class II div 2

Question 1

What is the BSI definition of class II div 2?

Answer 1

The lower incisors occlude posterior to the cingulum plateau of the upper incisors
The upper incisors are retroclined
The overjet is usually minimal but may be increased

Question 2

What is the incidence of class II div 2?

Answer 2

5-18%

Question 3

Describe the skeletal aetiology of class II div 2

Answer 3

Usually on a skeletal class II base
Reduced FMPA
Forward growth rotational pattern of growth of the mandible
Prominent chin - progenia

Question 4

Describe the soft tissue aetiology of class II div 2

Answer 4

High resting lower lip line
Marked labio-mental fold
High masseteric forces - ortho space closure problem
Trap lower lip

Question 5

Describe the dental aetiology of class II div 2

Answer 5

Retroclined upper centrals
Upper 2s often crowded - mesiolabially rotated
Reduced arch length so exacerbated crowding
Laterals have poor cingulum - leads to increased inter-incisal angle and increased OB
Lower incisors may occlude with upper incisors or palatal mucosa

Question 6

Describe the pathological aetiology of class II div 2

Answer 6

50% of cases have a congenital dental anomaly eg - impacted canines or lateral incisor microdontia

Question 7

Give 4 dental factors of a class II div 2

Answer 7

Any from:
- retroclined upper and lower incisors
- deep OB
- OJ usually reduced
- class II buccal segments
- increased inter-incisal angle
- upper laterals thin with poorly developed cingulum

Question 8

What are the reasons for treating a class II div 2?

Answer 8

Aesthetic concerns
Dental health concerns:
- traumatic OB
- IOTN DHC 4f

Question 9

What do the treatment options of a malocclusion depend on?

Answer 9

Severity of malocclusion
Age and motivation of patient
Dental health
Patients concerns

Question 10

What are the treatment options for a class II div 2?

Answer 10

Accept
Growth modification
Camouflage
Orthognathic treatment

Question 11

When can a class II div 2 be accepted?

Answer 11

Acceptable aesthetics
Patient not concerned about aesthetics
OB not a significant problem

Question 12

When is growth modification a valid option for class II div 2 treatment?

Answer 12

In a growing patient
If mild to moderate skeletal class II base
To convert class II div 2 into class II div 1
Detail occlusion with fixed appliance

Question 13

What functional appliance is used in a class II div 2 and what is it used for?

Answer 13

Modified twin block - springs or screws as active component
Proclined the upper incisors

Question 14

What is camouflage and how is it done for a class II div 2?

Answer 14

Accepting the underlying skeletal base relationship and aiming to treat to class I incisor relationship
Valid if mild to moderate class II skeletal pattern
Be careful in extraction decision

Question 15

How are fixed appliances used to treat a class II div 2?

Answer 15

OB reduction and reduction of inter incisal angle
Inter incisal angle corrected by palatal root torque of upper incisors - risk of root resorption

Question 16

When is orthognathic surgery valid to treat a class II div 2?

Answer 16

When the malocclusion is too severe for orthodontics alone
Can be done in non growing patients
If there is profile concerns

Question 17

What is decomposition?

Answer 17

Aligning the patients occlusion before surgery is carried out

Question 18

What are the difficulties in treating a class II div 2?

Answer 18

Future facial growth can affect stability
Rotated laterals and deep OB can relapse
Long term bonded retainer usually required

Question 19

When should a class II div 2 malocclusion be referred?

Answer 19

Deep OB best corrected when patient is growing
Orthognathic surgery if significant skeletal problems after growth