Treatment of patients with class II malocclusion

Question 1

Class II incisors

Answer 1

Lower incisor occludes behind upper incisor cingulum plateau

Question 2

Class II division I incisors

Answer 2

Proclined upper incisors

Question 3

Class II division II incisors

Answer 3

Retroclined upper incisors

Question 4

Skeletal pattern

Answer 4

Main limiting factor in class II treatments
-most important factor in aetiology and prognosis
Assess the face
Local and dental factors must be planned for

Question 5

Growing patient

Answer 5

• ->functional appliance

- ->orthodontic camouflage

Question 6

Non growing patient

Answer 6

• ->orthodontic camouflage

- ->orthognathic surgery

Question 7

Treatment of overjets

Answer 7

Straight wire appliance is poor at reducing overjets

A functional appliance is excellent at reducing overjets

Question 8

Functional appliance treatment

Answer 8

Activators
-mild non-crowded cases
Twin block appliance
-severe cases
-crowded cases

Question 9

Medium opening activator

Answer 9

Leaves space for eruption of molars to move upwards and forwards

Question 10

Twin blocks

Answer 10

2 piece functional appliance
-upper bite block
-lower bite block
7-8mm inclined plane

Question 11

Anchorage

Answer 11

Control of unwanted tooth movement
Anchorage requires careful planning
Loss of anchorage will result in lack of occlusion in buccal segments and residual overjet in class II case

Question 12

Indications for distal movement of upper buccal segments

Answer 12

Well-aligned lower arch
Half-unit class II molars
Co-operative patient

Question 13

Non-compliance appliances

Answer 13

Pendulum appliance

Distal jet

Question 14

Aetiology

Answer 14

Usually some degree of antero-posterior discrepancy (i.e. class II skeletal pattern)
–>main limiting factor in successful tx
Local/ dental factors superimposed which need to be planned for

Question 15

Treatment options

Answer 15

Accept mild overjet
-pt’s appearance may be quite acceptable
Removable appliances - used far less nowadays
Fixed appliances - cannot correct skeletal discrepancy
Functional appliances - either on their own or before fixed appliances
Orthognathic surgery - for a severe class II in non-growing patient

Question 16

Treatment for moderate to severe class II skeletal pattern

Answer 16

Best to use functional appliances in young patient (possibly followed by fixed appliances)
Best to use orthognathic surgery in non-growing patient
Simple removable appliances or complex fixed appliances may result in unacceptable retroclination of upper incisors
-poor profile
-poor functional occlusion

Question 17

Treatment for mild class II

Answer 17

Accept skeletal pattern

• removable appliances
• fixed appliances

Question 18

Orthodontic camouflage for class II

Answer 18

Approaches to class II treatment where skeletal pattern is to be accepted

Question 19

Orthodontic camouflage for class II: no lower arch crowding and class I molars

Answer 19

Non-extraction treatment
Anchorage reinforcement
-headgear
-palatal arches
-implants
-class II elastics

Question 20

Orthodontic camouflage for class II: no lower arch crowding and 1/2 unit class II molars

Answer 20

Non-extraction - distal movement
-bringing upper molar back to class I
Extraction U7s - distal movement
Extraction upper premolars
-upper molar to full unit class II
-mid palatal implant, mainscrew implant

Question 21

Orthodontic camouflage for class II: no lower arch crowding and full unit class II molars

Answer 21

Upper premolar extractions

Question 22

Orthodontic camouflage for class II: lower arch crowding and class I molars

Answer 22

Upper and lower extractions (upper 4s and lower 5s)

Question 23

Orthodontic camouflage for class II: lower arch crowding and 1/2 unit class II molars

Answer 23

Upper and lower extractions - need to correct molar relationship

• upper and lower first premolars
• upper and lower second premolars

Question 24

Orthodontic camouflage for class II: lower arch crowding and full unit class II molars

Answer 24

Very difficult case - avoid in general practice
Upper and lower extractions
Severe anchorage problems
-the molars must be changed to class I
Could consider extracting 4 upper teeth

Question 25

Problems in a class II division 2 case

Answer 25

Increased overbite
Retroclination of incisors
Reduced lower face height (reduced FMP angle)

Question 26

Class II division 2: methods of treatment

Answer 26

Accept - often these patients have quite a satisfactory appearance
Removable appliances
Fixed appliances
Functional appliances
Surgery

Question 27

Treatment aims with removable appliance treatment

Answer 27

Accept the overbite
Accept upper incisor retroclination
Align labially placed upper lateral incisors by retroclination
Do not extract in the lower arch

Question 28

Problems with removable appliance treatment

Answer 28

Overbite: due to inclination of incisors, any OB reduction will relapse as soon as appliances are withdrawn
Canine retraction:
-due to retroclination, if upper 3s retracted into class I, there will be spacing in upper anterior region
-if canines not fully retracted, they will not occlude properly and will be buccally placed

Question 29

Treatment method with removable appliances usually based on

Answer 29

Distal movement of buccal segments
-with or without extraction of upper second molars
Extraction of upper premolars only

Question 30

Fixed appliances for class II div 2: treatment procedures

Answer 30

Use of U&L allows correction of angulation of U&L incisors
Tx involves some proclination of lower incisors
-may be stable if normal inter-incisal angle obtained at end of tx (long-term evidence lacking)
Can be very difficult to treat
Usually based on non-extraction approach in lower arch
Upper arch can be treated non-extraction or suitable extractions of 7s or premolars

Question 31

Class II division 2: functional applaicnes

Answer 31

Active growth period

1. Removable appliance proclines upper incisors and reduces overbite (–> class II div 1)
2. Functional appliance
   * problem of development of lower incisor crowding following tx*

Question 32

Orthognathic surgery: class II div 2

Answer 32

Adults in severe cases

Following period of pre-surgical orthodontics