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Orthodontics > Retention > Flashcards

Flashcards in Retention Deck (38)
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1
Q

What are the four causes of relapse?

A

soft tissue
occlusal factors
facial growth
supporting tissues

2
Q

What soft tissue factors influence stability?

A

teeth need to be in the neutral zone
Lips cheeks and tongue need to be in balance and during treatment this balance changes and thus need to establish new balance

3
Q

What soft tissue factors influence stability in class 2/1?

A

lower lip in front of upper incisors following treatment

Severely incompetent lips at the start of treatment will mean unstable OJ reduction

4
Q

What occlusal factors influence stabilty in class 2/1?

A

need an appprotate inter incisal angle of 135 degree and lower incsors must be 2-3mm anterior to the centrol of upper incisors

All cases need good intercuspation

5
Q

What occlusal factor will influence stability in class 3?

A

adequate overbite

6
Q

What feature may worsen with posterior growth oattern?

A

AOB

7
Q

What malocclsuion worsens with anterior growth pattern?

A

class 3 and deep overbites

8
Q

what percentage of people need re treatment within 10 year spost ortho?

A

70%

9
Q

What are the components of the supporting tissues which influence stabilty?

A

bone
pdl
gingiva

10
Q

How long does it take bone to remodel?

A

3 months

11
Q

What happens to the pdl during treatment?

A

it is put under tension

12
Q

What happens to the pdl following treatment?

A

it has a tendancy to want to spring back

13
Q

How long does it take sharpey fibres to remodel?

A

1-2 months

14
Q

Which fibres within the gingiva are present?

A

supra-crestal fibres

free gingival fibres

15
Q

How long does it take supra crestal fibres to re model?

A

6 months

16
Q

how long does it take free gingival fibres to remodel?

A

12 months

17
Q

Which features of malocclusion are prone to relapse?

A

derotation
incisor crowding
periodontal disease
median diastemas

18
Q

What can you do to th gingiva in rotations?

A

pericision

this is when you the supracrestal fibres

19
Q

Why are incisor crowding prone to relpase?

A

narrow contact points
growth
eruption

20
Q

What are the types of retainers?

A

fixed

removable

21
Q

What are the types of removable appliaces are there?

A

hawley

VFR

22
Q

Which removable appliances are better at preventing relaps in the lower arch?

A

VFR

23
Q

What instuction do you give to people with VFR?

A

do not drink with them in

24
Q

When would you not give a VFR?

A

people with poor OH as VFR engages into the gingival undercut and if pateint has gingitivits then cannot engage

25
Q

What is relapse ?

A

The return following correction of features of the original malocclusion

26
Q

What is stability?

A

The dentition existing in a state of equilibrium between the forces imparted by the soft tissues lips checks and tongue

27
Q

What is retention?

A

Phase following active orthodontic treatment which is aimed at stabilisation of the achieved orthodontic correction

28
Q

What are graduates of relapse related to?

A

The factors affecting stability

29
Q

Which feature worsen with facial growth?

A

Class 3
AOB
Deep overbutes
Late incisor crowding

30
Q

What must be some with class 3 to avoid relapse?

A

Over correct or treat later

31
Q

What are the advantages and disadvantages of a removable retainer?

A

+Easier for OH
+Can be worn part time
-responsibility of the pt

32
Q

What are the advantages and disadvantages of a fixed retainer?

A

+Patients do not need to remember to wear them
+Useful when results are unstable

  • risk of debond and patient won’t know
  • technique sensitive
33
Q

Whh are fixed retainers advises?

A

Closure of spaced dentition eg median diastema
Rotations
Lower labial segment has had substantial movement
Combined perio and ortho

34
Q

What are the types of fixed retainers?

A

Multistrand which are bonded to each tooth in labial segment
Rigid canine and canine retainers bonded only to canines ( tend to result in relapse of unrestrained teeth)
Reinforced fibres (tend for fracture)

35
Q

What adjunctive techniques are there to preventing relapse?

A
  1. Pericison

2. Interproximal stripping

36
Q

How does precision work?bhow how effective is it?

A

Cut the interdental and dento gingival fibres above the alveolar bone level
Used of de rotated teeth
Reduces relapse by 30%

37
Q

How does interproximal stripping work?

A

Removal, of small amounts of enamel mesiodistal Distally to flatten contact points and increase stability
Not much evidence for this

38
Q

What material are fixed retainers made from?

A

Stainless steel

Used to be from eligloy