Functional appliances History Basis for functional applainces Functional appliance are loose removable appliances designed to alter the neuromuscular environment of the orofacial region to improve occlusal development and / or craniofacial skeletal growth

1. ACTIVATOR

2. CONTENTS
 Functional appliances
 History
 Basis for functional applainces

3. FUNCTIONAL APPLIANCES
 Functional appliance are loose removable
appliances designed to alter the neuromuscular
environment of the orofacial region to improve
occlusal development and / or craniofacial skeletal
growth
-Moyer-

4.  “ A removable or fixed appliance which favorably
changes the soft tissue environment”
-Frankel,1974
 “ A removable or fixed appliance which changes the
position of mandible so as to transmit forces generated
by the stretching of the muscles,fascia &/or
periosteum,through the acrylic and wirework to the
dentition and the underlying skeletal structures.
-Mills,1991

5. HISTORY

6. 1883- Wilhelm Roux-first to study the
influences of natural forces and functional
stimulation on form-foundation of both
general orthopedic and functional dental
orthopedic principles

7. In 1885, Julius Wolff wrote “Law of the Transformation
of Bone,” in which he stated that function produces
changes in internal architecture

8. • 1879-Norman Kingsley-Forward positioning
of mandible in orthodontics-Bite plane/Bite-
jumping appliance(vulcanite).
Drawback-tendency to relapse even with bite
guide.

9.  E. H. Angle used a pair of interlocking rings,
soldered to opposing first molar bands

10.  Hots –vorbissplate
 Patients with deep bite retrognathism
 Lower incisor –retroclined –hyperactive mentalis
 Hawleys bite plane –direct decendent of Kingsley
plate

11. • Ottolengui-removable plate
• 1902-Pierre Robin-first practitioner to use
functional jaw orthopedics to treat a
malocclusion-Monoblockin children
with glossoptosis syndrome.

12.  father of myofunctional therapy
 total-child approach and advocated muscular
exercises to improve neck, head, and tongue
posture and encourage nose breathing
 first to implicate the facial muscles for the growth,
development
ALFRED P. ROGERS (1873-1959)
Wahl N. Orthodontics in 3 millennia. Chapter 9: functional appliances to midcentury. American journal of orthodontics and dentofacial
orthopedics. 2006 Jun 1;129(6):829-33
12

13.  1909-Viggo Andresen- biomechanical working
retainer for his daughter
 Hawley-type maxillary retainer and On mandibular
teeth, a lingual horseshoe flange that guided the
mandible forward about 3 to 4 mm in occlusion.
 eliminated her Class II malocclusion.
 not initially well received.
THE ACTIVATOR
13

14. ViggoAndresen Karl Häupl

15.  Andresen moved to norway
 Associated with Haupl at the university of oslo
 They called it activator because its ability to
activate the muscle force

16. BASIS FOR
FUNCTIONAL
APPLIANCE

17. • “The three M’s-Muscles,Malformation and
Malocclusion”-By Graber,1963-described
effects of function & malfunction.
• The Functional Matrix Hypothesis by Melvin
Moss
• Identification of certain cartilages(eg.
Condylar cartilage) as secondary cartilages.

18. • Servosystem (or Cybernetic)
Theory,1980, by Petrovic & associates
• Growth Relativity
Theory(Vodouris & associates)

20. 

22. EFFICACY OF ACTIVATOR

23. According to Andresen & Haupl,
 Activator is effective in exploiting the interrelationship
between FUNCTION and changes in INTERNAL BONE
STRUCTURE.
 During GROWTH, there is also interrelationship between
FUNCTION and EXTERNAL BONE FORM.
 The CONDYLAR ADAPTATION to the anterior
positioning of the mandible consists of growth in an
upward and backward direction to maintain the integrity
of TMJ. This adaptational process in induced by the loose
fitting appliance.

24. CLASSIFICATION OF VIEWS
PETROVIC (1984): McNAMARA (1973)
Andresen Haupl's Concept that MYOTATIC reflex activity
and ISOMETRIC CONTRACTION induce
musculoskeletal adaptation by introducing a new
mandibular closing pattern.
• Superior head of lateral pterygoid plays an important role
in assisting the skeletal adaptations.
• Pertovics research on condylar cartilage growth
stimulation is by activating the lateral pterygoid.

25. SELMER - OLSEN, HERREN 1953, HARVOLD 1974
&WOODSIDE 1973 do not agree with the myotactic reflex.
According to their views,
• VISCOELASTIC PROPERTIES OF MUSCLE AND
STRETCHING OF SOFT TISSUES are decisive for
activator action.
• Each application of force induces secondary forces in
tissues which inturn introduces a bio-elastic process and
that is important in stimulating skeletal adaptation.

26. Stagesof Visco-ElasticReaction (Depends on magnitude
and duration of applied force)
 Empting of vessels
 Pressing out of interstitial fluid
 Stretching of fibres
 Elastic deformation of bone
 Bioplastic adaptation
• Woodside recommends opening the mandible upto 10-
15mm with the construction bite.

27. • SCHMUTH, WITT AND KOMPOSCH feel displacing
mandible 4 - 6 mm below intercuspal position to be ideal.
Observed long periods of continuous pressure from
mandibular teeth against the activator.
• ESCHLER 1952 refers to opening the vertical dimension
beyond 4mm in construction bite as the "muscle stretching
method" which works alternatively with isotonic and
isometric contractions.

28.  TRANSITION TYPE OF ACTIVATOR
 use muscle contraction and viscoelastic
properties of soft tissue
 Greater bite opening than andresen appliance
 Strech reflex resulting from activators in this group
is seen as a long lasting contraction

29. FORCE ANALYSIS IN ACTIVATOR THERAPY
• When functional appliance activates the muscles, various
types of forces are created - STATIC , DYNAMIC and
RHYTHMIC forces.
 Static forces are permanent (eg. force of gravity, posture,
elasticity of soft tissues and muscles)
 Dynamic forces are interrupted (eg. movements of head
and body, swallowing)
 Rhythmic forces are associated with respiration and
circulation. Mandible transmits rhythmic vibrations to the
maxilla.

30. • HOTZ, PETROVIC, OUDET, STUZMANN stated that
growth increments were greater at night due to increased
growth hormone secretion.
• SELMER-OLSEN said that the muscles could not be
stimulated during sleep as nature has designed them to be
at rest. Swallowing occurred only 4-8 times in an hour
during night.
• Electromyographic study of temporalis and masseter
with and without activators (AJO - Aug 1998)

31. • It is observed that there was
1. Similar postural activity for both muscles with or without
activator.
2. During swallowing of saliva, muscle activity was higher
with the activator.
3. During maximal clenching similar activity in anterior
temporalis with or without activator. Higher activity in
masseter muscle with the activator.

32. • Two principles employed in modern activator
– FORCE APPLICATION - the source is usually
muscular
– FORCE ELIMINATION - dentition is shielded from
normal and abnormal functional tissue pressures by
pads, shields and wires.

33. TYPESOFFORCESEMPLOYEDIN
ACTIVATOR THERAPY
• Growth potential includes eruption and migration of teeth
which produces natural forces and those can be
guided, promoted and inhibited by the activator.
• Muscle contraction and stretching of soft tissues
produces artificial forces effective in all three planes.
Sagittal plane
- mandible propelled down and forward so that force is
delivered to the condyle.
Vertical plane
- teeth and alveolar process either loaded or relieved of
normal forces.
Transverse plane - forces can be created with midline
reactions.

34. According to WITT,
• Approximate sagittal force
• Optimal vertical force
315 - 395gms.
70 - 175 gms.
• In a study by NORO et al (AJO - 94 Feb) magnitude of
forces generated by passive tension of soft tissues
increased from 80 - 160 gms in class II patients and 130 -
200 gms in class III patients when the construction bite
heights changed from 2 to 8mm.

35. MODIFICATIONS OF
ACTIVATOR

36. BIMLER APPLIANCE (1949)
 Hans .Peter Bimler
 Bite former
 Bimler stimulator
 Gebissformer
 Elastic oral adapter
 3 types

37. BIONATOR (1950)
 Wilhelm balter
 Skeltanised activator

38. THE KINETOR (1951)
 Dr . Hugo Stockfish
 Type of elastic activator
 Various screws and springs added
 Expand in 3 directions
 Latex tubing

39. HERREN SHAYE ACTIVATOR (1953)
 To maintain the correct mandibular posture during
sleep
 Advancement 3-4 mm beyond the neutral
relationship
 Jackson clasp/duyzing clasp / triangular arrow head
clasp
 Lingual flange extension
 Lower incisor bite on acrylic plane

41. LSU ACTIVATOR (1953)
 Louisiana State university activator
 Activator of Shaye
 Modification of Herren activator buy Dr.
 Robert SHAYE
 Longer the flange better ability to maintain position
during sleep
 Higher vertical dimension 8-12 mm
 Nocturnal device
 Phantom activator phenomenon
 JCO interviews dr, robert shaye on functionl appliances –JCO-1983

43. BOW ACTIVATOR OF AM SCHWARTS
(1956)
 2 parts connected by elastic bows
 Step wise sagital advancement possible
 Can be used in subdivision cases
 Expansion by screws

44. ELASTIC OPEN ACTIVATOR(1960)
 G. Klammet
 Acrylic bulk reduced and replaced by wire
 Increased flexibility
 More wear time
 Isotonic muscle contraction

45. KARWETZKY MODIFICATION (1964)

46.  Similar to bow activator
 2 plates joined by u bow in first molar region
 One short length and one long leg
 Horizontal movements created by constricting the u
bow

47. PROPULSOR (1968)
 Designed by Muhlemann
 Refined by Hots
 No wire component
 Vestibular screen +monobloc
 Hybrid appliance

48. HARVOLD/WOODSIDE ACTIVATOR
(1971)
 Bite open around 10 -15 mm beyond the postural
rest position
 Viscoelastic property
 Sagital advancement -3-5 mm distat to maximum
potrusion

49. WUNDERER MODIFICATION (1971)
 Class 3
 Upper and lower parts connected by screws
embedded in mandible
 Screw open-maxilla to move forward and mandible
to backward

50. CYBERNATOR OF SCHMUTH (1973)
 Reduced activator
 Cybernator similar to bionator has reduced acrylic
part in maxillary anterior area leaving a small flange
of acrylic on palatal slope.
 The two parts are connected by omega shaped
palatal wire.
 The lower acrylic part is splitted to permit
expansion.
 The appliance is made more resistant by a lower
labial bow

52. CUT OUT / PALATE FREE ACTIVATOR (1974)
 Metzelder
 Activator+bionator
 Maxilla –acrylic on palatal aspect of buccal teeth
and small part of adjoining gingiva
 Mandibular portion same
 Increased wear time

53. TEUSCHER –STOCKLI APPLIANCE (1978)
 Head gear combination appliance
 At the level of maxillary second premolar or first
molar buccal headgear tubes are incorporated in
the inter-occlusal acrylic.

54. VAN BEEK ACTIVATOR (1982)
 Headgear-activator combination appliance.
Between incisors a short and strong outer bow is
embedded in acrylic of the activator.
 Both upper and lower incisors are covered by
acrylic.
 Mandibular position is achieved
by lingual flange.

55. NOCTURNAL AIRWAY PATENCY APPLIANCE (1987)
 Designed by Peter T George.
 NAPA was fabricated to keep the airway patent
during sleep by posturing the tongue more
anteriorly by mandibular protrusion.

56. LEHMAN ACTIVATOR:(1988)
 Activator headgear appliance
 Maxillary acrylic plates to witch the outer bows
attached
 Mandibular lingual shield
 2 expansion screws
 Maxillary plate and mandibular shields are
connected by 2 s shaped wires

58. MAGNETIC ACTIVATOR DEVICE (1993)
 Developed by Dellinger, :
 1. MAD I: Correction of lateral mandibular
displacement.
 2. MAD II: Correction of Class II Malocclusion.
 3. MAD III: Correction of Class III Malocclusion.
 4. MAD IV: Correction of Open Bite.

60. ELASTIC ACTIVATOR FOR TREATMENT OF
OPEN BITE: (1999)
 intermaxillary rigid acrylic is replaced by elastic
rubber tubes.
 The elastic activator intrudes upper and lower
posterior teeth, by stimulating orthopaedic
gymnastics (chewing gum effect).
 It can be also used for eliminating habits by
incorporation of cribs

61. 0RTHO T ACTIVATOR
 This appliance was constructed by elastomeric
material.
 These are preformed activators, used in the
treatment from early through late mixed dentition.
 These appliances coined as EGAs (Eruptive
Guidance Appliance) also function as a positioner
and in correction of overbite and mild to moderate
crowding.

62. MODIFIED TEUCHER ACTIVATOR
(2006)
 It is modification of Teuscher activator designed
mainly to control upper incisor inclination.
 Headgear tube is present in the premolar region for
the use of high pull headgear

63. BIONATOR

64.  WILHELM BALTER 1960
 Modification of activator
 Skeletanised activator

65. PRINCIPLE OF BIONATOR
 Less bulky than activator
 The essential part of robin’s concept is function
whereas for Balter’s it is the tongue (which is the
center of activity in the oral cavity.

66.  The equilibrium b/w the tongue and cheeks,
especially b/w the tongue and lips in height, breadth
and depth in an oral space of maximum size and
optimal limits, providing functional space for the
tongue ,is essential for the natural health of the
dental arches and their relation to each other Every
disturbance will deform the dentition and during
growth that may be impeded too

67.  Reduced size
 It can be worn both day and night
 Action faster than activator –unfavorable forces are
avoided acting on dentition for longer time
 Constant wear so more rapid adjustment of
musculature
ADVANTAGES

68. DISADVANTAGES
 Difficulty in managing it
 Difficulty to stabilize and selective grinding of the
appliance
 It is vulnerable to distortion –because less support
in the alveolar and incisal region

69. INDICATIONS
 Dental arches well aligned
 Mandible in posterior position
 Skeletal discrepancy not severe
 Labial tipping of upper incisors evident
 Deep bite with accentuated c.o.s
 Class III where reverse bionator can be used
 Open bite

70. CONTRAINDICATIONS
 Class II – if caused by max prognathism
 Vertical growth pattern
 Labial tipping of mandibular incisors

71. TYPES OF BIONATOR
71
1. THE STANDARD BIONATOR
2. THE OPEN BITE BIONATOR
3. CI III OR REVERSED BIONATOR

72. THE STANDARD
APPLIANCE
Consists of
72
ACRYLIC COMPONENTS
- LOWER HORSE SHOE SHAPED ACRYLIC
LINGUAL PLATE FROM DISTAL OF LAST
ERUPTED MOLAR OF ONE SIDE TO OTHER
SIDE
- UPPER ARCH - LINGUAL
EXTENSION THAT COVER MOLAR
& PREMOLAR REGION

73. WIRE COMPONENTS
73
PALATAL BAR
LABIAL BOW WITH BUCCAL EXTENSION
PALATAL BAR
- 1.2 mm wire
- extents from a line connecting
distal surface of first permanent
molars to middle of 1st premolar’s
- ~ 1mm away from palatal mucosa
Function- orients the tongue & mandible
anteriorly by stimulating its dorsal surface
with palatal bar

74. 74
LABIAL BOW
-0.9 mm wire
- begins above contact point between canine and
upper 1st premolar –runs vertically
- labial portion of bow should be at a paper thickness
away from the incisors

75. 75
Anterior part - labial wire
Lateral part - buccinator bends
Objectives of buccinator bends
To keep soft tissue away from the cheeks –so the
bite is leveled & eruption proceed in buccal segment
Moves cheeks laterally , which favor expansion
tansverse development of dentition

76. OPEN – BITE APPLIANCE
76
Purpose of this appliance is t
o
close the anterior space
Acrylic part-
The lower lingual part extends
into the upper incisor region as a
lingual shield , closing the anterior
space without touching the upper teeth

77. Wire elements
Labial bow runs between the upper a
n
d
lower incisors at the height of lip
closure.
77

78. REVERSED BIONATOR
78
Encourage development of max
Bite opened 2mm for t
h
i
s
purpose
Acrylic portion
Extends incisally from canine to
canine behind the upper incisors
Acrylic is trimmed away by 1
m
m
behind the lower incisors

79. PALATAL BAR
79
R u n s forward with loop extending
as far as dec 1st m or pm
F u n c t i o n – tongue to contact
anterior portion of palate ,
encouraging forward growth of this
area.

80. LABIAL BOW
80
In front of lower incisors
Wire slightly touches the labial surface
lightly / it is at a paper thickness away

81. CONSTRUCTION BITE
81
Objective
To achieve a cIass I relation
Edge to edge relation of incisors – to
provide maximum functional space for
tongue
If overjet is too large – step by s
t
e
p
procedure is followed

82. 82
In Open Bite Bionator
Construction bite-is as low as possible with a
slight opening for interposition of posterior
bite blocks to prevent their eruption.
In Reverse Bionator
Construction bite- taken in more retruded
position so as to allow labial movement of
maxillary incisors &also to exert restrictive
force on lower arch

83. TRIMMING OF BIONATOR
83
As the volume of the appliance is reduced its
anchorage is difficult and trimming must be selective
because of simultaneous anchorage requirements
Balters has introduced certain terms
1.Articular plane
2.Loading area
3.Tooth bed
4.Nose
5. ledge

84. ARTICULAR PLANE:
84
This plane extends from the
tips of the cusps of the upper
1st molars,premolars &
canines to the mesial
margins of the central
incisors , running parallel to
the ala-tragal line.
Used to assess the mode of
trimming

85. LOADING AREA:
85
Palatal or lingual cusps
of the deciduous molars
(or premolars) are
relieved in the acrylic
part of the appliance.
The grinding enhances
the anchorage of the
appliance.

86. TOOTH BED
86
Some parts of the
loading areas are
trimmed away to the
articular plane

87. NOSE:
87
Between tooth bed
interdental acrylic
fingerlike projections
They serve as guiding
surfaces and provide
anchorage in the
sagittal and vertical
plane
NOSE mostly on the
mesial margin of lower
1st permanent molar

88. LEDGE :
88
Depending on the tooth
movement required the
acrylic is trimmed and the
nose is reduced .
This reduced extension
placed only on the occlusal
3rd of the interdental area
is called a ledge.
LEDGES are b/w premolars
or deciduous molars

89. BALTERS REFERS
89
prevention of eruption as l
o
a
d
i
n
gor
inhibition of growth
stimulation of eruption as
unloading or promotion of growth

90. Appliance can be trimmed until teeth reaches desired
relationship with the articular plane
Due to consideration for anchorage, appliance cannot
be trimmed in all areas at same time
90
Periodic loading and unloading of same area d
o
n
e

91. SELECTIVE TRIMMING
91
For extrusion of posterior teeth
Acrylic left between level of Articular plane –Tooth bed
Upper &lower molars trimmed first
Then lower premolar’s trimmed while molars loaded
Then upper premolar’s unloaded while lower premolar’s
&molars loaded
Occlusal surfaces of bionator trimmed for transverse m
o
v
t
For intrusion in case of open bite –posterior t
e
e
t
h
are
fully loaded

92. CLINICAL MANAGEMENT
APPLIANCE MUST BE WORN DAY AND NIGHT EXCEPT
W
H
I
L
EEATING.
92
Pt recalled after 1 wk to check sore points
Interval b/w visits 3-5 weeks based on the eruption of
the teeth.
It takes 1- 11/2 yrs to achieve correction
Labial bow away from the incisors.
Buccinator loops away from 1st & 2nd molars, s
h
o
u
l
d
not
irritate mucosa.

93. BIONATOR AND TMJ
Can be used for treating TMJ problems in adults
TMJ problems have coincident bruxism a
n
d
clenching during sleep.
The bionator relaxes the muscle spasm at LPM.
It prevents riding of the condyle over the posterior
edge of the disk which causes clicking.
Bi o n a t o r positions the mand forward soprevents
the deleterious effects at night
Bionator & local heat application with muscle
relaxants provides immediate relief for patients
93

94. BIONATOR IN ADULT PATIENTS
94
Petrovic has shown that protracted wear in adults c
a
n
permanently shorten the LPM and thus help the
patient maintain a protracted mandibular posture
even during the day time
Thus clicking sound and pain disappears

95. REFERENCES
 Dentofacial orthopedics with functional appliances –
GRP
 Removable orthodontic appliances –Graber &
Neumann
 orthodontics and dentofacial orthopedics – James A
Mc Namara
 Contemporary orthodontics – William R Proffit