URA design

Question 1

ARAB - what does this acronym stand for?

Answer 1

Active component
Retention
Anchorage
Baseplate

Question 2

Active component

Answer 2

the component(s) that will be moving teeth with application of forcer

Question 3

retention - define

Answer 3

resistance to displacement forces

Question 4

Types of forces which could displace a URA

Answer 4

• gravity
• occlusal
• masticatory
• active component

Question 5

Anchorage - define

Answer 5

the resistance to unwanted tooth movement

Question 6

Baseplate

Answer 6

connects all components together
provides Anchorage
assists with retention

Question 7

Active component used to retract canines (include gauge of wire)

Answer 7

palatal finger springs and guards, 0.5mm HSSW

Question 8

Retentive component for anterior teeth + gauge of wire

Answer 8

Southend clap, 0.7mm HSSW

Question 9

retentive component used for posterior teeth + gauge of wire

Answer 9

Adams claps, 0.7mm HSSW

Question 10

Baseplate is made out of…

Answer 10

self cure PMMA

Question 11

Baseplate modification to treat an overbite

Answer 11

Flat anterior bite plane, Overjet + 3mm

Question 12

components of stainless steel

Answer 12

72% iron
18% chromium
8% nickel
1.7% titanium
03% carbon

Question 13

Advantages of removable orthodontics

Answer 13

• tipping of teeth
• excellent anchorage
• generally cheaper than fixed
• shorter chair side time required
• OH 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

Question 14

disadvantages of removable orthodontics

Answer 14

• less precise control of tooth movement - only tipping
• can be easily removed by patient
• only 1-2 teeth can be moved at one time
• specialist technical staff required to construct appliances
• rotations can be difficult to correct

Question 15

information to give patient following delivery of a URA

Answer 15

appliance will feel big and bulky
- will get used to it, perfectly normal
may cause initial salivation
- will pass in 24 hours
may impinge on speech
- practice reading aloud
to be worn 24/7 including meal times and sleep
remove after every meal and clean with a soft brush
remove and store in protective container when participating in contact or active sports
avoid hard or sticky foods - be wary with hot food and drinks
missing appointments and non-compliance will significantly increase treatment time
emergency contact details

Question 16

steps taken prior to trying in URA

Answer 16

ensure patient details match details supplied for appliance
check appliance matches design specifications
inspect appliance and run finger over all surfaces looking for potentially sharp or traumatic areas
check integrity of the wire
insert appliance into patients mouth

Question 17

Write a prescription for a URA to expand the upper arch

Answer 17

Active component - midline palatal screw

retention - 16 + 26: Adam’s clasps: 0.7 HSSW
14 + 24; Adam’s clasps; 0.7mm HSSW

anchorage - reciprocal anchorage

baseplate - self cure PMMA

Question 18

what would you use to reduce a 6mm overjet in a URA?

Answer 18

22, 21, 11, 12; Roberts retractor; 0.5mm HSSW + 0.5mm ID tubing
stops; 13 + 23 mesial stops; 0.7mm (flattened) HSSW

Question 19

What active component would you use to retract a buccally placed canine?

Answer 19

Buccal canine retractor; 0.5mm HSSW and 0.5mm ID tubing