This document discusses various types of intrusion arches used in orthodontics to correct deep overbites. It begins by defining intrusion and describing the biomechanics and principles involved. It then covers 9 specific intrusion arch designs: 1) Rickett's Utility Arch 2) Tipback Springs 3) Burstone's Continuous Intrusion Arch 4) Burstone's Three Piece Intrusion Arch 5) K-SIR 6) Connecticut Intrusion Arch 7) PG Retraction Spring 8) Translation Arch 9) Lingual Arch for intruding lower incisors. For each type, it provides details on materials, design, and mechanics of intrusion.

1. INTRUSION ARCHESINTRUSION ARCHES
PRESENTED BY
SUSNA PAUL

2. CONTENTS
1. INTRODUCTION
2. MAJOR PRINCIPLES OF INTRUSION
3. BIOMECHANICS INVOLVED
4. VARIOUS INTRUSION ARCHES
1. RICKETT’S UTILITY ARCH
2. TIPBACK SPRINGS ( INTRUSION SPRINGS)
3. BURSTONE’S CONTINUOUS INTRUSION ARCH.
4. BURSTONE’S THREE PIECE INTRUSION ARCH
5. K-SIR (KALRA SIMULTANEOUS INTRUSION AND RETRACTION)

3. 5. CONCLUSION
6. REFERENCES
6. CONNECTICUT INTRUSION ARCH
7. PG RETRACTION SPRING
8. TRANSLATION ARCH
9. LINGUAL ARCH FOR INTRUDING AND UPRIGHTING LOWER INCISORS

4. .
INTRUSION
Intrusion refers to:
the apical movement of the geometric center of the root
(centroid) in respect to the occlusal plane or plane based on the
long axis of the tooth. - Burstone
Marcotte defines intrusion as the” tooth movement that occurs in
an axial (apical) direction and whose center of rotation lies at
infinity. It is an axial type of translation”
Nicolai as “ Translational form of tooth movement directed apically
and parallel to the long axis”

5. Correction of the deep overbite can be accomplished in a number of ways
depending on the initial diagnosis and treatment objectives. Deep bite can
be corrected by various tooth movements which include:
a) Extrusion of posterior teeth
b) Uprighting of posterior teeth
c) Increasing the inclination of incisors
d) Intrusion of anterior teeth
e) Combination of one or two of the above tooth movements

6.  Extrusion of the posterior teeth will result in increased lower facial
height, steepening of the occlusal plane, downward and
backward rotation of the mandible, resulting in worsening of the
class II skeletal relationship
 Intrusion of anterior teeth to correct deep overbite may be
indicated in patients with unaesthetic excessive maxillary incisor
showing at rest position of the lip (5-8mm)

7. MAJOR PRINCIPLES OF INTRUSION
Six major principle of intrusion should be followed; if genuine intrusion and
greater control of force system is needed:
1.CONTROLLING FORCE MAGNITUDE AND CONSTANCY.
2.ANTERIOR SINGLE POINT CONTACTS.
3.POINT OF FORCE APPLICATION.
4.SELECTIVE INTRUSION.
5.CONTROL OF REACTIVE UNITS.
6.AVOIDING EXTRUSIVE MECHANICS.
Burstone CJ. Deep overbite correction by intrusion. AmJ Orthod 1977;72:1-22

8. CONTROLLING FORCE MAGNITUDE AND
CONSTANCY
 TRUE INTRUSION LOW MAGNITUDE OF FORCE
 If the magnitude of force are too great; rate of intrusion will not increase
rate of resorption will increase reciprocal effect on posterior
anchorage

9.  In order to maintain a constant force during intrusion, wire with a
low load deflection rate should be used.
 If a high load deflection spring is used for intrusion as teeth moves,
a rapid drop in force magnitude occurs, so that optimal force may
be only momentarily reached..

10. ANTERIOR SINGLE POINT CONTACTS
 By having a single point of force application on the incisors, the
clinician knows more positively the full force system acting at the
incisor segment and buccal tube, thereby producing a statically
determinant system.
 By placing the intrusive arch into the brackets produces a statically
indeterminant system, which prevents the orthodontist from
knowing exactly what type of force he is delivering
 INTRUSION ARCH INTO THE BRACKET TORQUE TO THE
ANTERIOR SEGMENT INTRODUCED

11. LABIAL ROOT TORQUE
INCREASES THE MAGNITUDE OF INTRUSIVE FORCE
INCREASES THE SIDE EFFECTS ON ANCHORAGE UNIT
LINGUAL ROOT TORQUE
DECREASES THE INTRUSIVE FORCE

12. POINT OF FORCE APPLICATION
Passing through
center of resistance
Intrusion of incisor
segment
Passing labial to the
center of resistance
Flares the crown
more labially

14. Prevented by 2 ways:
if tooth is forwardly placed, retrude and then intrude.
apply the vertical force lingual to the center of resistance

15. SELECTIVE INTRUSION
 Leveling with a continuous arch or with a sectional wire can
produce undesirable side effects.
 Many times the overbite is corrected not because of intrusion but
by extrusion.

16. CONTROL OF THE REACTIVE UNIT
Two basic side effects should be anticipated from intrusive mechanics:
From the lateral view a moment is created which tends to alter the plane of
occlusion of the buccal segment and therefore in the upper arch, the plane is
steepened.
1.the force are kept as low as possible
2.teeth in the buccal segment are rigidly connected and the right and the left
buccal stabilizing segment are connected
3.So add more teeth for anchorage
4.Do as much retraction as possible to decrease the length of moment arm

17.  Second major side effect produced by an intrusive arch can be seen
from the frontal view with an intrusive force acting on the incisors,
there is an equal and opposite extrusive force acting at the molars
and since the extrusive force is acting buccaly at the tube, a moment
is created that tends to tip the crowns lingually and roots buccally.
One of the functions of the lingual arch is to resist side effectS.

18. AVOIDING EXTRUSIVE MECHANICS
 Extrusive mechanics should be avoided if one is to accomplish
genuine intrusion.
 One of the classic situation for inadvertently erupting incisors which
have been intruded or are going to be intruded is placement of
continuous arch wire.

19.  It is wise to intrude the maxillary incisors to a significant degree prior to any
retraction:
1. Bite opening is achieved by moving maxillary incisors into the alveolus
2. The potential for increasing a gummy smile is minimized
3. The unfavorable tipping of the occlusal cant will not be as common
4. It will minimize the chances of moving the apices into juxtaposition against
the dense cortical bone
5. There will be a reduction in the total amount of class II elastics that will be
required
6. The torquing requirements will be reduced, and when needed will be
accomplished within a more adequate anatomical area, and not
restricted by the lingual cortical plate.

20. INTRUSION FORCE
Intrusion Per-Side Total in Midline
Upper central inciosr 15-20(gm) 30-40(gm)
Upper central and
lateral incisor
30-40(gm) 60-80(gm)
Upper central lateral
and canine
60(gm) 120(gm)
Lower central incisor 12.5(gm) 25(gm)
Lower central and
lateral incisor
25(gm) 50(gm)
Lower central lateral
and canine
50(gm) 100(gm)
Dr. Charles J.Burstone., Modern Edgewise Mechanics and The
Segmental Arch Technique

21.  Proffit suggested 10-20 grams of force needed for intrusion.
 Bench, Gugino and Hilgers in 1978, advocated intrusive force of 15 to 20
grams per lower incisor and 60 to 80 grams for all four lower incisors.
 Lui and Herschelb in 1981 suggested use of 80 to 100 grams of force for four
incisors intrusion
Though there has been many opinions regarding an ideal force for intrusion, all
recognize the need for light continuous force

22. INTRUSION ARCHES

23. Intrusion can be accomplished in two ways with intrusion arches.
1. With continuous archwire that bypasses the premolars and canine
teeth.
2. With segmented base archwire. So that there is no connection
along the arch between the anterior and posterior segments and
an auxiliary depressing arch.

24. 1. RICKET’S UTILITY ARCH
2. TIPBACK SPRINGS ( INTRUSION SPRINGS)
3. BURSTONE’S CONTINUOUS INTRUSION ARCH.
4. BURSTONE’S THREE PIECE INTRUSION ARCH
5. K-SIR (KALRA SIMULTANEOUS INTRUSION AND RETRACTION)
6. CONNECTICUT INTRUSION ARCH
7. PG RETRACTION SPRING
8. TRANSLATION ARCH
9. LINGUAL ARCH FOR INTRUDING AND UPRIGHTING LOWER
INCISORS

25. RICKETT’S UTILITY ARCH
McNamara JA Jr. Utility arches. J clin orthod 1986;20:p.452-456.

26. UTILITY ARCH
 Utility arch designed by Robert M. Ricketts in the early 1950’s and
has been popularized as an integral part of bioprogressive therapy.
 continuous wire that extends across both buccal segments, but
engages only the 1st
permanent molars and four incisors .

27. MATERIAL FOR UTILITY ARCH
- Dimension in an 0.022" slot
Non heat treated blue elgiloy
0.016" x 0.016" or 0.016" x 0.022”(mandible)
0.016" x 0.022” (maxilla)
- Dimension in an 0.022" slot
Blue elgiloy 0.019" x 0.019”

28.  Molar segments
 Posterior vertical segment
 Vestibular segment
 Anterior vertical segment
 Incisal segment.

29. MOLAR SEGMENT
 It extends into a tube on the 1st
molar.
 This segment may be cut flush with the end of the tube or may be
bend gingivally if the utility arch is to be tied back.
 When utility arches are used in combination with full arch
appliances, it is necessary to have auxiliary tubes located in the
gingival portion of the 1st
molar bands..

30. POSTERIOR VERTICAL SEGMENT
 It is formed by making a 90° bend with 142 arch forming pliers.
 Posterior step typically is 3-4mm in length.

31. VESTIBULAR OR HORIZONTAL SEGMENT
 Vestibular segment is formed by placing a right angle bend at the
inferior portion of posterior vertical segment. The wire then passes
antero-inferiorly along gingival margin.

32. ANTERIOR VERTICAL SEGMENTS
 Anterior vertical segments should be about 5-8mm in length.

33. INCISAL SEGMENT
 Final 90° bend creates the incisal segment that should lie passively
in the brackets of anterior teeth

34. UTILITY ARCHES
 PASSIVE UTILITY ARCH
 INTRUSION UTILTY ARCH
 RETRACTION UTILITY ARCH
 PROTRUSION UTILITY ARCH

35. INTRUSION UTILITY ARCH
 Intrusion utility arch is similar in design to passive utility arch , arch is
activated to intrude the anterior teeth.
 Utility arch should produces 100 grams of force on the mandibular
incisors, force level considered ideal for mandibular incisor intrusion.

36. Activation
occlusally directed gable bend in the
posterior portion of the vestibular segment
of the arch wire

37.  Bench has advocated an alternative method of activation of utility
arch to produce intrusion. This type of activation involves placing a
tip – back bend in the molar segment .
 However placing a tip back bend can occasionally lead to
unintentional posterior tipping of 1st
molars.
 Thus activating the Utility arch by placing a gable bend in the
posterior aspect of the vestibular segment seems to avoid
unwanted tipping.

38. Retraction Utility Arch
 Retraction and intrusion can be
produced by activating the retraction
arch in a similar fashion previously
described of the intrusion utility arch.
 The incorporation of the loop into the
design allows for a longer range of
activation.

39. Protraction Utility Arch
 When passive, anterior segment lies
approx. 2mm anterior to the
expected position in the incisor
bracket.
 Protrusion force produced by tying
anterior segment into the anterior
brackets.
 Activation:

40. BIO – MECHANICS OF INTRUSION ARCHES
 One couple systems
 Two couple systems

41. 41
One Couple Appliances—Statically Determinate
Systems
The end that is tied as a point contact only force
The end which is engaged in the bracket slot a force and a couple
1-couple system couple is generated only at the site of full engagement.
It is statically determinate magnitudes of the forces and moments
produced can be determined clinically after the appliance is inserted into
the bracket.

42. Two Couple Appliances - Statically
Indeterminate Systems:
Both the ends of the wire is engaged into brackets
 magnitudes of the forces and moments produced can not be determined
clinically after the appliance is inserted into the bracket.
 Because of the inability to measure force systems produced by 2-couple
appliances clinically, they are referred to as being statically indeterminate.

43. INTRUSION ARCHES
 Two factors in the action of the intrusion arch are :
1. the relationship of the point of force application relative to the
center of resistance of the incisor segment
2. whether the incisors are free to tip facially as they intrude or
whether the arch is cinched back.

44. TWO COUPLE SYSTEM (utility arches)
 At the incisors:
a moment to tip the crown facially (Mf) is created by the distance of
the brackets forward from the center of resistance, and an
additional moment in the same direction is created by the couple
within the bracket (Mc) as the inclination of the wire is changed as it
is brought to the brackets.

45.  Placing a torque bend in the utility arch creates a moment to bring
the crown lingually, controlling the tendency for the tooth to tip
facially as they intrude increases the magnitude of the
intrusive force on the incisor segment and the extrusive force and
the couple on the molar

46.  Cinching back the utility arch creates a force to bring the incisors
lingually, and a moment of this force opposes the moment of the
intrusive force. At the molar, a force to bring the molar mesially is
created along with a moment to tip the molar mesially.

47. BURSTONE’S INTRUSION SPRING

48. TIP BACK SPRINGS (Intrusion Springs)
 By Burstone
 The upper and lower arches have to be leveled and aligned and a
rigid stainless steel wire, preferably 0.017”x 0.025” dimension is
engaged.
 Anchor is reinforced by TPA and lingual holding arch.

49.  The intrusion springs are made from 0.017" x 0.025" TMA wire without
a helix or 0.017" x 0.025" stainless steel wire with a helix so that
forces can be made optimal for intrusion.
 Wire is bend gingivally mesial to the molar tube and then a helix is
formed.
 The mesial end of the spring is bend into a hook and is engaged
distal to lateral incisor (activation)

50. BURSTONE INTRUSION ARCH
Burstone CJ. Deep overbite correction by intrusion. Am J Orthod 1977;72:1-22

51. Continuous intrusion arch
 The intrusion arch, as described by Burstone in 1977, is significantly
different in its force deliver because it is not engaged in the incisor
brackets.

53. The basic mechanism for intrusion consists of three parts:
1. The posterior anchorage unit.
2. The anterior segment.
3. The intrusion arch itself.

54. 54
Posterior anchorage unit
Early in treatment the posterior teeth are aligned and joined
together with a buccal stabilizing segment of heavy wire.
Right and left posterior segments are joined together across
the arch by means of a transpalatal arch in the maxilla and a lingual
arch in the mandible.
Whenever possible, at least the first molars and second
premolars should be used and the addition of other teeth would
further enhance the anchorage potential.

55. Intrusive arch spring
 The intrusive arch consists of an 0.016 x 0.022 inch or 0.017 x 0.025 inch
TMA..
 A step down is placed to the canine bracket to avoid this bracket upon
activation of the intrusion arch.

56. Anterior segment
 Initial alignment of anterior teeth is not necessary when performing
intrusion..
 Intrusive spring is tied to the wings of the brackets of incisor not into
the slot.
 Formed to fit the teeth to be intruded.

57. Continuous intrusion arch

58. Three-piece Intrusion Arch
Segmented approach to simultaneous intrusion and space closure:
biomechanics of three piece base arch appliance” Am J Orthod dentofac
Orthop 1995:107: 136-43

59.  In patients with proclined incisors, a continuous intrusion arch tied
at the midline cannot be used because the force system
generated tends to worsen the axial inclination of the anterior teeth
 So the selection of the point of application of the intrusive force with
respect to the center of resistance of the anterior segment is
important to precisely define the type of tooth movement that will
occur

60.  In many extraction cases the axial inclination of flared anterior teeth is
corrected first by retraction of the incisors during initial space closure.
 When no further retraction is possible because of the presence of a
deep bite and the reduction of the overjet, intrusion is initiated to
open the bite and allow subsequent space closure.
 To achieve deep overbite correction and close extraction spaces
simultaneously,

61.  An appliance design needs to incorporate a variable point of
application of the intrusive force, as well as a mechanism to direct the
intrusive force along the long axis of the anterior teeth.
 This is a segmented approach to simultaneously intrude and retract
the flared by using frictionless mechanics
 Introduced by Bhavna Shroff, Steven J. Lindauer, Charles J. Burstone,
Jeffrey B. Leiss in 1995.

62. principles of the segmented arch
technique
 different wire cross-sections in a given arch rather than continuous
wires
 develop a precise and predictable force system between an
anterior segment (incisors) and a posterior segment (premolar and
molars) enabling pure intrusion of the anterior teeth and control of
their axial inclinations

63. Three piece intrusion arch
Consists of:
 Posterior anchorage segment
 Anterior segment with posterior extension
 Intrusive cantilevers
 Sometimes chain elastics

64. ANTERIOR SEGMENT WITH POSTERIOR EXTENSION
 It is bent gingivally distal to the laterals and then bent
horizontally creating a step of approximately 3 mm
 Distal part extends to distal end of canine bracket where it
forms a hook
 0.021 X 0.025 SS
POSTERIOR SEGMENT
 Aligned posteriors
 0.017 X 0.025 SS
 TPA can be given for more consolidation

65. CANTILEVER OR INTRUSION SPRING
Made from 0.017" X 0.025" TMA wire.
The wire is first bent gingivally mesial to the molar tube and then a
helix is formed. On the mesial end the cantilever, hook is bent through
which the intrusion force can be applied to the anterior segment.
The cantilever is then activated by the making a bend mesial
to the helix at the molar tube, and then cinched back.

66. A small distal force can be added by attaching chain elastic from the hook of
anterior segment to the molar tube to facilitate simultaneous intrusion and
retraction of the anteriors on each side

67. Biomechanics
Intrusive force through CR will intrude incisor along line of
action of this force.
An intrusive force perpendicular to the distal extension and
through CR will have the same effect as in A.

68.  To obtain a line of action of the intrusive force through the center of
resistance and parallel to the long axis of the incisors, the point of force
application must be more anterior and a small distal force should be given

69.  If the intrusive force is placed farther distally and an appropriate
small distal force is applied, intrusion and simultaneous retraction of
the anterior teeth occurs because of the tip back (clockwise)
moment created around the center of resistance of the anterior
segment consisting of four incisors.

71. K- SIR APPLIANCE
Varun Kalra, “simultaneous intrusion and retraction of the anterior teeth”
JCO 1998 p535-540.

72.  The K-SIR (Kalra Simultaneous
Intrusion and Retraction)
archwire is a modification of
the segmented loop
mechanics.
 K-SIR archwire: .019“x.025"
TMA archwire with closed U-
loops 7mm long and 2mm
wide.
K- SIR APPLIANCE

73.  90° bends placed in archwire at level of U-loops.
 Centered 90° V-bend creates two equal and opposite moments (red) that
counter the moments (green) produced by activation forces.

74.  Archwire with off-center 60° V-bend placed about 2mm
distal to U-loop.
 Off-center V-bend creates greater moment on molar,
increasing molar anchorage and intrusion of anterior teeth.

75.  20° antirotation bends placed in archwire just distal to U-loops.

76.  Trial activation performed on each loop..
 Archwire after trial activation.

77. Neutral position of loop determined with mesial and distal legs extended
horizontally. In neutral position, loop is 3.5mm rather than 2mm wide.

78. K-SIR archwire in place prior to cinching back. First molar and second premolar
are connected by segment of .019"x .025" TMA wire.
Archwire cinched back to activate loop about 3mm, so that mesial and distal
legs are barely separated.

79. advantages
 simplicity of design, with a minimal amount of wire in the loop
configuration
 material properties of TMA combine to produce relatively low
forces, a low load-deflection rate
 the presence of the off-center V-bend, which acts like an anchor
bend, molar anchorage control is excellent

80. THE CONNECTICUT INTRUSION ARCH
JCO, VOLUME 32 : NUMBER 12 : PAGES (708-715) 1998
RAVINDRA NANDA, ROBERT MARZBAN, ANDREW KUHLBERG, DMD, MDS

81. THE CONNECTICUT INTRUSION ARCH
 The CTA is fabricated from a nickel titanium alloy. It incorporates the
characteristics of utility arch as well as those of the conventional intrusion arch.
 Two wire size are available 0.016” x 0.022” and 0.17” x 0.25”.

82. In most cases, the wire is not directly ligated into the bracket
slots, the anterior wire dimension is adequate to allow for it.
The bypass, located distal to the lateral incisors, is available in
two different lengths to accommodate for extraction,
nonextraction or mixed dentition cases.

83. Dimensions of preformed CONNECTICUT INTRUSION ARCHES
Maxillary CTA Mandibular CTA
Anterior dimension 34mm 28mm
Posterior dimension: long
(non-extraction)
22mm 22mm
Posterior dimension: short
(extraction and mixed
dentition)
15mm 15mm

84. MECHANICS
 The CTA’s basic mechanism for force delivery is a V bend lies just
anterior to the molar brackets.
 When the arch is activated, a simple force system results, consisting
of a vertical force in the anterior region and a moment in the
posterior region.

85.  Incisor intrusion requires 50g of force directed apically along the
center of resistance.
 The moment created at the molar will also vary, according to
the amount of force at the incisor multiplied by the distance at
the molars. These minor changes can be made to ensure proper
force delivery.

86.  A pure intrusion arch would have a point contact at the incisors.
 Insertion of the wire into the incisor brackets, however, will tend to flare
the incisors, which may or may not be desirable.
 The CTA’s point of force application is anterior to the center of
resistance, which will flare the incisors.
 A tight cinch-back—a sharp bend distal to the molar tube, preventing
forward slippage of the wire—will prevent incisor flaring during intrusion
and produce some retraction of the incisors.

87. PG RETRACTION SPRING
POUL GJESSING, DDS A Universal Retraction Spring J Clin
Orthod.1994;28:04:p.222-242

88. PG RETRACTION SPRING
(P0UL GJESSING, 1985)
 Prefabricated ,standardized springs
 0.017 X 0.025“ or 0.016 X 0.022” SS wire is used for PG
springs.

89. CANINE RETRACTION INCISOR INTRUSION &
RETRACTION

90. DESIGN
Configuration of double helix to produce 100g of horizontal driving force.
PG Universal Retraction Spring with curved posterior extension.

91. DESIGN & ACTIVATION FOR INCISOR INTRUSION &
RETRACTION
The posterior extension of the spring is always inserted in the gingival
auxiliary molar tube, but the anterior extension can be attached to
the lateral bracket in several ways.

92.  The most practical is to use .018"´.025" lateral incisor brackets with
vertical Broussard-type slots. The anterior extension is placed in the
vertical slot of the lateral incisor bracket, pulled as far occlusally as
possible, and locked with a mesial bend. These accommodate
the .017"´.025" PG springs.

93.  The spring is activated by pulling distal to the molar tube until the
two loops separate.
 The wire is secured with a gingival bend in the posterior extension.
 Reactivation to the initial spring configuration should be done every
four to six weeks

94. THE TRANSLATION ARCH
Martina R. Paduano S. The Translation Arch. J Clin Orthod.
1997;3;11:p.750-753

95. The Translation Arch
This is a kind of utility arch that can be used in bioprogressive
therapy and similar techniques to simultaneously retract,
torque, and intrude or control the extrusion of the maxillary
incisors.

96.  The Translation Arch is made of .016" × .022" TMA.
 The posterior teeth are tied together with .017" × .025" stainless
steel sectional wires and transpalatal arch.
 A distal activation of 2mm on each end of the arch will produce
the 100g of horizontal force needed for incisor retraction

97. A. Translation Arch has anterior segment inserted into incisor
brackets and two buccal segments inserted into gingival first
molar tubes.
A. Vertical loops between segments extend as far as possible. Arc
—should be bent into each buccal segment to produce an
intrusive force of 40g on the incisors
Design

98. LINGUAL ARCH FOR INTRUDING AND
UPRIGHTING LOWER INCISORS
W Senior. A lingual arch for intruding and uprighting lower
incisors. J Clin Orthod. 2003 Jun;37(6):302-6

99.  This technique was introduced by WINSTON SENIOR. An .036" lower
lingual arch is soldered to first molar bands.
Distal extensions form occlusal rests on the second molars to prevent
distal tipping of the first molars as the incisors are intruded.
 Four elastic chains are attached to the anterior bridge of the
lingual arch with a mosquito forceps .

100.  After cementation of the arch, the elastics are stretched to four lingual
buttons on the lower incisors . These should be bonded as far as possible
from the gingival margin to facilitate intrusion

101. Palatal elastics from TPA
- modification given by Prof. Dr. Jayade

102. CONCLUSION
 These appliances are integral part of interceptive and
comprehensive orthodontic treatment. It is efficient in intruding ,
protruding or retruding anterior teeth.

103. REFERENCES
Charles J. Burstone “ Biomechanics of deep overbite correction” semin
orthod 2001: 7: 26-33
Bhavana Shroff, Steven J Lindauer , Charles J Burstone “ Segmented
approach to simultaneous intrusion and space closure: biomechanics of three
piece base arch appliance” Am J Orthod dentofac Orthop 1995:107: 136-43.
Richard J. Smith, Charles J. Burstone, “ Mechanics of tooth movement” vol
85, 294-307
McNamara JA Jr. Utility arches. J clin orthod 1986;20:p.452-456.
Martina R. Paduano S. The Translation Arch. J Clin Orthod. 1997;3;11:p.750-753

104.  Charles J. Burstone, Modern edgewise mechanics and the segmented
arch technique” ed. Ormco 1995.
 Steven J. Lindauer, “Basics of mechanics” semin orthod, 7, 2001: 1-15
 Burstone CJ. Deep overbite correction by intrusion. AmJ Orthod
1977;72:1-22
 Varun Kalra, “simultaneous intrusion and retraction of the anterior
teeth” JCO 1998 p535-540.
 Nanda R, Marzban R, Kulberg, “The Connecticut Intrusion Arch”
JCO1998 p 708 – 715
 POUL GJESSING, DDS a universal retraction spring j clin
orthod.1994;28:04:p.222-242
 W Senior. A lingual arch for intruding and uprighting lower incisors. J Clin
Orthod. 2003 Jun;37(6):302-6

105. THANK YOUTHANK YOU