URA

Question 1

what type of active components are there for URAs

Answer 1

springs
bows
screws

Question 2

what are springs used for

Answer 2

moving teeth not being used in retention

Question 3

what are bows used for

Answer 3

for retention but can be modified for the movement of anterior teeth

Question 4

what type of springs are there

Answer 4

Z springs
T springs
Palatal finger spring
active labial bow

Question 5

Z springs
what are they made out of
what are they used for
how are they activated

Answer 5

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

Question 6

T springs
what are they made out of
what are they used for
how are they activated

Answer 6

constructed in 0.5mm stainless steel
used to move individual teeth labially or buccally
activated by pulling spring away from baseplate

Question 7

palatal finger springs
what are they made out of
what are they used for
how are they activated

Answer 7

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

Question 8

active labial bow
what are they used for
when are they used
how are they activated

Answer 8

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

Question 9

what are screws used for

Answer 9

for tipping teeth being used in retention

Question 10

how are screws used

Answer 10

patient uses key to turn to screw

Question 11

how often do patients adjust the screw on the URA
how much expansion is caused by this?

Answer 11

turned one 1/4 weekly or biweekly
1/4=0.25mm

Question 12

how many clasps should be used in a URA

Answer 12

at least 2 posterior clasps and 1 anterior clasp for sufficient retention

Question 13

what clasps are used in posterior teeth in a URA

Answer 13

adam’s clasp
plint clasp

Question 14

adam’s clasps
what are they made out of
where are they most commonly used
how does it work

Answer 14

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

Question 15

plint clasp
what are they made out of
how does it work

Answer 15

used usually with a fixed appliance
constructed in 0.7mm stainless steel
engage the undercuts on a maxillary band

Question 16

what clasps are used on anterior teeth in URAs

Answer 16

southend clasp
ball-ended clasp
labial bow

Question 17

southend clasp
what is it made out of
what teeth is it used on
how does it work

Answer 17

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

Question 18

ball-ended clasp
how does it work
how is it activated

Answer 18

Engages into interproximal undercuts between the teeth
Activated by bending the ball towards the contact point

Question 19

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

Answer 19

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

Question 20

what are flat anterior bite planes used for
describe how this works

Answer 20

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

Question 21

what information should be given when prescribing a FABP

Answer 21

the patient’s overjet
depth of the FABP (describe in terms of height of the upper incisors)

Question 22

what is posterior capping used for
how is this achieved

Answer 22

correction of crossbite
acrylic over the occlusal surface of the posterior teeth props the incisors apart so there is movement of the incisors