Treatment of patients with class II malocclusion Flashcards
Class II incisors
Lower incisor occludes behind upper incisor cingulum plateau
Class II division I incisors
Proclined upper incisors
Class II division II incisors
Retroclined upper incisors
Skeletal pattern
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
Growing patient
- ->functional appliance
- ->orthodontic camouflage
Non growing patient
- ->orthodontic camouflage
- ->orthognathic surgery
Treatment of overjets
Straight wire appliance is poor at reducing overjets
A functional appliance is excellent at reducing overjets
Functional appliance treatment
Activators -mild non-crowded cases Twin block appliance -severe cases -crowded cases
Medium opening activator
Leaves space for eruption of molars to move upwards and forwards
Twin blocks
2 piece functional appliance
-upper bite block
-lower bite block
7-8mm inclined plane
Anchorage
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
Indications for distal movement of upper buccal segments
Well-aligned lower arch
Half-unit class II molars
Co-operative patient
Non-compliance appliances
Pendulum appliance
Distal jet
Aetiology
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
Treatment options
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
Treatment for moderate to severe class II skeletal pattern
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
Treatment for mild class II
Accept skeletal pattern
- removable appliances
- fixed appliances
Orthodontic camouflage for class II
Approaches to class II treatment where skeletal pattern is to be accepted
Orthodontic camouflage for class II: no lower arch crowding and class I molars
Non-extraction treatment Anchorage reinforcement -headgear -palatal arches -implants -class II elastics
Orthodontic camouflage for class II: no lower arch crowding and 1/2 unit class II molars
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
Orthodontic camouflage for class II: no lower arch crowding and full unit class II molars
Upper premolar extractions
Orthodontic camouflage for class II: lower arch crowding and class I molars
Upper and lower extractions (upper 4s and lower 5s)
Orthodontic camouflage for class II: lower arch crowding and 1/2 unit class II molars
Upper and lower extractions - need to correct molar relationship
- upper and lower first premolars
- upper and lower second premolars
Orthodontic camouflage for class II: lower arch crowding and full unit class II molars
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
Problems in a class II division 2 case
Increased overbite
Retroclination of incisors
Reduced lower face height (reduced FMP angle)
Class II division 2: methods of treatment
Accept - often these patients have quite a satisfactory appearance Removable appliances Fixed appliances Functional appliances Surgery
Treatment aims with removable appliance treatment
Accept the overbite
Accept upper incisor retroclination
Align labially placed upper lateral incisors by retroclination
Do not extract in the lower arch
Problems with removable appliance treatment
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
Treatment method with removable appliances usually based on
Distal movement of buccal segments
-with or without extraction of upper second molars
Extraction of upper premolars only
Fixed appliances for class II div 2: treatment procedures
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
Class II division 2: functional applaicnes
Active growth period
- Removable appliance proclines upper incisors and reduces overbite (–> class II div 1)
- Functional appliance
* problem of development of lower incisor crowding following tx*
Orthognathic surgery: class II div 2
Adults in severe cases
Following period of pre-surgical orthodontics
