- Frankel's functional regulator (FR) is a functional appliance developed by Rolf Frankel to correct malocclusions by expanding the oral space. - It works by altering muscle function through the use of acrylic shields and wires rather than directly moving teeth. - Studies on the FR have found it effective in correcting Class II malocclusions through dentoalveolar changes rather than true skeletal changes. It induces downward and forward mandibular rotation. - Modifications to the FR include capped designs, modifications to address vertical maxillary excess, and hybrid designs combining FR and activator elements. Comparative studies found it and twin block effective but with different dentoalveolar effects.

1. FRANKEL’S FUNCTIONAL
REGULATOR
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2. FRANKEL’S FUNCTIONAL
REGULATOR
Introduction
Frankel’s philosophy
Fabrication of the appliance
Appliance delivery & Clinical handling
FR in class 2 and class 3
Modification of FR
Studies on FR
Comparison b/w FR and other functional
appliances

3. Rolf frankel
Zwichau- Germany
1967 functional
regulator

4. FRANKEL’S PHILOSOPHY
Moss
Functional performance of the muscular
portions of the capsule influence the
developing functional spaces
Functional spaces also influence by
atmospheric pressure

5. FRANKEL’S PHILOSOPHY
Pressure on soft tissue
Muscular
forces
Sub atmospheric
pressure
Studies of Mobius
During swallowing
Vacuum in oral
cavity

6. FRANKEL’S PHILOSOPHY
‘ SPACE FACTOR’ important aspect
of epigenetic regulation

7. FRANKEL’S PHILOSOPHY
Functional space deficiency in
transverse and vertical planes

8. Perioral muscles had restraining effect on
dental arches
Insertion of appliance –expands capsule and
allows for new functional adaptation of
muscles
Activator – ‘ push from within’
FR – ‘ought to be matrix’
All activities of oral cavity – muscle training
FRANKEL’S PHILOSOPHY

9. FRANKEL’S PHILOSOPHY
Buccal shields and lip pads exert
periosteal pull
exp not verified this effect
Graber (1988) exp- on primates
showed that this effect is temporary

10. FRANKEL’S PHILOSOPHY
The mechanical effect of the appliance
directed to the capsular matrix and not
to teeth / alveolar process.
MOYERS
‘altering the condition that determine the pattern of
occlusal development rather than altering the
occlusion directly.’

11. Classification of FR
FR1
Types a , b and c
FR 2
FR3
FR4
MODIFICATIONS OF FR

12. FR 1
Acrylic components
Buccal shield
Lip pads
Lingual shield

13. Buccal shields
Extension
Thickness
2.5mm
Expansion of
the capsule

14. Lip pads
extension and
Tear drop shape
Smoothen sulks
Lip posture and seal
seal
5 mm

15. Lip pads and buccal shields
Concomitant
action in
mandibular
retrusion

16. Lingual shields
extension
Over comes the
poor posture of
mandibular muscles
Different action from
activator
Action only in step
advancement

17. Labial
bow
Canine
loop
Palatal
bow
Cross
over wire
Wire components of FR 1

18. Wire components of FR 1
Lower lingual
wires
Cross
over
wires
Labial bow
Palatal bow Canine loop

19. Labial bow
Position and
extension
Stabilizing
Connecting
‘Function
activated’

20. Palatal bow
Extension
Occlusal rest on
maxillary molar
Stabilizing action
Intermaxillary
anchorage

21. Canine loop
Extension
Guide eruption
of canine
Intermaxillary
anchorage

22. Lower lingual wires
Extension
Prevent lingual
movement of
incisors
Function activated
element in deep bite
and retruded
anteriors

23. Cross over wires
Run b/w 1st and
2nd premolars
Not to be lodged
interdentally
Cause movement
of buccal
segments
No training effect

24. FR1a and FR1 b
Lower lingual
loops
Overjet 5mm
Lower lingual
shield
Overjet 7mm

25. FR 1C
Step by step opening
in the anterior and
vertical direction
Overjet > 7mm

26. FR 2
Canine
loop and
labial
bow
Upper
lingual wire

27. Upper lingual wire
Runs b/w canine
and lateral
Stabilizing effect
Prevents lingual
tipping of anteriors
in div 2 cases
corrected in pre fr
phase

28. Upper lingual wire
Preferred in
class2 div 2 with
horizontal
growth pattern
Bite opening
action similar
anterior bite
plane/activator
Bite opening
effect also due
to buccal
shields

29. FR 3
Lower
labial wire
Upper
lingual
wire
Upper lip pads
Occlusal
rests

30. Buccal shields in FR 3
Stand away from
maxilla but not
from mandible

31. Lip pads in FR 3
Larger in size
Stands away from
alveolar process
Expansion of
capsule and
correction of
postural imbalance

32. Palatal bow and occlusal rests
Palatal bow not
lodged
interdentally
Additional
occlusal rest on
lower molar in
deep bite

33. Upper lingual wire and lower
labial bow
Upper wire not
touch the anteriors
but can be
activated to
protrude incisors
Lower labial bow
must touch the
incisors

34. FR 4
4 occlusal rests
Palatal bow
Lower labial pads and
buccal shields
upper labial bow

35. Construction of the FR
appliance

36. Impression technique
Reproduce
whole alveolar
process and
depth of the
sulcus
Tray selection
Adequate base

37. construction bite
Differs from
other functional
appliances
Advancement
only by 2-3mm
in first step

38. Preparation of the casts
Gauge to measure the
correct depth of the
sulcus
Properly carved
working models

39. Preparation of the casts
seating grooves:
Seating
grooves are
cut in the
maxillary
model in FR
1 and FR 2 in
the
permanent
dentition

40. Preparation of the casts
seating grooves
Seating grooves in
maxillary model for
permanent dentition
Notching in the
deciduous dentition

41. Preparation of the casts
Sulcus
trimming
and position
of lower lip
pads
12 mm
Extension of
lower lip pads

42. Preparation of the casts
wax relief:
Maximum
thickness of wax
padding under
buccal shield
Wax padding under the
buccal shield to allow for
dentoalveolar expansion

43. Wire fabrication
Correct position of wires on the maxillary work
model
Labial bow 0.9mm
, canine loop 0.8mm
and palatal bow 1mm

44. Wire fabrication
Palatal bow
Canine loop

45. Wire fabrication
Correct position of lip pads and lingual shields
and wires
Lo-la 0.9mm
Lo –li 0.8mm

46. Wire fabrication
Correct
position b/w
wires and wax
up -0 .75mm

47. Wire fabrication
Lingual wires 0.8mm
Extension arm
of cross over
wire 1mm
Single piece 3 separate pieces

48. Wire fabrication
Future splitting of buccal shield with use
of metal sheet

49. Wire fabrication – FR 2
Palatal bow and upper
lingual bow (0.9mm)
in FR 2 seated inter
proximally for locking

50. Bite registration - most comfortable
retruded position
Wire fabrication - FR 3

51. Preparation of models- FR 3
Trimming of
maxillary casts

52. Wax relief – FR 3

53. FR 3
CORRECT POSITION OF THE UPPER LIP PADS

54. Wire fabrication - FR 3
Correct position of protrusion and
palatal bow

55. Wire fabrication - FR 3
Occlusal rest
below palatal bow
Mandibular
labial bow

56. Timing of treatment
7-8 ½ years
Best therapeutic effect when mandibular
lateral incisors erupt
Class2 div I with mandibular retrusion-
males till a 15-16 years
Not start during circum pubertal growth
period /late mixed dentition.

57. Treatment phases with FR
Initial phase
Active phase
Retention phase

58. Initial phase
Appliance delivery
Check
Smoothness of margins
Lip pad –tear drop
Separation b/w teeth
In mixed dentition make notches

59. Initial phase
Appliance delivery
Check
appliance fit
Overextension of shields
Palpate face to to check for sharp
edges

60. Initial phase
Wearing the appliance
Success of treatment – lip seal
Emphasis on lip exercises
Duration of wear
Ist week – 1-3 hrs in afternoon only
2nd week – 4-6 hrs
3 – 4 months – full time wear

61. Active phase
Check after every 4 weeks
Mucosal irritation
Stability of appliance
Impingement of cross over wires
Appliance adjustments
Canine loop -occlusally
Molar rests – gingivally

62. Active phase
Appliance adjustments
Labial bows & lingual wires-retract
/close spaces
Lingual wires – towards cingula
Further advancement in severe cases

63. Active phase
After 3 months of full time wear
Check
Expansion
Overjet
Overbite
molar relationship-(6-8 months)
Leveling of curve of spee
Decrease in mentalis activity

64. Retentive phase
Different from fixed appliances
Labial and lingual wires can hold altered tooth
positions
Used as retainer in pts where the training
effect not satisfactory
Fixed treatment may be required
2 hrs in afternoon
6 hrs in night
Only night – i year
6 months

65. FR in treatment of class II
Mandible displaced anteriorly- retractor
muscle force –600gms
Activator-force transmitted to single teeth
Bjork : rapid reaction in the dental system
TMJ unaffected
Major dental changes – Proclination of lower
incisors

66. FR in treatment of class II
Activator treatment
before after

67. FR in treatment of class II
Mode of action of
activator in the
treatment of
mandibular
retrusion

68. FR in treatment of class II
Suspending muscles relax during sleep
Mandible drops inferiorly and backwards
Proclination of lower anteriors
2-3mm advancement
initial afternoon wear

69. FR in treatment of class II
Post –sup
elongation of
condyle
Remodeling at
ramal-corpus
junction- elongation
of corpus

70. The adjustive function of the
ramus

71. FR in the treatment of class 2
Mandibular retrusion to be overcome by
Expanding the oral space
Suspending muscles of mandible
provide dynamic force
Correct immature patterns b/w
protractors and retractors
Keep mandible forward but not
mechanically

72. FR in the treatment of class 2
Change in position brought by lingual
shields
Initial bite 2-3 mm
Advancement in small steps for biologic
reasons.

73. FR in the treatment of class 2
Step by step advancement by splitting the
buccal shields
Suspending muscles are not overstrained
Activator –extreme alteration of mandibular
position –occlusal instability & TMD
FR advancement in steps stability in post
retention periods

74. FR in the treatment of class 3
Characterized by diminished
volume of the superior part of
the oro-facial capsule
Related to structural and
postural imbalance of
muscles
Lingual volume not to be
diminished

75. FR in the treatment of class 3
Expansion of
upper oral
space
Tongue
space not
diminished

76. FR in the treatment of
class 3
Septo premaxillary ligament pull
translates upper incisors bodily
FR3 promotes max basal bone
development and translates maxilla
forward
Appliance should not be locked in the
maxilla by wires

77. FR in the treatment of skeletal
open bites
Aimed at correcting the
poor lip valve
mechanism.
Marked activity of
temporalis and
masseter when lips are
closed
Acc to Frankel tongue
thrust is compensatory

78. Modifications of FR appliance
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79. Modifications of FR appliance
1. Capped frankel appliance-OTTON et al
1992
2. Modified functional regulator for VME -
Owen1985
3. Change in the angulation of cross over wire
–Chate 1986
4. Hybrid appliance –activator –FR
combination -1986
5. KINGSTON modified buccal shields
6. Fr with continuous buccolabial shield and
palatal acrylic support – Haynes 1986

80. CAPPED FR
controls tipping
Indicated in deep bite cases

81. CAPPED FR
Disadvantages
- need of sufficient posterior separation
- capping may impinge on U1 as
treatment progresses
- difficult to clean

82. Change in the angulation of cross
over wire
Strictly
horizontal
advancement
results in incisal
movements of
the lower wire
and shields

83. Change in the angulation of cross
over wire

84. Change in the angulation of cross
over wire
Difficulty in establishing normal lip functions

85. Change in the angulation of cross
over wire
In cases with
step
advancement
FR to be
constructed so
that it be
parallel to the
downward and
forward
repositioning of
the mandible

86. Modified FR for VME
Posterior part of maxilla –important for
vertical growth control
½ -1/3 mm posterior eruption increases
AFH by 1mm.
Molars intruded chin translated forward
improving profile

87. Modified FR for VME
Modified FR for VME
by adding posterior
bite blocks
Added head gear
tubes

88. Modified FR for VME
25 pts av age 7 yrs 3 months,bite 3-4
mm assessed after 19 months
U1 retracted
No proclination of L1
Horizontal movement of the chin
AFH decreased
Gumminess of smile reduced

89. HYBRID FUNCTIONAL APPLIANCE
(fr and activator combination)
Hybrid appliances are those that are
specifically and individually tailored to
exploit the natural process of growth
and development
1. Bite planes
2. Shields and screens
3. Construction and working bite

90. HYBRID FUNCTIONAL APPLIANCE
(fr and activator combination)

91. HYBRID FUNCTIONAL APPLIANCE
(fr and activator combination)

92. FR with kingston modified buccaL
SHIELDS

93. Modified Fr with continuous buccolabial shield
and palatal acrylic support- haynes ajo 1986
To eliminate lip
trap
No pressure on
the gingival
dentoalveolar
tissues

94. Studies on Frankel‘s
appliance
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95. N.R.E Robertson AJO 1983
12 cases with FR2 and FR3 using cephs
and conclude the principle changes were
dentoalveolar
MC NAMARA AJO 1984
3 adult patients with class 2 malocclusion
with mandibular retrusion
Length of mandible not increased but
vertical dimensions increased
Adaptation minimal not sufficient to
overcome malocclusion

96. FACIAL GROWTH DURING
TREATMENT WITH FR APPLIANCE
Leth Nielsen AJO 1984
10 pts treated with FR showed maxilla
retrognatic
No indication that mandibular growth was
promoted
Changes more in vertical plane
Not necessarily improved the profile

97. Skeletal and dental changes following FR
therapy on class II patients
MC NAMARA AJO 1985
100 pts treated for 24 months and
compared with controls
No change in maxilla
If considered pt A then slight retrusion
of maxilla
U6 forward movement reduced but not
vertical
L6 vertical movement

98. Skeletal and dental changes following FR
therapy on class II patients
MC NAMARA AJO 1985
U1 tipped posteriorly
some tipping of L1
Downward movement of mandible
noticed
Some forward movement noticed in
some pts

99. The effect of FR 4 in class 1 skeletal anterior
open bite
ELIT ERBAY AJO 1995
20 treated and 20 controls
Useful in treatment
Diminished AFH ,growth rate of AFH (3.9
mm)decreased ,& PFH increased (4.5 mm).
Caused forward and upward rotation of
mandible
Reduction in mandibular plane angles i.e Sn-
GoMe,AnsPns-GoMe

100. Frankel-post vestibular shields caused
inferior translation of mandible,growth at
condyle increase in ramal length
Anterior part of mandible rotated upward
because of the lip seal
Erbay’s study noted FR inhibited
posteriors and improved the axial
inclination of U1

101. Comparison of FR with other
functional appliances

102. FR Vs twin block
toth/mc namara AJO 1999
4O PTS WITH TWIN BLOCK AND FR COMPARED
TO CONTROLS
Results
Increase in mandibular length
Twin block – 3mm > controls
FR – 1.9MM
Vertical dimension & dentoalveolar changes TB > FR
TB -mandibular skeletal & dentoalveolar changes
FR – more skeletal and less dentoalveolar

103. FR Vs herbst appliance
mc namara ,howe ajo 1990
45 herbst and 41 FR pts compared with controls
Results
Both appliance – no effect on maxilla
herbst – prevented vertical eruption and caused
posterior movement of u6
U1 lingual tipping- both
Lower proclination L1 – herbst > FR
mandibular length
Control - 2.1mm/yr
Herbst - 4.8mm
FR – 4.3mm

104. FR Vs fixed mechanotherapy
CREEKMORE,RADNEY AJO 1983
FR compared to edgewise with headgear
Edgewise had greater retractive force on
maxilla
Retraction of u1 > FR
Retraction of L1
Backward growth of condyle But 1.2mm < FR
Pog forward 1mm< FR

105. Fr therapy in cleft palate patients
keere,welch ajo 1981
9 pts treated with Fr for 6-18 months
To treat collapsed maxilla and cross bite
Results
Not clinically useful in cleft patients

106. Frankel’s functional regulator
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107. The occipital reference system
Orientation to
the earth’s
surface

108. The occipital reference system

109. The occipital reference system

110. Case 1
Class2
Mandible
retruded
No lip seal
+ VTO
FR 1
8 yrs 4
months
1 1/2
year post
retention

111. Case 1
Pre treatment After FR 1 ½ years post
retention

112. Case 1
bjork
Occipital
reference
system

113. Case 2
Class 2
Mandibular
retruded
open bite
no lip seal
8 yrs 5
months
22 yrs .9 years
post retention

114. Case 2

115. Case 2

116. Case 3
12 yrs
16 yrs

117. Case 3

118. Case 3

119. Case 4
Class 3
Maxillary
retrusion
Mandibular
prognatism
No lip seal
Flaccid lips
6 yrs 5
months
7 yrs 3
months

120. Case 4
After FR 7 yrs post retention

121. Case 4

122. Case 5
Class 3
Incompetent lip
valve
retruded
maxilla
5 years 7
months

123. Case 5

124. Case 5

125. Case 6
Class 2
div 1
skeletal
open bite
Lips
habitually
parted
hypotonic
9 yrs 10
months
20 yrs

126. Case 6
4 yrs 11
months
9 yrs
After FR
At 20 yrs

127. Case 7
Stability of transverse dimensions in post retention periods
Pre FR Post FR 7 years post
retention

128. Case 7

129. Case 8
Pre FR
8 yrs
Post FR 17 yrs
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