W11 - Fixed Appliances - Abdalla

Question 1

What is the E arch?

Answer 1

The first appliance developed by edward Angle based on Fauchards device
- Cause tipping only

Question 2

What is the pin and tube appliance?

Answer 2

Second appliance by angle

• could cause couple force
• good 3D control
• very sdifficult to adjust

Question 3

What is the edgewise appliance?

Answer 3

• Wire inserted “edgewise” into the appliance
• Basically the modern dental bracket
• Could cause forwards/backwards movements, tipping

Question 4

What are the movements of edgewise appliances?

Answer 4

Question 5

What was the significant thing thata Charles tweed did?

Answer 5

Challenged angles non-extraction philosophy - started taking out premolars in problematic, failed cases

Question 6

Limitation of edgewise appliances (2)

Answer 6

Time consuming to bend the first, second and third order movements for each tooth into the archwire

High forces

Question 7

Who is Raymond Begg?

Answer 7

Australia’s first significant orthodontist that treated non-extraction edgewise cases (independent of Tweed)

• Re-treated cases by doing premolar extractions
• Wrote the “Stone Mans dentition” discussing how we have more teeth than needed

Question 8

What is the Begg appliance?

Answer 8

Angle’s Ribbon Arch bracket turned upside down

• Used work hardened wires
• “Light wire” technique
• Round wires tip crown into correct position
• Springs upright the roots
• Low force
• Quick
• Very efficient at treating extraction cases
• Faster than edgewise

Question 9

Best feature of nickel titanium

Answer 9

• Elastic properties

- Will return to its original shape when bent

Question 10

6 Principles describes by andrew Larry

Answer 10

1. Class 1 molar relationship - distal surface of the upper molar occludes with the mesial surface of the mesiobuccal cusp of the lower second molar
2. Correct crown angulation
3. Correct Crown inclination (buccolingual inclination)
4. No rotation
5. Tight contacts (no spaces)
6. Flat occlusal plane (no large curve of spee)

Question 11

Features of straight wire appliance?

Answer 11

Replaced Begg technique

• No wire bending
• Simple
• Easy to use
• Most popular appliance system today
• Equivalent treatment times to Begg appliance

Question 12

Components of a fixed appliance

Answer 12

Brackets / tubes

• Bonded to teeth with GIC
• Metal or ceramic
• Slot widths of 0.018 and 0.022”

Auxilliaries
Archwires

Question 13

Pros and Cons of ceramic brackets

Answer 13

Pros:
Aesthetic
diffiuclt to debond

Cons:
High friction
brittle
wear of opposing teeth

Question 14

What are orthodontic auxillaries? (4)

Answer 14

Elastic modules
Intra oral elastics
Wire ligatures
Elastic chains

Question 15

What are stainless steel wires used for? (2)

Answer 15

Gross tooth movement

Finishing/detailing

Question 16

When are different sized wires used?

Answer 16

Full thickness - straight teeth / retainer

Question 17

Steps in straightwire appliance ortho treatment

Answer 17

Levelling and aligning - NiTi wires

Gross tooth movement - stainless steel wires

Finishing / detailing - stainless steel wires

Question 18

Two shapes of archwire

Answer 18

Rectangular/square

Round

Question 19

How many sizes ae there for rectangular vs round wires

Answer 19

Rectangular - 2 sizes

Round - 1 size

Question 20

Why are square/rectangular wires not used initially during ortho treatment?

Answer 20

They have an increased thickness -> will put too much pressure on tooth

• Must use a smaller diameter, flexible wire (round) at the start (lighter force)
• Only use full size wire / engage full slot of the bracket once teeth are relatively straight

Question 21

When are flexible wires used vs rigid wires?

Answer 21

Soft/Flexible - correcting position, lining teeth up

Rigid - closing space