URA Flashcards
what type of active components are there for URAs
springs
bows
screws
what are springs used for
moving teeth not being used in retention
what are bows used for
for retention but can be modified for the movement of anterior teeth
what type of springs are there
Z springs
T springs
Palatal finger spring
active labial bow
Z springs
what are they made out of
what are they used for
how are they activated
constructed in 0.5mm stainless steel
used to move one or two teeth labially
activated by pulling the spring away from the baseplate angle 45 degrees
T springs
what are they made out of
what are they used for
how are they activated
constructed in 0.5mm stainless steel
used to move individual teeth labially or buccally
activated by pulling spring away from baseplate
palatal finger springs
what are they made out of
what are they used for
how are they activated
constructed in 0.5mm stainless steel
used to move teeth mesially or distally along the dental arch
activated when tightened as the helix unwinds and toothmovement occurs
active labial bow
what are they used for
when are they used
how are they activated
used to reduce increased overjet by tipping teeth palatally
used when the upper labial segment is proclined and spaced
activated by bending the vertical arms of the bow towards the palate and trimming acrylic behind the upper incisors to allow palatal movement
what are screws used for
for tipping teeth being used in retention
how are screws used
patient uses key to turn to screw
how often do patients adjust the screw on the URA
how much expansion is caused by this?
turned one 1/4 weekly or biweekly
1/4=0.25mm
how many clasps should be used in a URA
at least 2 posterior clasps and 1 anterior clasp for sufficient retention
what clasps are used in posterior teeth in a URA
adam’s clasp
plint clasp
adam’s clasps
what are they made out of
where are they most commonly used
how does it work
constructed in 0.7mm stainless steel wire
most commonly used on first permanent molars
arrowheads engage the undercut at the mesial and distal corners of the buccal tooth surface
plint clasp
what are they made out of
how does it work
used usually with a fixed appliance
constructed in 0.7mm stainless steel
engage the undercuts on a maxillary band
what clasps are used on anterior teeth in URAs
southend clasp
ball-ended clasp
labial bow
southend clasp
what is it made out of
what teeth is it used on
how does it work
Constructed in 0.7mm stainless steel wire
Used on the incisor teeth
Activated by bending the U-loop towards the baseplate, which the clasp back into the labial undercut of the tooth
ball-ended clasp
how does it work
how is it activated
Engages into interproximal undercuts between the teeth
Activated by bending the ball towards the contact point
labial b ow
what is it made out of
how does it work
where should it be placed to be most effective
how is it activated
Constructed from 0.7mm stainless steel wire
Provides retention from the labial surface of the incisor teeth
To be effective, it should sit approximately half way up the labial surface of the incisors
Afforded flexibility by incorproating U-Loops at each end, which allows activation by compression
what are flat anterior bite planes used for
describe how this works
used to reduce an increased overbite
thickened acrylic palatally to the upper incisors
the lower incisors occlude on this FABP and so there is disclusion of posterior teeth
over time the posterior teeth erupt into this occlusion
this may result in condylar growth
therefore there is reduction of an overbite
what information should be given when prescribing a FABP
the patient’s overjet
depth of the FABP (describe in terms of height of the upper incisors)
what is posterior capping used for
how is this achieved
correction of crossbite
acrylic over the occlusal surface of the posterior teeth props the incisors apart so there is movement of the incisors
