Class II div 1

Question 1

british standards definition of a class II div 1 malocclusion

Answer 1

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

Question 2

why treat class II div 1 malocclusions

Answer 2

1. aesthetic concerns
2. dental health concerns e.g trauma

Question 3

most common skeletal aetiology for a class II skeletal base

Answer 3

retrognathic mandible

Question 4

what aspect of soft tissues may be an aetiological factor of a class II div 1 malocclusion

Answer 4

lip trap

Question 5

what is the most common molar classification in class II div 1 patients c

Answer 5

class 2

Question 6

name 4 potential features of a digit sucking habit

Answer 6

proclination of upper incisors
retroclination of lower incisors
narrowed maxillary arch
localised AOB
unilateral posterior crossbite

Question 7

what habits may be an aetiological factor of class II div 1 malocclusions

Answer 7

non nutritive sucking habits

Question 8

why might digit sucking see a narrowed maxillary arch

Answer 8

freeway space is increased, tongue is lowered and buccinator is left unopposed

Question 9

normal SNA value

Answer 9

81 +/- 3

Question 10

normal SNB value

Answer 10

78 +/- 3

Question 11

normal ANB angle

Answer 11

3 +/- 2

Question 12

normal FMPA

Answer 12

27 +/- 4

Question 13

normal inclination of upper incisors

Answer 13

109 +/- 6

Question 14

normal inclination of lower incisors

Answer 14

93 +/- 6

Question 15

beyond what age is use of growth modification appliances limited

Answer 15

14

Question 16

what do functional appliances do

Answer 16

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

Question 17

what malocclusion are functional appliances most commonly used for

Answer 17

class II div 1

Question 18

name an example of a tooth borne and a soft tissue borne removable functional appliance

Answer 18

tooth - twin block
soft tissue - frankel (expensive and difficult to make)

Question 19

when should a functional appliance ideally be used

Answer 19

during period of maximal growth i.e pubertal growth spurt
as a guide 11-13 in females and 13-15 in males

Question 20

discuss the therapeutic effect of functional appliances

Answer 20

mostly dentoalveolar changes - distal movement of upper dentition, mesial movement of lower
- proclination of lowers, retroclination of uppers
only minor degree of skeletal changes, studies estimate 1-2mm of mandibular growth

Question 21

early treatment with functional appliance

Answer 21

involves 2 phases , initial functional appliance stage whilst still in mixed dentition
then fixed appliance at a later date for fine tuning of occlusion

Question 22

advantages and disadvantages of early use of a functional appliance

Answer 22

advantages - improved appearance at earlier age, reduced risk of trauma, better compliance with wear*
disadvantages - early skeletal effects may not be maintained longterm, overall treatment time increased, research show s little difference in results between those treated early and those treated late

Question 23

treatment of choice for patients with mild -moderate class II div 1 maocclusion who is concerned with tooth position rather than jaw position

Answer 23

camouflage with fixed appliances
premolars may be extracted to give adequate space

Question 24

do you still need fixed appliances if getting orthognathic surgery

Answer 24

yes, they will be required before and after surgery

Question 25

can URAs be used in treatment of class II div 1 malocclusions

Answer 25

limited role in treatment of increased overjets
only if very mild class II or class I due to proclined incisors