Class II Div 1 Malocclusion

Question 1

what is the BSI classification for a class II division 1 malocclusion

Answer 1

lower incisor edges lie posterior to cingulum plateau of upper incisors
increased overjet
upper central incisors are proclined

Question 2

what are the two main reasons its important to treat CLass II division 1 malocclusions

Answer 2

aesthetic concerns
dental health - trauma

Question 3

what are the four overall aetiological factors of a class II div 1 malocclusion

Answer 3

skeletal pattern
soft tissues
dental factors
habits

Question 4

what can an overjet be due to

Answer 4

skeletal pattern
tooth inclination

Question 5

what is the normal values for SNA on a lateral ceph

Answer 5

81 degrees (plus and minus 3)

Question 6

what is the normal values for SNB angle on a lateral ceph

Answer 6

78 (plus or minus 3)

Question 7

what is the normal ANB angle for a lateral ceph

Answer 7

3 (plus or minus 2)

Question 8

what soft tissue feature can be an aetiological factor in class II division 1 malocclusions

Answer 8

lower lip trap

Question 9

what habits can cause a class II division 1 malocclusion

Answer 9

sucking habits

Question 10

what are five occlusal features of a sucking habit

Answer 10

proclination of upper incisors
retroclination of lower incisors
localised AOB
narrow upper arch
possible unilateral posterior crossbite

Question 11

what are five management options for treatment of class II division 1 malocclusions

Answer 11

accept
attempt growth modification
simple tipping of teeth
camouflage
orthognathic surgery

Question 12

what features would make you more inclined to accept a class II div 1 malocclusion

Answer 12

overjet is mildly increased
significant overjet but pt is not unhappy

Question 13

what appliances can be used to attempt growth modification

Answer 13

headgear - tries to restrain growth of maxilla horizontally or vertically
functional appliance

Question 14

what are the two broad types of functional appliances

Answer 14

removable or fixed

Question 15

what are examples of removable functional appliances

Answer 15

toothborne - twinblock

Question 16

what is an example of a fixed functional appliance

Answer 16

herbst

Question 17

what is the aim of a functional appliance in class II div 1 malocclusions

Answer 17

restraint of maxillary growth and encourage mandibular growth

Question 18

when should a functional appliance be used

Answer 18

during growth - if possible coincide with pubertal growth spurt

Question 19

what are four dento-alveolar changes caused by functional appliance use

Answer 19

distal movement of upper teeth
mesial movement of lower teeth
retroclination of upper incisors
proclination of lower incisors

Question 20

what are two disadvantages of functional appliances

Answer 20

skeletal effects not maintained long term
treatment time increased due to two phase treatment

Question 21

what are three benefits of functional appliance use

Answer 21

improves appearance earlier
reduce risk of trauma
better compliance with appliance wear

Question 22

what is the active component when trying to retrocline anterior teeth

Answer 22

robert’s retractor with 0.5mm ID tubing - include mesial stops

Question 23

when might orthognathic surgery be indicated for class II div 1 malocclusions

Answer 23

skeletal discrepancy is severe in AP or vertical plane