilaterally balanced (group function)
- mutually protected (canine guidance)

Front 16

bilaterally balanced occlusion

Back 16

- used primarily in removable prosthetics
- a maximum # of teeth should contact in all excursive movements
- useful to prevent tipping of dentures
- will cause excessive wear to natural teeth

Front 17

unilateral balanced occlusion

Back 17

- group function
- elimination of all tooth contact on the non-working side
- all teeth on the working side are in contact during lateral excursions
- distributes occlusal load
- causes abfractions on posterior teeth

Front 18

mutually protected occlusion

Back 18

- canine guidance (cuspid rise)
- anterior teeth bear all the excursive load and posterior teeth are discluded in any excursive movements
- anterior teeth protect posterior teeth in all mandibular excursions
- posterior teeth protect the anterior teeth at the intercuspal position

Front 19

why use anterior guided occlusion?

Back 19

- force is more favorably placed on teeth
- class 3 level is the least efficient and thus less force placed on anterior teeth

Front 20

1. class 1 lever
2. class 2 lever
3. class 3 lever

Back 20

1. similar to a crowbar- power, fulcrum, work
2. simiar to a wheelbarrow - fulcrum, work, power
3. similar to a drawbridge (all power in back to pull it up)- fulcrum, power, work
(fulcrum = condyle, power = mm, work = anterior teeth)

Front 21

criteria for optimum occlusion

Back 21

there are 5 criteria that should be fulfilled if an occlusion is to function w/ optimum stability and maintainability:
1. stable stops on all teeth when the condyles are in their most superior-anterior
2. an anterior guidance that is in harmony w/ the border movements of the envelope of function
3. disclusion of all posterior teeth in protrusive movement
4. disclusion of all posterior teeth on the non-working side (side of the orbiting condyle)
5. disclusion of all posterior teeth on the working side (side of pivoting condyle)

Front 22

mouth is what type of lever?

Back 22

class 3

Front 23

abfractions

Back 23

wear at gingival area