The Frankel functional regulator is a removable orthodontic appliance developed by Dr. Rolf Frankel to effect changes in the jaw relationship during mixed and early permanent dentition. It consists of upper buccal shields, lower lip pads, and wires. The shields and pads act to change muscle function and guide jaw growth. Indications include Class II malocclusions with a retruded mandible. Contraindications include severe crowding. The appliance aims to correct jaw positions through muscle adaptation and differential tooth eruption guidance between the arches.

1. 1
PRESENTED BY –
DR. FIRDOSH ROZY
THE FRANKEL FUNCTIONAL
REGULATOR

2.  Introduction
History
Synonyms
Philosophy
Mode of action of
FR
Indications and
Contraindications
Advantages and
Disadvantages
Components
Diagnosis
Types
 modifications
Treatment
objectives
Clinical handling
Instructions
Journal reviews
Conclusions
References

3. INTRODUCTION :
 Functional appliances are defined as loose fitting or
passive appliances which harness or eliminates the
natural forces of the orofacial musculature that are
transmitted to the teeth and alveolar bone through the
medium of appliance.

4.  The basis of functional treatment in general is a principal that
a “new pattern of function” dictated by the appliance, leads to
corresponding “new morphologic pattern.”

5.  The functional regulator is a removable orthodontic appliance
developed by Prof. Rolf Frankel.
This appliance is used during the mixed and early permanent
dentition stages to effect changes in anteroposterior, transverse
and vertical jaw relationship.
The frankel appliance has 2 main treatment effects-
First, It serves as a template against which the craniofacial
muscles function .
The 2nd effect of frankel appliance is its influence on
skeletal and dental development.

6. Dr. Rolf Frankel was an orthodontist
from the obscure town of Zwickau ,
East Germany wrote of his
functional appliance developments.
His first contributions were in
German attracted very little attention
abroad. However, 2 events occurred to
change the odds.
HISTORY :

7. First, Rolf Frankel learned English.
2nd a professor of orthodontics at the university of Chicago recognized the
significant contributions being made by frankel, saw the results and
documentations and invited him to US to present his philosophy & show his
treated cases. Seminar were arranged there under the aegis of Dr. James
McNamara, Dr. T.M. Graber at universities of Michigan & Detroit.
The original introduction of Dr. Frankel had been arranged by Bedrick
Neumann of Czechoslovakia, & subsequent team effort by Neumann & Graber
produced Removable Orthodontic Appliances, which incorporated a chapter
on the Frankel Regulator.
Dr. CHARLES NORD was correct when he called the frankel method “ A
Revolution in orthodontic appliances.

8. SYNONYMS :
1. FRANKEL APPLIANCE
2. VESTIBULAR APPLIANCE
3. ORAL GYMNASTIC APPLIANCE
4. FUNCTIONAL REGULATOR
Frankel postulates that increase in crowding is the result of
hypertonic muscles in the buccinator mechanism restricting the
lateral growth of the teeth and their supporting tissues. One
objective of the vestibular shield is to regulate the hypertonic
muscles of the buccinator and the perioral muscles, thereby
giving rise to the name…FUNCTIONAL REGULATOR.

9. THE PHILOSOPHY OF FRANKELAPPLIANCE

10. A major tenet of the frankel philosophy is that the dentition is heavily
influenced by
The functional matrix
The buccinator mechanism
The orbicularis oris complex.
1. VESTIBULAR ARENA OF OPERATIONS :
FR is largely confined to the oral vestibules, & hold away the buccal
& labial musculature from the dentition in those areas in which
pressure on the dentoalveolar structures has restricted the outward
development of these structures during the critical transitional
phase of dental development.

11. FMH of Melvin Moss : Buccal shields of frankel directly alter the soft
tissue configuration, increasing the oral volume, that is the capsular matrix
that allows the muscle to exercise and adapt and improve.

13.  The 2nd pillar of the FR philosophy is the method by which the sagittal
correction is achieved. Frankel has designed the FR so that there is no tooth
contact at all in the lower arch. The forward posturing of mandible is
achieved by an acrylic pad that contacts the alveolar bone only behind the
lower anterior segment.
Appliance is fixed on the upper arch by grooves mesial to the 1st
permanent molar and distal to the canine in the mixed dentition period.
 Presence of the lingual pad acts as a proprioceptive stimulator and helps
in the forward posturing of the mandible.
2. SAGGITAL CORRECTION VIA TOOTH BORNE MAXILLARY
ANCHORAGE :

14. 3. DIFFERENTIAL ERUPTION GUIDANCE :
By being free of the mandibular teeth, selective differential
eruption of the lower posterior teeth is possible, which not only
corrects vertical dimension deficiencies but also helps in the
sagittal correction of class II malocclusions.
4. MINIMAL MAXILLARY BASAL EFFECT :
 Little sagittal protrusive effect seen in maxilla with FR
therapy, even though lateral Maxillary expansion in seen,
in contrast to a significant forward change of the
mandible.

15. 4. BUCCAL SHIELDS, LIP PADS, & PERIOSTEAL PULL :
Research by Enlow, Hoyt, & Moffet has shown that pull
on periosteal tissue enhances growth beneath it.
Frankel reasons that there will be an outward periosteal
pull by maximal extension of the shields & pads into the
depth of the buccal and labial vestibule to the point at which
the depth of the sulcus is under tension.

16. Since the thin, bony shell beneath this area houses the
erupting permanent teeth , an outward growth of membranous
bone , plus relief of any restrictive tissue pressure , results in
bodily transverse changes in the posterior segments and bone
formation at the apical base contiguous to the lip pads. Both of
these occurrences are desirable treatment objects that have been
unattainable with conventional fixed or removable appliances.

17. MODE OF ACTION OF FR :
1. Increase in transverse and sagittal direction - by
use of buccal shields and lip pads.
2. Increase in vertical direction - by allowing the
lower molar to erupt freely because appliance is
fixed to the upper arch

18. 3. Muscle adaptation - Development of new patterns of motor
function by buccal shields and lip pads of FR can be achieved
by-
a) massaging the soft tissues
b) loosening the tight muscles
c) Improving the blood circulation
d) improving muscle tonicity
e) Providing new functional matrix for perioral muscle to act
upon it- ‘Ought-to-be matrix’

19. 4. Mandibular forward positioning- Position of mandible
can be changed by gradual training of the protractor and
retractor muscles followed by condylar adaptation.

20. Mixed dentition period with growth spurts.
Skeletal class II malocclusion with prognathic
maxilla and retrognathic mandible (Positive VTO)
 Functional class II malocclusion.
In a horizontal or neutral growth vector case.
Class III malocclusions.
 Bimaxillary protrusion and open bite problems.
INDICATIONS :

21. Fr- VTO :
 The Fr- VTO is a simple, yet very important
maneuver that is performed before making a decision
to use the FR appliance.
The patient is first asked to close the teeth in
habitual occlusion and relax the lips. The profile view
is carefully studied and can be photographed at this
time to obtain an instant imprint. Then the patient is
asked to posture the mandible forward into a correct
sagittal relationship, reducing the overjet. A
photograph of this profile can be taken again & can be
compared with the teeth in occlusion. If this clinical
maneuver improves the profile, the FR appliance is
probably indicated.

23. CONTRAINDICATIONS :
Class I malocclusion with severe crowding
Thumb sucking habit.
Severe dentoalveolar problems in permanent dentition.
 Uncooperative patients.

24. ADVANTAGES
1. It enables elimination of abnormal muscle function
thereby aiding in normal development.
2. Treatment can be initiated at early age .
3. Less chair side time is spent.
4. The frequency of the patients visit is less.
6. They deal with skeletal as well as dent alveolar
problems.

25. 1. The appliance is bulky and the cooperation of the patient
is essential.
2. They cannot be used in adult patients were the
growth has ceased.
3. Cannot be used to bring about individual tooth
movement and in cases of crowding.
4. Fixed appliance therapy may be required at the
termination of treatment for final detailing of
the treatment.
DISADVANTAGES :

26. COMPONENTS OF FRANKEL :

28. LOWER LINGUAL PAD :
It lies lingually below the gingival margin of mandibular teeth
and extends distally to the roots of lower second premolar.
Operational Purpose:
Forced Training: It is used to overcome poor postural performance
of muscles suspending the mandible.
ACRYLIC PART

29. BUCCAL SHIELDS :
They should extend deep into the sulcus,
particularly in the apical region of maxillary first
premolar and maxillary tuberosity.
The shield must be at an appropriate distance
from the lateral aspect of the teeth and alveolus
for expansion. The thickness of the shield should
not exceed 2.5mm in order to make the wearing
of the appliance comfortable

30. PURPOSE OF BUCCAL SHEILD
1. To restrain the cheek musculature
2. The action of the tongue, acting from within the oral cavity
brings about an expansion of the dental arches.
3. The shields -first premolar and maxillary tuberosity area-
stretches the periosteum cause tension -deposition of bone
along the lateral aspects of maxilla.

31. The vestibular shield creates tension at the depth of the
mucobuccal fold in a lateral direction.
 This tension is directed at influencing the erupting permanent
teeth to erupt further laterally than normal, thereby resulting in
arch expansion.
 Notice that less influence is seen on fully erupted teeth, as
shown by the open arrow.

32. LABIAL PADS :
These pads are rhomboid in shape .
 In crossection they should be in tear drop
shape.
 The upper edges of the lip pads should
be at a distance of 5mm from gingival
margin.
The distal edge should not overlap the
labial protuberance of canine root

33. Operational purpose:
◂ The lip pads when correctly positioned in depth of sulcus
have a supporting effect on lower lip smoothing the
mentolabial sulcus and improving lip posture.
◂ Thus the lower lip makes a normal contact with the upper
lip which is important for establishment of competent lip
seal.

34. Forced training:
◂ The main purpose of lip pads is to prevent hyperactive
mentalis muscle.
◂ This inhibitory action is necessary in order to achieve a
training effect on lip muscles which are designed to bring
about physiological lip seal.

35. WIRE COMPONENTS :
1. PALATAL BOW
It originates in the central groove
of maxillary first molar forming an
occlusal rest that is parallel to the
occlusal plane so as to allow
expansion of molars laterally.
 The wire makes a loop in the
buccal shield and recurve to cross
in the interproximal groove
between maxillary second premolar
and first molar.

36. The wire then crosses the palate
with a posterior curve that
approximates between hard and
soft palate. From there it recurves
in a similar manner.
It is constructed by 1mm gauge
of wire.
 It is used for posterior appliance
stability and
intermaxillary anchorage.

37. 2. CANINE LOOP :
Canine loop is embedded in the
buccal shield at the level of the
occlusal plane.
 It rises sharply to the gingival
margin of maxillary first deciduous
molar, and fits in the embrasure
between the deciduous first
molar and the canine to lock the
appliance in place on the maxilla.

38. The loop wraps around the
lingual surface of the canine and
emerges labially in the canine-
lateral incisor
embrasure, curving distally over the
canine cusp.
The free end can be bend.
In the mixed dentition stage the wire
embedded in the acrylic can be adjusted to prevent interference
with the proper eruption of the canine and first premolar.
It is fabricated by 0.9mmgauge of wire.
 It helps in canine guidance and proper stabilization of the
appliance.

39. 3. LABIAL BOWS :
The labial wire turns gingivally at right angle between
the maxillary lateral incisors and canine to form the
canine loops.

40. 3. LOWER LABIAL WIRES :
They are fabricated by 0.9mm diameter of wire.
 It supports the lip pads in proper position.
 The average distance between the labial wires embedded in
the lip pads and gingival margin is 7mm.

41. Three wires are used for fabrication of labial wires.
 The central wire is bend in the shape of inverted “V” and must
be high enough to prevent irritation of labial frenum.
Lateral wire are positioned 0.75mm away from wax relief in
order to ensure that they will be firmly embedded in the future
buccal shield.

42. 4. LOWER LINGUAL WIRES :
 The central wire follows the contour of lingual apical base at
approximately 1mm to 2mm from the mucosa and 3mm to
4mm below the lingual gingival margin of incisors, to allow the
addition of the acrylic.
 It is fabricated by 0.8mm dia of wire.

43. Two lingual springs emerges from the lingual shield occlusally and are
contoured to the lingual surface of the lower incisors right above the
cingulum of the lower incisors.
If they are to be used as “function activated” element they may be
placed on the lingual surface of lower incisors superior to the
cingulum. This should only be done in severely tipped lower incisors.

44. 5. LOWER LABIAL SUPPORT WIRES :
 The lingual contour of the wire is positioned 1mm away from the mucosa. It
should run posteriorly , and the free ends, about 9mm to 10mm below the
lingual gingival margin ,are then bend at right angle to secure a firm seat
in the acrylic.
 It is important that the wire pass interocclusally without contacting upper
and lower teeth.

45. They are then bend laterally to insert in buccal shield.
The lateral end of the wire are parallel to the occlusal plane because
they will be used as guides when lower anterior section of appliance is
advanced to change mandibular position step by step.
For this purpose the portion of the wire embedded in the acrylic
should be straight so that it can slide through the acrylic of the shield.

48. Impression making
Impressions should reproduce the whole alveolar process
to the depth of the sulci, including maxillary
tuberosities.
Gauge to measure the correct depth of sulcus

52. TYPES OF FRANKELAPPLIANCE :

55. 1 lingual pad

57. FR 1 a

59. FR I b

60. Lower lingual springs
Surface of the lower incisors right
above the cingula .
Lower labial wire
It supports the Skelton for the lip
pads .

62. Labial bow
The bow originates in the
buccal shield and lies in the
middle of the labial surfaces of
incisors , turning gingivally at
right angles between maxillary
lateral incisors and canines.

63. Canine loop
The loop wraps around the lingual
surface of the canines .It is embedded
in the buccal shield at the occlusal
plane level. It rises sharply to the
gingival margin and fits in the
embrasure.

64. FRI c
The buccal shields are split
horizontally and vertically into 2
parts –
Anteroinferior portion contains
the wires for lingual acrylic
pressure pad or shield and for the
lower lip pads. Vertical split is
opened to the desired position by
a 2 to 3 mm advancement and is
then filled with acrylic.
Used if overjet > 7mm

65. FR II
FRANKEL’S REGULATOR ACRYLIC COMPONENT WIRE COMPONENT
FR II 2 LOWER LIP PADS
2 BUCCAL SHIELDS
LOWER LINGUAL ACRYLIC PAD
a. palatal bow.
b. labial bow.
c. canine extensions.
d. upper lingual wire.
e. lingual cross over wire.
f. support wire for lip pads.
g. lower lingual springs.

66. CONSTRUCTION

68. 2. Impression
Deep upto vestibules.
•The purpose of this mandibular manipulation is to relocate the jaw
in the direction of treatment objectives.
•This creates artificial functional forces and allows assessment of the
appliance's mode of action.
As discussed earlier.
3. Bite construction

72. 6. Work model mounting …
mount the models on the straight line fixators.

73. 7. Wax relief:

74. 8. Wire formation

76. FR III

77. INDICATION :

80. The proposed method of action of
the FR-3 appliance. The distracting
forces of the upper lip are removed
from the maxilla by the upper labial
pads. The force of the upper lip is
transmitted through the appliance
to the mandible because of the close
fit of the appliance to that arch (after
Fränkel1).
MODE OF ACTION

81. Construction bite
The procedure of taking the
construction bite is done by retruding
the mandible as much as possible with
the condyle in its most posterior
position.
The vertical opening is kept to a
minimum to allow lip closure with
minimal stress

82. Wax relief
No wax is applied to the mandibular arch.

83. FR IV

84. • Correction of open bite and bimaxillary protrusion.
• Exclusively confined to mixed dentition
INDICATION :
MODE OF ACTION :
The downward and backward growth direction of the mandible was
changed to a upward and forward direction by FR-4 therapy, allowing
the skeletal anterior open bite to be successfully corrected through
upward and forward mandibular rotation.

85. INDICATED :
Long face syndrome having a high mandibular
plane angle
and vertical maxillary excess
FR V
Modification of Frankel by Albert H Owen (1985 –JCO)

86. FRANKEL’S REGULATOR ACRYLIC COMPONENT WIRE COMPONENT
FR V 2 LOWER LIP PADS
2 BUCCAL SHIELDS
LOWER LINGUAL ACRYLIC PAD
ACRYLIC BITE BLOCK
ADDITIONAL
a. palatal bow.
b. labial bow.
c. upper lingual wire.
d. lingual cross over wire.
e. support wire for lip pads.
f. lower labial wires

87. It also has head gear tubes that
accept a face bow for an occipital
pull headgear.
Additional bite blocks – to arrest
molar eruption.

89. MODIFICATIONS OF FRANKEL APPLIANCES :
1. Capped FR appliance – OTTON et al, 1992
2. Modified FR for VME – OWEN 1985
3. Change in angulation of cross over wire – Chate , 1986
4. Hybrid appliance , FR –ACTIVATOR combination – 1986
5. KINGSTON modified buccal shields
6. FR with continuous buccolabial shield and palatal acrylic
support – Hynes 1986

90. 1. Capped FR appliance – OTTON et al, 1992
Given by Raymond Otto in 1992
◂ Indicated in deep bite cases
◂ Controls labial tipping of
mandibular
incisors
Disadvantages
◂ Need of sufficient posterior
separation
◂ Capping may impinge on maxillary
incisors as treatment progresses

91. 3. Change in angulation of cross over wire – Chate , 1986
 Strictly horizontal advancement
results in incisal movements of lower
wire and shield.
Difficulty in establishing normal lip function

92. 4. Hybrid appliance , FR –ACTIVATOR combination –
1986
•Given by Dr. Peter Vig and Dr. Katherine Vig in 1986
•Hybrid appliances are specifically and individually tailored for
every patient.
•Problems of every patient is recognized and Instead of using a
“named” appliance for the treatment of a class
of malocclusion, various components of different functional
appliances can be used to make a composite appliance.

94. 5. KINGSTON modified buccal shields

95. 6. FR with continuous buccolabial shield and palatal
acrylic support – Hynes 1986
Palatal acrylic support and continuous buccolabial acrylic construction,
which replaces conventional function regulator with separate buccal
shields and lip pads.
The appliance is not "locked" into the mesial embrasure of the maxillary
first molars by a cross-palatal bar.

96. CLINICAL HANDLING OF THE FR :
Stabilizing the appliance at the delivery is absolutely essential.
Pre placement, all margins are checked for smoothness .
Check vertical dimension.
Over extension of the labial ,lingual, lip and buccal pads causes
tissue irritation . So the extension should be correct.

97. Wearing time
For the first two weeks the appliance should be worn for 2 to 4
hours during the day.
During the next 3 weeks the time is extended to 4 to 6 hours.
It usually takes 2 months before the appliance is worn at night.
The appliance and treatment progress should be checked at 4
weeks interval.
An initial end to end molar relationship is corrected in 6 months.

98. INSTRUCTIONS FOR THE PATIENT:
A little discomfort is to be expected initially.
Salivation may be increased but it should not be a problem.
Instruction on appliance care and oral hygiene maintenance .
Demonstrate the lip seal exercise .
Ask the patient to speak a few words and reassure that speech
would normalize.
Wearing time should be correctly followed.

99. JOURNAL REVIEWS

104. References
•Dentofacial orthopedics with functional appliances .Graber,Rakosi,
Petrovic
• Graber Neumann
•McNamara JA, Bookstein FL, Shaughnessy TG. Skeletal and dental
changes following functional regulator therapy on Class II patients.
American journal of orthodontics. 1985 Aug 1;88(2):91-110
•Falck F, Fränkel R. Clinical relevance of step-by-step mandibular
advancement in the treatment of mandibular retrusion using the
Fränkel appliance. American Journal of Orthodontics and Dentofacial
Orthopedics. 1989 Oct 1;96(4):333-41

106. •McNamara JA, Howe RP, Dischinger TG. A comparison of the Herbst
and Fränkel appliances in the treatment of Class II malocclusion.
American Journal of Orthodontics and Dentofacial Orthopedics. 1990 Aug
1;98(2):134-44.
•Hamilton SD, Sinclair PM, Hamilton RH. A cephalometric, tomographic,
and dental cast evaluation of Fränkel therapy. American Journal of
Orthodontics and Dentofacial Orthopedics. 1987 Nov 1;92(5):427- 34