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23 Cards in this Set
- Front
- Back
anterior protected articulation
canine protected articulation |
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
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occlusal interference
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any tooth contact that inhibits the remaining occluding surfaces from achieving stable and harmonious contacts
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types of occlusal interferences
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- centric
- protrusive - working side - non-working side |
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centric slide:
what is it? what % of the pop. does it occur in? what does it result in? |
- 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 |
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protrusive interference
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- 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 |
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working side interference
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- 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 |
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non-working side interference
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- 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 |
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which type of interference is the most destructive?
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non-working side interference
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vertical determinants determine what?
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cusp height and fossa depth
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1. gradual eminentia slope requires ______ cusps
2. steep eminentia slope requires ______ cusps |
1. short
2. longer |
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1. deep vertical overlap permits _______ cusps
2. minimum vertical overlap requires ______ cusps |
1. longer
2. shorter |
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1. pronounced horizontal overlap requires ______ cusps
2. minimum horizontal overlap permits ______ cusps |
1. shorter
2. longer |
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1. excessive immediate side-shift requires ______ cusps
2. gradual immediate side shift permits ______ cusps |
1. shorter
2. longer |
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how may short cusps be increased in length?
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by increasing effects of anterior guidance:
1. reducing horizontal overlap 2. increasing vertical overlap |
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types of occlusion
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- bilaterally balanced
- unilaterally balanced (group function) - mutually protected (canine guidance) |
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bilaterally balanced occlusion
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- 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 |
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unilateral balanced occlusion
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- 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 |
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mutually protected occlusion
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- 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 |
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why use anterior guided occlusion?
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- force is more favorably placed on teeth
- class 3 level is the least efficient and thus less force placed on anterior teeth |
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1. class 1 lever
2. class 2 lever 3. class 3 lever |
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) |
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criteria for optimum occlusion
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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) |
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mouth is what type of lever?
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class 3
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abfractions
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wear at gingival area
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