The document discusses different types of functional appliances used in orthodontics including simple functional appliances like lip bumpers and oral screens, as well as more complex removable appliances like the Frankel regulator, Bionator, activator, and twin block. It describes the indications, contraindications, components, and mechanics of several commonly used functional appliances. The document emphasizes that functional appliances aim to alter the neuromuscular environment and utilize muscle forces to effect skeletal and dental changes.

1. Dr. Rashid Mahmood

8. Discrepancies
Skeletal
Dental
Soft-tissues

9. Three dimensions
↔Transverse
→Sagittal
↕Vertical

10. Transverse Discrepancies

11. Vertical Discrepancies

12. Sagittal Discrepancies

13. Sagittal Discrepancies

14. Sagittal Discrepancies

15. In Orthodontics

16. Definition:
Removable or fixed orthodontic appliances which use
forces generated by the stretching of muscles, fascia and
/ or Peridontium to alter skeletal and dental
relationships.

17. Form follows function

18. Form follows function

19. “If compensatory, adaptive lip and
tongue function could exacerbate
excessive over-jet in class II-type
malocclusions and if abnormal
swallowing and prolonged finger-
sucking habits could create anterior
open-bite and narrow maxillary arches,
could not the same muscles be used to
correct these and other problem????”

20. Background
 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

21. The appliances used to improve functional relationship of dento-facial
structures by eliminating unfavorable developmental factors and
improving the neuromuscular environment enveloping the developing
occlusion

22. Function
Muscular Action
Effect on dento-alveolar
development

23. What they do…..?
 Alter the neuromuscular environment of oro-facial region to improve
occlusal development and/or craniofacial skeletal growth
 Utilize muscle forces to effect bony and dental changes
 Disarticulate the teeth
 Encourage new mandibular position
 Require a tight lip seal during swallowing
 Selectively alter the eruptive path of teeth

24. When???

25. When???
 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
 Duration---------------------------10-12 hours a day
 These appliances should be worn at night-time as this is
when growth takes place

26. INDICATIONS
1. Growing ages (Mixed dentition and/or early permanent dentition)
2. Skeletal Considerations (Sagital correction of class II &III)
Skeletal Class II with Short mandible
a) Class II division 1
b) Class II division 2 (Convert div 2 to div 1)
1. Vertical Considerations
a) Normal to low angle cases
2. Dental Considerations
a) Local irregularity & rotation of incisors especially upper incisors
b) Crowding or dental compensation (Pre-functional Orthodontics
require
3. Open bite/ deep bite correction
4. Cross bite correction
5. To correct mal-forming dysfunction

27. CONTRAINDICATIONS
1. Children with neuromuscular disorders
a. Poliomyelitis
b. Cerebral palsy
2. Compliance
3. Hyperdivegent faces
4. Unfavorable growth
5. Protruded lower incisors
6. Severe crowding
7. Age

28. Treatment Principles
 Force Application: Compressive stress and strain act
on the structures involved resulting in primary
alteration in form and secondary adaptation in
function e.g all removable appliances
 Force Elimination: Abnormal and destructive
environmental influences are eliminated to allow
optimum development
like lip bumpers and frankel buccal sheilds

29. Mode of Action
 Functional Appliances influence facial skeleton through
condylar and sutural areas.
 Goal is to
 Use the functional stimulus of oro-facial muscles
, channeling this stimulus to the jaws, condyles and teeth to
bring the change.
 Purely functional and intermittent forces

30. Limitations
 Adult Age(Ineffective in adults)
 High Angle Cases(Increases vertical height of patient)
 Compliance
 Precise detailing of tooth position not possible
 Crowding (Cases with ALD are difficult to manage)
 Precise correction of Incisor inclination not possible
 Increased lower incisor inclination (They tend to increase lower incisor
inclination & thus proper Sagital correction may not be possible if not properly
managed)

31. Functional appliances if used
properly & at right time then
they help in improving the
profile and eliminating the need
for Orthognathic Surgery

32. TYPES
Active
Passive

33.  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

34. FUNCTIONAL
APPLIANCES
SIMPLE FIXED
FUNCTIONAL FUNCTIONAL
APPLIANCES APPLIANCES
REMOVABLE
FUNCTIONAL
APPLIANCES

35. SIMPLE FUNCTIONAL APPLIANCES
Force elimination appliances e.g
Oral shields,
Tongue cribs ,
Habit breakers,
Lip bumpers
JAW ORTHOPEDICS APPLIANCES
 REMOVABLE FUNCTIONAL APPLIANCES
 FIXED FUNCTIONAL APPLIANCES

36. TYPES
Tooth Borne
Tissue Borne

37. Simple functional appliances
 Can be used for both mand and
maxilla
 Uses the muscular force from
upper or lower lip to provide distal
Lip bumper
force specially to molars
 In lower arch headgear is less
acceptable so lip bumper is useful
 Remove soft tissues forces from
labial aspect
 Result increased lower incisor
inclination by influence of tongue
This can be reduced by placing it
as low as possible in labial sulcus
so that upper part of lip is in
contact with teeth

38. Simple functional appliances
Oral screens
 Forerunner of functional
regulator
 Consists of vestibular shields
which holds the lip away from all
teeth except upper incisors b/c
pressure from lips is transferred
to U I and acts to move them
palatally
 Can be used in mixed dentition
and aids patient with digit
sucking

39. Jaw Orthopedic Functional
Appliances
 Removable Functional Appliances
 TOOTH BORN
 MONOBLOCK
 ACTIVATORS
 BIONATORS
 TWIN BLOCKS
 MAGNETIC APPLIANCE
 TISSUE BORN
 FRANKEL FUNCTIONAL APPLIANCE
 Fixed Functional Appliances
 Flexible Fixed Functional Appliances (FFFA)
 Rigid Fixed Functional Appliances (RFFA)
 Hybrid Appliance
 Fixed version of RFA (fixed twin block , dynamix appliance)
 Elastics

40. TYPES
 MYOTONIC
 Depend upon displacement of mandible in AP and vertical
plane. e.g Activators
 MYODYNAMIC
 Not only translate the mandible AP & vertically but also
attempt to utilize and translate muscular movements e.g
Bimler appliance

41. Passive functional appliances
 Frankel

42. Active functional appliances
 Removable active functional appliances
 Bionator

43. Active functional appliances
 Removable active functional appliances
 activator

44. Active functional appliances
 Removable active functional appliances
 Twin-block appliance

45. Active functional appliances
 Fixed active functional appliances
 Herbst

47. Andresen Activator Viggo Andersen
 Mono-block
 As upper and lower plates appear joined together
 Activator
 Norwegian appliance

48. Modified Andresen–Häupl-type activator
 Class II cases Div I
 For better control of lower incisor inclination,
the lower incisors are covered with acrylic,
which is relieved on the lingual surface
 Correct overjet, overbite and molar relationship
during active growth
 Labial bow to prevent incisors proclination
 Maximum extension of lower lingual flanges in order to
redistribute the force on mucoperiostium of mandible
 Coffin spring instead of palatal plate
 Canine loops ----- screening loops of bionator and
buccal shields of FR.

49. Limitations
 Difficulty in speech
 Needs removal during eating
 Arch expansion cannot be carried out
simultaneously

50. Andresen
Labial view of the Andresen appliance. The picture shows labial Bow in
0.8mm S.S wire with tubing and lower incisal capping.

51. Andresen
Models removed

52. Andresen
Lingual or palatal view

53. Andresen
Buccal Views

54. Dr. Rolf Frankel
FRANKEL APPLIANCE
FRANKEL CORRECTOR
FUNCTIONAL REGULATOR

55. Dr. Rolf Frankel
 Passive functional appliance
 Essentially tissue borne
 Appliance of choice in class II due to mandibular retrusion.
FRANKEL APPLIANCE
 Used in early mix dentition.
 Has direct effect on neuromuscular system.
FRANKEL CORRECTOR
 Causes anterior advancement of mandible and increase in LAFH.
 Expands dental arches.
FUNCTIONAL REGULATOR

56. FUNCTIONAL REGULATOR
 Oral vestibule is used as operational basis for the
treatment of dentoalveolar discrepancies.
 It combines the principles of Anderson’s appliance
and oral screen.
 Mode of action depends upon the relieving and
lifting the pressure on teeth from lips and
cheeks, so that the jaws can be allowed to grow and
the teeth can be guided to move into new more
favorable position.

57. Frankel
Appliance
The wire assembly anchors the appliance on
the maxillary arch at the mesial embrasure of
the of first molar.

58. Frankel
Appliance
Rolf Frankel
A cross palatal
stabilizing wire on the
maxillary arch.

59. FUNCTIONAL REGULATOR
 FR I
a. Class I
b. Class II div 1 <5mm
c. Class II div 1 >7mm
 FR II Class II div 2
 FR III Class III
 FR IV Open bite & mild bimax

60. FUNCTIONAL REGULATOR
 FR I
a. Class I
It is mainly used to treat cases of Class I
malocclusion with minor to moderate crowding
or arrested development of dental bases.
It can also be used in class I malocclusion with
deep bite.

61. FR I Appliance
The components include:
Upper
• Palatal wire 6 / 6 in 0.9mm S.S wire.
• Canine wires 3 / 3 in 0.9mm S.S
wire.
• Labial Bow 2 / 2 in 0.9mm S.S wire.
Lower
• Lip Pads and Joining wires in 0.9mm
S.S wire.
• Hanger wires 5 / 5 in 0.9mm S.S
Labial view wire.
• Lingual Pusher Springs 3 / 3 in
0.7mm S.S wire.

62. FR I Appliance
Buccal view of the Frankel appliance.

63. FR I Appliance
Frankel appliance - lingual / palatal view.

64. FR I Appliance
Frankel appliance with upper model removed.

65. FR I Appliance
Frankel appliance with lower model removed.

66. FUNCTIONAL REGULATOR
 FR I
b. Class II div 1 where over-jet is <5mm
c. Class II div 1 where the over-jet is >7mm

69. FUNCTIONAL REGULATOR
 FR II Class II div 2
Prior to the functional therapy the incisor need to be
aligned

70. FR II Appliance
1. Flexible Appliance
2. The lingual and labial segments in lower portion encourage holding the mandible in a postured
position to alter the lip behavior.
3. By retraining the facial muscles & muscles of mastication to occupy new position.
4. The maxilla & mandible will be influenced to grow into corrected position.
5. Stretching of periosteum, osteoblastic activity & thus the bone formation.
Labial Bow Palatal Arch
Canine Clasps
Buccal Shields
Occlusal Rests
Labial Pads

71. FUNCTIONAL REGULATOR
 FR III Class III
Mild Class III cases
The correction of class III Malocclusion is by dento-alveolar
means, not because of skeletal growth modification

73. Registration of Bite
 Varies with the type used.
 Move mandible forward by 4 – 6 mm.
 Or edge to edge contact of incisors
 2.5 to 3.5 occlusal clearance.
 Correction of sagittal discrepancy in 2 or 3 stages.
3 dimensional effect of FR

74. Bionator
 1.Light Appliance
 2.Better Compliance
 3.Full Time Wear
Timing for Bionator Therapy
 Effective and stable when it is initiated immediately before the pubertal growth
spurt. Optimal timing to start treatment with the Bionator is when a concavity is
evident at the lower borders of both the second and the third cervical vertebrae
(CVMS II).
 In the long term, the amount of significant supplementary elongation of the
mandible in subjects treated with the Bionator during the pubertal growth spurt
is 5.1 mm more than that in untreated subjects with class-II malocclusion.
Significant increments in mandibular ramus height and for a significantly more
backward direction of condylar growth.

75. • Used in mix dentition.
• Major indication is in extremely deep
bite.
• Used to bring mandible in forward
position and to increase LAFH by
eruption of posterior teeth…California
Bionator.
• Can be used to close bite and
maintaining bite.
• Protusion springs may be used in class
II div2

76. Labial Bow
Bionator
Facets in the acrylic
which accepts maxillary
& mandibular teeth &
hold them in postured
position
Palatal spring
(Reverse coffin
spring)
Lingual horseshoe of acrylic

77. Twin Block
Indications
 Class II div 1
 Distal molar and canine relationship of at least half premolar
width
 Overjet more than or equal to 5mm
 Protrusion of maxillary incisors
 Class II skelatal type ANB≥ 4
 Occlusal development ..late mixed dentition or early
permanenet dentition
 Normal & low angle cases

79. Effects of twin block
 Skeletal effects: mandibular length increses,during 1 yr, restrains
maxilla
 Dentoalveolar change: upper incisors tip back
 Lower incisors move forward
 Overjet reduction.,.(correction achieved by skelatal and dentoalveolar
reduction
 Correction of buccal segment achieved by combination of distal movement
of upper molars &forward movement lower molars
 ANB reduction
 Increased vertical dimensions..(inc lower facial height)mandibular plane
angle increases
 Reduction of facial convexity

80. Contraindications
 TMJ problems
 Sk assymetries
 Syndromic pts

81. ClarK 1988
Twin Block In Function
Adams Clasp
Labial Bow
Inclined Plane
Modified
Adams Clasp
Bite block Inclined Plane
Expansion Screw Bite block

82. “where there is a will there is a way”

83. Chapter 13

84. Jaw Orthopedic Functional
Appliances
 Removable Functional Appliances
 TOOTH BORN
 MONOBLOCK
 ACTIVATORS
 BIONATORS
 TWIN BLOCKS
 MAGNETIC APPLIANCE
 TISSUE BORN
 FRANKEL FUNCTIONAL APPLIANCE
 Fixed Functional Appliances
 Flexible Fixed Functional Appliances (FFFA)
 Rigid Fixed Functional Appliances (RFFA)
 Hybrid Appliance
 Fixed version of RFA (fixed twin block , dynamix appliance)
 Elastics

85. • Fixed functional.
• should be used in permanent
dentition.
• Easily tolerated by the patient.
• Should be changed after some time .

86. Fixed Functional Appliances
Advantages
 Continuous stimulus for mandibular growth (24 hr use)
 They are smaller in size permitting better adaptation to functions such as a
mastication, swallowing, speech and breathing.
 Non-compliance Class II devices, which are able to treat Class II malocclusions
successfully,
 while reducing the need for patient co-operation and overall treatment time.
 Allows greater control by the orthodontist.
Disadvantages
 Application of force is transmitted directly to the teeth through a support system,
 the main disadvantage that may be encountered is dental movement that takes
place during treatment

88. APPLIANCE DISCRIPTION
 Can be compared to the artificial
joint between maxilla & mandible.
 A bilateral telescopic mechanism
keeps the mandible in continuous
anterior position.
 Appliance consists of a tube to which
plunger fits. Tube is fixed to the distal
end of maxillary molars & rod into
the lower first premolars.

89. Herbst Appliance
 The Herbst appliance consists of two tubes, two plungers, axles and screws
 Type I is characterized by a fixing system to the crowns or bands through the use
of screws.
 It is necessary to weld the axles to the bands or crowns and then fix the tubes and
plungers with the screws
 Type II has a fixing system that fits directly onto the archwires through the use of
screws
 Disadvantage is the fracture of archwires
Type III is for anchorage
Type IV has a fixation system with a ball attachment, which allows greater
flexibility and freedom of mandibular movement.
 Disadvantage in relation to other similar appliances is that it needs brakes to
stabilize the joint. The brakes are small and sometime difficult to fit. When a
fracture occurs or a brake is lost, the appliance comes loose

91. FFF-Appliance
Jasper Jumper

92. Jasper Jumper Herbst Appliance

93. Indications
of FFFA
 Class I (An anchorage reinforcement)
 Class II division 1 and 2
 Class III malocclusions
 Molar distalization
 Midline discrepancy

94. Flexible Fixed Functional Appliances
Inter-maxillary torsion coils, or fixed springs.
Advantages
 Elasticity
 Flexibility
 Allow great freedom of movement of the mandible
 Lateral movements can be carried out with ease
Disadvantages
 Fractures can occur both in the appliance itself (mainly in areas that have more acute angles) and in the
support system (mainly in the lower arch)
 If on one hand flexibility is an advantage, on the other hand it does tend to produce fatigue in the springs
 Tendency of the patient to chew on the appliance, possibly contributing to breakage or damage.
 It is not possible for the patient to completely open his mouth, depending on the way the system is fixed
onto the lower arch, good opening can be achieved.
 Expansive & replacement of broken parts adds cost
 Inventory
 Unhygienic but covering of springs make them hygienic

95. Mechanism of Action
 FFFAs allow the patient to close in centric relation
 When the patient closes in centric relation, the contour of the bow should
be significantly increased
 By slightly overactivating the appliance in centric relation, the patient will
automatically position the mandible forward. This is a natural response to
decrease the force module and alleviate discomfort.

96. Clinical Relevance
 In brachyfacial cases, due to their strong musculature, it is necessary to use more force
(greater activation) than in dolicofacial cases.
 If the patient has large cusps with good intercuspation, it will be necessary to exert greater
activation on the spring.
 Greater force for orthopedic effects while lesser for dento-alveolar movements
 To maximize the dentoalveolar movements in the upper arch and minimize any loss of
anchorage in the lower, the upper archwire is not tied back.
 It can be used to obtain maximum anchorage, holding upper molars back as the upper
incisors are retracted.

97. Unwanted Effects
 Due to the intrusive force on the upper molars, a posterior open bite is common
as well as posterior expansion due to the deflected force module.
 Tendency for the lower molar to rotate mesiobuccally, causing a mild posterior
crossbite especially when the second molars have not been banded
 Proclination of lower incisors..
 Not recommended in mixed dentition, especially late mixed dentition to avoid
unwanted dental movements.

98. Jasper Jumper
 Intrusion and distalization of the upper molars, with occasional opening of the
posterior bite similar to that seen with a Herbst ppliance.
 Some indication of condylar growth.
 Anterior migration of the mandibular teeth through alveolar bone.
 Intrusion of the lower incisors.

99. Advantage
 comfortable because of its covering.
Disadvantages
 The large inventory that must be kept,
 the coating material may degrade
 Fractures

100. Contd.
 Canines can be retracted against
mandibular dentition.
 As the force modules cause
asymmetric forces, it can be used
to treat dental asymmetries.
 Causes mandibular advancement
and increase in LAFH.
 Can be used in post surgical
stabilization of class II patients.

101. Indications.
 Dental Class II malocclusion.
 Skeletal Class II with maxillary excess as opposed to mandibular deficiency.
 Deep bite with retroclined mandibular incisors.
 Midline Correction
Contra-indications.
 Cases predisposed to root resorption.
 Dental and skeletal open bites.
 Vertical growth with high mandibular plane angle and excess lower facial height.
 Minimum buccal vestibular space.

102. Rigid Fixed Functional Appliances
 RFFAs do not easily fracture but neither do they have elasticity or flexibility.
 After fitting and activation they do not allow the patient to close in centric relation.
This means that the mandible is in a forward position 24 hours a day creating
greater stimulus for mandibular growth than with FFFAs.
 Skeletal effects produced with this type of appliance are greater than with FFFAs
 Mechanism of Action
 Telescopic mechanism which encourages forward repositioning of the lower jaw as
the patient closes into occlusion

103. Indications.
 Dental Class II malocclusion due to retrognathic mandible
 Skeletal Class II mandibular deficiency.
Deep bite with retroclined mandibular incisors.
They can be used as an anterior repositioning splinting patient with TMJ disorders.
 Residual growth can be utilized in post adolescent patients.
 Can be used in mouth breathers.
Contra-indications.
 Cases predisposed to root resorption.
 Dental and skeletal open bites.
 Vertical growth with high maxillomandibular plane angle and excess lower facial height.

104. TYPES OF APPLIANCE
 Bonded herbst (High Angle Cases)
 Banded herbs
 Flip locked herbst
 Crowned herbst

105. The Flip-Lock Herbst Appliance
 Reduced number of moving parts that can lead to breakage or failure.
 Easy to use
 Comfortable
 Instead of a screw attachment, it has a ball-joint connector so it needs no
retaining springs.
 Less chairside time activation

106. Bonded Herbst Appliance It is a wire reinfofced acrylic splint.
The pivots are fixed to the wire
framework at distobuucal aspect
High Angle Cases of the upper first molar mesial
aspect of lower first premolar.
Tube is fitted to the pivot in the
upper molars & shaft is fixed to
mandibular premolar region

107. BANDED HERBST
 Upper & lower first premolar & first molars
are banded.the tubes are fixed to pivots
soldered to distobuccal aspect upper first
molars.
 The shaft or rods are fixed to pivots soldered
to lower first premolar band.

108. CROWNED HERBST

109. Hybrid Functional Appliances
Hybrid appliances are specifically and individually tailored to exploit
the natural processes of growth and development.
These appliances blend several components designed to address
specific problems

110. Asymmetric mandibular deficiency
or facial asymmetry in children

111. Condylar fracture

113. Fixed Version Of RFA
• Dynamax Appliance
• Fixed Twin Block
• Magnetic Appliances
• Elastics

114. Fixed version of RFA
 Clip-on Fixed Functional Appliance
Advantages of the Appliance
 Patient co-operation is not required.
 It works for 24 hours a day.
 A full fixed appliance can be placed at the same time as the Class II correction is
being carried out.
 Treatment time is short because of full time wear.
 There is no transitional phase between functional phase and the fixed phase so
treatment time reduced.
 Overlap of the functional and fixed phase further reduces treatment time.
 It is less bulky than other functional appliances.

115. Fixed version of RFA
JO March 2001
 Clip-on Fixed FA Occlusal blocks with lingual tube attachments
Inclined Planes
Occlusal blocks with palatal
tube attachments.

116. Disadvantages of the Appliance
 Breakage of the Appliance
 Construction of the Appliance
.
 Oral Hygiene Problems
 Airways Clearance
Clip-on Fixed Functional Appliance
The results showed that this appliance was effective in correcting
Class II malocclusion; the noncompliance rate was only 6%

117. Extra-oral force
Dento-facial orthopedics

118. Head Gears
 Orthopedic appliance that control growth of facial
structures
 Various designs.
 Used with growing patients.

119. USES OF HEAD GEAR
 CORRECTION OF SKELETAL CLASS II AND REDIRECTION OF GROWTH
;(excess growth of maxilla/deficient growth of mandible)
Head gear restrain the forward and downward growth of maxilla by holding
back the growth of upper jaw, allowing the lower jaw to catch up and thus
the correction of class II.
 MOLAR DISTILIZATION.
head gear may be used to distalize maxillary molar to correct the
class II molar relation ship or to gain space for relief of crowding.
 AS AN ANCHORAGE
In some situations ,to maintain the bite, the orthodontist will not
want the back teeth to come forward. The headgear serves to hold them
back to maintain anchorage.

120. USES OF HEAD GEAR
 REINFORCEMENT OF ANCHORAGE.
head gear can be used to reinforce anchorage in high
anchorage cases.
 MOLAR ROTATION.
can also be brought about with the inner bow of headgear.
 CORRECTION OF SKELETAL CLASS III.
(deficient growth of maxilla/excess growth of mandible).; by
protraction or reverse pull head gear that causes the
anterior displacement of maxilla.

121. CORRECTION OF SKELETAL CLASS II AND REDIRECTION OF GROWTH
;(excess growth of maxilla/deficient growth of mandible)

122. CORRECTION OF SKELETAL CLASS II AND REDIRECTION OF GROWTH
;(excess growth of maxilla/deficient growth of mandible)

123. CORRECTION OF SKELETAL CLASS III

124. TYPES OF HEAD GEAR
 High pull
 Cervical pull
 Combination pull
 Reverse pull
 Asymmetric Head Gear

125. TYPES OF HEAD GEAR

126. TYPES OF HEADGEAR
High pull Cervical Pull Combination Reverse pull
pull
Asymmetric
headgear

127. COMPONENTS PARTS OF HAEDGEAR
. Face bows;
( Inner and outer bow)
. Release modules
. Straps or cushions
. Other items.

128. FACE BOW STYLES.
 KLOEHN
Regular
Cushion Loop
 J-HOOK
 ASHER
 BITE PLATE

129. FACEBOW STYLES
Kloehn style
Bite plate
Cushion loop
Asher facebow
J -hook

130. BIOMECHANICS OF HEAD GEAR
 CENTER OF RESISTANCE OF MAXILLA AND MOLAR TOOTH.

131. BIOMECHANICS OF HEADGEAR
 The relation ship of line of action of force to the
center of resistance of maxilla or first molar
determines whether translation (bodily )or rotation
(tipping) takes place.
 When a force does not pass through the center of
resistance of the maxilla/molar, A moment is
produced.
 The direction of line of force can be changed by
adjusting the length and position of outer bow.

133. High Pull Head Gear
 Bodily movement of molar
(no tipping) when line of
force is passing through the
center of resistance of
molar.
 Both backward and upward
movement of molar.
 When line of force is above
CR --- mesial tip of crown and
distal tip of root.
 When line of force is below
CR --- mesial tip of root and
distal tip of crown.

134. Low Pull/Cervical Head Gear
 Bodily movement of molar (no
tipping) when line of force is
passing through the center of
resistance of molar, as determined
by the outer bow length and
position
 Both backward and downward
movements of molar.
 When line of force is above CR ---
mesial tip of crown and distal tip of
root.
 When line of force is below CR ---
mesial tip of root and distal tip
of crown.
 The outer bow is always longer
than that used in High pull.

135. BIOMECHANICS OF HEAD GEAR
 Similar considerations
apply to maxilla. Unless
the line of force is
through the center of
resistance, rotation of
maxilla occurs.
 Control of line of force is
easier when face bow
inserted into the splint
covering all teeth.
 With all teeth splinted; it
is possible to consider the
maxilla as a unit and to
relate the line of force to
the center of resistance of
maxilla.

136. RULE TO CHECK WHETHER THE LINE OF FORCE IS THROUGH THE
CENTER OF RESISTANCE IN HIGH PULL AND CERVICAL PULL
HEADGEAR
 In order to determine the proper position of
outer bow. Use index finger to apply
pressure in direction of head gear selected.
 A)In case of high pull headgear we move
index finger below the outer bow, pushing
up and back. As the finger is moved on the
outer bow applying force. The bow will move
up between the lips.
 B)In case of cervical pull headgear we move
index finger above the outer bow, pushing
down and back. As the finger is moved on
the outer bow applying force. The bow will
move down between the lips.

137. BIOMECHANICS OF HEADGEAR
 When the bow moves up, the roots of
maxillary first molar will move distally.
. When the bow moves down, the roots
of maxillary first molar will move
mesially and crown distally.
. When the bow does not move. The
force is through the center of
resistance of the maxillary first molar
and molar will move bodily and not
rotate.

138. BIOMECHANICS OF HEAD GEAR
 EFFECT OF THE LENGTH OF OUTER BOW.
 The longer outer bow bend up and shorter bow
bend down could produce the same line of force
through the center of resistance of molar.

139. High Pull Head Gear
 Derives anchorage from parietal region. It
produces intrusion and distalization of teeth.
 INDICATIONS.
 Open bite cases.
 High mandibular plane angle.
 Long face cases with an increase in lower
anterior facial height.
High pull headgear can be used as.
 HIGH PULL HEADGEAR TO MOLARS.
 HIGH PULL HEADGEAR TO MAXILLARY
SPLINT
 HIGH PULL HEADGEAR TO FUNCTIONAL
APPLIANCE.

140. CERVICAL HEAD GEAR
 The anchor unit in this head gear is
nape of neck. It causes extrusion
and distalization of molars along
with distal movement of maxilla.
Indications:
 short face,class II
 Anchorage conservation.
 early treatment of classII

141. Combination pull Headgear
 Derives anchorage from
at least two regions ; the
neck and occiput. It
causes distal and slight
superior force on maxilla
and dentition.

142. Protraction head gear.
 The rationale for protraction headgear is to apply heavy force
on the mid face in order to advance the maxilla anteriorly.
 In this type inner bow is bent to achieve distal insertion ,outer
bow is modified to make hook in premolar region for elastic
attachment.
 The center of resistance of mid face is difficult to locate but
most studies shows it 5-10mm below the orbit.

143. Protraction head gear.
 A line of force closer to
center of resistance of
mid face will deliver a
translatory force and
line of force closer to
occlusal plane has
rotational force.

144. Petit Face Mask
 For the protraction of
maxilla and maxillary
dentoalveolar segments.
 developing Class III
pattern.
 Cleft lip and palate
patients.
 Extra-oral elastics
(heavy)

145. Asymmetric head gear.
 Asymmetic force is
achieved with a head
gear by using an
asymmetric outer
bow,can be useful in
regaining bilateral but
asymmetric lost space.

146. Time, Duration and Force of Headgear
Therapy.
 FORCE. 500 TO 700gm(orthopedic )150-
200gm(orthodontic force).
 DURATION 12 -14hrs /Day, emphasis on wearing it from
early morning.
 Treatment Duration. 12 TO 18 Months.

147. TREATMENT EFFECTS
SKELETAL EFFECTS
 Frontomaxillary,zygomaticotemporal,zygomaticomaxil
lary n pterygopalatine r most imp growth sites for
development of maxilla.
 head gears act by compressing the sutures thus
restricting the normal downward n fowad growth of
maxilla.
DENTAL EFFECTS
 Distalization of molars.
 Extrusion and intrusion of molars

148. SIDE EFFECTS OF HEAD GEAR
 Compensatory erruption of max And mand molars but
can be controlled by fixed lingual arch.
 Distal tipping of max molars.
 Increased facial height.

149. SIDE EFFECTS OF HEAD GEAR