Removeable appliances Flashcards
where do the forces that move the teeth come from in the appliance?
springs
screws
bows
what are some advantages of removable appliances?
easy to clean good anchorage less chairside time less inventory moves blocks of teeth cheap easy to adjust
what are some disadvantages of removable appliances?
dependent on pt co op tipping movement only speech affected retention is difficult lower appliance can be difficult to wear
what movements can a removable appliance cause?
tipping space maintenance bite opening crossbite correction single tooth movement
what are the 4 components of the appliance?
baseplate
activator
retention
anchorage
what materials are used in making an appliance?
SS 18:8 chromiun :nickel
elgiloy - soft, heat treated to increase strength
acrylic - pmma - self cured heat cured light cured
what is the job of the baseplate?
holds components together
active or passive
can hold biteplanes
what is the job of an anterior biteplane?
reduce overbite
what is the job of a posterior biteplane?
eliminates occlusal interferneces
what is put in a baseplate to make it active?
springs
what is the force of the appliance dependent on?
length of wire
radius of wire
stiffness of wire
if you increase the length of the wire what happens to the force?
lighter force exerted
length of wire is restricted by size of mouth, how can this be fixed?
add coils to wire
double the diameter of the wire, force?
double the length?
increase forces
decrease forces
tooth movement happens in what direction?
perpendicular to point of contact of spring with tooth
if spring is 0.5mm, activation is?
if spring is 0.7mm, activation is?
3mm
1mm
palatal springs can cause movement in what direction?
mesial
distal
buccal
size of palatal springs?
- 5mm
0. 7mm molars
buccal canine retractors cause movement of canines in what direction?
palatally and distally
what size are buccal canine retractors?
how are they activated?
0.7/0.5mm with supportive tubing
activated by winding coil or adjusting arm
what size are Z springs?
0.5mm SS
what are Zsprings?
double cantilever increasing wire length where space is limited
where to Z springs sit?
perpendicular to palatal surface
how are Z springs activated?
pull 1-2mm away from baseplate at angle of 45 degrees in direction of desired movement
what size are T springs?
0.5mm SS
what are T springs used for?
move teeth buccally
how are T springs activated?
pull spring away from baseplate at angle of 45 degrees
are bows active or passive?
can be either
what is the job of an active bow?
retraction of proclined incisors
what are the sizes of bows?
07/0.8mm, 0.5mm if unsupported
what is a roberts retractor used for?
0.5mm and used to retract incisors
what direction to screws move teeth?
labiolingually
where do screws get force to move teeth?
via acrylic contacting tooth and transversley expand
how often are screws turned?
once a week at start of tx
twice a week further into tx
what can screws be used for?
to move teeth required for retention
how do adams clasps and cribs clasps give retention?
engage undercuts at mesio distal
what size are adams and cribs clasps?
- 7mm SS molars
0. 6mm premolars and deciduous teeth
what are southend and c clasps used for?
anterior teeth
what size are southend and c clasps?
how do they give retention?
undercut beneath contact point
0.7mm SS
how to ball ended hooks work and what size are they?
0.7mm
soldered ball engage undercuts interproximally
where to labial bows give retention?
how are they activated?
anterior retention
squeeze U loop to tighten
what is anchorage?
forces created as a reaction to a active component provided by - other teeth/baseplate/other forces
how is anchorage increased?
clasping more teeth
using lighter forces
what tools are used to fit appliances?
adams clasps spring forming pliers marker measuring device acrylic trimmer
when can removable appliances be taken out?
contact sports
cleaning
what problems can happen with these appliances?
breakages
loose fitting, falls out
palatal inflammation
excessive tilting
