quiz 2 Flashcards
Cusp angles in anatomic denture teeth are what? when are anatomic teeth used?
10,20,30,40. For esthetics, coordinated jaw movements, when dentures oppose natural teeth
Non anatomic teeth in dentures
0 degree. Used when there are jaw size descrepancies, ridge resorption, uncoordinated jaw movements
overlaps with non-anatomic teeth
no vertical overlap, normal horizontal overlap
posterior tooth selection
shade, size, number and form
describe the buccolingual size affect of the posterior teeth
should be smaller than natural teeth to reduce the size of occlusal table.
the anteroposterio dimension of the posterior teeth
is determined by the space between the canine and ascending area of ridge.
should teeth be placed on the ascending area?
no. this causes a dislodging force.
vertical length of posterior teeth.
depends on length of anterior teeth and available interarch distance
anatomic form cusps of dentures
range from 20-45 degrees with average of 33.
when are non-anatomic cusps used?
cross-bite relations, TMJ disturbances, neuro-muscular co-ordination loss, ridge resorption.
what jaw relationship classes are good for non-anatomic cusps?
2 and 3
in summary when are anatomic denture teeth used?
balanced occlusion is achievable, young people, good ridges
in summary when are non-anatomic denture teeth used?
old patients with poor ridges and poor neuromuscular control
advantages of anatomic teeth
more efficient in cutting food, esthetically acceptable, can be arranged in balanced occlusion
disadvantages of anatomic teeth
use adjustable articulator, eccentric records must be taken, clinical remount is essential, balances occlusion is lost during setting, more horizontal forces, frequent relining , fast bone resorption
advantages of non-anatomical teeth
comfortable, greater range of movements, less horizontal forces, only centric record needed,
disadvantages of non-anatomical teeth
not natural looking, less cutting efficiency, 2 occlusion dimensions, but mandible has 3
when are acrylic teeth used?
limited arch space, maxillary denture opposing natural teeth, opposing teeth with gold occlusal surface.
Hanau quints describe what 5 factors that affected occlusal balance
condylar inclination, incisal guidance, occlusal plane inclination, cuspal inclination, compensating curve
theilmans formula for balanced occlusion
condylar inclinationX incical guidance/ occplaneX cuspal inclinationX comp curve
what happens when one of the factors of theilmans formula is off?
the others have to change to compensate for the differences
What is a balancing ramp?
its a way to compensate for disclusion . It increases the occlusal plane and or compensating curve
more on balancing ramps
they provide posterior contact in eccentric positions
what should be done with the incisal guidance when using zero degree cusps?
it should be decreased.( this would maintain the occlusal plane)
what is the one factor that dentists have no control over?
condylar inclination
what does the minimizing the incisal guidance do in dentures?
minimizes the horizontal forces
forces in linear occlusion
directly vertical to the flat surfaces
anatomy of the linear occlusion
lower anteriors have 0 vertical overlap, lower teeth sit on flat occlusal plane, lower posteriors buccal surfaces are straight up and down
what does monoplane occlusion help with?
lateral forces reduced, improves stability
monoplane occlusion in the anterior teeth
make contact in excursions
when can monoplane occlusion be unstable?
when condylar guidance is steep( posterior teeth seperate while anterior stay in contact)
define balanced occlusion
simultaneous contact of upper and lower arches with smooth bilateral gliding from the centric position to eccentric positions
what is bilateral occlusal balance?
equilibrium onboth sides of denture due to the simultaneous contact of teeth in the centric and eccentric positions. Requires a minimum of 3 contacts for equilibrium
what is protrusive occlusal balance?
balance between teeth when mandible protrudes
what are some advantages of balanced occclusion?
distribution of load, stability, reduced trauma, functional movement, efficiency, comfort
advantages of bilateral occlusion
contacts occur evenly while swallowing, chewing helps seat the denture in a stable position, prevents destructive lateral forces of parafunctional movements
how are anatomic and semi-anatomic denture teeth different?
degree of cuspal inclination and precision of intercuspal relationships.
degree of anatomic denture cusps vs semi-anatomic
anatomic is 30 degrees
semianatomic is 10-20 degrees
the compensating curve is analogous to what?
curve of spee.
what is the curve of wilson?
medio-lateral curve
where does the curve of spee and wilson begin?
molar region, the mesiolingual cusp is the only one that touches the plane
2nd maxillary molar in curve of spee
elevated even more than the 1st molar. its elevated about 15 degrees in average person.
where does the mesial buccal cusp of the mandibular 1st molar engage?
embrasure between 1st molar and 2nd premolar
for bilateral occlusion, what is the first mandibular tooth that is placed?
the 1st molar, make sure it occludes where it needs to and is directly over the ridges
where does the mandibular second premolar occlude?
adjacent margins of the maxillary 1st and 2nd premolars
where does the mandibular first premolar occlude?
mesial marginal ridge of maxillary 1st PM, there is a space between the canine.
where do mandibular premolars go in balanced occlusion?
solid centric occlusion.
mandibular premolar cusp contact during lateral excursion in bilateral balanced occlusion
lingual cusps should not be contacting
balanced occlusion for non-anatomic teeth may be accomplished by:
- compensating curve
- tilting the second molar
- placing the balancing ramp
general considerations for bilateral balanced occlusion
ideal balance can be achieved in cases with large ridges.
narrow buccolingual teeth provide ideal balanced occlusion
ideal balance can be achieved by arranging the teeth slightly on the lingual side of the ridge
what factors influence balanced occlusion in bilateral occlusion?
condylar guidance, occlusal plane, cuspal angulation, compensating curve
maintining balancing contacts
change occlusal plane angle, increase compensating curves, increase cusp angles
how to check for balance with finished dentures
put fingers on canines and move on articulator, it should be smooth movements
