Class 2 Division 2

Question 1

What is the definition of class 2 division 2

Answer 1

The lower incisors occludes posterior to the cingulum plateau of the upper incisors
The upper incisors are retroclined
The overjet is reduced but can also be increased
Third most common incisor relationship (5-18%)

Question 2

What can the aetiology of class 2 div 2 be split into

Answer 2

skeletal
soft tissue
dental features

Question 3

What is the skeletal AP aetiology

Answer 3

Usually associated with a mild or moderate class 2 base but it is possible for it to occur on a class 1 or class 3 base
Often have a small under-developed mandible (retronghatic)

Question 4

What is the vertical skeletal aetiology

Answer 4

Reduced FMPA typically
Often associated with a forward rotational pattern of growth of the mandible
Often have a prominent chin (aka progenia)
Usually have a low LAFH ratio

Question 5

What is the soft tissue aetiology

Answer 5

high resting lower lip line secondary to the decreased lower face height and this can retrocline the incisors due to the active mentalis
Marked labiomental fold
High masseteric forces which can make space closure difficult so must make careful extractions decisions
Can sometimes see flaring of the laterals vs retroclination of the centrals

Question 6

Why are the laterals spared from being retroclined

Answer 6

Upper 2’s may end up being normal inclinication/proclined as their shorter clinical crown means they escape the effect of the lower lip
Can result in a lip trap tendency

Question 7

What are the dental features in the aetiology of class 2 div 2

Answer 7

• Retroclination of the upper centrals
• Upper 2s often crowded- rotated and may be either normal or proclined
• Reduced arch length- exacerbates crowding
• Lateral incisors have poor cingulum which can result in lack of an interocclusal stop producing an overbite

Question 8

Why are class 2 division 2 prone to a deep overbite

Answer 8

Lateral incisors often have poor cingulum which can result in a lack of interincisial occlusal stop which can lead to a deep overbite

Increased interincisal angle

Question 9

Why are class 2 division 2 more prone to impacted canines

Answer 9

55% have more than 1 dental anomaly associated
If they have got peg laterals/microdontia in their laterals then this can influence the canine eruption pattern leading to impacted canines

Question 10

What are the reasons for treatment of class 2 division 2

Answer 10

Aesthetic concern
Dental health concerns
Traumatic overbite = IOTN DHC 4f

Question 11

What are the treatment options dependant on

Answer 11

o Severity of malocclusion
o Age and motivation of px
o Dental health
o Patient concerns

Question 12

What are the treatment options

Answer 12

accept malocclusion
growth modification
camouflage
orthognathic surgery

Question 13

When is accepting the malocclusion the best option

Answer 13

Good treatment option when there is acceptable aesthetics, patient is not concerned or not suitable and the overbite is not a significant problem

Question 14

Who is growth modification best suited for

Answer 14

growing patient in their growth sport
mild/moderate class 2 pattern

Question 15

What does growth modification do

Answer 15

Convert the class II div 2 to Class II div 1
Followed by fixed appliances to detail occlusion

Question 16

What is the function of the functional appliances

Answer 16

to procline the upper incisors

Question 17

What is the common appliance used for class 2 division 2

Answer 17

modified twin block - uses springs/screws to help procline the incisors
sometimes used in combination with sectional fixed appliance to help with improving inclination of the labial segment

Question 18

What is camouflage

Answer 18

Accepting the underlying skeletal base relationship and aiming to treat to class 1 incisor relationship

Question 19

Who is camoulfage suitable for

Answer 19

Suitable for patients who are past their growth spurt and who have a mild/moderate class II skeletal pattern

Question 20

What appliance does camouflage use

Answer 20

fixed

Question 21

What does stable correction of class 2 division 2 require (camouflage)

Answer 21

overbite reduction
correction of inter-incisial angle (reduction)

Question 22

Why is it important to reduce the overbite in class 2 division 2 cases

Answer 22

overbite will relapse if not corrected

Question 23

What are the indications for orthognathic surgery

Answer 23

When a patients malocclusion is too severe for orthodontics alone
Non-growing patient
Profile concerns

Question 24

What is done prior to orthognathic surgery

Answer 24

Pre-surgical orthodontics
Increase the overjet and convert to class 2 division 1
Can take up to 18 months

Question 25

Why is orthodontics used post surgery

Answer 25

Usually there is a 3 point landing where there is only contact on incisors and terminal molars resulting in lateral open bites
Settled orthodontics is used to close lateral open bites and guide the occlusion together, can take 6 months
Aiming for class 1

Question 26

What can effect stability post treatment

Answer 26

Future face growth can affect stability
Rotated laterals and deep overbite can relapse
Long term bonded retention usually required

Question 27

When are deep overbites best corrected

Answer 27

when px is growing

Question 28

What is appliances are best used for deep overbites

Answer 28

Growth modification with functional appliance if AP discrepancy
URA with FABP