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2. Functional appliances has been widely used in Europe
for more than 60 years.
Today they are appropriately regarded as
biomechanical tools of dentofacial orthopedics.
According vig and vig (Ajo 1986) concepts such as
functional correction are expressed in an interesting but
scientifically fair Manner.
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3. It Implies an understanding of
Craniofacial Biology
The cause of malocclusion
The specific adaptation response to each named
appliances.
Clearly all appliances are capable of producing some
changes with proper diagnostic objectivity .
The clinician can take advantage of the best parts of the
appliance.
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4. Hybrid functional appliances are specifically and
individually designed to exploit the natural processes
of growth and development.
It determines the selection of the component and
their assemblies, resulting in appliance design that
matches the needs of individual patient.
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5. Modifications of activator
The bow activator of A.M. Schwarz:
The bow activator is a horizontally split activator having a maxillary
portion and a mandibular portion connected together by an elastic bow.
This kind of modification allows stepwise sagittal advancement of the
mandible by adjustment of the bow. In addition this design allows certain
amount of transverse mobility of the mandible.
The independent maxillary and the mandibular portions can have screw
incorporated to allow arch expansions.
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6. Wunderer’s modification:
used in treatment of Class III malocclusion.
This type of activator is characterized by maxillary and
mandibular portions connected by an anterior screw.
By opening the screw the maxillary portion is moved
anteriorly, with a reciprocal backward thrust on the
mandibular portion.
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7. The reduced activator of cybernator
of Schmuth:
This modification of the activator is proposed by
Professor G.P.F. Schmuth.
This appliance resembles a bionator with the
acrylic portion of the activator reduced from the
maxillary anterior area leaving a small flange of
acrylic on the palatal slopes.
The two halves may be connected by an omega
shaped palatal wire similar to bionator.
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8. The propulsor:
Designed by Muhlemann and refined by Hotz.
This appliance can be said to be a hybrid appliance
that combines the features of both the monobloc and
the oral screen.
The propulsor is devoid of any wire components and
consists of acrylic that covers the maxillary buccal
portion like an oral screen.
This acrylic portion extends into the inter occlusal
area and also as a lingual flange that helps position
the mandible forward.
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9. Cutout or palate free activator:
This is a modification proposed by Metzelder to combine
the advantages of bionator and the Andersen‟s activator.
The mandibular portion of the appliance resembles an
activator while the maxillary portion has acrylic covering
only the palatal aspect the buccal teeth and a small part of
the adjoining gingiva.
The palate thus remains free of acrylic thereby making
the appliance more convenient for patients to wear the
appliance for longer hours.
According to Dr Klaws Metzelder the appliance is
excellent in mandibular positioning in TMJ dysfunction
cases. www.indiandentalacademy.com
10. The Karwetzky modification:
This consists of maxillary and mandibular plates joined
by a „u‟ bow in the region of the first permanent molar.
The maxillary and mandibular plates not only cover the
lingual tissues and lingual aspects of teeth, it also extends
over the occlusal aspect of all teeth.
This type of activator allows stepwise advancement of
the mandible by adjustment of the U loop.
The U loop has a larger and a shorter arm. Based on
their placement pattern we can have three types of
Karwetzky activators.
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11. Type I: used in the treatment of Class II division I.here
the larger lower leg is placed posteriorly. Thus when the
two arms of the U bow are squeezed the lower plate moves
sagitally forwards.
Type II: This is used for the treatment of Class III
malocclusion. In this appliance the larger lower leg is
placed anteriorly. Thus when the U bow is squeezed
the mandibular plate moves distally.
Type III: They are used in bringing about asymmetric
advancement of the mandible. The U bow is attached
anteriorly on one side and posteriorly on the other side
to allow asymmetric sagital movement of the mandible.
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13. Herren’s modification of the activator
Herren modified the activator in 2 ways:
1. By over compensating the ventral position of the
mandible in the construction wax bite.
2. By seating the appliance firmly against the
maxillary dental arch by means of clasps
(arrowhead, triangular or Jackson‟s)
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14. The construction bite is taken in a strong mandibular
protrusion.
This advanced position of the mandible causes the
retractor muscles to try to bring the mandible back to
original position. This causes a backwardly directed force
on upper teeth and mesially directed force on lower teeth.
According to Herren, with every 1 mm increase of
forward position of the mandible, the sagittal force on the
jaws will increase by 100 gm. The amount of forward
positioning of the mandible is 3-4 mm beyond the neutral
occlusion i.e. in case of Class II molar relation the
mandible is brought forward to Class I molar plus an
additional 3-4 mm forward. A vertical opening of 2-4 mm
is recommended. www.indiandentalacademy.com
15. Vig designed an appliance for the treatment of patients with
the following problems
- sagittal mandibular deficiency
- Increase overjet and overbite
-Bilateral cross bite of mandibular posterior teeth.
-lack of space for eruption of second premolars
FRANKEL HYBRID APPLIANCE (AJO
1986)
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16. Components
•mandibular component has the features of frankle2
appliance (Lippads, Buccal shields, lingual pad with
wire resting on the Cingulum.
•Maxillary portion has a bilateral posterior bite – block.
Mode of action
•The maxillary bite blocks prevents vertical emption and
mesial and buccal movement of the upper posterior teeth.
• Lower buccal shields prevent processes from the buccal
musculature hence the lower posterior teeth can erupt
vertically and laterally under the influence of the tongue
pressure. www.indiandentalacademy.com
17. •Wires contacting the upper and lower lingual
prevents the further eruption of anterior teeth.
• The bite registration in taken with the mandible
in a forward position to correct the molar relation.
• The functional phase of treatment lasted for 10
months, which led to differential skeletal growth
and mandibular change that shortened the
treatment time of the fully banded appliances
considerably.
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20. Introduced by Neville Bass
Used – In growing patients with skeletal Class
II malocclusion to optimize facial appearence
and to rapidly and effectively correct the class
II dental relationship.
Mode of action of Bass appliance
- A well secured maxillary splint assures control
of the upper arch. The anterior torquing spring
prevents tipping and produces bodily movement of
the incisors.
THE BASS APPLIANCE SYSTEM (JCO 1987)
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21. -The maxillary arch is expanded with a
Jackscrew or spring to prevent cross bite and
allow more space for dental alignment.
- The lingual pads helps to hold the mandibular
incisors in a protrusive position, the pads are
progressively reactivated every 6-8 weeks as
the mandible develops forward.
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22. -A rigid face bow connected to a high full
headgear is used to retard maxillary growth and
control vertical development of the maxillary
dentition.
- Buccal screens are used to improve the soft tissue
environment of the developing dentition.
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23. Advantages
- Facial features are harmonized with good chin position.
- Balance and function of orofacial musculature is improved.
- Flattening of upper lip from retraction is avoided.
- The orthopedic phase last only 6-10 months.
-Speech quickly returns to normal ,there is no wire or acrylic
lingual to the lower incisors
-- There are little chances of breakage.
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24. --------------------------------
Fig. 4 A. Anterior torquing spring. B. Cross-section of
torquing spring. Stippled area is relieved to avoid soft tissue
swelling. Spring is lightly activated in palatal direction,
forming force couple between points x and x'. Small acrylic
ledge Is required at point x'. C. Class II elastics attached to
torquing spring. D. J-hook headgear attached to torquing
spring. E. Attaching extraoral traction anteriorly allows more
vertical pull and greater premaxillary control.
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25. .
Fig. 6 A. Housing
module with sliding
mechanism for lingual
pads and side screens.
B. Assembled module
(patents pending). C.
Module with preformed
side screen
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26. • Fig. 7 A. Top edge
of lingual pads lies
3mm below
gingival margin of
Iower bicuspids.
There is no contact
with mandibular
dentitlon. B. Pads
are reactivated
forward about every
seven weeks. Each
side is slid forward
about 2mm, and
lower Internal
sliding tube Is
gently squeezed
with small plier to
prevent retraction.
C. After four
activations.
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27. Fig. 8 A. Side screen on model. B. Prefabricated side screen.
C,D. Insertion of side screen. E. Inserting wire bent slightly
with triple beak plier for retention. (Custom screens are made
to lie 2-3mm away from teeth and soft tissue and do not need
adjustment.)
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28. Fig. 12 A. Maxillary splint replaced on models and waxed out
for addition of side screens and labial screen. B. Screens built
up In acrylic, wax boiled out, and appliance removed from
model.
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30. Fig. 14 Finished appliance. A. With mandibular pads
In place. B. With side screens. C. With lip screens. D.
Intraoral view.www.indiandentalacademy.com
31. Designed by – Mickey Judras.
Used – for treatment of Class II malocclusion in the
mixed dentition period.
Components
- Two molar bands with lingual attachments
- Connecting wire (0.040) from molar bands.
- Anterior bite plate.
- Incisal ramp
RICK – A – NATOR APPLIANCE
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32. The Rick – a – Nator in a very simple appliance which
consists for 2 molar bands, Ist molar bands attached to an
anterior bite plate.
Initially to encourage patient compliance, the
anterior bite plate is flat for one month.
- next month the anterior bite plate places the
incisor forword by the addition of an incisal
ramp.
- The incisal ramp encourages the mandible to
come forward which corrects the Class II molar
relationship to class I and eliminates the overjet.
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33. POSTERIOR BITE PLATE WITH HEADGEAR
Orton used posterior bite plate with headgear for the
correction of Class II malocclusion with anterior open
bite.
•The objective of this appliance is to intrude the upper
posterior segment by at least 2 mm, so as to cause auto
rotation of the mandible there by enabling, closure of the
anterior open bite and 5-6mm of reduction in overjet.
• Here only the teeth in occlusion are overlaid with
acrylic.
• The appliance is stabilized by Adam‟s clasp on the
upper permanent first molars and on Ist premolars.www.indiandentalacademy.com
34. -The palate is relieved so that full intrusion from
occlusal and headgear pressure is taken by the
posterior teeth.
- Another advantage is total freedom from spontaneous
vertical development of upper and lower buccal
segments there by reducing the anterior open bite.
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35. • ACTIVATOR HEADGEAR
TREATMENT
• Head gear and activator have both been used
effectively for the treatment of Class II
malocclusion.
• Hypothetically a simultaneous application of both
appliances may result in number of desirable
treatment effects greater than those induced by
each appliance.
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36. These changes believed to be are:
-Restraining the maxillary growth.
-Selective guidance of maxillary and mandibular
dentoalveolar development.
-Some influence on mandibular growth or position.
Indications
-Adolescent patients with class II div 2 Molars.
-Preferably well formed dental arches although an
abnormal arch shape or dental crowing in not necessarily
contra indicated.
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37. - Maxillary prognathism, mandibular retrognathism
and decrease or increase facial height as treated
differentially by varying the design and application
of the appliance.
-The cervical headgear is claimed to be the most
effective type of headgear for initiating an
orthopedic displacement of the maxilla.
-Pfeiefer and Grobiky (Ajo 1982) preferred the use
of cervical hedgear
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38. Uses of CERVICAL HEADGEAR
- Extrusion of maxillary molars
- Applying orthopedic traction to the maxilla.
The cervical headgear with a long outer bow is used. The
inner bow is inserted into buccal tube attached to the
maxillary Ist molar and the outer bow is adjusted to about 50
bellow the inner bow. This produces a predominantly distal
forces through the centre of resistance of the molar teeth and
lesser extrusive force component.
The Neck Strap produces a forces of approximately 400gms
measured unilaterally, the activator used is modified for use
with headgear applied to the maxillary Ist molars.
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39. -Patients instructed to wear the appliances for 14
continuous hours a day, patients are seen once every 6
weeks
-During treatment once a Class I molar occlusion has
been established this outer bow is raised above the inner
bow for uprighting the molars .
Teuscher (Ajo 1978)
Recommended the use of activator and high pull
headgear as means of inducing vertical land sagittal
maxillary displacement, achieving auto rotation and
increase forward displacement of the mandible
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41. Fig. 3 Patient with counterclockwise mandibular rotation. A.
Before treatment. B. After headgear activator treatment. C. Five
years later. D. Superimposition of pre-and post-treatment tracings.
E. Superimposition of post treatment and five year post-treatment
tracings.
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42. In The correction of large saggital discrepancies
between maxilla and mandible, the orthopedic effect of
treatment is often of small magnitude when compared
with the dentoalveolar changes.
A considerable amount of orthopedic improvement is
needed in patient with large saggital discrepancies
between the maxilla and the mandibular in order to
accomplish a stable, esthetically and functionally
satisfactory treatment result.
HEADGEAR – HERBST APPLIANCE
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43. The appliances is constructed with cast splint banded to the
lower arch and with bands on the upper perm Ist molar.
The bands were linked with a palatal bar and connected to
the lower splint with Herbst Teclescopic arms, constantly
keeping the mandible in a forward jump position.
Addition, a plate was constructed in the jaw as an anchorage
for a Headgear to be worn 12-14 a day.
Lenant (Ajo-1993) found that prolongd retention period of
over several years of activator wear was required.
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44. A. Before treatment.
B. B. Splints bonded to
teeth.
C. C. Herbst telescoping
arms for correction of
intermaxillary
relationship.
D. Headgear worn at
night.
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45. -Albort oven used the functional regulator with headger for
the treatment of vertical maxillary excess.
Long face syndrome is manifestated primarily by
excessive lower face height.
This may result due to a number of reasons.
- Clockwise rotation of the mandible
- High angle.
- Narrow arches.
- excessive exposure of maxillary teeth and gingiva.
- Open bite.
- Short ramus.
FUNCTIONAL REGULATOR WITH
HEADGEAR (Jco 85)
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46. The appliances consists of a regular headgear
tubes to accept a face bow of a high pull headgear. The
construction bite was 3-4mm protrusive, with 3-4mm
inter maxillary clearance in the molar area.
The appliance was worn 20 hours/day and the
headgear 12 hrs/ day, liplseal exercises are important for
proper lipseal, treatment usually lasted for19 months.
Treatment of results
Maxillary skeletal – no change
Maxillary dental – incisor tipped lingually
Mandibular dental – no change
Mandibular skeletal – chin moves forward.
Vertical – changed towards Brachy facialwww.indiandentalacademy.com
47. Fig. 2 A. Modified function regulator. B. Occlusal
view. C,D. Side views. E. With facebow attached.www.indiandentalacademy.com
48. Fig. 3 Bite block discourages eruption of posterior teethwww.indiandentalacademy.com
49. Fig. 4 High pull headgear holds or
intrudes posterior teeth.www.indiandentalacademy.com
50. Fig. 5 Case 1 before (top) and after
(bottom) treatment.www.indiandentalacademy.com
51. Robert Miller (1996) introduced this appliance
which reduces the number of moving parts that can lead
to breakage. It is easy to use and more comfortable for
the patient than the conventional cantilever type herbst.
Instead of a screw attachment, it has a ball joint
connector and it needs no retaining springs.
To place the appliance, the maxillary sleeve attachments
are fastened in a lock and key manner, after the crowns
are cemented . The rods must be long enough so that
they donot come out of the sleeves on maximum
opening. They have forked ends that are crimped into
the mandibular balls
FLIP LOCK HERBST APPLIANCE
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52. This appliance was designed to prevent accidental or
intentional removal by the patient as often happens due to
loose screws, but it can be removed at the chair with a
loop forming plier.
It is reactivatd every six to eight weeks using 1-3 mm
spilt bushing that are crimped on to the rods as needed.
The molar tubes can be attached for fixed
mehanotherapy.
The flip lock herbst can be combined with Jackscrew
appliance.
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54. Fig. 4 End of rod crimped onto
mandibular ball.www.indiandentalacademy.com
55. Fig. 5 Split bushings used for
reactivation.www.indiandentalacademy.com
56. Fig. 5 Split bushings used for
reactivation.
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57. Mandibular Advancement Locking Unit (MALU) The
MALU consists of two tubes, two plungers, two upper
“Mobee” hinges with brass pins, and two lower key hinges
with brass pins.
In the upper arch of the edgewise Herbst MALU
appliance, only the Ist molars are banded, with 0.051”
headgear tubes. A palatal arch can be used in cases of over
expansion.
In the lower arch, the Ist molars are banded and the
anterior segment is bonded from cuspid to cuspid with
0.22” brackets. The bicuspids may be left un – bracketed
to help in settling the occlusion.
MODIFIED EDGEWISE HERBST APPLIANCE
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58. Maxillary Malu attachment with copper pin opening. B. Mandibular
Malu attachment with archwire slot and copper pin opening.
Assembled Herbst with Malu attachments
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59. A 0.021” x 0.025” stainless steel archwire with slight
labial torque in the anterior segment, is bent back tightly at
the distal ends. Tipback bends mesial to the lower Ist
molars are helpful in controlling the incisors.
Each upper Mobee hinge is inserted into the hole at the
end of the MALU tube and secured to the Ist molar
headgar tube with the brass pin.
Each lower hinge is inserted into the hole at the end of the
plunger and locked to the each, distal to the cuspid, with
the brass pin.
the length of the tube plunger assembly is adjusted
according to the amount of mandibular protrusion needed.
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60. by Ralph M. Clements and Alex Jacobson.
The function of the MARS appliance is similar to that
of the Herbst appliance. in that the mandible is
maintained in a continuous protruded position via
compressive struts.
However there are several important differences
between the two appliances.
advantages
1. Requires neither soldering nor extensive laboratory
procedures.
2. Has minimal incidence of breakage.
THE MARS APPLIANCE
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61. 3. Does not depress the canines, open spaces in the
premolar area, or flare mandibular incisors
(provided the mandibular rectangular archwire is
tied back to the terminal molars).
4. Is easily attached to or removed form the arch wire
of a multi banded orthodontic appliance .
.
Appliance design
The MARS appliance is composed of a pair of
telescope struts, the ends are attached to the upper
and lower arch wires of a multibonded fixed
appliance by means of locking device
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62. Each strut is composed of two separate parts; a piston or
a plunger and a cylindrical or hollow tube.
These two components telescope together, forming an
individual strut.
The free ends of the plunger and the hollow tube (strut)
are attached to the upper and lower archwires by means
of a slot and screw arrangement, which locks them
securely in position on the arch wire.
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63. Fig. 2. Telescoping struts of MARS appliance.
Locking screw is illustrated in box at lower left-hand
corner of diagram.
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64. Fig. 3. Piston fitted to the cylinder of
a MARS appliance.
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65. Fig. 4. A, Jaws in closed Class II centric position.
B, Jaws protruded, condyle located toward crest
orarticular eminence. C, MARS appliance attached
to jaws in position. D, Jaw opening with appliance in
position.www.indiandentalacademy.com
66. The AVC consists of 2 posterior occlusal splints, one for
the upper and one for the lower jaw.
Samarium cobalt magnets are incorporated into the
occlusal splints over the occlusal region of the teeth to be
intruded.
One magnet per distal quadrant is used.
The magnets in the upper splints are incorporated in a
mode to repel the magnets in the lower splints.
Therefore the appliance is a combination of acrylic
posterior bite blocks and repelling magnetic forces.
ACTIVE VERTICAL CORRECTOR
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67. To prevent unwanted cross bite development due to the
shearing forces of repelling magnets ,angled buccal
flanges are added to the lower occlusal splints to stablize
the appliance during lateral jaw movements.
A heavy gauge stainless steel wire connects the occlusal
splint of each arch.
The magnets are cylindrical in shape with a diameter of
10mm.
The magnents along with bite blocks measures 12mm in
height.
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68. Because SmCo is a highly reactive rare earth material
they are best kept isolated from the oral environment.
Hence, they are sealed in stainless steel capsules.
If the anterior open bite is of skeletal origin than dental
origin, it is preferred.
Hence, patients in the growing age and in the mixed
dentition period are preferred to elicit maximum skeletal
response.
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69. When the posteriors are intruded , auto rotation of the
mandible take place and the mandible moves anteriorly
to close the open bite.
The AVC can be cemented or bonded.
At end of 12 weeks the appliance can be removed and
can be used as a removel appliance.
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70. Fig. 1. Example of the Active Vertical Corrector
(AVC). Occlusal and tooth contact views of
mandibular appliance (A) and maxillary appliance
(B).
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71. Fig. 2. Seated Active Vertical
Corrector (AVC).
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72. Fig. 3. The AVC intrudes posterior
teeth by reciprocal action as noted
by the arrows.www.indiandentalacademy.com
73. Fig. 4. Intrusion of posterior teath
results in closure of the open bite
and autorotation of the mandiblewww.indiandentalacademy.com
74. The inclined plane mechanism plays an important part in
determining the cuspal relationship of the teeth as they erupt
into occlusion.
Occlusal forces transmitted through the dentition provide a
constant proprioceptive stimulus to influence the rate of
growth and the trabecular structure of the supporting bone.
The muscles are the prime movers that modify the bone
growth to meet the demands of function via the
proprioceptive feedback mechanism.
When the appliance is removed at mealtime, the patient
reverts to functioning with the mandible in a retrusive
position.
TWIN BLOCK
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75. The strongest functional forces are applied to the dentition
during mastication and the proprioceptive functional
stimulus to growth is lost if the appliance is removed while
eating.
All the functional appliance that have evolved from the
monobloc share ,the limitation that the upper and lower
compartments are joined together. As a result, the patient
cannot eat, speak of function normally with the appliance.
Moreover, it is impossible for the patient to wear a single
piece appliance full time.
But the Twin Block appliance designed by William Clark
(1989) can be worn for full time and it overcomes all the
disadvantages of the other functional appliances.www.indiandentalacademy.com
76. Bite Registration
In class II division I, a protrusive bite is
registered to reduce the overjet and the disto –
occlusion on average by 5-10 mm.
The length of the patient’s protrusive path is
determined by recording the overjet in centric
occlusion and fully protrusive occlusion.
The activation should not exceed 70% of the
protrusive path.
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77. If there is an overjet of upto 10mm , the bite may be
activated edge to edge on the incisors with a 2mm inter
incisal clearance. This allows an overjet of upto 10mm to
be corrected on the first activation, without further
activation of the Twin Blocks.
Larger overjet invariably require partial correction
, followed by reactivation after the initial correction is
complete.
Because the young patients commonly have a protrusive
path of 13 mm and will tolerate activation upto 10 mm.
Beyond this range the muscles and ligament cannot adapt
to altered function.
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78. In the vertical dimension, a 2 mm inter incisal clearance is
equivalent to an approximately 5 or 6 mm clearance in the I
premolar region.
This usually leaves 3 mm clearance distally in the molar
region and ensures that the space is available for vertical
development of posteriors to reduce the overbite.
It is very important to open the bite slightly beyond the
clearance of the freeway space to encourage the patient to
close into the appliance, rather than to allow the mandible
to drop out of contact into rest position, which is one of the
disadvantages of making the blocks to thin.
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79. The earliest Twin Blocks were designed with the
following basc components;
1. A midline screw to expand the upper arch.
2. Occlusal bite blocks
3. delta Clasps on upper molars and premolars
4. Delta clasps on lower premolars (it is similar
to the Adam‟s clasp in principle ,but incorporates
new features to improve retention, reduce metal
fatigue and minimize the need for adjustment)
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80. 5. Ball end clasps on lower incisors (originally it was
given on lower incisors, but it can be given only on the
lower canines mesially, in mixed dention, “C” clasps
can be given on all deciduous molars)
6. Labial bow. (It should be passive. If retraction of
upper incisors is done prematurely, it limits the scope
for functional crrection for mandibular advancement.
Later the design was changed from labial bow to ball
end clasps – in between upper canine and premolars.
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81. Occlusal inclined plane
The inclined plane on the lower bite block is angled from
the mesial surface of the II premolars or deciduous molars
at 700 to the occlusal plane.
In most cases, the inclined planes are angled at 700 to the
occlusal plane although the angulation may be reduced to
450 if the patient fails to posture forward consistently and
thereby to occlude the blocks correctly, to the marginal
ridge on the lower II premolar or deciduous molar.
The upper inclined plane is angled from the mesial
surface of the upper II premolar to the mesial surface
of the upper I molarwww.indiandentalacademy.com
82. Clinical management
The twin block treatment is described in two stages:
1. Active phase – the sagittal correction is achieved
before vertical development of the posteriors is
complete.
Rapid soft tissue changes occur during this phase. The
changes in the muscle activity has been described by
McNamara as the “pterygoid Response” which results
from altered activity of the medial head of the Lateral
Pterygoid muscle in response to mandibular protrusion.
During this phase, selective grinding of the upper bite
blocks occluso-distally for allowing supra-eruption of
posteriors is important in management of deep bite
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83. 2. Supportive phase – the aim of the 2nd stage is to
retain the corrected incisor relationship until the buccal
segment occlusion is fully established. The upper
inclined guide plane is only placed and fixed appliance
can be initiated.
If the direction of growth is vertical rather than
horizontal, the mandible may be advanced more
gradually to allow adequate time for compensatory
mandibular growth to occur.
Phased activation is recommended in adult tratment,
where the muscles and ligaments are less responsive to
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84. The Concorde Facebow
When the response to functional correction is poor, the
addition of orthopedic traction force may be considered. The
indications are confined to a minority of cases with growth
patterns where maxillary retraction is the treatment of choice.
For example
1. In the treatment of serve maxillary protrusion
2. To control a vertical growth pattern by the addition of vertical
traction to intrude the upper posteriors.
3. In adult treatment where mandibular growth cannot assist the
correction of a severe malocclusion.
A method was developed to combined extra oral and inter
maxillary traction adding a labial hook to a conventional face bow and
extending elastic, back to be attached to the lower appliance in the
incisor region.
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85. Magnetic Twin Block
Dr. William J. Clark has modified Twin Blocks
by the addition of attracting magnets to occlusal
inclined planes, using magnetic force as an activation
mechanism to maximize the orthopedic response to
treatment.
Attracting magnets
The increased activation can be built into the
initial construction bite for the appliances. The
attracting magnetic force pulls the appliance together
and encourages the patient to occlude actively and
consistently in a forward position.
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86. Repelling Magnets
It may be used with less mechanical built into the
occlusal inclined planes. It is intended to apply
additional stimulus to forward posture as the
patient closes into occlusion.
Indication for Magnetic Twin Blocks:
1. The patient with weak musculature fails to
respond to functional therapy
2. Used only where speed of treatment is an
important considerations.
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87. Fig. 1. Twin blocks appliance design. A, Anterior and lateral views show the
following components. Upper appliance: (1) labial bow (0.8 mm) from mesial
, (2) clasps (0.8 mm) incorporating coils to accommodate the Concorde face-
bow, and (3) occlusal inclined planes occlude at a 45° angle in region. Lower
appliance: (1) ball-ended interdental clasps (1.0 mm) in region, (2) delta clasps
(0.8 mm) on (the delta clasp, designed by the author, gives excellent retention on
lower premolars and requires minimal adjustment), and (3) inclined planes in
region. B, Occlusal views. The upper appliance has a midline screw for
compensatory lateral expansion. Where necessary, a midline screw or recurved
lingual bow (as in a Jackson appliance) can be included in the lower appliance.
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88. Fig. 1 (Cont'd). C, The Concorde face-bow effectively combines extraoral
and intermaxillary traction in the treatment of severe skeletal
discrepancies. A recurved labial hook is added to a conventional face-
bow. Outer bow is 1.5 mm; inner bow is 1.13 mm reinforced with tubing;
labial hook is 1.13 mm.
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89. D, Intraoral views showing twin blocks in open and
closed positions. The Concorde face-bow is
illustrated with detail of the recurved labial hook and
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90. Carlos M.C. Filho (1995) introduced the Mandibular
protraction appliance for the treatment of Class II
malocclusion.
It is a cost efficient appliance in case of fabrication
and rapid installation, with infrequent breakage.
It is also comfortable to the patient.
Mandibular protraction appliance
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91. Mandibular Protraction Appliance No. 1
Fabrication
Mandibular Protraction
Appliance with stops placed in
mandibular archwire distal to
cuspids
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92. Small loop bent at right angle to end of
.032" stainless steel wire.
Appliance length measured from
mesial of maxillary tube to
mandibular archwire stop with
mandible in proper protruded
position.
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93. Small right-angle loop bent in opposite
direction into other end of .032" stainless
steel wire
Circles closed with plier after appliance placement.
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94. A. Appliance slides distally along mandibular archwire and
mesially along maxillary archwire upon opening. B. Buccal
offset in lower archwire to allow clearance for sliding
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95. Mandibular Protraction Appliance No. 2
MPA No. 2 made with right-angle
circles in two pieces of .032" stainless
steel wire.
Coil of .024" stainless steel wire
slipped over one wire.
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96. One end of each wire inserted through
other wire's loop
Travel of each wire limited by wire coil.
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97. Improper relationship of wires is
prevented by coil
Maxillary archwire has occlusally
directed circles against molar
tubes; mandibular archwire has
occlusal circles 2-3mm distal to
each cuspid.www.indiandentalacademy.com
98. Measurement between mesial surface of
maxillary molar tube and mandibular
circle.
Appliance length transferred to wire
assembly; attachment loops bent in wire
ends for maxillary and mandibular occlusal
circles.
Attachment loops inserted into archwire
circles and squeezed closed.
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99. Mpa-3
Problems of breakage, restricted opening, and patient discomfort
associated with the MPA No. 1 and the difficulty of chairside
construction of the MPA No. 2 have discouraged many
orthodontists from using these appliances.
Many of the limitations of the first two MPA designs
have been overcome with the development of the MPA No. 3.
This version eliminates much of the archwire stress and permits
a greater range of jaw motion while keeping the mandible in a
protruded position.
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101. John Devincenzo (1997) designed this appliance. The
forerunner to this spring was a system devised by Northcutt
(1974).
The device incorporates significant changes to the
Northcutt‟s design including triple telescoping action,
flexible ball and socket attachment, a completely encased
spring that remains intact even if the device becomes
disengaged, and a shaft for guiding the spring.
The main component of the spring is an open wound coil
spring encased in a plunger assembly.
The ram is made from a special work hardened SS wire that
has been precision machined with three different radii.
EUREKA SPRING
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102. At the attachment end ,the Ram has either a closed or an open
ring clamp that attaches directly to the arch wire.
The plunger has a tolerance of 0.002 inch within the cylinder.
A triple telescoping action permits the mouth to open as wide as
60mm before the plunger becomes disengaged, even if it
disengages it can be reassembled easily.
The cylinder assembly is connected to a molar tube with 0.032
inch wire that has been annealed at the anterior end.
A 0.036 inch solid ball at the posterior end acts as a universal
joint permitting lateral and vertical movements of the cylinder.
The spring is within 1.5mm of full compression.
The force of the open wound spring is linear throughout the
length of the Ram thrust and is 16.6 gm for every mm of Ram
compression.
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103. The maxillary molar crowns rolls buccally and intrudes while
the mandibular anteriors intrude and the cuspid crowns tend to
move lingually.
Since there is no tendency for extrusion of lower molars as in
the Class II elastics, downward and backward mandibular
rotation and elaboration of the face anteriorly will be minimal.
Since the Eureka spring intrudes the lower anteriors, over bite
correction reduces, more by leveling the occlusal plane than
by the downwrd and backward mandibular rotation.
Thus the spring tends to create the combination of forces ideal
for improving facial form in most Class II malocclusion.
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104. However these same forces work against facial form
improvement during the correction of Class III problems.
Hence the force will have a tendency to intrude the
maxillary anteriors and depress the mandibular molars.
Thus there will be a tendency towards development of
anterior open bite as the maxillary anteriors are pushed
forward and upward.
The mandibular molar crown will tend to roll bucally
producing an increase in intra molar distance.
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105. This may increase the tendency for a posterior cross bite.
Additional downward and backward mandibular
rotation, which is frequently desirable, will not occur.
Do not expect any orthopedic effect from the Eureka
springs.
All correction is entirely dentoalveolar.
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107. It can be used in all phases of treatment in the mixed or
permanent dentition and with removable or fixed appliance.
Like other mandibular protrusion appliances, the UBJ uses a
telescopic mechanism, an active coil spring can be added if
necessary. It can be used in Class II and III cases.
the UBJ is attached to the maxillary Headgear tube with a
ball pin. In the mandibular arch ,the sliding rods end in a 900
hook that is fixed to the each wire.
Lower cantilever type of UBJ is also available when used
with removable acrylic splints; two lateral UBJs link the
maxillary molar areas and the mandibular Ist premolar areas.
THE UNIVERSAL BITE JUMPER
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108. They are attached to 1.2-mm ball clasps, which are
constructed on the working cast and then incorporated into
the thermoformed splints.
The lower loop of the UBJ should be oriented in an
anteroposterior direction.
Re- activation is made every 6-8 weeks by crimping 2-4mm
splint bushing on to the rods.
UBJ with NiTi coil springs do not need to be activated.
Adjusting one side or the other of the appliance can easily
treat midline or asymmetrical problems.
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110. The disadvantages of the Herbst appliance are the
rigidity of the Herbst bite jumping mechanism itself.
Although every attempt is made to allow freedom of
movement of enlarging the attachment holes of the tube and
plunger to the axles, the bite jumping mechanism restricts
lateral movements of the mandible.
In an attempt to overcome these problems, Jasper
developed a new pushing device that is flexible. This
appliance produces both sagittal and intrusive forces, and
affords the patient much freedom of mandibular movement.
The jasper jumper can be attached to most of the commonly
used fixed appliances .
JASPER JUMPER
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111. The system is composed of 2 parts –the force module and
anchor units
Force module
The force module, analogous to the tube and plunger parts
of the Herbst, is constructed by a stainless steel coil 0r
spring that is attached at both ends to stainless steel end
caps, in which holes have been drilled in the flanges to
accommodate the anchoring unit.
This module is surrounded by opaque polyurethane
covering for hygiene and comfort.
The modules are available in seven lengths, ranging from
26mm –38mm.
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112. They are designed for use on either side of the dental arch.
When the force module is straight it remains passive, as the
teeth come into occlusion the spring of the force module
curves axially.
As the muscle of mastication elevate the mandible
producing a range of forces from 1 to 16 ounces, this
kinetic energy is then captured when the force module is
curved.
This force is converted into potential energy to be used for
a variety of clinical effects.
If properly installed to produce mandibular
advancement, the spring mechanism will be curved or
activated 4mm relative to its resting length, thus storing
about 8 ounces (250gm) of potential energy for force
delivery.
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113. If less force is desired the jumper is not fully activated.
Increasing the activation beyond 4mm does not yield
more force from the module, but only guilds excessive
internal stress in the module.
The tendency to increase the force for faster treatment
results is to be avoided.
To determine the proper length of the module measure
from the mesial of upper I molar buccal tube to distal of
lower lexan ball.
Adding 12mm to this measurement will give the
appropriate length of the module.
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114. If the Class II molar relationship is not corrected
completely by the initial activation, the module should
be re-activated after 2-3 months.
The modular system is activated by shortening the
attachment to the maxillary I molar.
The pin extending through the force bow tube is pulled
anteriorly I to 2mm on each side to re-activate.
Activation of the force module can also be made
through adjustments in the lower arch by crimpable
stops (1-2mm) placed mesial to the Lexan ball.
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116. The Churro Jumper is effective and
inexpensive, alternative force system for the antero –
posterior correction of class II and III malocclusions.
Although the Chrro Jumper was conceived as an
improvement to the MPA, it functions more like the
Jasper Jumper.
It is secured by bending the pin down on the mesial end
of the tube.
THE CHURRO JUMPER
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119. The Churro Jumper has several disadvantages that
sometimes limit its usefulness:
The restriction of mouth opening to 30-40mm is intolerable
for some patients.
Archwire breakage is common if larger wires are not used.
Patients with a low tolerance for discomfort will often break
the appliance (as well as the spirit of the orthodontist).
Presently, it must be manufactured in the office.
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120. ADVANTAGES
It provides a constant force.
It can be used either unilaterally or bilaterally
.
It can be used to correct Class II or Class III malocclusions.
Very inexpensive
It can be constructed from commonly available materials
universal in size
When broken, it is easily and inexpensively removed and
replaced.
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121. SEVERAL ADJUSTABLE INTER
MAXILLARY FORCE SPRING (SALF Spring )
SAIF spring is a fixed force system, which are available in
either 7mm or 10mm lengths.
The 10mm spring, extended from the 2nd molar to the
cuspid, provides the optimal horizontal force for antero –
posterior correction.
Placement of right and left springs takes about 5 minutes.
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122. 1. during mixed dentition treatment, while using a
functional utility arch wire, simply crimp a hook onto
the anterior vertical leg of the wire. With full fixed
appliances, make an offset bend in the maxillary arch
wire, between the cuspid and the lateral
incisor, where the hook is to be placed. This will
prevent the crimpable hook from sliding on the arch
wire and opening spaces.
2. offset the eyelet end of the spring so that it cant slip
easily over the molar hook.
3. close the molar hook so that the eyelet will not slip
off.
The procedure is an follows:
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123. 4. activate the spring 2-3mm and cut off the excess
leader coil.
5. after attaching the leader over the anterior hook, close
both the leader and the hook so that they will not come
apart.
(Ajo 1997, Austria) Weiland et al did a study to see the
initial effects of treatment of Class II malocclusion
with the Herren Activator, activator headgear
combination, and Jasper, Jumper.
They found that -
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124. The correction of molar relationship and overjet was
more complete in patients with Jasper – Jamper than
in patient with the activator.
- Skeletal changes, that accounted for overjet
correction by the Herren type activator was 42%.
By Headgear activator was 35% and by Jasper
Jumper was 48%.
- The correction of molar relationship occurred to
55%, 46% and 38% respectively.
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125. Ajo (1989) – Poncherz et al, did a study to compare the
class II correction in bass and Herbst therapy.
He found that, after 6 months of treatment with bass
appliance secured to have greater influence on
mandibular jaw base position than the herbst appliance.
But the correction in overjet and saggital molar
relationship was more complete in Herbst than in Bass
patients.
This was due to more dental changes taking place in the
Herbst subjects.
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126. CONCLUSION
• Fixed functional appliances form an useful
addition to the clinician‟s orthodontic
armamentarium. But many of these appliances
need further studies to substantiate the claims
made by their respective originators. With this in
mind, clinicians must take great care in selecting
the right patient and also pay attention to every
detail in the manipulation to attain successful
results with these appliances
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127. For more details please visit
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