orthodontics

Question 1

what is IOTN?

Answer 1

index of orthodontic treatment need - measure impact of malocclusion on individuals dental health + psychosocial wellbeing

1 (least need) - 5 (greatest need)

dental health + aesthetic component

Question 2

what is PAR?

Answer 2

peer assessment rating - quantitively measures malocclusion + efficacy of treatment

Question 3

4 ways to modify growth

Answer 3

1. functional appliance
2. headgear
3. temporary anchorage devices
4. palatal implants

Question 4

mode of action for removable appliances?

Answer 4

tipping

Question 5

what is a flat anterior bite plane used for?

Answer 5

overbite reduction

Question 6

what is an expansion appliance used for?

Answer 6

widen maxilla

Question 7

what is a cover plate used for?

Answer 7

after exposure surgery - for 2 weeks

Question 8

what is a space maintainer?

Answer 8

maintains space after early tooth loss for a prosthesis/successor

Question 9

3 types of retainers post ortho

Answer 9

1. essix
2. hawley - full time 3/12 then nights
3. fixed/bonded

Question 10

what is a functional appliance?

Answer 10

removable or fixed using forces generated by stretching of muscles, fascia +/- periodontist to alter skeletal + dental relationships

Question 11

what functional appliance is usually used for class II malocclusions?

Answer 11

twinblock

OJ>6mm

Question 12

when is appropriate for use of functional appliance?

Answer 12

when actively growing

f = 11-13 years
m = 12-14 years

Question 13

3 components of skeletal diagnosis

Answer 13

1. classification
2. FMPA
3. Lower face height

Question 14

what would an obtuse nasolabial angle suggest?

Answer 14

poor lip support - extractions to be avoided

Question 15

measurements for mild, moderate + severe crowding?

Answer 15

mild = <4mm
moderate = 4-8mm
severe = >8mm

Question 16

which cusps of molars normally occlude with each other?

Answer 16

upper buccal cusp, buccal to lower

Question 17

risks of leaving impacted teeth?

Answer 17

cyst formation

root reosorption

Question 18

risks of exposing impacted teeth?

Answer 18

root damage, crown damage, ankylosis

Question 19

inevitable amount of induce inflammatory root resorption after orthodontic?

Answer 19

1-2mm

Question 20

over what period of time for elastic recoil PDL fibres remodel?

Answer 20

~1y

Question 21

4 main risk to explain when gaining consent for orthodontic treatment

Answer 21

1. pain
2. root resorption
3. decalcification
4. relapse/retention

Question 22

examples of soft tissue/habits that change occlusal classfication

Answer 22

1. lip trap = II
2. large tongue = III
3. active lowerlip = II
4. digit sucking = II

Question 23

movement made by fixed appliances?

Answer 23

bodily movement

Question 24

what physics law does orthodontic anchorage use?

Answer 24

newtons 3rd law

Question 25

6 ways to create space?

Answer 25

1. leeway space 2. distal movement 3. arch expansion 4. incisor proclamation 5. inter proximal stripping 6. extractions

Question 26

when should teeth be extracted?

Answer 26

1-2 weeks before appliance placement

Question 27

is GA justified for orthodontic extraction?

Answer 27

no

Question 28

a in IOTN

Answer 28

overjet

Question 29

h in IOTN

Answer 29

hypodontia

Question 30

I in IOTN

Answer 30

impedance

Question 31

m in IOTN

Answer 31

reverse overjet

Question 32

p in IOTN

Answer 32

clefts

Question 33

s in IOTN

Answer 33

submerged

Question 34

c in IOTN

Answer 34

crossbites

Question 35

d in IOTN

Answer 35

displacement

Question 36

e in IOTN

Answer 36

open bite

Question 37

factors affecting teeth resorption risk with fixed appliance

Answer 37

``` distance moved existing resorption pipette shaped roots/thin roots previous trauma asthma ```

Question 38

normal measurement for overbite

Answer 38

40%

Question 39

normal amount of incisor showing on smiling

Answer 39

75-100%

Question 40

how to describe overbite

Answer 40

% + complete/incomplete

Question 41

components of intra-oral ortho assessment

Answer 41

``` OH, periodontal status incisor, canine, molar relationship overjet + overbite centreline discrepancies crowding cross bite/displacements ```

Question 42

reasons to take radiograph for ortho assessment

Answer 42

pathology suspected skeletal discrepancies developmental - uneurpted teeth/submerged/impacted

Question 43

aesthetic rating qualifying for NHS treatment

Answer 43

6 or above

Question 44

nemonic for order of IOTN

Answer 44

MOCDO ``` m=missing = h o = overjet = a c = cross bite = c d = displacement = d o = overbite ```

Question 45

which premolars extracted for severe crowding

Answer 45

4s | 5s for less

Question 46

what is SNA

Answer 46

position of maxilla relative to anterior cranial base

Question 47

what is SNB

Answer 47

position of mandible relative to anterior cranial base

Question 48

what is ANB

Answer 48

relative position of maxilla to mandible

Question 49

benefits of ortho

Answer 49

``` function relieve impaction - resorption/cysts reduce perio/caries reduce trauma risk psychological ```

Question 50

when should upper 6s be extracted?

Answer 50

8-10yrs

Question 51

when should lower 6s be extracted?

Answer 51

8-10yrs - 7s bifurcate 9/9.5

Question 52

biology of tooth movement

Answer 52

force applied, bone layed down where PDL under tension, resorbed in areas of PDL compression

Question 53

normal angle for nasolabial angle

Answer 53

90-110

Question 54

3 indications for taking lateral cephalogram

Answer 54

skeletal discrepancy anterior-posterior movement of incisors is planed monitoring of growth

Question 55

3 options for skeletal problems

Answer 55

orthodontic camouflage growth modification surgery

Question 56

when might you retain poor prognosis 6s

Answer 56

retain until 7s erupted if severe overjet or anterior crowding - space maintenance

Question 57

what is vertical subsigmoid osteotomy used to achieve?

Answer 57

setback on mandible

Question 58

what is a sagittal split osteotomy used to achieve?

Answer 58

advance or pushback mandible or asymmetry IAN complication most common surgery

Question 59

most common maxillary surgery

Answer 59

le fort 1 osteotomy

Question 60

orthodontic treatment done before orthographic surgery is called what

Answer 60

decompensation - may make worse to start with

Question 61

prevalence of cleft lip/palate

Answer 61

1/700 Caucasians

Question 62

syndrome often associated with cleft lip/palate

Answer 62

treacher collins