Retention

Question 1

What are the four causes of relapse?

Answer 1

soft tissue
occlusal factors
facial growth
supporting tissues

Question 2

What soft tissue factors influence stability?

Answer 2

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

Question 3

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

Answer 3

lower lip in front of upper incisors following treatment

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

Question 4

What occlusal factors influence stabilty in class 2/1?

Answer 4

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

Question 5

What occlusal factor will influence stability in class 3?

Answer 5

adequate overbite

Question 6

What feature may worsen with posterior growth oattern?

Answer 6

AOB

Question 7

What malocclsuion worsens with anterior growth pattern?

Answer 7

class 3 and deep overbites

Question 8

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

Answer 8

70%

Question 9

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

Answer 9

bone
pdl
gingiva

Question 10

How long does it take bone to remodel?

Answer 10

3 months

Question 11

What happens to the pdl during treatment?

Answer 11

it is put under tension

Question 12

What happens to the pdl following treatment?

Answer 12

it has a tendancy to want to spring back

Question 13

How long does it take sharpey fibres to remodel?

Answer 13

1-2 months

Question 14

Which fibres within the gingiva are present?

Answer 14

supra-crestal fibres

free gingival fibres

Question 15

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

Answer 15

6 months

Question 16

how long does it take free gingival fibres to remodel?

Answer 16

12 months

Question 17

Which features of malocclusion are prone to relapse?

Answer 17

derotation
incisor crowding
periodontal disease
median diastemas

Question 18

What can you do to th gingiva in rotations?

Answer 18

pericision

this is when you the supracrestal fibres

Question 19

Why are incisor crowding prone to relpase?

Answer 19

narrow contact points
growth
eruption

Question 20

What are the types of retainers?

Answer 20

fixed

removable

Question 21

What are the types of removable appliaces are there?

Answer 21

hawley

VFR

Question 22

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

Answer 22

VFR

Question 23

What instuction do you give to people with VFR?

Answer 23

do not drink with them in

Question 24

When would you not give a VFR?

Answer 24

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

Question 25

What is relapse ?

Answer 25

The return following correction of features of the original malocclusion

Question 26

What is stability?

Answer 26

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

Question 27

What is retention?

Answer 27

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

Question 28

What are graduates of relapse related to?

Answer 28

The factors affecting stability

Question 29

Which feature worsen with facial growth?

Answer 29

Class 3 AOB Deep overbutes Late incisor crowding

Question 30

What must be some with class 3 to avoid relapse?

Answer 30

Over correct or treat later

Question 31

What are the advantages and disadvantages of a removable retainer?

Answer 31

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

Question 32

What are the advantages and disadvantages of a fixed retainer?

Answer 32

+Patients do not need to remember to wear them +Useful when results are unstable - risk of debond and patient won't know - technique sensitive

Question 33

Whh are fixed retainers advises?

Answer 33

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

Question 34

What are the types of fixed retainers?

Answer 34

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)

Question 35

What adjunctive techniques are there to preventing relapse?

Answer 35

1. Pericison | 2. Interproximal stripping

Question 36

How does precision work?bhow how effective is it?

Answer 36

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

Question 37

How does interproximal stripping work?

Answer 37

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

Question 38

What material are fixed retainers made from?

Answer 38

Stainless steel Used to be from eligloy