URA retract canines
take out 4s
A - palatal finger springs 0.5mm hssw
R - adams on 6s, southends on 1s
A - moving 2 teeth
B - self cure PMMA
what is bone remodelling controlled by?
PDL
URA design retract canines and reduce overbite
take out 4’s
A - palatal finger springs 0.5mm hssw
R - adams on 6s, southends on 1s
A - moving 2 teeth
B - self cure PMMA
FABP overjet +3mm
uses of study casts
- tx planning when patient not there
- used to make dentures
- foresnics
- teaching
- patient encouragement
- medical and legal records
- diagnosis
- 3d model mouth
- retrospective studies
defintion overbite
- vertical overlap incisors
defintion overjet
upper front eeth protrude outward
- horizontal measurement
diff between heat cured and light cured pmma
- heat cured less porous, hard and easier to clean last longer
- self cured quick and easy to use and don’t need ot send to lab
what are displacement forces that can dislodge URA?
- mastication
- talking
- gravity
- tongue
- newton 3rd law
what happens of too great force put on tooth?
- damage to PDL, cuts off blood supply resulting necrotic tooth
- bone won’t have time to remodel
advanatges of URAs?
Tipping of teeth
Excellent Anchorage
Generally cheaper than fixed
Shorter chairside time required
Oral hygiene is easier to maintain
Non- destructive to tooth surface
Less specialised training required to manage
Can be easily adapted for overbite reduction
Can achieve block movements
disadvantages of URAs?
-Less precise control of tooth movement
- Can be easily removed by the patient
- Generally only 1-2 teeth can be moved at one time
- Specialist technical staff required to construct the appliances
- Rotations very difficult to correct
