Fixed Appliances Flashcards

1
Q

What is a Fixed Appliance?

A

An Orthodontic appliance which is fixed to the teeth and cannot be removed by the pt

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2
Q

What movements are created by a fixed appliance?

A
  1. Tipping
  2. Bodily
  3. Torque
  4. Extrusion
  5. Intrusion
  6. Rotation
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3
Q

Indications for Fixed Appliances

A

*mild/moderate skeletal discrepances
* Intrusion/extrusions
* corrections of rotations
* Overbite reduction
* Multiple tooth movements
* Space closure
* Psychological well being

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4
Q

Advantages for Fixed Appliances

A
  • AP, Transverse and verticle movements
    *Bodily Movement
    *complex maloclussions
    *space closure
  • Multiple tooth movements
    Upper and lower arches
  • intrusion/extrusion
    *overbite reduction
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5
Q

Disadvantages for Fixed Appliances

A
  • High Anchorage demands
    *OH
  • Increased Chairside
    *Ulcers
    *Breakages
  • Root Resorption
    *not very aesthetically pleasing
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6
Q

Describe Mode of Action

A

Forces applied to the teeth by a fixed appliance

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7
Q

Describe Force Couple

A

Magnitude of force applied to tooth x Distance between them

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8
Q

Components of a Fixed Appliance

A
  1. Bands
  2. Brackets
  3. Archwires
  4. Auxilaries
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9
Q

What are Bands made of and where are they usually placed?

A

Stainless Steel
Premolars and Molars
S
oldered to the applaince

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10
Q

What appliances are bands used for?

A
  • Fixed applainces
  • Headgear
    *TPA
    *RME
    *Quadhelix
    *Lingual arches
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11
Q

When are bands used?

A
  • Failure with bonding Eg. Crowns and large restorations
  • Restricted access
  • mositure control
  • when used with an applaince for anchorage
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12
Q

What are bands cemented with?

A

GIC (Bandlock PolyF Zinc Phosphate)
* Adhers to enamel
*fluoride releasing
*sets with contact to saliva
*indent always placed buccally

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13
Q

Advantages of Bands

A
  • Less chance of debonding
    *more stable
  • canbe used for an additional attachment EG.TPA
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14
Q

Disadvantage of Bands

A

*Seperation needed
*less aesthetic
*irritaion to gingivae
*Slower to bond than brackets
* More appointments
*Expensive
*Gaps after debond

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15
Q

What is the function of a Bracket?

A

Spreads and contrls forces that are applied from the archwires and auxiliaries

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16
Q

Where can brackets be bonded?

A

Enamel surface of the crown:
Labial - buccal fixed
palatal/lingual surface - ligual applainces

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17
Q

Names the three types of Brackets

A
  1. Edgewise
  2. Ribbonwise
    3.Self ligating
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18
Q

Name the two types of Edgewise Brackets

A
  1. Standard - no prescription
  2. Preadjusted - prescription in the bracket
  3. Tip edge - prescription in the bracket
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19
Q

Name the two sizes of Edgewise brackets

A
  1. 0.018in x 0.025
  2. 0.022 x 0.028
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20
Q

Edgewise Characteristics

A
  • Single archwire and 4 tiewings
    *reduced interbracket span
    *width increased- control of rotations and tooth width
    *elastomeric modules used
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21
Q

Advantages of Edgewise Brackets

A
  • available both standard and preadjusted
    *preadjusted - reduce the need of wire bending
    *good sliding mechanisms
    *good finishing
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22
Q

Disadvantage of Edgewise Brackets

A
  • ignore biological variation
  • produces friction + more anchorage needed
  • can create poor OH with elastomeric modules
    *modules = more chairside
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23
Q

What is a working wire for a 0.018 x 0.025 Edgewise bracket

A

16x22 SS

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24
Q

What is a workig wire for a 0.022 x0.028

A

19x25 SS

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25
Q

Name the three most common Preadjusted Edgewise appliances

A
  1. Andrews
    2.Roth
    3.MBT Mclaughlin, Bennet, Trevisi (highest Torque)
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26
Q

What Bracket type needs wire bends?

A

Standard Edgewise

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27
Q

Name the Three wire bends

A
  1. First order bend
  2. second order bend
    3.Third order bend
28
Q

First Order Bend

A
  • IN/OUT movements
  • Corrects tooth widths
    *Bucco - lingual
  • labial - Palatal
    *AP movements
29
Q

Second Order Bend

A
  • TIP movements
  • corrects angulation
  • bends in the vertical plane to create mesiodistal angulation
30
Q

Third Order Bend

A

*Torque Movements
* Rectangle Wires
*palatal and buccally root torque by archwire being twisted forwards

31
Q

Narrow Brackets =

A

*larger bracket interspan
* archwire= more flexible
* Faster alignment

32
Q

Wider Brackets =

A

*Less bracket Interspan
* used for derotation and mesiodistal control of the teeth

33
Q

What is a Begg Appliance?

A

Light wire and light force Appliance

34
Q

List the components of a Begg Appliance

A
  • Brackets
    *Pin
    *Archwire
35
Q

What are the advantages of a Begg Appliance?

A
  • overcomes high anchorage demands - light anchorage appliance
36
Q

What wires does a Begg Appliance use?

A

Round wires only which loosely fit into the bracket = alot of slop

37
Q

In a Begg Appliance what is used to hold the archwire in?

A

Pin

38
Q

What auxiliaries are used to create tooth movements for Begg Appliances

A
  • Inter maxillary Elastics - tips teeth
  • springs and loops - Upright the roots + rotational movements
39
Q

Name the features of a Tip Edge Appliance

A
  • Round wires and light forces
  • detailed finishing - each bracket has a built in prescription
40
Q

Name the three stages of the Tip Edge Appliance

A
  1. Align Teeth
  2. Start Space closure
  3. Incline teeth
41
Q

Describe the bracket of an Self Ligating Appliance

A

Door/clip which ensures full engangment and holds the archwire

42
Q

Name the two types of Self Ligating Appliances

A
  1. Passive
    2.Active
43
Q

Describe an Active Self Ligating Appliance

A

Active forces on the wire

44
Q

Describe an Passive Self Ligating Appliance

A

Slide mechanisms - passive and places no active force on the archwire

45
Q

Advantages of Self Ligating Appliances

A
  • Arch circumference increased= wider smiles
    *reduced chairside
    *Different torques available
    *Produce lower friction
    *improved OH due to no modules
  • longer time inbetween appts
46
Q

Advantages of Buccal Appliances

A
  • Good access
  • good finishing and detail
  • can now get aesthetic brackets
  • quicker than lingual
47
Q

Disadvantages of Buccal Appliances

A
  • visible
    *Decalcification
  • Aesthetic brackets can fracture
48
Q

What are the brackets called which are used for Lingual Appliances

A

Preadjusted Ribbonwise brackets

49
Q

How are Lingual Brackets different?

A

They are thicker vertically than horizontally

50
Q

What are the components of a Lingual Appliance?

A
  • Custom brackets/wires
    *indirect bonding - in a jig
51
Q

Advantages of Lingual Appliances

A

*Aesthetically pleasing
* less decalcification
* good fro treating overbites as they can act as a bite plane
* indirect bonding with a jig - correct position

52
Q

Disadvantages of Lingual Appliances

A
  • Speech
    *Ulcers
  • demanding on clinician
  • reduced interbracket span
    *finishing difficult
    *cost - if lost a new bracket needs to be ordered
53
Q

List Bracket materials

A

1.Metal
2.Stainless Steel
3. Cobalt - chromium
4. Titanium
5. Ceramic
6. Plastic

54
Q

List the two materials of Aesthetic brackets

A
  1. Plastic
    2.Ceramic
55
Q

List the plastic material used for Aesthetic brackets

A

*Polyurethane
*polycarbonate reinforced ceramic
*Fiberglass fillers

56
Q

List the Ceramic material used for Aesthetic brackets

A

Aluminium oxide either:
1.opaque - Polycrystalline
2.Clear - Monocrystaline

57
Q

Advantages of Ceramic Brackets

A
  • Visually pleasing
    *popular with patients
  • Better than plastic
58
Q

Disadvantages of Ceramic Brackets

A
  • Brittle/fracture
  • Cause wear on opposing teeth
  • enamel fracturing @debond
  • increase of friction ( now brackets have a metal slot to prevent)
  • expensive
  • poor tie wings
59
Q

List the two ways Brackets are manufactured

A
  1. Spot Welded
  2. Injection Moulded
60
Q

Describe a spot welded bracket

A

*Base and bracket separately stuck together
* cheaper and can debond from each other

61
Q

Describe a Injection moulded bracket

A
  • base and bracket injection moulded together
  • Expensive
62
Q

List the two ways a bracket is bonded

A
  1. Direct bonding
  2. Indirect bonding
63
Q

What is Direct bonding?

A

When a bracket is placed individually

64
Q

What is Indirect bonding?

A

when a bracket is placed in a positioning tray EG. lingual appliances

65
Q

Name the two bonding methods

A
  1. Mechanical bonding/interlock
  2. Chemical Bond
66
Q

What is Mechanical Bonding

A
  • interlocking of molecules
    *Phospheric acid applied to the tooth surface
  • washed and dried
  • exposed cystalline structures within the enamel
    *allows bond to flow and is increased by mesh base on the bracket
67
Q

What is Chemical Bond

A
  • Composite and primer
  • allows polymerization
    ( 2 molecules join and share anatomical structures)