Class II Division 1 Malocclusion Flashcards

1
Q

The diagnosis of a Class II Div 1 malocclusion
is based on the

A

incisor relationship

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Definition of class II div 1 malocclusion

A

Lower incisor edges are palatal to the
cingulum plateau of the upper incisors and the
upper incisors are proclined or of average
inclination, with an increased overjet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

overjet is … and normal in mm is …

A

Horizontal relationship
between the upper incisors
and lower incisors
 2 - 4 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

incidence is .. hence common/uncommon?

A

20-30 percent of all malocclusions (UK)
common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

proportion of class II div 1 that have skeletal base

A

II (if skeletal base I think possible habit?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

significance of class II div 1

A

 Poor dental appearance
 Facial profile often poor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

increased risk of

A

upper incisor trauma – over 40% risk with overjets 9mm+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

often associated with

A

deep overbite and possible palatal trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the IOTN

A

Index of orthodontic treatment need
 Used in N.Ireland since 2014 to decide which
cases are severe enough to warrant treatment
under the NHS
 Has been used in rest UK for many years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does it work?

A

 IOTN DHC grades 1 – 5
 series of criteria
 IOTN AC grade 1 – 10
 series of 10 photographs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

IOTN and II/i - dental health component

A

— Grade 2 = OJ 4 – 6mm with competent lips
 mild crowding

— Grade 3 = OJ 4 - 6mm with incompetent lips
 moderate crowding

— Grade 4 = OJ >6 – 9mm
 severe crowding
 mild hypodontia or supernumeraries
 deep traumatic OB

— Grade 5 = OJ 9mm +
 impacted teeth
 supernumerary teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

aetiology of class II/i

A

 Growth - AP skeletal discrepancy ( > 70% of
cases)- Mandibular retrognathia

 Habits eg. thumb sucking

 Soft Tissues - lower lip maintains proclination

 Dental factors – maxillary crowding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

EO features of II/i (mild)

A

mandible relatively behind the maxilla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

EO features of II/i (severe)

A

severity of discrepancy can be disguised by a prominent chin point

lower vertical facial proportions often reduced (reduced MMA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ceph values

A

upper incisors are proclined (>109 degrees)

ANB > 4 degrees

(ANB= SNA-SNB)- sna is a measure of maxillary AP position, SNB is a measure of mandibular AP position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

IO features (inclination, overjet, overbite)

A

 proclined or average upper incisors
 overjet increased
 overbite increased

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IO features (buccal segments and crowding)

A

class II buccal segments
crowding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

treatment of II/i - why?

A

Improved dentofacial appearance
 Improved self-esteem – reduce teasing
 Improved psychosocial wellbeing
 Reduction in trauma
 Improved function / reduce lip incompetence
 ? improved speech

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

aims of treatment II/i

A

 Improve facial profile
 Reduce overjet (OJ)
 Reduce overbite (OB)
 Relieve crowding and align arches
 Correct centre-lines
 Deal with impacted / ectopic / supernumerary
/ missing teeth as appropriate
 Produce a stable result / retain result

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What functional appliances are there

A

 Functional appliances
- (Andresen, MOA or most commonly Clarke Twin-Block, +/- FA)

 Upper removable appliances
- normally to facilitate transition between functional and fixed phase
- occasionally as complete Tx (historical)

 Fixed appliances
-often in conjunction with functional appliances +/- extractions
- Or with class II correctors eg. PowerScope (AO)

 Headgear
- used less and less frequently

 Orthodontic mini-implants
- to improve anchorage balance – becoming more popular

 Surgical orthodontic treatment
- Non-growing patients

 New developments
- Invisalign® with class 2 elastics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Treatment: no skeletal discrepancy

A

Fixed appliance only
(occasionally URA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Treatment: mild sk discrep

A

Functional / Fixed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

 Moderate: sk discrep

A

Functional / URA / Fixed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Severe sk discrep

A

Surgery + Fixed – possibly try
functional aged 12/13 to reduce
discrepancy – key is informed
consent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Treatment: Functional appliances- indications
 Age 10-13  Mild to moderate skeletal discrepancies
26
functional- complete treatment-
for well aligned arches
27
functional- 2 stage treatment-
functional to reduce overjet 2nd stage of fixed +/- extractions
28
types of functional appliances
 Activator (Andresen)  Bionator  Twinblock lower arch block slides along slope of upper arch block and forwards
29
twinblock
lower arch block slides along slope of upper arch block and forwards
30
URAs- and class II/i
1. extract upper 4s 2. retract canines 3. retract incisors
31
overbite and overjet relationship important how in relation to II div i and URAs
increased overbite prevents full overjet reduction therefore first reduce the overbite to normalthen reduce the overjet
32
treatment of II i with URA and overbite reduction
anterior biteplane incorporated into URAs start overbite reduction early (during canine retraction)
33
palatal finger spring retractor do what
retract canines/ premolars
34
palatal finger spring retractors work how (crib what tooth, diameter springs? activate by how much?)
crib 6s activate by 1/2 width of canine or premolar 0.5mm springs
35
buccal canine retractor do what
reatract canines (to relieve crowding/ reduce overjet)
36
buccal canine retractors work how - crib, what springs, activate by how much
crib 6s 0.7mm springs activate by 1/3 width of canine
37
roberts retractor do what
retract incisors (class II div 1)
38
roberts retractors work how (crib etc. )
 Crib 6s  0.5 mm labial bow supported by SS tube  should lie just behind incisal edges when passive
39
fixed appliances benefits
 Excellent tooth control, now treatment of choice
40
Fixed appliances
Mild (to moderate) skeletal discrepancies Crowded upper / lower arches
41
preparation for fixed?
 Extract -- upper premolars -- to provide space for overjet reduction. -- If lower crowding then consider upper 4’s & lower 5’s -- to improve anchorage balance
42
may need what for fixed appliances
 May need headgear / orthodontic mini implants
43
fixed appliances are commonly used when
 Commonly used after initial phase of functional.
44
cases not suitable for removable appliances are
bodily movement etc
45
overjet reduction: fixed vs URA- with regards with upper incisor angulation
URA- tipping only Fixed- bodily movement
46
what is anchorage demanding with fixed appliances in class II div 1
bodily retraction
47
what teeth to extract for better anchorage balance?
 Usually extract upper 4s, provide better anchorage balance than upper 5’s*
48
consider banding/bonding what teeth to improve anchorage balance?
upper 7s
49
what might also be needed to help anchorage balance
headgear or orthodontic mini implants now also an option
50
anchorage balance is needed for what purpose in Tx of II/i
to carry out initial phase of functional Tx
51
Orthognathic surgery what skeletal discrepancy and what patients
severe class II skeletal discrepancy and in patients too old for functional appliances
52
what procedure is needed before mandibular advancement (+/- maxillary procedure)
fixed appliances to align and coordinate individual arches
53
typical treatment plan for II/i
2 phase treatment- phase 1 - functional appliance phase 2 fixed appliance
54
Prognosis
ask functional appliance patients to continue wearing appliances for a period of time
55
Stability
enhanced by lower lip control of upper incisors
56
rarely stable?
advancement of the lower incisors in attempt to reduce the overjet
57
common malocclusion
class II div i
58
main treatment aim II/i
overjet reduction
59
best timing for treatment II/i
late mixed or early permenant dentitions, functional appliances freq used
60
if lower crowding present in upper or lower arches?
fixed appliances
61
severe skeletal discrepancies are classed as
>10mm
62
severe skeletal discrepancies are
difficult to fully treat with functional appliances
63
significant skeletal discrepancies in non growing patients require
surgery