Class II division 1

Question 1

What is the BSI definition for Class II div 1 malocclusion?

Answer 1

• The lower incisor edges lie posterior to the cingulum plateau of the upper incisors
• there is an increased overjet
• the upper central incisors are proclined or of average inclincation

Question 2

What would be the IOTN if the overjet is more than 9mm?

Answer 2

5a

Question 3

with which skeletal pattern is class II div 1 associated with?

Answer 3

• Class II
• and less commonly Class 1
• Rarely with class 3

Question 4

What is the overjet in class II div 1 due to?

Answer 4

• Skeletal pattern
• Tooth inclincation
• Combination of both

Question 5

What 2 soft tissue features associated with Class II div 1?

Answer 5

• Incompentent lips
• Lower lip trap - factor in increased overjet

Question 6

3 ways a patient with Class II div1 can achieve anterior lip seal?

Answer 6

• by activity of circum-oral musculature with posturing the mandible allowing lips to meet
• Lower lip drawn up behind upper incisor and tongue placed forward between incisors to lower lip
• Combination of these

Question 7

3 dental factors associated with Class II div 1 ?

Answer 7

• Increased overjet
• Varying overbite
• Exacerbation of periodontal disease due to drying of gingivae from incompetent lips

Question 8

What habits are associated with Class II div 1?

Answer 8

Sucking habits of
* Thumb
* Finger
* Blanket
* Lip

Question 9

Describe the dental (occlusal) Features of sucking habit?

Answer 9

• Proclination of upper incisors
• Retroclination of lower incisors
• Localised anterior open bite or incomplete overbite
• Narrowing of upper arch ± unilateral posterior crossbite

Question 10

3 Principles of treating habits?

Answer 10

• Stop habit
• Allow spontaneous improvement
• Treat residual malocclusion

Question 11

3 ways to stop sucking habit?

Answer 11

• Reinforcement
• Removable appliance habit breaker
• Fixed appliance habit breaker

Question 12

5 management options for Class 2 div1 ?

Answer 12

• Accept
• Attempt growth modification
• Simple tipping of teeth using URA
• Camouflage
• Orthognathic surgery

Question 13

When would you accept in class 2 div 1?

Answer 13

• Mild overjet
• Patient not unhappy with overjet

Question 14

How would you attempt growth modification in Class 2 div 1?

Answer 14

• Headgear
• Functional appliance

Question 15

Describe how headgear works in class 2 div1?

Answer 15

Restrain the growth of the maxilla and encourage mandibular growth (horizontally or vertically )

Question 16

Describe how a functional appliance work?

Answer 16

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

Question 17

How is a the mandible postured when a patient wears a functional appliance for treatment of class 2 div 1?

Answer 17

• Down and forward

Question 18

What are the two types of functional appliances in class 2 div 1?

Answer 18

• Removable : tooth borne and soft tissue borne
• Fixed

Question 19

2 examples of tooth borne removable functional appliances for class 2 div 1?

Answer 19

• Twin-block
• Activator and bionator

Question 20

An example of soft tissue borne removable functional appliance for class div 1 ?

Answer 20

• Frankel ( FR II)

Question 21

An example of a fixed functional appliance for Class 2 div 1?

Answer 21

Herbst

Question 22

Explain four dento-alveolar changes that happens during growth modification in class 2 div 1 with a functional appliance?

Answer 22

• Distal movement of upper dentition
• Mesial movement of lower dentitoin
• Retroclination of upper incisors
• Proclination of lower incisors

Question 23

Although there are very minor skeletal changes with functional appliances in class 2 div 1 , what can this change be?

Answer 23

1-2mm of maxillary restraint and mandibular growth

Question 24

When is the best time to use a functional appliance?

Answer 24

During growth , coincide with pubertal growth

Question 25

When would the early use of a twinblock be used ?

Answer 25

Age of 10 , would be two phase treatment of functional appliance then fixed appliance

Question 26

When would the later use of twinblock be ?

Answer 26

Late mixed or permanent dentition (1 phase)

Question 27

What is the disadvantages with using a twin block/headgear at age of 10 ( early use)

Answer 27

• Early skeletal effects of functional appliance would not be maintained long term
• 2 phase treatment (increased treatment time)

Question 28

3 benefits of early treatment with functional appliance?

Answer 28

• Improve appearance preventing any negative psychological effects
• Reduce the risk of trauma
• Better compliance with appliance wear

Question 29

When would the use of URA be beneficial in the treatment of overjets despite it having a limited role of treatment overjets in general? (3)

Answer 29

• Very mild class 2 or class 1
• Overjet due to proclined and spaced incisors
• Favourable overbite

Question 30

Write a URA prescription of correct an overjet by retroclining anterior teeth ?

Answer 30

• Active - Roberts retractor 0.5mm in tubing
• Retention - Adams clasps 0.7 HSSW on 6s
• Anchorage - mesial stops in 3s
• Base plate : flat anterior biteplane

Question 31

If you use fixed appliances to reduce the overjet , what is required before that?

Answer 31

• Extraction to provide space (usually 4s)
• or Distal movement of teeth

Question 32

When would orthognathic surgery be indicated? 2

Answer 32

• When growth is complete
• Severe skeletal discrepancy in AP or vertical

Question 33

When would fixed appliances be required when carrying out orthognathic surgery?

Answer 33

• Before surgery
• During surgery
• After surgery