Class II Div 1

Question 1

BSI definition

Answer 1

The lower incisor edges lie posterior to the
cingulum plateau of the upper incisors
INCREASED OJ
Upper centrals are proclined

Question 2

Incidence of this malocclusion?

Answer 2

15-20%

Question 3

Why treat?

Answer 3

HIGH risk of trauma (esp. incompetent lips)
IOTN 5a (OJ>9mm)

Question 4

Skeletal pattern? Why?

Answer 4

Class 2
Retrognathic mandible

Question 5

Lip features?

Answer 5

Incompetent lips due to prominence of incisors/ skeletal pattern
Lower lip trap seen

Question 6

How to achieve anterior oral seal?

Answer 6

Lip to lip seal by circum-oral musculature
Posture mandibles to meet
Lower lip behind upper incisors + tongue between lowers and lip
Combination

Question 7

Dental features

Answer 7

Increased OJ
OB Varies
Parted lips lead to drying of gingiva and exacerbation of pre-existing gingivitis

Question 8

Occlusal features of sucking habit

Answer 8

Proclination of upper anteriors
Retroclination of lower anteriors
Localised AOB
Narrow upper arch (may see unilateral post crossbite)

Question 9

Habit tx principles

Answer 9

Stop habit by:
Reinforcement
Removable appliance habit breaker
Fixed appliance habit breaker
Allow spontaneous improvement
Treat residual malocclusion

Question 10

Management options

Answer 10

Accept
Attempt growth modification
Simple tipping of teeth
Camouflage
Orthognathic surgery

Question 11

Growth modification

Answer 11

Headgear (try to restrain growth of maxilla) (1-2mm)
Functional appliance

Question 12

What does functional appliance do?

Answer 12

Functional appliances utilize, eliminate, or
guide the forces of muscle function, tooth
eruption and growth to correct a
malocclusion

Question 13

Types of functional appliances?

Answer 13

Removable:
Twinblock
Activator/ bionator
Frankel 2
Fixed:
Herbst

Question 14

When to use functional appliance?

Answer 14

Coincide with pubertal growth
Early use ( about 10yrs) 2 phase tx
Later use (late mixed/ early permanent dentition) 1 phase tx

Question 15

Disadvantages of early tx?

Answer 15

early skeletal effects not maintained long term
2 phase treatment
very little difference in results between early and late tx

Question 16

Advantages of early tx?

Answer 16

Improve appearance
Psychological benefit
Reduced risk of trauma
Better compliance

Question 17

Simple tipping of teeth

Answer 17

Limited role in tx of OJ unless:
Mild Class 2
OJ due to proclined and spaced incisors
OB favourable

Question 18

URA for retroclining upper teeth

Answer 18

A: Roberts Retractor in 0.55mm tubing
R: Adams clasp 16/26 in 0.7mm HSSW
A: Mesial stops 13/23
B: FABP

Question 19

Orthognathic Surgery

Answer 19

When growth is completed
Skeletal discrepancy is severe in A/P or vertical direction
Usually mandibular surgery
Fixed appliance needed: Before, During, After