Functional appliances utilize the natural forces of the orofacial musculature to produce skeletal and dental changes. They are based on Moss's functional matrix theory which proposes that muscles and glands influence bone growth. Functional appliances can be active or passive and produce orthopedic, dentoalveolar, and muscular changes through forces of compression, elimination of restrictive influences, and mandibular repositioning. Common functional appliances discussed in the document include Bionators, Twin-Blocks, Herbst, Frankel Regulator, and Jasper Jumper. They vary in their mode of action, indications, advantages, and disadvantages.

1. FUNCTIONAL
APPLIANCES
prepared by :
Hana f.abdullah

2. Introduction
 Are appliances that utilize natural forces of orofacial and
masticatory musculature for their action
 Functional appliances are conceptually based on Moss’
functional matrix theory
 Functional matrix theory proposes that functional
matrices, tissues like muscles and glands influence
skeletal units such as jaw bones and ultimately control
their growth

3. Treatment principles
 FORCE APPLICATION
 Compressive stress and strain act on the structures
involved and result in a primary alteration in form with
a secondary adaptation in function
 FORCE ELIMINATION
 The principle involves the elimination of abnormal and
restrictive environmental influences on the dentition
thereby allowing optimum development thus
function is rehabilitated with a secondary change in
form. these components produce skeletal and
dentoalveolar changes by acting on the following
 1. eruption
 2. linguofacial muscle balance
 3. mandibular repositioning

4. Action of functional appliance
 Functional appliance can produce following
changes
1. Orthopedic changes
2. dentoalveolar changes
3. muscular changes
 1.Orthopedic changes
 Myofunctional appl are capable of accelerating
growth in condylar region
 They bring about remodelling of glenoid fossa
 They can change direction of growth of the jaws

5. Action of functional appliance
2 - Dentoalveolar changes
They can bring about changes in sagittal
,transverse, and vertical directions most MFA allow
upper anterior to tip labially
In transverse direction they can bring about
expansion of the dental arches by incorporating
screws in them
In vertical plane they allow selective eruption of
teeth
3 - muscular changes
Functional appliance can improve tonicity of the
orofacial musculature

6. Classifications of functional
appliances:
1. removable functional appliance
A)removable tooth borne appliance
B)removable tissue borne appliance
2. fixed functional appliance

7. Functional appliance types
 Orthodontic functional appliances may be
active or passive:
 Active appliances reposition the mandible so
that the condyle is forced out of the glenoid
fossa and this in turn is thought to stimulate the
posterior/superior growth of the condyle
 Passive appliances act by repositioning the
musculature associated with the mandible so
that the jaw bone itself responds by growing to
the new equilibrium position

8. Active functional appliances
 Bionator

9. Active functional appliances
 Woodside activator

10. Active functional appliances
 Twin-block appliance

11. Passive functional appliances
 Frankel

12. Active functional appliances
 Herbst

13. Mode of action
 Most of functional appliances act by utilizing
one or more the following
1. a forced mandible. Posture which transmits
forces to the teeth and jaws.
2. bite planes which produce deferential
eruption

14. Advantage of functional
appliances
1. Functional appliances are effective in
vertical control of increased over bite
2. Patient on growth
3. Can be used in mixed dention
4. Minimal chair side adjustment

15. Disadvantage
 1.succes of functional appliances depend
on patient cooperation.
 2.there is no precise tooth movement
 3.treatment duration is often prolonged.
 4.need to faces treatment to complete
treatment

16. Duration and timing of wear
 Functional appliance treatment should be started
before the pubertal growth spurt
 This is the time when the mandible may exhibit
increased growth which may be influenced
 Functional appliances should be worn for at least 10-
12 hours a day
 These appliances should be worn at nighttime as this
is when growth takes place

17. Frankel functional appliance
 Developed by Rolf Frankel
 Also called oral gymnastic appliance
 It has two main treatment effects
1. It serves as a template against which the cranio
facial muscle function
2. The appliance removes muscle forces in labial
and buccal areas that restricts skeletal growth
thereby providing an environment which enables
skeletal growth

18. MODE OF ACTION
The following are effects of frankel appliance
1. Increase in saggital and transverse intra oral space
2. Increase in vertical space where appliance is kept
free from posterior teeth
3. Mandibular protraction
4. Muscle function adaptation the pads and shield
massage the blood vessels increase circulation
5. Shields loosen up the tight muscles and improve
muscle tone
 Frankels exercises or oral gymnastics
1. lips closed at all times
2. swallowing speaking etc becomes exercise while using
the appliance

19. Types of frankel appliance
 FR 1 : Class 1, class2 division 1 malocclusion
 FR2 : Class2 division 1&2
 FR3 : Class3
 FR4 : Open bite and bimaxillary protrusion
 FR5 : They are functional regulator which
incorporate head gear indicated in long face
patients having a high mandibular plane angle
and vertical maxillary excess

20. ACTIVATOR
 Activators induces musculo skeletal adaptation by
introducing a new pattern of mandibular closure
 The appliance loosely fits in the mouth the pt has to
move the mandible forward to engage the appliance
this result in stretching of elevator muscles of mastication
which starts contracting thereby setting up a myotactic
reflex

21. ACTIVATOR
 This generates kinetic energy that cause
1. Prevention of further forward growth of the maxillary
dento alveolar process
2. Movement of maxillary dento alveolar process
distally
3. Reciprocal forward force on the mandible
4. force is generated while sleeping and swallowing

22. ACTIVATOR
 Indications: In actively growing individuals with favorable
growth patterns.
1. CLASS 2 division 1&2
2. Class 3 malocclusion
3. Class 1 open bite
4. Class1 deep bite
5. Before major fixed appliance therapy
6. For post treatment retention
7. Children with lack of vertical height

23. Contraindications
-correction of class I cases with crowded teeth caused by
disharmony b/w tooth size & jaw size.
-in children with excess lower facial height.
-in children whose lower incisors are severely procumbent.
-in children with nasal stenosis caused by structural
problems w/in the nose or chronic untreated allergy.
-in non-growing individuals.

24. Advantages
-uses existing growth of the jaws
-minimal oral hygiene problems
-intervals b/w appointments is long
-appoints are short,minimal adjustments required
-hence, more economical

25. Disadvantages
- requires very good patient cooperation
- cannot produce a precise detailing &
finishing of occlusion.
- may produce moderate mandibular
rotation(hence contraindicated in excess
lower facial height cases)

26. Modifications:
BOW ACTIVATOR By A.M.Schwarz
Wunderer’s modificaiton for Class III

27. BIONATOR
 Modified activator less bulky & more elastic
 3 types-
> Standard type-class II div I having narrow
dental arches
> Class III Appliance
>Open bite appliance

28. Types of bionator
Standard type
Class III Appliance Open Bite Appliance

29. TWIN BLOCK APPLIANCE
 The Twin Block appliance is a removable, orthodontic
functional appliance that is used to help correct jaw
alignment, particularly an underdeveloped lower jaw.
 Effectively combines inclined planes with intermaxillary & extraoral
traction.

30. TWIN BLOCK APPLIANCE
 The removable twin block is a tooth-born functional appliance that is
worn fulltime. It helps in the advancement of the mandible. It is a two-
piece appliance composed of an upper and lower bite block. Orthopedic
traction can be added in cases of severe skeletal discrepancies. This
includes the use of a Concord Facebow (or headgear) at nighttime.
Upper & lower bite blocks interlock at 70
0
angle.

31. TWIN BLOCK APPLIANCE
 The fixed twin block is similar to the removable twin block, but
can be used in non-compliant patients. It is similar in design to
the Herbst appliance, however the telescopic tubes of the Herbst
appliance are replaced with two bite blocks.

32. Advantages
 -very good patient acceptance.
-bite planes offer greater freedom of
movement & lateral excursion.
-less interference with normal function.
-significant changes in patient’s
appearance within 2-3 months.

33. HERBST APPLIANCE
 Fixed functional appliance developed by Emil
Herbst in early 1900’s.
 Indications:
-correction of class II MO due to retrognathic
mandible.
-can be used as anterior repositioning splint in
patients having TMJ disorders.

34. Specific indications
 -Post adolescent patients: T/t completed w/in 6-8
months,hence possible to use the residual growth in
these patients.
-Mouth breathers
-Uncooperative patients
 2 types:
-Banded Herbst
-Bonded Herbst

35. Types of herbs appliance
Banded Herbst Appliance
Bonded Herbst Appliance

36. Advantages and disadvantages
 Advantages:
- continuous action
- T/t duration is short
- less pt cooperation needed
- can be used in pts who are at the end of their growth
- can be used in pts with mouth breathing habit.
 Disadvantages:
- cause minor functional disturbances.
- increased risk of development of dual bit,with TMJ
dysfunction symptoms as a possible consequence.
- repeated breakage & loosening of appliance occurs,esp.
in lower premolar area.
- plaque accumulation & enamel decalcification can
occur
- tendency for posterior open bite.

37. JASPER JUMPER
 A relatively new flexible,fixed ,tooth borne FA.
 Introduced by J.J.Jasper ,1980
 Actions similar to Herbst appliance but lack rigidity.
 Basically indicated in skeletal class II mo with max.
excess & mandibular deficiency.

38. Advantages
- produce continuous force
- does not require patient compliance
- allows greater degree of mandibular freedom
than Herbst appliance
- oral hygiene is easier to manage.

39. POST DELIVERY INSTRUCTION
1. Teach the patient to wear and remove the
appliance in front of mirror
2. Should be worn 2-3 hours daily initially
3. When not in use keep in water
4. Any pain ,soreness etc report to the clinic
5. If no pain also report the clinic after 2 wks
6. Pt advised to maintain lip seal by conscious
effort
7. Time charts should be given to record duration
of wearing the appliance

40.  Discomfort, as both upper & lower teeth are
joined together.
 Mainly depends on patient’s compliance
 Can be used only if a favorable horizontal
growth pattern is present in cases of Class II
correction.
 It has to be removed during mastication ,
particularly when strongest forces are applied.
 May interfere with speech.
 Treatment duration is often long
Limitations & complications