This document discusses various methods and appliances for distalizing maxillary molars, including removable and fixed options. Removable appliances discussed include extraoral traction using headgear as well as removable appliances with finger springs or sliding jigs. Fixed appliances discussed include intramaxillary devices like Wilson's 3D appliance as well as intermaxillary appliances like Herbst or Jasper Jumper. Factors like the presence of second molars, skeletal pattern, and growth prognosis must be considered when determining whether molar distalization is indicated.

1. Molar
distalization –
current trends
Dr Tony Pious

2.  Current orthodontic philosophies have been oriented toward
conservative treatment modalities to avoid extractions and, at
the same time, to try to eliminate the need for patient
cooperation; consequently, there are many devices for
gaining space, particularly for the distalization of the maxillary
molars.

3.  The appliances used for molar distalization can be divided into
 Removable appliances and
 Fixed appliances.
Removable appliances are:
 Extra oral traction
 Removable appliances with finger springs
 Sliding jigs with intermaxillary elastics.

4. The fixed appliances are
A. Intramaxillary appliance
1. Wislons 3D appliance
2. Repelling Magnets
3.The pendulum appliance
4. Niti based appliances : archwires – single loop,
double loop; Compressed coil springs
5. Jones jig
6. Distal Jet
7. Fixed piston appliances
8. IBMD 9. K-loop 10. Distalix
11.Franzulum appliance 12. Lokar appliance
13. First class appliance 14. Carriere’s Distalizer

5. B. Intermaxillary appliance:
1. Herbst appliance
2. Jasper Jumper
3. Eureka Spring
4. Klapper superspring
C. SAS supported distalization:

6. DISTALIZATION DIAGNOSIS
 The first step is to confirm the diagnosis of a forward maxillary
molar position.
 1. Check the centric relation position (and vertical status).
Before considering the molar relationship in terms of dental or
skeletal malocclusion, it is desirable to check the TMJ status.
All records must be correlated, ie, cephalo-metrics, functional
axiographics, and radiologic exams (MRI, CT scan).

7.  Korn has cautioned against
using extraoral force in
patients with undiagnosed
meniscus disorders who are
borderline clickers with an
"end-on click.
 a. Korn has shown that the
distalization may push back
the maxillary molar ----
 b. causing more posterior
tooth contacts and then
moving the condyle
backward into a more
posterior position, now with a
"true click”.
 c. The mandible then
assumes its normal position,
but the meniscus is now too
far forward.

8.  2. Check the sagittal relationship.
(1) The pterygoid vertical plane (PTV)/maxillary molar
relationship and
(2) the convexity prognosis.
 According to Ricketts, the normal maxillary molar (M1)
position is given by the distal face of the molar to the
PTV. The clinical norm is age + 3 mm, and clinical
deviation is 3 mm.
 In good skeletal and dental Class I relationships, the
facial axis normally crosses the mesial cusp of M1.
 However, the maxillary molar analysis must not be
static only, but also dynamic. If the distance M1/PTV is
shorter than the normal measurement, the possibility for
distalization is low and possible extractions will depend
on growth potential and the presence of 3rd
molar.
 Therefore, posterior dental arch analysis must include
mesiodistal measurement of all molars to determine the
posterior space available at maturity

9.  To determine a positive convexity, differentiation must
be made between a forward maxilla and a backward
mandible.
 Patient age must be considered, to determine what
the positive convexity will be with time and growth.
 For example, a +4 mm convexity at 8 years of age
could be completely different at maturity, according
to the facial pattern.
 In some borderline clinical situations, the long-range
growth forecast could be useful. This might permit the
clinician to know if extraoral force and/or distalization
are indicated.
1.Brachyfacial
2.Mesofacial
3.Dolichofacial

10. DISTALIZATION INDICATION
 In the growing patient, only the growth
prognosis scientifically reveals the indication
for distalization. When a young patient has a
Class II maxillary molar relationship with a
forward maxilla, the molar relationship could
worsen, remain the same, or improve,
depending on mandibular growth.
 The best way to determine the indication for
distalization is to conduct a Ricketts long-
range growth forecast, from the original
profile tracing. The new convexity and molar
relationship can then be observed.

11.  Define the treatment
objectives to construct a long-
term VTO, according to the
following procedure:
 1. Draw the mandibular arch
with the estimated position of
the mandibular incisor and the
mandibular molar position
according to the dental arch
analysis.
 2. Place the maxillary molar in
a corrected Class I on the
VTO, because this is the
eventual therapeutic goal.
 3. Do the S3 Ricketts
superimposition; superimpose
the VTO tracing on the original
tracing, on the palatal plane
with registered anterior nasal
spine

12.  4. Determine the necessary
therapeutic molar movement
needed to obtain the correction
:
 (1) If the maxillary molar moves
downward, but does not go
forward, distalization would not
be recommended
 (2) If the maxillary molar
naturally moves x millimeters
forward, distalization would not
be useful
 (3) If the maxillary molar needs
a back-ward movement of x
mm to finish in a Class I
relationship at the end of
growth, then distalization would
be strongly indicated.

13. INDICATIONS & CONTRAINDICATIONS
THE INDICATIONS FOR MOLAR DISTALIZATION
 1. In non-extraction treatment of Class II
malocclusion cases.
 2. In low & average mandibular plane angle
cases.
 3. In class I skeletal pattern cases.
 4. In patients with mild arch length discrepancy.
 5. In cases where the upper permanent molars
have moved mesially due to early loss of
deciduous molars.
 6. In patients where the second molars
extractions are planned or where it has not yet
erupted.
 7. In second molar extraction cases where the
third molars are well formed and erupting
properly.

14. CONTRAINDICATIONS FOR MOLAR DISTALIZATION
 In high mandibular plane angle cases.
 Skeletal and Dental open bite
 Class II & III skeletal pattern
 Severe arch length discrepancy patients.

15. INFLUENCE OF 2ND
MOLAR ON DISTALIZATION OF 1ST
MOLAR
 A controversy exists concerning the influence of second
molars on the distal movement of the first molars.
 Graber noted that extraoral traction on the first molars,
when the second molars have not totally erupted, led to
distal tipping only and not to bodily distal movement.
Bondemark et al (AO 94 Magnets vs NiTi coils) stated
that the presence of second molars did influence
tipping and distal movement of the first molars.
 Gianelly (AJO 91 NiTi coils) also found that treatment
time was increased with the presence of second molars.
 Muse et al (AJO 93 Wilsons BDA) found that the
presence of maxillary second molars did not correlate
with the rate of maxillary first molar movement or with
the amount of tipping that occurred.

16. Studies on Pendulum Appliance
 The findings of the Byloff’s study (AO 1997)
were similar to those of Muse et al i.e. no
statistically significant differences in linear or
angular changes were found among three
groups of eruption stages of second molars.
 According to studies by Bussick and
McNamara (AJO 2000March); Ghosh and
Nanda (AJO 96); and Joseph and Butchart
(Seminars in Orthod 2000) the position of the
2nd
molar when distalizing the first molar with a
pendulum appliance is of little if any
importance

17. Kinzinger et al (AJO 2004 Jan) used modified pendulum appliance
for bilateral maxillary molar distalization in 36 adolescent patients
in various stages of the molar dentition.
 In PG 1, eruption of the second molars had either not yet taken
place or was not complete.
 In PG 2, the second molars had already developed as far as the
occlusal plane, with the third molars at the budding stage.
 In PG 3, germectomy of the wisdom teeth had been carried out
and the first and second molars on both sides had completely
erupted.
 Analysis of cephalograms to identify any changes in the sagittal
plane showed that, in the direction of distalization, a tooth bud
acts on the mesial neighboring tooth like a fulcrum.
PG1 PG2 PG3

18.  The degree of distal tipping of first molars was less in
patients with erupted second molars (PG 2 and PG 3)
than in those whose second molars were not yet
erupted (PG 1).
 Tipping of erupted second molars was much more
marked in PG 2 but much less pronounced in PG 3
than the corresponding movement of the second
budding-stage molars in PG 1.
 In PG3 almost exclusively bodily distalization of both
molars is possible, even without bands being applied
to the second molars.
 However, if the first and second molars are distalized
simultaneously with a pendulum appliance, the
duration of therapy will be longer, greater forces will
have to be applied, and more anchorage will be lost.

19. REMOVABLE APPLIANCES ARE :
 EXTRA ORAL FORCES
 REMOVABLE APPLIANCES
 THE CETLIN APPLIANCE
 EXTRA ORAL FORCES
 One of the earliest methods of molar
distalization introduced and proved to be
effective was by extra oral forces
employing use of the head gear.
Components of Head Gear:
 Force delivering Unit:
 Force Generating Unit.
 The Anchor Unit:

20. SELECTION OF HEADGEAR:
 1. Headgear anchorage location: location of the anchorage
unit determines the type of force that will be applied to the
unit. The relation of the force to the Cres of the unit to which it
is applied determines the effects that will be produced by the
orthopedic force.
 High pull headgear: this applies a superior (intrusive) and
distal force to the maxilla and the maxillary dentition.
 Cervical pull: this produces an inferior (extrusive) and
distalising force on the maxilla.
 Combination headgear: no moment is produced
and a distalising force is applied to the maxilla.
 Since the Cres of the molar is located in the mid root region,
force vectors above this point will result in a distal root
movement. Forces below this point will result in a distal crown
movement. Similar considerations apply to the maxilla.

21. TYPES OF HEADGEARS:
CERVICAL HEADGEAR:
 This was first introduced by
SILAS KLOEHN in 1947. It is
the most commonly used
facebow in clinical
practice. Typically it is used
in growing patients with
decreased vertical
dimension. The purpose of
the facebow is to restrict
the forward growth of the
maxilla. The vector of force
is below the occlusal plane
producing both extrusive
and distalising effects.

22.  Effects of cervical headgear:
 to erupt the entire upper jaw
 tends to move the upper jaw
distally
 Steepen the occlusal plane.
 Expansion of the upper arch.Effect of different positions of the outer bow:Effect of different positions of the outer bow:
when the outer bow is bent upwardswhen the outer bow is bent upwards::
The forces that are produced areThe forces that are produced are
A distalising force to the upper teeth, which is good for correctionA distalising force to the upper teeth, which is good for correction
of class II relation.of class II relation.
When the outer bow is bent upwards, bringing it down to theWhen the outer bow is bent upwards, bringing it down to the
occlusal plane tends to produce a negative moment that flattens theocclusal plane tends to produce a negative moment that flattens the
occlusal plane. Hence the steepening effect of the cervical headgearocclusal plane. Hence the steepening effect of the cervical headgear
is nullified.is nullified.
Eruption of the entire upper arch tends to increase the mandibularEruption of the entire upper arch tends to increase the mandibular
plane angle and tends to worsen the class II skeletal relationship.plane angle and tends to worsen the class II skeletal relationship.
this type is good for patients with forward growth rotationthis type is good for patients with forward growth rotation

23. when the outer bow is bent
downwards:
 Forces that are produced are
 Positive moment on the occlusal
plane is seen that tends to
steepen the occlusal plane since
the pull is below the Cres.
 Extrusive force and a distalising
force.
 When the outer bow and inner
bow are in the same level, no
moment is produced and there
is a net distalising and extrusive
force.
When theWhen the outer bow is shorterouter bow is shorter than the inner bow, the headgear strapthan the inner bow, the headgear strap
hook is placed too far anteriorly. This results in a greater tendency tohook is placed too far anteriorly. This results in a greater tendency to
steepen the occlusal plane when the straps are engaged. The pull of thesteepen the occlusal plane when the straps are engaged. The pull of the
bow is further forward from the Cres and this tends to steepen thebow is further forward from the Cres and this tends to steepen the
occlusal plane. When theocclusal plane. When the outer bow is longouter bow is long, there is a tendency to, there is a tendency to
flatten the occlusal plane.flatten the occlusal plane.

24. Advantages
 Direction of pull is advantageous in
treatment of short face class II maxillary
protrusive cases with low MPA and deep
bites.
Disadvantages:
 It normally causes extrusion of the upper
molars. This movement is seldom desirable
except in patients with reduced lower
anterior facial height. It is contraindicated in
patients with steep mandibular planes and in
open bite cases.

25. Long term study on cervical headgear:
Melsen et al in AJO 2003 studied the
intramaxillary molar displacement 7 years after
treatment with Kloehn headgear and cervical
traction. Two groups of 10 patients were studied.
In one group, the outer bow was tilted upward
by 200
and in another group, it was tilted down
by 200
. In the group that had the outer bow
tilted downwards, molar correction was faster. In
both the groups, the maxilla was moved
backward and downward. A strong tendency
of the molars to return to the key ridge was
demonstrated, and there was no evidence that
the Class I relationship obtained by extraoral
traction was more stable than that obtained by
functional or intramaxillary appliances.

26. OCCIPITAL HEADGEAR:
 The occipital headgear consists of a
facebow which fits over the occiput of
the head. The force generated by a
high pull (occipital) has both distalising
and intrusive forces since the force is
exerted above the occlusal plane.
Such forces are used in conditions
where vertical control of the molars is
important. As growth guiding
appliance, a high pull headgear can
decrease the vertical development of
the maxilla, thereby allowing for
autorotation of the mandible and
maximizing the horizontal expression of
mandibular growth.
Occipital pull with short outer bow (force anterior to Cres)Occipital pull with short outer bow (force anterior to Cres)
This results in a force system at the unit’s Cres with a moment thatThis results in a force system at the unit’s Cres with a moment that
tends to flatten the occlusal plane and creates distalising and intrusivetends to flatten the occlusal plane and creates distalising and intrusive
components.components.

27. b. occipital pull with force
passing through Cres
 There is no moment that is
created and hence there is
no change in the cant of the
occlusal plane. Intrusive and
distal components of force
are produced.
c. occipital pull with long outer
bow( force posterior to Cres)
 The force system at the unit’s
Cres has a moment that
tends to steepen the occlusal
plane. Intrusive and distalising
forces are produced. This
system might be required in
class II open bite patients.

28. Advantages:
 These headgears can be used in patients with steep
mandibular planes and in cases wherein mandibular growth is
more vertical than horizontal. They can also be used in certain
open bite cases caused due to excessive eruption of buccal
teeth.

29. COMBINATION HEADGEAR.
Combination headgears have both
occipital and cervical traction springs.
This is perhaps the most versatile type
because the pull can be readily
controlled by selecting the force level
of the springs and by controlling the
length of the outer bow. For distal
translation of the upper posteriors, a
distal traction is needed that passes
through the Cres, neither above nor
below. The combination type
headgear will allow a distal force
straight through Cres by having equal
occipital and cervical components on
the outer bow, which is angled
upwards to allow the force to pass
through the Cres.

30. Based on occlusal plane requirements:
Action desired Outer bow angulation
 distal force and flattening - outer bow above
Cres
 distal force and steepening - outer bow below
Cres
 distal force and no moment-- outer bow at Cres

31. REMOVABLE APPLIANCES
 Alain (JCO 1972) explained the use of a removable
appliance for distalizing the molars. The appliance was
originally devised by G.Vienne and later produced by
A.Lorette.
 The appliances were introduced as the appliances with
wires sliding in tubes.
THE PRINCIPLE
 The appliance consists of a stationary part and a movable
part. Both these parts are held together by a long,
horseshoe shaped wire which moves the movable part by
virtue of the elasticity of the wire. Each end of the wire is
inserted into a tube, one in the fixed part of the appliance
and the other inthe removable part.

32. THE APPLIANCE
 The movable part has an adams clasp and two
parallel tubes embedded for the molars to be
moved distally.
 The stationary part contains the other clasps for
the retention of the plate and one tube which
contains the other end of the horse shoe shaped
active wire.
ACTIVATION
 Using the 139 plier, the wire coming out of the
tube embedded in the stationary part is bent,
which makes the movable part slide distally.
DISADVANTAGE
 A delicate appliance, since the two wires
holding the movable part should do so without
binding.

33. 3. THE CETLIN APPLIANCE
JCO 1983 Cetlin and Tenhoe
 The appliance involves a combination of extra oral
force in the form of head gear and an intraoral force in
the form of a removable appliance.
 The Cetlin appliance utilises a removable appliance
intraorally to tip the crowns distally and then an
extraoral force to upright the roots. So the intra oral
removable appliance can be called the crown mover
while the extra oral force, the root mover.
ANCHORAGE
 The anchorage for the removable appliance is by
proper adaptation to the palate, an acrylic shield
around the four maxillary incisors and a modified adams
clasp on the first premolars.

34. THE EXTRA ORAL FORCE
 The extra Oral appliance is a headgear which is inserted
into molar tube. The headgear used is generally cervical
or a high pull, depending on the usual consideration of
the skeletal pattern.
THE APPLIANCE
 The removable appliance is worn 24 hours a day. The
appliance also contains a bite plane to disengage the
molars (to aid in rapid molar movement).
THE FORCE APPLIED
 In the removable appliance, the spring is activated only
1 to 1.5 mm, measured along the occlusal of the molar
and it supplies force on the molars of only 30 gms. The
springs are placed as far gingivally as possible to
minimize crown tipping and to cause molar movement
without irritation.
 The extra oral head gear on the other hand exerts a 150
gm force per tooth and is used to control root position.
The headgear is adviced to be worn for 12-14 hours/day.

35. INTRAMAXILLRY APPLIANCES
WILSONS' RAPID MOLAR DISTALIZATION
Advocated by William L. Wilson & Robert C.Wilson
(1984 JCO)
under modular orthodontics.
 the pre-treatment antero-posterior positions. The
Wilson treatment achieves molar distalization without
extra oral forces.
 THE CONCEPT
 Newton’s' 3rd law of motion states that 'for every
force, there is an equal and opposite force', (i.e.) for
every moment, there is a counter moment.
 Implicit in Newton’s' law is the concept that control
of counter moments increases the efficiency of the
moment of force. Modular orthodontic units have
been designed to control countermoments,
eliminate 'round trips', and reduce headgear use.

36.  DESIGN OF APPLIANCE
 Wilson advocates maxillary
bimetric distalizing arches (BDA)
and a mandibular three
dimensional lingual arch. The
bimetric arch produces a coil
spring action against the molars
and producing an anterior
counter moment against the
incisors, which is controlled by the
wearing of class II elastics.
 These, in turn, react with a lower
molar mesial force vector which is
controlled by the 3D lingual arch
with a design for anchorage
resistance. This is supplemented
by molar buccal root torque and
cortical resistance to satisfy
increased anchorage needs.

37. The vertical component of elastic force is controlled
by using the elastic load reduction principle, in
which the elastic force is reduced to physiologically
acceptable levels. Mandibular anchorage and
elastic load reduction control the reactive
countermoments and produce a relatively friction
free, rapid distalizing of molars; without headgear
and with preservation of mandibular arch integrity.
Wilson's Schedule for Maximum Mandibular
Anchorage
 6 ounce elastics for 5 days.
 4 ounce elastics for 5 days and
 2 ounce elastics for 11 days.
For minimal mandibular anchorage:
 6 ounce for 10 days
 3 ounce for 11 days.

38. REPELLING MAGNETS
 Anthony A. Gianelly (AJO 1989)
Design:
 Nance appliance extends anteriorly to the incisor segment by
means of an 0.045-inch wire soldered to the lingual aspect of the
premolars. The acrylic component is placed against both the
palatal vault and the incisors.
 Bilateral distal extensions (0.045-inch wire) with loops at the end are
soldered to the labial aspect of the premolar bands so that the
loops approximate the molar tubes.
 Anchoring the modified Nance appliance to the first premolar
encourages the distal drift of the second premolars that normally
occurs as first molars are moved posteriorly.

39. The modified Nance appliance serves two functions:
 Activation of the magnets
 Contains the reaction force arising from the action
of the magnets.
 Molars were moved distally 2.0 mm while the
premolars moved anteriorly 2.1 mm.
 When 2nd
molars were not present, the fastest molar
movement was observed and Class I molar
relationships were attained within 2 to 5 months.
Disadvantages :
 Magnets tend to be expensive and bulky.
 Magnetic force dissipates rapidly with increasing
intermagnet distance.
 Requires frequent recall reactivation appointment.
 Because of these drawbacks, Darendeliler has
concluded that magnets offer no advantage over
conventional systems in molar distalization.

40. PENDULUM APPLIANCE
JAMES J. HILGERS, JCO 1992
 The Pendulum Appliance is a
hybrid that uses a large Nance
acrylic button in the palate for
anchorage, along with .032"
TMA springs that deliver a light,
continuous force to the upper
first molars without affecting the
palatal button. Thus, the
appliance produces a broad,
swinging arc— or pendulum—
of force from the midline of the
palate to the upper molars.

41. Fabrication
 The right and left Pendulum
springs, formed from .032" TMA
wire, consist of a recurved molar
insertion wire, a small horizontal
adjustment loop, a closed helix,
and a loop for retention in the
acrylic button.
 The springs are extended as
close to the center of the
palatal button as possible to
maximize their range of motion,
to allow for easier insertion into
the lingual sheaths, and to
reduce forces to an acceptable
range.

42.  The anterior portion of the appliance can be retained in
place with occlusally bonded rests or soldered to bands
on either the deciduous molars or the first and second
bicuspids.
 The Nance button should be made as large as possible to
prevent any tissue impingement. It should extend to
about 5mm from the teeth, to avoid the highly vascular
cuff of tissue near the teeth and to allow adequate
hygiene.
 If expansion of the upper arch is needed, a midpalatal
jackscrew can be incorporated into the center of the
Nance button . The screw is activated one-quarter turn
every three days, after a week or so for patient
adjustment, to produce a slow, stable expansion. This
version of the appliance is called a "Pend-X".

43. Preactivation and Placement
 The springs should be bent parallel to the midline of the
palate. About one-third of this overactivation is lost in
placement, and the remaining pressure is tolerated easily
by the patient.
 Once the appliance is cemented in place, each
Pendulum spring is brought forward with finger pressure,
the mesial end of the recurved loop is grasped with a
Weingart plier and the spring is seated in the lingual
sheath. . Distal pressure holds the spring in the sheath quite
effectively, but an elastic "O" ring can be used to secure it.

44.  A. As the molar is driven distally, it moves on an arc toward
the midline of the appliance— in other words, toward
crossbite.
 B. This tendency can be counteracted by opening the
adjustment loop slightly to increase the expansion and
molar rotation.
 Distal root tip can also be produced by adjusting this
horizontal loop on the Pendulum spring. Tipping back the
recurved portion of the spring at the loop causes a more
direct distal movement of the molars.

45. Reactivation
 The spring is reactivated
by pushing the centre of
helix distally toward the
midline with a bird beak
plier.
Stabilization
 Molars must be stabilized
in their new distalized
positions or they will
rapidly drift back
mesially. It is also
important to move the
buccal segments into a
Class I relationship to
harness the full
advantages of the
appliance.

46. The molars can be stabilized in any of four ways:
 The Nance portion is removed and a full upper
fixed appliance is bonded. An upper utility arch
holds the molars back with the incisors as
anchorage.
 After removal of the Pendulum Appliance, a
smaller, easier-to-clean Nance button ("Insta-
Nance”) is placed.
 The entire upper arch is bonded and a continuous
archwire with omega loops mesial to the upper first
molar tubes is placed.
 A headgear is worn.
Drawbacks of PA
 The pendulum appliance not only drives the molars
distally, there is also a slight lingual tipping.
 Causes the anterior bite to open
 Not very easy to fabricate.

47. MODIFICATIONS IN PA
SCUZZO JCO 1999 Nov
 The Modified Pendulum:
 M-Pendulum
 In the original design by Hillgers,
adjustable loop was distally
oriented to compensate for the
tendency toward crossbite during
distalization.
 M-Pendulum was designed by
reversing the loop to the mesial
to provide bodily movement of
both the roots and crowns of the
maxillary molars, rather than
tipping or rotation. After some
distalization has occurred, the
loop is reactivated simply by
opening it.
Hillgers design
M Pendulum

48.  If the horizontal Pendulum loop is inverted, it will
allow bodily movement of both the roots and
crowns of the maxillary molars. Once distal
molar movement has occurred, the loop can be
activated simply by opening it. The activation
produces buccal and/or distal uprighting of the
molar roots and thus a true bodily movement
rather than a simple tipping or rotation.

49.  Before intraoral placement of the appliance,the
Pendulum springs are activated to about 40-45° with
a Weingart plier, resulting in about 125g of force on
each side. This activation is repeated until the
desired distalization of the molars is obtained.
 The inverted loop should not be adjusted until the
spring has deactivated following each phase of
distalization. A passive fit of the distal ends of the
Pendulum springs in the lingual sheaths, with no
distal force applied to the molar crowns, will allow
backward tipping of the molar roots. The terminal
ends of the M-Pendulum springs are straight, rather
than looped as in the original appliance.
 The Pendulum springs should be activated primarily
by a derotational bending of the distal ends, as with
a conventional palatal bar. After distalization is
complete, the terminal ends of the springs should be
deactivated to allow a passive fit in the lingual
molar sheaths.

50. SCUZZO JCO 2000 April
 A further modification of the M-
Pendulum appliance was made by
using removable TMA arms that can
be reactivated outside the mouth.
Fabrication and Activation
The modified appliance is
fabricated as follows:
 Double over two 7-9mm lengths of .
032" TMA wire to form bayonets.
Attach each bayonet to an M-
Pendulum arm, either by using a
laser welder or by wrapping .010"
ligature wire around the arm and
soldering the unit together with
silver wire and a miniflame.

51.  Embed each
bayonet in the soft
acrylic that will be
used to form the
Nance button,
producing sheaths in
which to insert the
removable arms
 Activate the arms as
desired on the
working cast

52.  Place the appliance in the mouth,
inserting the terminal ends of the
arms into the lingual molar band
sheaths
 The removable arms can be
reactivated during treatment
without debonding and rebonding
the occlusal rests of the Nance
button. Distal molar movement
can then be more precisely
controlled than by opening the
horizontal loops in the mouth. The
conventional Pendulum or M-
Pendulum produces about 5mm
of distalization in three to four
months. With the removable arms,
distal movement can be
continued at a rate of about
1.5mm per month for as long as
necessary

53. Advantages
 Dramatic reduction in chair time.
 Sound biomechanical principles, producing
more precise and predictable results.
 Less chance of unwanted side effects.
 Easy replacement of Pendulum springs without
refabrication of the entire appliance.
 Ability to replace the active arms with passive
stainless steel auxiliaries after distal movement,
thus producing a “quick” Nance appliance for
stabilization.

54. STUDIES EVALUATING PA
 Ghosh and. Nanda. (AJO 1996)
 Friedrich K. Byloff (1997 AO) part 1 & Part 2
 Bussick & McNamara, AJO 2000March

55. Ghosh and. Nanda. (AJO 1996) evaluated the effect
of Hilgers PA on 41 patients , mean age 12 years and 5
months.
DENTAL EFFECT
Sagittal Plane
 The correction of the Class II relationship was achieved
by a mean maxillary first molar distalization of 3.37 mm.
Average distal tipping of 8.36°occurred in 1st molar.
 The second molar teeth were distalized to a mean of
2.27 mm,and tipped distally 11.99°.
 There was a statistically significant correlation between
the amount of distalization and the amount of first
molar tipping.
Vertical plane
 The vertical change in molar position was insignificant.
There was a mean intrusion of 0.47 mm in second molar
position

56. Transverse plane
 The transverse width at the maxillary second premolars
increased by 1.95 mm as they drifted distally into a wider
part of the arch.
 The arc described by the spring during its distal movement
causes a mesiobuccal rotation instead of distobuccal
rotation. The width between the mesiobuccal cusps of the
right and left first molar teeth increased by 1.40 mm,
whereas that between the distobuccal cusps showed no
increase. The second molar teeth also showed an
expansion of 2.33 mm between the mesiobuccal cusps.
 Distalization of the maxillary first molars with this appliance
therefore causes both distal as well as buccal tipping of the
second molars.
 The effect of distalization on the maxillary third molars was
extremely variable. The third molars showed a net distal
tipping of 2.49°, but an insignificant amount of horizontal or
vertical change in position 0.19 mm distalization and 0.22
mm intrusion

57. Anchorage loss & effect on anterior segments
 Loss of anchorage was measured at the first
premolar teeth. For every millimeter of distal molar
movement, the premolar moved mesially 0.75 mm.
 The overjet increased by 1.30 mm and the overbite
decreased by 1.39 mm as a result of treatment. The
maxillary central incisor was proclined an average
of 2.40° relative to the SN line.
 The upper lip protruded 0.31 mm and the lower lip
protruded 0.95 mm relative to the E plane.
Effect of eruption of the maxillary second molar
 This study indicates that the eruption of maxillary
second molars had minimal effect on first molar
distalization.

58. Skeletal effects with the pendulum appliance :
 The pendulum appliance caused insignificant
changes in the cant of the palatal and occlusal
planes. The mandibular plane, on the other
hand, showed a small backward rotation of
1.09° with treatment, which caused a decrease
in the overbite by 1.39 mm.
 Because there was no vertical change in the
maxillary molar position and only an extrusion of
0.5 mm in mandibular first molar position, most
of the backward mandibular rotation was
caused by distalizing the maxillary molar "into
the wedge." The lower anterior face height, as
a result, increased by 2.79 mm.

59. Effect based on MPA
 The patients in the sample were arbitrarily
divided into three groups, based on their initial
Frankfort horizontal to mandibular plane angle
(FMA) measurements.
 There was a trend for greater increase in FMA
in group with FMA greater than 25°.
 Patients with high mandibular plane angles
showed posterior mandibular rotation and
increase in lower face height, 4.13 mm as
compared to 1.97 mm in average MPA group.
 The increase in the lower face height as a
result of molar distalization, was more than
double in high angle group (4.13 mm) than in
average group (1.97 mm).

60. Friedrich K. Byloff (1997 AO) part 1 studied, the dental and
skeletal effects of the pendulum appliance, applying 200 to
250 g of force to the molars in 13 patients (age range 8 years
to 13 years 5 months) by means of cephalometric
radiographs.
 This study suggest that the pendulum appliance is effective in
moving the maxillary first molars distally at a mean monthly
rate of 1.02 mm using an initial force of 200 to 250 g in a
mean period of 4 months.

61. Distal molar movement, molar and incisor tipping:
 The pendulum appliance produces 3.39 mm ±1.25 mm
distal molar movement with a mean bimolar intrusion of
1.17 mm ± 1.29 mm. This positive finding can be related to
prevention of dentoalveolar vertical growth by the rigid
bonded appliance.
 Molar distal tipping of 14.5° ± 8.33° occurred. The
trajectory of the TMA springs may account for the
excessive tipping found in this study.
 Maxillary expansion is possible for transverse deficiencies
in combination with distal molar movement.
 The pendulum appliance does not create dental or
skeletal bite opening.
 Anchorage loss: Second premolar anchorage loss found
in this study was 1.63 mm (±1.37 mm) i.e. 29 %. Distal
molar movement represented 71% of the space opened
between molars and premolars. Incisor anchorage loss
was minimal

62. Friedrich K. Byloff (1997 AO) part II
 In this study, the appliance was modified by
incorporating an uprighting bend into the
distalizing spring during the second phase of
treatment to avoid excessive distal tipping of
the maxillary molars.
 Treatment changes were analyzed and
compared with the previous study.
 Due to the initial moderate dental transverse
deficiency, 8 of the patients required maxillary
expansion of 2 to 4 mm.
Appliance design and activation:
 The major difference was the incorporation of
the molar uprighting bends. An expansion screw
was added to the PA in 8 of the subjects who
required 2 to 4 mm of transverse development;
the appliance was activated every seventh day
to achieve a slow rate of expansion.

63.  Active treatment in this study, contrary to the previous
one, consisted of two phases.
 1. Distal molar crown movement: Molar distalization was
done until an overcorrected Class I relationship was
obtained.
 2. Molar root up righting: The appliance was modified
by adding a bend to the spring design to upright the
molars by moving the roots distally. In order to make the
uprighting bends, the angle between the recurved end
of the spring, which is engaged into the palatal molar
sheaths, and the long arm of the spring was increased
intraorally in the sagittal plane 10° to 15°, using a
Weingart plier. The moment created was expected to
upright the molars. The springs were left slightly active in
the sagittal plane to maintain the position of the molar
crowns. The appliance was left in place until the molar
crown seemed to be sufficiently uprighted.

64. Treatment time
 Mean total experimental time using the PA was 27.25 ±
7.12 weeks (6 months 3 weeks ± 7 weeks).
 1st phase of treatment, ( obtaining a super Class I
relationship) the distal movement phase, took 16.45 ± 6.67
weeks.
 2nd phase -- to upright the maxillary molars required
another 10.9 weeks.
 Thus the total treatment time was increased by 64.1%.
Distal molar movement & molar tipping:
 The percentage of molar movement compared with total
space opening decreased from 70.92 % to 64.16.
 Rate of movement was between 0.69 mm ± 0.29 mm and
1.20 mm ± 0.74 mm per month, depending on the rate of
uprighting.
 For 6.07° ± 5.15° of final molar tipping, rate of movement
was 0.69 mm ± 0.29 mm per month.
 During the uprighting phase, the average monthly distal
movement of the apex was 1.01 mm ± 0.57 mm.

65. Second molar eruption stages
 In both study the position of the second molars didn’t
influence the amount of distal molar movement or
premolar or incisor anchorage loss.
Intrusion—extrusion
 Increases in the premolar and incisor extrusion and
decrease in molar intrusion when compared with the first
study might be a result of the vertical reactive component
of the uprighting bend.
Anchorage loss
 The price for more space opening and distal molar crown
movement, and especially for more root movement and
reduced final tipping of the molars, was increased total
treatment time and 0.61 mm more anchorage loss at the
premolars and 0.62 mm at the incisor edge level.
 The effects of the original pendulum appliance were not
significantly changed by the incorporation of the
uprighting bends, although slightly more anchorage loss
was noted on the maxillary incisal edge.

66. Bussick & McNamara, AJO 2000March
 Subjects were: Varying facial patterns (high,
neutral, and low mandibular plane angles).
 Cephalometric radiographs obtained from
13 practitioners were used to document the
treatment of 101 patients (45 boys and 56
girls).
 The relative effect of erupted maxillary
second molars on distalization of the first
molar and the effects, if any, of permanent
versus deciduous dentition based
anchorage on distalization of maxillary
molars were also evaluated.
 Treatment with a pendulum/pendex
appliance, similar to the type described by
Hilgers,was initiated in all patients

67. Treatment effects:
1. An increase in overjet was shown.
2. The average maxillary first molar distalization was 5.7 mm, with a distal
tipping of 10.6°.
The maxillary first molars intruded 0.7 mm, and the first premolars extruded
1.0 mm.
 The maxillary molar distalization contributed to 76% of the total space
opening anterior to the maxillary first molar, whereas 24% was due to
reciprocal anchorage loss of the maxillary premolars.
3. Anchor teeth
 Second premolar moved mesially by the 1.8-mm with a mesial tipping of
1.5°.
 The maxillary central incisors proclined slightly during treatment.
4. Second deciduous molars vs second premolar anchorage :
 A. The reduction in overbite was significantly greater in the second
premolar group (average –1.5mm) than in the second deciduous molar
group (average –0.3mm).
 B. Patients with erupted second premolars demonstrated significantly
greater increases in lower anterior facial height (2.4 ± 1.3 mm) than did
second deciduous molars (1.6 ± 1.5 mm).
 These changes are related to a downward and backward rotation of the
mandible.

68. 5. Presence or Absence of Erupted Permanent Maxillary Second
Molars
 1. No significant differences were noted in the anteroposterior
movement of the maxillary first molar and sagittal anchorage loss
between the 57 patients who had erupted maxillary second
molars and the 44who had not.
 2. In patients with erupted maxillary second molars, there was a
slightly greater increase in lower anterior face height and in the
mandibular plane angle and a slightly greater decrease in
overbite in comparison to patients with unerupted second
molars.

69. 6. Variation in Facial Patterns:
 Lower anterior facial height increased 2.2 mm;
there was no significant difference in lower
anterior facial height increase between
patients of high, neutral, or low mandibular
plane angles.
 For maximum maxillary first molar distalization
with minimal increase in lower anterior facial
height, this appliance appears to be best used
on patients with maxillary second deciduous
molars for anchorage and the absence of
erupted permanent maxillary second molars,
although significant bite opening was not of
major concern in any patient in the study.

70. Distalization appliances based on NiTi wires and coils
 Superelastic coils
 Superelastic archwire: single looped,
double looped

71. 1. SUPER ELASTIC NiTi COILS
 Anthony A. Gianelly (AJO 1991) used Japanese
NiTi super elastic coils, exerting 100 gm of force,
compressed against the maxillary first molars
and moved the molars distally 1 to 1.5
mm/month.
 Coils are used in conjunction with a vertically
slotted (0.020-inch) fixed appliance.
 A passive 0.016 ´ 0.22-inch wire with stops that
abut the distal wings of the premolar brackets is
inserted to ensure that the wire cannot move
past the first premolars, thus placing the reaction
force on the Nance appliance. Coils are placed
on the wire between the first premolars and the
molars.
 The coils are activated 8 to 10 mm by
compressing and maintaining them against the
molars by crimpable hooks or Gurin locks.

72. Anchorage
 A Nance-type appliance was cemented onto the first
premolars. The appliance extends from the incisors to the
molar area and a bite plate is added to the incisal portion
to disclude the posterior teeth slightly
Anchorage enhancement:
 To enhance anchorage further, a 0.018-inch uprighting
spring is placed in the vertical slot of the premolar
brackets, directing the crowns distally.
 Class II mechanics are used only when anchorage loss is
at least 1 mm.
 When Class II elastics are attached, a rectangular wire
with 10° of incisor lingual root torque is inserted in the
mandibular arch to maintain lower incisor position.
 100 gm superelastic coils can be used successfully in
patients with Class II malocclusions to move molars
posteriorly at the rate of 1 to 1.5 mm/month with little or no
cooperation from the patient.

73. SUPER ELASTIC NiTi WIRES
 The use of shape memory, superelastic Nickel Titanium
wires in
 distalizing the molars have been discussed by Ranieri &
Antony A.Gianelly in 1992.JCO
FABRICATION
 Gianelly used a superelastic NiTi arch wire here.
 1. A 100 gm Neosentalloy wire with regular arch form is
placed over the maxillary arch. The superelastic NiTi wire is
an 0.018 X 0.025 inch wire that also applies 100 gm of
force.
 The wire is then marked in three places on each side.
 A. At the distal wing of the first premolar bracket.
 B. 5-7 mm distal to the anterior opening of the buccal
tube
 C. Between the lateral incisors and canines

74.  A stop is then crimped on the arch wire at each of the
posterior marks and a hook is then added for inter-
maxillary elastics between the lateral incisors and canines.
3. The wire is then inserted into the molar tube until the
posterior stop abuts the tube.
 To place the wire through the first premolar bracket, the
anterior stop is grasped and the wire gently forced distally
so that the stop abuts the distal wing of the first premolar
bracket, when ligated.
 Since the wire is 5-7 mm longer than the available space,
the excess will be deflected gingivally into the buccal
fold.

75. ACTION OF THE WIRE/APPLIANCE
 The distalization of the molars occur as the wire returns to its
original shape, exerting a distal force of 100 gms against the
molars and a reactionary mesial force on the first premolars,
canines and incisors.
 There is also a tendency for the premolars to move buccally.
THE ANCHORAGE
The anchorage can be controlled by
 a. Placing a 100-150 gm class II elastics against the first
premolars. (or)
 b. Placement of hooks between the lateral incisors and canines
(or)
 c. A Nance appliance cemented to the first premolars.

76. THE ADVANTAGE OF THE APPLIANCE
 1. The appliance distalizes the molar at the rate of 1-2 mm per
month with little loss of anchorage.
 2. The Neosentalloy wire is easy to insert even after all teeth
have been bracketed or banded.

77. Giancotti, & Cozza (JCO 1998 April) used double loop
for simultaneous distalization of both molars
 Superelastic nickel titanium wires have been found as
effective as other means in producing distal
movement of the maxillary first molars. When the
distalization is carried out before the second molars
have erupted, it can reliably produce 1-2mm of
space. Once the second molars have erupted,
however, the distal movement can be more difficult
and time-consuming, and loss of anchorage is likely.
Author used Nickel Titanium Double-Loop System for
Simultaneous distalization of First and Second Molars.
Appliance Design
 The mandibular first and second molars and second
bicuspids are banded, and the remaining mandibular
teeth are bonded. A lip bumper is placed to prevent
any extrusion from the use of Class II elastics.
 The maxillary molars and bicuspids are banded, and
the anterior teeth are bonded

78.  An 80g NeoSentalloy archwire
is placed on the maxillary arch
and marked distal to the first
bicuspid bracket and about
5mm distal to the first molar
tube . Stops are then crimped
in the archwire at each mark
(distal to 4 and 6)
 Two sectional nickel titanium
archwires (one for each side)
are prepared by crimping
stops distal and mesial to the
second bicuspids and about
5mm distal to each second
molar tube.
 Uprighting springs are inserted
into the vertical slots of the first
bicuspid and Class II elastics
are placed

79. JONES JIG APPLINCE
 Introduced by Jones & White in 1992.
 Jones Jig uses an open-coil nickel titanium spring to deliver 70-
75g of force, over a compression range of 1-5mm, to the
molars.
Appliance Fabrication
 A modified Nance appliance provides anchorage for the use
of the Jones Jig.
Modification in Nance:
 It can be attached to the first bicuspids, second bicuspids, or
deciduous second molars.
The appointment sequence is as follows:
 Appointment 1 : Separators are placed between the first
molars and the anchor teeth.
 Appointment 2 :Impression is made with bands. Pour the
impression with the bands in stone.
A .036" stainless steel wire is adapted to the palate on the
cast, extending it as far as the canines, and soldered to the
anchor bands.

80. The Jones Jig assembly consists of a mainframe of two
prescriptions (0.018 & 0.22 inches respectively), which can
be contoured in the anterior one third. It also consists of a
mainframe hook which is tied to the hook of the molar tube.
The force is delivered by a Nickel Titanium coil spring, which
acts along the mainframe wire, when activated using a
ligature. A 0.014 inch ligature wire is generally used to fasten
the eyelet tube to the premolar bracket, which compresses
the NiTi coil springs. The distal end of the mainframe consists
of a keeper wire (0.018 inch) which goes into the archwire
slot and a mainframe wire which enters the head gear slot
of the molar tube. The extreme mesial end of the
completed assembly should rest no further than the distal
1/3rd of the bicuspid.

81. ACTIVATION
 A 0.014 inch ligature wire is wound around the buccal
tube and the mainframe hook very lightly. Then a 0.012
inch-ligature wire is wound twice around the premolar
bracket and the mesial end passed through the eyelet
tube. The ligature wire is then tightened until 'light'
through the middle of the open coil is barely seen.
 Bunching or over activation of the coil spring should the
avoided as it can lead to unwanted tipping and palatal
irritation along the palatal button.
 Although the force of the Jones Jig is applied in a Class I
direction, the appliance may be contraindicated in
cases of extreme vertical growth patterns, because
extrusion of the molars is not restricted.
REACTIVATION
 Reactivation takes very little chair time and is due over a
period or four to five week intervals.

82. TREATMENT TIME
 In Pseudo class II where it is the rotated class I
which needs to be corrected, the treatment
time is 90-120 days.
 In true class II molar relationships, the corrected
class I relationship can be achieved in 120-180
days. However the treatment time is slightly
increased in brachyfacial patterns.
Drawback:
 The use of the Nance appliance causes palatal
tissue impingement.
 Laboratory expense
 Extra appointment needed to fit the Nance
appliance.
 Coils demand extra diligence in cleaning

83. Comparison of Jones jig molar distalization appliance
with extraoral traction
Seda Haydar (AJO 2000 Jan)
 20 patients in late mixed dentition period with skeletal
Class I or slight Class II malocclusions, with dental Class
II relationship were treated with Jones jig and
headgear.
 Ten cases were treated with the Jones jig appliance for
upper molar distalization, and 10 patients used cervical
headgear for correction of dental Class II relationship.
 The mean age was 10.6 and 10.7 years, respectively,
for headgear and Jones jig group.
 Long cervical face bows were used, and the outer
bows were parallel to the occlusal plane exerting 600 g
of force with an average use of 16 hours per day until
a Class I molar relationship was reached. Average
treatment time for distalization with headgear was 10.7
months followed by a fixed appliance phase of 11
months.

84.  In the Jones jig group, the spring was activated at 4
week intervals and 75 g of force was applied because 5
mm of activation was made at each visit. A modified
Nance appliance was used as an anchorage unit. The
average treatment time to move molars distally was 2.5
months. After distalization of molars, fixed appliance
therapy was applied to each patient and total
treatment time was 15.1 months.
Skeletal change:
 In the headgear group the decrease in SNA angle was
found statistically significant, downward tipping of
palatal plane was also found statistically significant.
 On the other hand, none of these effects occurred in
the Jones jig treatment group.
 In this study, no increase was observed in GoGnSN
angle in both groups.

85. Effect on molars and premolars
 In the headgear group, the distalization of
maxillary first molars and maxillary second
premolars was a consistent finding
 In the Jones jig group, the distalization and
distal tipping of maxillary first molars and
mesial movement of premolar occurred.
 Extrusion of maxillary first molars was
observed in both groups, but it was found
statistically significant only in Jones jig
group.

86.  Jones jig group, showed mesial tipping of the
anchorage unit, this is contrary to the finding in
the headgear group in which spontaneous
distalization of premolars was observed as a
result of the distalization of molar teeth.
Effect on Incisors
 Headgear group, showed the extrusion and
retrusion of incisors that might occur as a result
of the retraction effect of headgear on
anterior teeth.
 Jones jig group showed protrusion of the
incisors because the incisors were part of the
anchorage unit

87. Average treatment time
 The average treatment time for molar
correction with headgear and Jones jig was
10.7 and 2.5 months, respectively. Because
intraoral distalization moves molars distally in a
very short time, total treatment time is reduced
by at least 6 to 8 months despite the fact that
the anterior teeth move or tip mesially during
molar correction. Although a distal drift of
premolars take place during distalization, this
does not reduce the total treatment time
because treatment may cease at times when
headgear cooperation is poor.
 Intraoral distalization seems more appropriate
for regaining space for cases in which no
orthopedic effect is desired on the maxilla as
with skeletal Class I or borderline Class II
patients.

88. Brickman, & Nanda ( AJO 2000 NOV) evaluated the
effects of the Jones jig appliance on distal movement of
maxillary molars and reciprocal effects on premolars and
maxillary incisors.
 Measurements were made on a matched sample of 35
patients treated with cervical headgear and compared
with result of 72 patients treated with Jones jig.
 Both series of patients were treated to correct an Angle
Class II molar relationship.
The results from the Jones jig sample showed
 Mean maxillary first molar distal movement was 2.51 mm
& distal tipping of 7.53°.
 The mean reciprocal mesial movement of the maxillary
premolar was 2.0 mm and mesial tipping of 4.76°.
 The maxillary first molar extruded 0.14 mm & the maxillary
premolar extruded 1.88 mm
 The maxillary second molars were also moved distally
2.02 mm and tipped distally 7.89°.

89.  The Jones jig sample demonstrated effective
distal molar movement and maintenance of
the Class I molar relationship. Cervical
headgear sample showed treatment results
comparable with Jones Jig.
 The longitudinal assessment showed
significant differences between the Jones jig
sample and the cervical headgear sample
for lower lip to E-line and SNA.
 1. The Jones jig sample showed a mean
decrease in lower lip to E-line of 0.25 mm
versus 1.20 mm for the headgear sample.
 2. SNA decreased 0.40° for the Jones jig
sample versus 1.20° for the headgear
sample.

90. DISTAL JET
 Distal jet was designed by
Aldo Carano & Mauro in 1996.
Appliance Design
 Bilateral tubes of .036" internal
diameter which is attached to
an acrylic Nance button.
 A NiTi coil spring and a screw-
clamp are slid over each tube.
 The wire extending from the
acrylic through each tube
ends in a bayonet bend that is
inserted into the lingual sheath
of the first molar band. An
anchor wire from the Nance
button is soldered to bands on
the second premolars

91. Components:
 1. The Transpalatal connector – rigidly immobilizes the premolars and
provides a support to the Nance button.
 2. The bayonet director unit - Lumen of the tube portion supports the
molar bayonet, while its outside diameter supports the spring and the
activation lock.
 3. The molar bayonet - It is drawn out of the bayonet director unit
during distalization and inserts into the lingual sheath.
 4. The Distal stop - Prevents the spring from riding up on the vertical
arm of the molar bayonet while activation of the appliance.
 5. Nickel titanium springs - Two force ranges - 180 gms and 240 gms.
 6. Activation locks - To compress and activate the springs.
 7. Lock wrench - To engage and tighten the screw of the activation
lock
1. TP connector
2. Bayonet director
3. Molar bayonet
6. Activation lock
7. C Res

92. Activation:
 The Distal Jet is reactivated
by sliding the clamp closer
to the first molar once a
month.
 Once distalization is
complete, the appliance
can be converted to a
Nance retainer simply by
replacing the clamp-spring
assemblies with cold-cure
acrylic and
cutting off the arms to the
premolars.

93. Advantage of distal jet :
 The appliance is relatively easy to fabricate, easy to insert, is
well tolerated and is esthetic.
 Easy activation
 Ease of conversion to a Nance holding arch to maintain the
distalized molar positions.
 The Distal Jet also permits the simultaneous use of full bonded
appliances, possibly avoiding the need for two phases of
treatment

94. MODIFICATIONS OF DISTAL JET
 Bowman (1998 Sept JCO) described several
modifications to the original appliance.
 Conversion to Nance Holding Arch:
Upon completion of molar distalization, the
Distal Jet is converted to a Nance holding
arch to prevent further distal movement and
consequent anchorage loss. It can be done
by these two methods:
 1. One way to stop movement of the bayonet
wire through the tube is to flow a light-cured
acrylic around the coil spring, over the distal
bayonet bend, and over the activation collar
to produce a solid extension from the molar
bands to the acrylic button.

95.  2. Wrap an .014" stainless steel ligature wire
around the end of the doubled back wire
(extending distally from the lingual sheath on the
first molar band) and tie it around the tube just
mesial to the activation collar. The coil spring
should be compressed completely and the set
screw tightened to prevent mesial movement of
the molars.

96. Double -Set -Screw Distal Jet
 A modification of the Distal Jet
incorporating two set screws into
the activation collar permits an
easier, cleaner, and more
reliable conversion to a molar
Nance holding arch.
 The mesial set screw is used
during active distalization .The
distal screw is set on the bayonet
wire, locking the two pieces
together to prevent molar
movement.
 The premolar supporting wires
are sectioned where they enter
the acrylic button, using a high-
speed handpiece and diamond
bur.
 The bayonet wire or tube can be
bent with a three-prong plier to
adjust the pressure of theacrylic
button against the palate

97. Conversion of double-set-screw Distal Jet to Nance holding
arch:
A. Upon completion ofmolar distalization, double-set-screw
activation collar is slid mesially to gain access to coil spring.
B.Free end of coil spring is grasped with plier. Coil spring is
removed by peeling it away from bayonet wire.
C. Distal end of tube, where bayonet wire enters, can now
be seen.
D. Double set-screw collar is slid back to this junction, mesial
set screw is locked on tube, and distal screw is set on
bayonet.

98. Quick & Angela Harris (JCO 2000 July)
 The Distal Jet is a fixed palatal appliance that is
most commonly used to distalize the maxillary
molars, either unilaterally or bilaterally.
 Disadvantage of Distal jet: Lies in activation
 The appliance is activated by sliding a collar
along the supporting tube to compress a coil
spring, then fixing the collar in place by
tightening a small set-screw.
 This procedure is sometimes difficult because of
the small size of the screw, the moisture and
confined space of the intraoral environment,
and food impaction in the screw head.
 In addition, activation requires the use of a small
Allen wrench, which has the risk of being
swallowed or aspirated.

99. Appliance Design
 The basis of the modification is
the rear entry of the sliding
section into the lingual molar
sheath, so that the appliance
pulls rather than pushes the
molars distally. The doubled-
backwire (or “foot”) is inserted
into the lingual sheath from the
distal. The foot should be a little
longer than the sheath so it can
be tied back to the sliding
section with an elastomeric or
metal ligature.
 Either .030" or .032" wire is suitable
for the sliding sections. Support
tubes of corresponding internal
diameter are embedded in the
acrylic Nance button. The
desired amount of activation is
achieved by compressing the
coil spring between the distal
end of the support tube and a
stop soldered to the sliding wire.

100.  To reactivate the appliance, the safety ligature is cut, the
sliding wire is pulled out distally, and a new, longer section of
coil is placed over the wire.
 In addition, no set-screws or Allen wrenches are used,
simplifying the activation procedure.
 After molar distalization is completed, the molar positions are
held by replacing the open coils with either closed coils or
solid tubing to prevent anterior relapse or a new Nance
button can be made.

101. THE FIXED PISTON APPLIANCE
 The appliance was described by
Raphael U.Greenfield in 1997.
 The appliance proposed to achieve
distal bodily movement of the molars
without tipping the crown with no loss
of posterior anchorage.
THE APPLIANCE
The components of the appliance
are:
 a. Maxillary first molar and first
bicuspid bands.
 b. 0.036" stainless steel tubing
(soldered to the bicuspids).
 c.0.030" stainless steel wires (soldered
to the first molar).
 d. Enlarged Nance button reinforced
with an 0.040" stainless steel wire for
control of anterior anchorage.
 e. 0.055" hyperplastic nickel titanium
open-coil springs - to provide a light
but continuous force.

102. Fabrication
 1. The first molars are banded
with a double or triple tube.
 2. The first / second bicuspids are
then banded. Normally the
buccal and lingual piston
assemblies should extend to the
embrasure of the cuspid and first
bicuspid to be long enough for
adequate distalization.
 In maximum molar distalization
however, the piston assembly
may be extended beyond the
first bicuspids.
 3. A full arch silicone/vinyl
impression is then taken such that
the bands seat securely in the
impression.
 4. The bands are then waxed and
a working cast in stone is made.

103.  5. A 0.040" stainless steel wire is then adapted to the
palate and is brought posteriorly to the gingival third of
the bicuspid for soldering.
 6. A 0.036" stainless steel tubing is then soldered to the
buccal and lingual occlusal thirds of the bicuspid bands.
 7. The 0.030" stainless steel wire is soldered to the buccal
and lingual surfaces of the first molar bands. 0.040"
stainless steel Nance wire is then soldered to the bicuspid
bands.

104.  The piston assemblies must be
parallel in both the occlusal
and sagittal views.
 A slight palatal cant from distal
to mesial can however be
given to prevent occlusal
displacements of the palatal
acrylic.
 A 2mm split ring stop is than
added to the mesial of the
buccal and lingual tube on
each piston assembly every 6 to
8 weeks. This provides around
25 gms of force to each piston
assembly which works out to 50
gms per tooth.

105. THE ADVANTAGES
The fixed piston appliance has been proved to be
effective in molar distalisation and is said to have the
following advantages:
 Bodily movement of maxillary first molars (with no loss of
posterior anchorage).
 Minimum patient compliance.
 Allows the use of head gear if needed.
 In non-extraction cases, it is proved to reduce treatment
time as it distalizes at the rate of 1mm per month.
 Maintains the arch width after expansion with Haas or
Hyrax appliances.
 Uses a light, controlled force of only 1-2 ounce per tooth.
Because of this there is no loss of anterior anchorage and
no inflammation of the palatal mucosa beneath and
adjacent to the modified Nance button.
 Does not interfere with the occlusal plane, thus
maintaining effective control over the vertical
dimensions.

106. IBMD
 Ahmet Keles¸AJO (Jan 2000)
 15 patients were treated with IBMD , their
average age was 13.53 years old ranging
from 11 to 16 Years old. Second molars were
present in all the cases.
Appliance Construction
 The intraoral bodily molar distalizer (IBMD
was composed of 2 parts: the anchorage
unit and the distalizing unit.
 The anchorage unit was a wide Nance
button, and the active unit consisted of
distalizing springs
 The springs had 2 components: the distalizer
section of the spring applied a crown tipping
force, while the uprighting section of the
spring applied a root uprighting force on the
first molars.

107.  Maxillary first molars and premolars were banded. On
the palatal side of the first molar bands, 0.032 × 0.032
inch slot size hinge cap palatal attachments were
welded, and a maxillary impression was taken. On the
model, a wide acrylic Nance button was constructed
and attached to the first premolar bands with 0.045
inch in diameter stainless steel retaining wires.
 The acrylic button was constructed that functioned as
an anterior bite plane to disclude the posterior teeth
and enhance molar distalization.
 For molar distalization 0.32 x 0.32 inch size TMA springs
were bent and oriented from the acrylic. The springs
had 2 components. The distalizer section of the spring
applied a crown tipping force, whereas the uprighting
section of the spring applied a root uprighting force to
the first molars

108. B. The intraoral bodily molar distalizer (IBMD) was cemented
to the first premolars without the springs engaged.
B. After the cementation, the hinge caps on the molar
bands were opened.
C. Activation of distalizing component
D. Activation of the springs was accomplished by pulling
from distal to mesial with the help of a Weingart plier and
then seating into the slot of the palatal hinge cap
attachments. It applied a total of 230 g of distal force.

110.  This study showed that maxillary 1st molars were
distalized bodily 5.23mm on average. Maxillary molar
extrusion was not observed after distalization. Maxillary
molars did not rotate and intermolar distance did not
change after distalization.
 Class I molar relationship was achieved in an average
period of 7.5 months.
 Maxillary first premolars moved forward 4.33 mm, were
extruded 3.33 mm, and tipped 2.7° distally.
 A 4.77 mm protrusion and 6.73° proclination of the
incisors were observed.
 The overjet was increased by 4.1 mm; whereas the
overbite was reduced by 2.63 mm. Mandibular first
molars were extruded by 1.53 mm.
 After the removal of IBMD, incisor protrusion and mesial
migration of premolars spontaneously relapsed distally

111. Skeletal change:
Mandibular plane angle
increased by 1.26°.
Anterior lower face height to
total face height ratio was
increased by 0.95 mm.
SNA increased by 1.56°, whereas
ANB angle increased by 1.66°.

112. K-Loop
Put forward by Valrun Kalra (JCO 1995)
The K-Loop molar distalizer consists of
 1. A K-Loop to provide the forces and moments.
 2. A Nance button - to resist anchorage.
 The k-Loop is made of 0.017’ x 0.025' TMA wire which can be
activated twice as much as stainless steel, before it undergoes
permanent plastic deformation.

113. A. The loop of the 'K' should be 8 mm long and
1.5 mm wide.
B. The legs of the 'K' are to be bent down 20 °
and inserted into the molar tube and the
premolar bracket.
C. The wires are marked at the mesial of the
molar tube and the distal of the premolar
bracket.
A B C

114. D. Stops are bent into the wire 1 mm distal to
the distal mark and 1 mm mesial to the
mesial mark. Each stop are well defined and
are about 1.5mm long.
E. These bends help keep the appliances
away from the mucobuccal fold, allowing a
2mm activation of the loop
D
E

115.  The bends in the appliance legs produce
moments that counteract the tipping
moments created by the force of the
appliance, and these moments are
reinforced by the moment of activation as
the loop is squeezed into place. Thus, the
molar undergoes a translatory movement
instead of tipping. Root movements are said
to continue even after the forces dissipate.

116.  For additional molar movement, the reactivation
is 2mm after 6 to 8 weeks.
 The premolars move forward by 1 mm during 4
mm of molar distalization (the anchorage loss).
To prevent anchorage loss a head gear (straight
pull or high pull) with forces of 150 g to the
premolars can be used.
Advantages
 Simple & efficient
 Controls moment to force ratio to produce
bodily movement
 Easy fabrication and placement
 Hygienic and comfortable to the patient
 Low cost.

117. First class appliance Jco 99
June
 Bands are placed on
the maxillary first molars
and on either the
maxillary second
premolars or the
second deciduous
molars.
 Impressions are taken
with these bands in
place, and a working
cast is poured.

118. Vestibular components:
Formative screws are
soldered on the buccal sides
of the first molar bands,
occlusal to the .022" × .028"
single tubes, so they will not
interfere with subsequent
insertion of the archwire .
 Split rings, welded to the
second premolar or second
deciduous molar bands,
control the vestibular screws.
 Stop screws are used to
maintain the distal positions
of the molars after active
movement has been
completed.

119. 2. Palatal components. In the palatal aspect, the appliance
is much like a modified Nance button, but is wider and has
a butterfly shape for added stability and support during
retention . The butterfly section is soldered to the second
bicuspid or deciduous molar bands.
The embedded .045" wires should be in single sections,
without welded joints, to prevent breakage. Sections of .
045" tube are soldered to the palatal sides of the first
molar bands for insertion of the butterfly component of
the appliance. These tubes allow the molars to be
distalized without undesirable tipping.

120. Nickel titanium .010" × .045" coil springs,
approximately 10mm each in length, are fully
compressed between the bicuspid solder joints
and the tubes on the deciduous molar or
second bicuspid bands. These springs are
designed to balance the action of the
vestibular screws, preventing molar rotations
and development of posterior crossbites.

121.  Bodily distalization of first molars on both
sides; detail of formative screw at end of
activation

122.  Fortini et al (AJO 2004 June) evaluated the treatment
effects of FCA on 17 patients.
 The FCA produced rapid molar distalization: bilateral
Class II molar relationship was corrected in 2.4 months on
average. The maxillary molar distalization contributed to
70% of the space created anterior to the first molars: 30%
was due to reciprocal anchorage loss of the maxillary
second premolars.
 The maxillary first molars were moved distally an average
of 4.0 mm per side with a mean distal tipping of 4.6°.
Rate of distalization was 1.7mm / month.
 Anchorage loss measured at the second premolars
was1.7 mm with 2.2° of mesial tipping.
The maxillary central incisors proclined slightly during
treatment (2.6°) with minimal increase in Overjet (1.2
mm).
No significant changes in sagittal or vertical skeletal
relationships were observed.

123. Carriere Distalizer
 LUIS CARRIERE (JCO 2004 April) developed a new Class II
distalizer with advanced computer technology.
 Brachyfacial patterns respond best to treatment;
dolichofacial types are less responsive. Growing patients
are ideal, but adults can be treated as well. Mixed
dentition Class II cases with fully erupted first molars are
candidates for first-phase treatment.
Biomechanics:
 The Carriere Distalizer is designed to create a Class I molar
and canine relationship. The biomechanical objectives of
the appliance are as follows:
 1. Produce a distal rotational movement of the maxillary
first molars.
 2. Produce a uniform force for distal molar movement.
 3. Independently move each posterior segment, from
canine to molar, as a unit.

124. Appliance Design
 The Distalizer is made of mold-injected, nickel-free
stainless steel. It is bonded to the canine and first molar
as follows:
 The canine pad, which allows distal movement of the
canine along the alveolar ridge without tipping,
provides a hook for the attachment of Class II elastics.
This pad is the mesial end of an arm that runs
posteriorly over the two upper premolars in a slight
curve.
 The posterior end of the arm is a permanently
attached ball that articulates in a socket on the molar
pad.

125.  The ball and socket joint provides torque (3D) control of
both the canine and molar
 The posterior portion of the Distalizer accomplishes three
types of molar movement:
 1. Uprighting of the crown, if it is mesially in-clined .Once
the molar has been upright-ed; the articulation of the
ball with the socket prevents distal tipping.
 2. Distal rotation around the palatal root. When the
molar has been derotated, the shoulder of the posterior
base contacts the mesial arm to prevent over rotation.
 3. Distal displacement without concurrent distal tipping
of the crown

126.  Appliance Placement
 The Distalizer comes in three
sizes: 23mm, 25mm, and
27mm. The appropriate size
is deter-mined by measuring
from the midpoint of the
maxillary first molar's buccal
surface to the mid-point of
the maxillary canine crown,
using a caliper or the
supplied Dentometer.
 In case of blocked out
canines it is bonded to 2nd
molar and 1st premolar.
 Appliance is bonded to 1st
molar and canine with a
light cured adhesive

127. Possible 5 sources of anchorage:
 Passive .036’ lingual arch
 0.45’ SS Hamula lingual arch
 Full mandibular fixed appliances
 Lower Essix appliance with hooks for elastics in lower molar
region.
 Miniscrews
Patient is instructed to wear heavy 6 ½ oz , ¼ “ Class II
elastics 24 hours a day, except during meals.

128. BYLOFF et al (JCO 2000 sept) made a new device,
based on the Pendulum that can distalize mandibular
molars without the drawbacks of other appliances.
Appliance Design
 The Franzulum Appliance’s anterior anchorage unit is
an acrylic button, positioned lingually and inferiorly to
the mandibular anterior teeth, and extending from the
mandibular left canine to the mandibular right canine.
 Rests on the canines and first premolars are made
from .032" stainless steel wire. Tubes between the
second premolars and first molars receive the active
components. The posterior distalizing unit uses nickel
titanium coil springs, about 18mm in length, which
apply an initial force of 100-120g per side

129.  A J-shaped wire passing through each coil is inserted into
the corresponding tube of the anchorage unit the
recurved posterior portion of the wire is engaged in the
lingual sheath of the mandibular first molar band.
 The anchorage unit is bonded with composite resin to the
canines and first premolars.
 The J-shaped distalizing unit is then ligated to the
lingualsheaths of the molar bands, compressing the coil
springs. Thus, the active part of the appliance runs
lingually at a level close to the center of resistance of the
molar, to produce an almost pure bodily movement

130. During the distalization phase, the mandibular molars moved
4.5-5mm distally while the incisors moved 1mm anteriorly.
The mandibular right molar crown tipped 4° distally, and
the mandibular incisor crowns tipped 1° labially. Thus, the
movement of the incisor crown resulted in an anchorage
loss of 1mm and 1°.

131. B. Intermaxillary appliance:
1. Herbst appliance
2. Jasper Jumper
3. Eureka Spring
4. Klapper superspring

132. Herbst Appliance
 The Herbst appliance is completely tooth-borne and
uses both the maxillary and mandibular dentition to
transfer the force exerted from the telescopic arms of
the Herbst bite jumping mech-anism to the bases of
the maxilla and the mandible. The telescopic system
produces a posterosuperiorly directed force on the
maxil-lary posterior teeth and an anteriorly directed
force on the mandibular dentition. As a result, Class II
molar correction generally is a combina-tion of
skeletal and dentoalveolar changes irre-spective of
facial morphology.

133. The Herbst telescoping bitejumping mechanism places
a distal and intrusive force on the maxillary molars and
the force vector passes occ1usally to the center of
resistance. This force system produces backward and
upward movements of maxillary molars in conjunction
with distal crown tip-ping. Because of the intrusive
effect, distal movements of maxillary molars do not
tend to open the mandible. These effects are similar to
those produced by high-pull head-gear.
 In general, maxillary molar distal-ization has been
shown to comprise approxi-mately 25% to 40% of molar
correction with the banded Herbst appliance, whereas
in the acrylic design it accounts for 20% to 25% of the
correction.


134.  The distalizing effects are reported to range from an
average of 1.8 mm in the study by Franchi et al (AJO
1999) to 2.8 mm in the study by Pancherez (AJO 1982).
The intrusive effects are 1mm approximately. The
amount of distal and vertical movement of maxillary
molars is found to be independent of the presence of
erupted 2nd
molar.
Stability
 In a long-term study on the results of Herbst treatment,
Pancherz (AJO 1991) compared two groups of Herbst-
treated patients with and without relapse in the
occlusion. Skeletal and dentoalveolar changes in the
mandibular arch were found to be similar in both
groups 5 years after treatment. The reason for relapse
was thought to be the anterior movements of maxillary
dentition owing to muscular influence from the lips or
tongue, or to an unstable occlusal condition after
treatment.


135.  The Klapper Superspring II:
 In 1997 Lewis Klapper introduced
the Klapper Superspring for the
correction of Class II malocclusions.
It resembles a Jasper Jumper with
the substitution of a cable for the
coil spring. In 1998 the cable was
wrapped with a coil.
 The Klapper Superspring II inserts
from the mesial and is rigidly
secured to the molar by an oval
attachment tube. The Klapper
Superspring creates a mo-ment on
the molar, which is expressed
clinically as distal root tip, but
extended wear of the appliance
results in excessive distal root
tipping.


136.  Because the Klapper Superspring inserts gingivally on
the molar and cannot roll to the buccal as readily as
a Jasper Jumper, there may be a greater vertical
component to the force vector. If this were of clinical
significance, a patient with a pro-nounced curve of
Spee would level more quickly with the Klapper
Superspring. However, extended wear should pro-
duce excessive intrusions and may require removal
before sagittal corrections have been completed.
 Disadvantages of the Klapper Superspring:
 1. Requirement of a special molar tube,
 2. Limitation to maximal opening,
 3. Risk of injury to the patient if breakage oc-curs
 4. Extended wear may cause excessive distal root
tipping to the maxillary molar and more intrusion to
the molars and incisors than desired

137.  The Eureka Spring
 1997 JCO
 The interarch Eureka Spring became
available in 1996, has a pure
compression action, and therefore
delivers linear force throughout its
range. It permits unlimited
mandibular move-ments and has
good patient acceptance. It can
be used in Class II and Class III
malocclusions, does not require
molar tubes, and can be used in
conjunction with extraoral force.
These springs come in two sizes and
are converted at the time of
insertion into left or right action;
therefore inventory is minimal.

138.  No auxiliary attachments are required. Because it is
truly a compression spring, it is less prone to breakage
than curvi-linear than Jasper Jumper. A constant force
of 16 grams per millimeter is generated, which permits
the clinician to visually determine the force at any
time and adjust the force as needed
 A cephalometric evaluation of the first 50
consecutively treated bilateral Class II patients
indicated the following:
 Average anteroposterior correction was at the rate of
0.7mm per month.
 For every 3 mm of anteroposterior correction, the
maxil-lary molars intruded 1 mm and the mandibular
incisors intruded 2 mm.

139.  The maxillary dentition moved distally 1.5 mm
and the mandibular dentition moved mesially
1.5 mm.
 No increase occurred in anterior face height
between the dolichocephalic and
brachycephalic subgroups.
 As with the Jasper Jumper, intrusion of teeth
occurs dur-ing treatment. However, unlike the
Jasper Jumper the amount of intrusive force
can be altered by changing the force vector
and magnitude

140. IMPLANT SUPPORTED
DISTALIZATION
 Karaman - implant-supported modified distal
jet appliance
 Graz implant supported pendulum
 Sugawara & Umemori SAS supported
mandibular distalization

141. Karaman (AO 2002 April ) A
case report
 In this study, author used an
implant-supported modified
distal jet appliance that has the
advantages of implants and
intraoral distalization
appliances, and assessed its
effect on dentofacial structures.
 Molar bands with palatal tubes
were fitted to the upper first
molars. An anchorage screw
three mm in diameter and 14
mm in length was placed at the
anterior palatal suture, two–
three mm posterior to the
canalis incissivus under local
anesthesia .

142.  Anchor wires 0.8 mm in
diameter were soldered to
the tubes for occlusal rests on
the first premolars. The 0.9-
mm wire extended through
each tube, ending in a
bayonet bend that was
inserted into the palatal tube
of the first molar band.
 For force application, Niti
open-coil springs were
adjusted.
 The implant-supported
modified distal jet appliance
was attached to the anchor
premolars and implant with
light-cured composite
adhesive.

143.  The screw was removed without anesthesia and
with no discomfort for the patient during the
removal.
 Maxillary molar moved distally 5mm after 4 months
of treatment and intruded by 2mm without
movement of premolars.
 Upper incisor position, MPA, and LAFH remained the
same.
 The main advantages of the appliance are its
stability against rotational movements. Adequate
distal movement of the molar tooth was achieved
without the loss of anchorage.
 Irritation of the palatal mucosa and gingival
hyperplasia didn’t occur because the patient could
maintain optimum oral hygiene.

144. GRAZ IMPLANT SUPPORTED PENDULUM
 Byloff et al (Int J Adult Orthod. Orthognathic Surg
2000)
 To avoid mesial movement of anchor teeth,
extraoral anchorage such as headgears and
intraoral Nance holding arches are commonly
used.
 Advances with implants have made it possible to
use them as a means of anchorage in adult
orthodontic patients.
 But with orthodontic patients, when only the
question of anchorage must be addressed, the
retro molar area or the palate as implant
locations are preferred because they do not
interfere with orthodontic tooth movement.

145. Site for Orthodontic Implants:
 The histomorphology of the palatal bone
shows that the median palatal region is the
best location for an endosseous implant.
Implant loading:
 Implants are loaded after a period of
approximately 12 to 24 weeks to allow
healing and osseointegration, which seems
to be a general rule in the use of implants.
 Byloff described a newly designed palatal
anchoring system, the Graz implant-
supported pendulum (GISP) .This system can
be loaded within 2 weeks to distalize and
anchor maxillary first and second molars.

146. The anchorage part of the GISP consists of a
simple surgical plate (15 X 10 mm) with 4 screw
holes. Two cylinders (10 mm long and 3.5 mm in
diameter) are soldered at right angles to the
center of the plate.
The plate is fixed to the palatal bone via four 5-
mm-long titanium mini-screws The 2 cylinders
perforate the palatal mucosa to enter the oral
cavity .The entire anchorage device is made of
100% Titanium.

147.  Implant is placed under GA.
 Maxillary impression is taken after 2 weeks of
healing.
 Removable PA is fabricated.
 TMA springs are activated extraorally to
generate 250 g of force

148. Because molars tend to tip back when
distalized with a PA,an uprighting bend
( Byloff AO 1997) was introduced into the
recurved end of the spring when
necessary.
 After the 8 months of molar distalization,
the first and second premolars have drifted
distally, presumably under the influence of
the elastic fibers in that area. The molars
were almost in a full Class II relationship at
the beginning of treatment

149. Advantages:
1. Class II elastics to support anchorage are
unnecessary, and side ef-fects on the mandible are
avoided.
2. This system can be loaded almost immediately,
which is an advantage over implants requiring a
healing and osseointegration time of at least 3 – 4
month.
3. Unilateral distalization can be done without any
effect of generated moment.
4. Treat-ment time is decreased because of the
anchorage provided by the GISP. En masse retraction
of anteriors can be done shortening the treatment
time considerably.
5. Stability against rotational movements
Disadvantage: Invasive surgical procedure for insertion
and removal of anchorage plates.

150. Sugawara & Umemori, (Ajo 2004Jan)
 The skeletal anchorage system (SAS) consists of
titanium anchor plates and monocortical screws
that are temporarily placed in either the maxilla or
the mandible, or in both, as absolute orthodontic
anchorage units, Distalization of the molars has
been one of the most difficult biomechanical
problems in traditional orthodontics, particularly in
adults and in the mandible, However, it has now
become possible to move molar's distally with the
SAS to correct anterior crossbites, maxillary dental
protrusion, crowding, dental asymmetries without
having to extract premolars.

151. Skeletal anchorage system (SAS) uses pure
titanium anchor plates and screws as
absolute orthodontic anchorage units. The
anchor plates are monocortically placed at
the piriform opening rim, the zygomatic
buttresses, and any regions of the mandibular
cortical bone, Because the anchor plates
work as the onplant and the screws function
as the implant, SAS enables the rigid
anchorage that results from the
osseointegration effects in both the anchor
plates and screws.

152.  SAS does not interfere with tooth movement.
Therefore, it is possible to distalize the
mandibular molars with anchor plates
placed at the anterior border of the
mandibular ramus or mandibular body

153.
 Sugawara & Umemori evaluated the treatment
and posttreatment changes during and after
distalization of the mandibular molars, In 15 adult
patients, a total of 29 mandibular molars were
successfully distalized with SAS.
 The amount of posterior displacement at the
crown and root levels was measured on the
occlusograms and the cephalometric tracings,
respectively. The type of tooth movement was
evaluated by the crown and root movement
ratio. When the percentage ratio of the root
movement to the crown movement (the tipping
ratio) was less than 25%, the type of tooth
movement was determined to be tipping.

154.  The average amount of distal move-ment with SAS
was 3.5 mm at the crown level and 1.8mm at root
apex level. The maximum amount of distalization at
the crown level was 7.1 mm, and the minimum was
1.0 mm at the first molar. The average tipping ratio
was 46.3%. Although most of the first molars showed
bodily movement, 9 of 29 molars showed tipping
movement, in which the tipping ratios were less than
25%.
 Maximum relapse was 0.8 mm. and the maxi-mum
relapse rate was 40%. The average amount of
relapse was 0.3 mm at both the crown and root
apex levels. No significant correlation was found
between the amount of relapse and the tipping
ratio and the amount of tooth movement.

155. The SAS has outstanding advantages not provided by
the other mechanisms for distalizing the mandibular
molars.
 1. It is possible to intrude the mandibular molars with
the SAS. Therefore the extrusion of the mandibular
molars after the tipping of the molar distalization can
be corrected easily.
 2. En masse distalization of the mandibular buccal
segments or the entire dentition is also possible if the
mandibular dentition is aligned.
 3. With the SAS, it is not always neccssary to extract
the mandibular first or second premolars even in
patients with moderate to severe crowding.
 4. Molar relationship in patients with symmetric or
asymmetric Class III molar relationship can be
corrected without having to extract mandibular
premolars.

156. Conclusion
Traditionally, the arch length deficiency has
been calculated anterior to the first molars
because molar distalization was assumed to
be nearly impossible. However by using the
space posterior to the second molars 14
permanent teeth can be well aligned in the
alveolar bone as demonstrated by these
studies. Therefore it will now become
necessary to find an indicator to determine
the posterior limits of the alveolar region from
the standpoints of orthodontics, anatomy,
and periodontology. E.g. Location of
mandibular 3rd
molar