14 - Functional appliances Flashcards
What is a functional appliance?
What is their mode of action?
Functional appliances utilise what?
What class malocclusion are they used for?
These favour/utilise mandibular growth in Class II malocclusions
MOSTLY USED IN CLASS 2 DIV 1
(Pt below
- severe skeletal 2 with a retrusive mandible
- reduced vertical pattern
- incompetent lips with lower lip trap
- large overjet - which he’s self conscious - risks of trauma to u incisors )
Effect of functional appliances on skeletal pattern:
Aim at mandibular condylar and / or maxillary sutures by applying force to teeth and indirectly to skeletal structures
- combination of skeletal and dental changes
Functional appliances
Phases of treatment :
Need 2nd phase as Functional appliances will give gross anterior posterior correction but will not align teeth or rotations or crowding
Timing of functional appliances
Very important
Refer at 11 years old
Give 3 theories of how growth modification works?
Advantages + Disadvantages of functional appliances
Adv-
Aesthetics
Improvement in psychosocial problems (large overjets)
Large overjet - higher risk of trauma - esp those with incompetent lips
DISADVANTAGE:
- lengthy treatment
- need cooperative pt
Types of functional appliances
- Andresen (Activator) appliance
- Bionator appliance
- Twin block (Clark) appliance
- Frankel appliance
Andresen (Activator) appliance
1- uses
2 - Consists of
Earliest functional appliance - acrylic with with labial bow with u loops from 3-3
Andresen (Activator) appliance
Cases suitable for Andresen:
Limitations
Need to be used where we have underlying skeletal problem - aetiology is skeletal and not something else
Andresen (Activator) appliance - Procedure
Mode of action of Andersen
Patient can only close together with mandible postured forward in forward position - mesial force to mandible and distal force to maxilla - by muscles of mastication
Bionator
Comparison to Andresen
Uses
Consists of
Action?
Better tolerated - less bulky hence it was introduced after Andresen
Bionator case example
Suitable case - exactly same as Andresen
Patient below has severe skeletal 2 with retrusive mandible, reduced vertical pattern, late mixed dentition - starting early permanent dentition
Intraorally - large overjet, class 2 div 1 and class 2 molar relationship
Aetiology of this class 2 malocclusion is the underlying skeletal pattern so ideal patient for growth modification using a functional appliance
Just approaching pubertal growth spurt - so ideal time
Skeletal; 2
Approaching pubertal growth spurt
IO - large overjet , class 2 div 1 of skeletal aetiology
Class 2 molar relationship
Functional appliance
THEN fixed appliance
Leading to class 1 molar and incisor relationship
More severe
Large overjet
Class 2div 1 due to Skeletal aeiotlogy and retrusive mandible
Incompetent lips
Lower lip is incompetent and trapped behind the upper incisors
IO- U central incisors have been traumatised - common findings
Has composite build ups on central incisors - due to large overjet and incompetent lips - higher risk of traumatised upper incisors
Bionator appliance - after this middle left pic
Then second phase of fixed appliances
Profile improved
Able to achieve lip competence
Class 1 occlusoin - canine and molar
Twin block (Clark) appliance
What is it?
Advantages -2
Consists of
Improvement of prev appliances
Split Andresen appliance into U and L
Better than prev 2
This is the main functional appliance of choice - as well tolerated
3-
Clasps and retention competents - to hold into position
U arch - labial bow
Slanted bite blocks
Class 2 div 1 - skeletal origin, retrusive mandible, reduced vertical pattern
Incompetent lips - unable to achieve a lip seal
Large overjet - risk of trauma
Already traumatised upper central incisors Incisal edges
Class 2 whole unit molar relationship
Can see the twin blocks - slanted bite blocks locking patient in postured position
Bottom right image - after twin block treatment - slightly over corrected
Then fixed appliance to align teeth and get teeth into good occlusion
Large overjet shown in profile , incompetent lips
Class 2 molar relationship
Bottom middle - end of twin block treatment
Upper and lower fixed - bottom right at end of treatment
Very severe case
Very severe skeletal 2 dental base relationship with reduced vertical pattern and retrusive mandible
Incompetent lips - no lip seal
IO - class 2 div 1 incisor relationship with large overjet and deep overbite and class 2 molar relationship
Frankel appliance
NOT USED NOW
Functional appliances for Class III
Not that commonly used
Functional appliances for Class II div 2
Herbst appliance
fixed functional appliance
Summary functional appliances
Very useful in which type of patient - age and skeletal problem:
What do we use most -
3 things needed:
Favourable growth = forward mandibular growth pattern
