This document discusses various orthodontic prescriptions and appliances, focusing on Andrew's Straight Wire Appliance (SWA). It describes Andrew's research establishing six keys to normal occlusion and the measurements he took of tooth positions. It explains how Andrew's SWA is a fully programmed appliance that guides teeth using unbent archwires by incorporating built-in tip, torque, and rotation into customized brackets for each tooth. The document also summarizes other prescriptions like Roth and their philosophies regarding overcorrection of tooth positions.
3. Introduction
“ All you can do is to push or pull or turn a
tooth. I have given you an appliance. Now
for God’s sake use it!” – Angle.
“There is only one disease – malocclusion. The
medicine is force, and there are a number of
ways to apply that force” - Weinstein
Handles of force delivery
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4. Strive for simpler and yet efficient
Basis of most prescriptions - Andrews
keys of occlusion.
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5. Various prescriptions
• Andrew’s straight wire appliance (SWA).
• Roth prescription.
• The level anchorage system
• Alexander’s The Vari Simplex discipline.
• Hilgers – linear dynamic system.
• MBT system.
• Viazis – The bioefficient therapy.
• Bowman and Aldo Carano: The Butterfly
system.
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7. Andrew’s SWA
5 studies:
1st
1960 – examination of post treatment
dental casts to assess static occlusion.
No intent to develop new appliance.
2nd
1964 – 120 naturally and good to excellent
occlusion casts collection,
3rd
discovery of 6 characteristics,
4th
thousands of measurements made of the
crowns of the 120 casts,
5th
evaluation of occlusal characteristics of
the post treatment dental casts of 1150 patients.www.indiandentalacademy.com
8. Andrews 6 keys to normal
occlusion
Key I:- Inter arch relationships.
7 parts:
1 2
3
4
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10. Key II: Crown Angulation (tip)
The angle formed by the FACC and a line
perpendicular to the occlusal plane.
+ve - occlusal portion of FACC is mesial to the
gingival portion -ve when distal.
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11. Key III: Crown Inclinations (labiolingual
or buccolingual)
Angle formed between a line perpendicular to the
occlusal plane and a line that is parallel and
tangent to the FACC at its mid point.
Positive if FACC is facial to its gingival portion
negative if lingual.
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14. Key VI: Curve of spee
A, A deep curve of Spee
results in a more confined
area for the upper teeth,
creating spillage of the
upper teeth progressively
mesially and distally.
B, A flat plane of occlusion
is most receptive to normal
occlusion.
C, A reverse curve of Spee
results in excessive room
for the upper teeth.www.indiandentalacademy.com
15. Terminologies
Andrews plane’s:
The surface or plane on which the mid
transverse plane of every crown in an arch will
fall when the teeth are optimally positioned.
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16. Clinical crown:
Means the amount visible in late mixed
dentitions and adult dentitions with gingivae
that is healthy and not recessed.
Anatomical crown height minus 1.8mm -
Orban.
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17. Facial axis of clinical crown:
For all teeth except molars, the most prominent
portion of the central lobe on which each
crown’s facial surface, for molars the buccal
grooves separates the 2 large facial cusps.
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18. Facial axis point:
the point on the facial axis that separates the
gingival half of the clinical crown from the
occlusal surface.
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19. Crown Angulations:
The angle formed by the FACC and a line
perpendicular to the occlusal plane.
+ve - occlusal portion of FACC is mesial to
the gingival portion -ve when distal.
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20. Crown inclinations:
Angle formed between a line perpendicular to
the occlusal plane and a line that is parallel
and tangent to the FACC at its mid point.
Positive if the occlusal portion of crown,
tangent line, FACC is facial to its gingival
portion negative if lingual.
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21. Research values from Andrew’s study
Measurements made in:
1. Bracket area of each tooth type,
2. Vertical crown contour,
3. Crown angulation,
4. Crown inclination,
5. Maxillary molar offset,
6. Horizontal crown contour,
7. Facial prominence of each crown and
8. Depth of the curve of spee.
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28. Non-programmed appliance
Definition
A set of bracket designed the same for all
tooth types, relying totally on wire bending
(except possibly for angulations if the
bracket is angulated) to achieve the optimal
position for each individual tooth.
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29. Partly programmed appliance
Definition
A set of brackets designed with some
built in features but that always requires
some wire bending (though less than in
required by non programmed appliance).
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31. The appliances consist of 2 series of bracket
system.
a. Standard bracket that do not require
translation.
b. Translational brackets.
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32. Design features of a standard
bracket
• Slot siting features,
• Convenience features, do not play role
• Auxillary features. in slot.
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33. Slot siting features
Explained in 3 planes:
Mid transverse,
Mid sagittal plane and
Mid frontal plane.
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34. Mid transverse plane
Mid transverse plane and facial extension of the
crowns - coincide.
3 siting features.
1. The mid transverse plane of the slot, stem,
and crown must be the same.
2. Inclination of the base of the bracket.
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35. 3. Bracket base curvature of the crown.
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36. Advantages
Eliminates several kinds of bends:
2nd
order bends to deal with occlusogingival
disharmony,
3rd order bends
for inclinations
and other bends
to deal with
inherent side
effects of wire
bending.
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37. Mid Sagittal Plane
Mid sagittal plane of each slot must super impose on a
facial extension of the crowns mid sagittal plane.
4 features
1. The mid sagittal plane of the slot, stem and crown
must be the same.
2. The plane of the bracket must be identical to the
facial plane of the crown at the FA plane.
maxillary molars – 1000
and other crowns – 900
.
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38. 3. Contouring of the base of each bracket to the
mesiodistal contour.
Prevents any play between the base and the
crown.
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39. 4. In each fully programmed bracket,
The vertical and horizontal components are
designed parallel to one another.
The vertical landmark parallels to the crown’s FACC.
The horizontal components makes the base point of
the bracket to mate with the crown FA point.
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40. Mid frontal plane
The mid frontal plane of each slot must super
impose on its crown’s prominence plane.
Within an arch, all slot points must have the same
distance between them and the crowns
embrasure line.
This eliminates 1st order wire bends to
accommodate for varying crown prominence.
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48. Additional slot features incorporated into the
standard brackets done by Andrews in 1972.
Bodily tooth movements esp. in extraction spaces
All qualities of standard along with a power arm
and 2 additional slot siting features:
1. Counter rotations,
2. Counter mesiodistal tip.
Maxillary molars 3rd
feature counter buccolingual
tip. www.indiandentalacademy.com
49. Categories
Different translational bracket required depending
on the ranges
Minimum translation bracket:
Tooth has to be translated < 2mm.
Medium translation bracket:
Tooth has to be translated
2 - 4mm.
Maximum translation bracket:
Tooth has to be translated > 4mm.www.indiandentalacademy.com
50. Terminologies
Counter Buccolingual tip:
Slots siting feature for maxillary molars that
counter acts buccolingual tip during translation
and then over corrects.
Counter Mesiodistal tip:
The slot siting feature that counters acts mesial
or distal tipping during translation and then
over corrects.
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51. Counter Rotation:
A slot sitting feature that counters acts rotation
during translation and then over corrects.
Power Arm:
A lever arm extending gingivally from the
bracket used for delivering forces forward the
crowns center of resistance.
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52. Translation bracket:
A fully programmed bracket for teeth that
require translation. It is designed to promote
bodily movement during mesial or distil
movement and to over correct in proportion to
the distance moved.
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53. Translations defined as uniform motion of a
body in a straight line.
Force on center of resistance i.e., center of
resistance is in the root.
From the stand point of physics, a bracket
located on a crowns place is a wrong place in
two ways.
Translation problems
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54. 1. Bracket is occlusal to the center of resistance
of the tooth and when a mesial or distal force
is applied, the tooth instead of translating will
tend to tip around its horizontal center of
rotation.
2. The bracket is also located laterally to the
tooth center of resistance, so instead of
translating when a mesial or distal force is
applied, the tooth will tend to rotate at it’s
center of rotation.
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55. Translation solutions
2 fundamental methods – involve different
amount of force, bone and efficiency.
Translation and
Tipping – angulating, compels a portion of
root to go through the bone twice.
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56. Slot sitting feature
Counter rotation and counter mesio distal tip are
two slot sitting features common to all
translation brackets. In addition, maxillary
molar translation brackets have counter
buccolingual tip.
Criteria:
The farther the tooth needs to be translated
greater the rebound potential.
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58. Used SWA and reported its experience in 1976.
Discussed his experience, the disadvantages of
non angulated brackets, torque in the base.
Original SWA used for treating only non
extraction cases with ANB of 50
Later reintroduced many series include
extraction series, ANB differentials and
anchorage requirements.
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59. Roth’s Philosophy and Rationale
Need for inventory, for application in most
cases.
After trail and error ROTH set up was
developed.
To provide over corrected tooth position prior to
appliance removal which would allow the teeth
in most instances to settle.
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60. Roth’s Philosophy and Rationale
Reasons:
1. Impossible to attain precision.
2. After appliance removal teeth shifted slightly
from their position attained – overcorrection.
3. Non-orthodontic models had curve of spee –
alter brackets placements for complete leveling
of spee.
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61. Compensating and reverse curve of spee to
achieve desired tooth positions.
Anterior brackets placed more incisally.
Anchorage control in extraction cases.
Auxillaries:
• Double and triple tubes.
• Additional hooks.www.indiandentalacademy.com
62. Overcorrection
Not expressed intraorally in extraction cases as:
1. There is an angle of deflection between the
bracket slot and the archwire.
2. Ultimately, the force values drop so low that
they are below the values needed to move the
teeth, even though full bracket expression has
not been obtained.
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63. Overcorrection
3. The teeth tend to relapse back to their
original positions.
4. We need to build in offsets for the undesirable
side effects of tooth-moving mechanics
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64. Twin bracket on all the teeth with tip, torque and
rotation built into the brackets.
0.018” - pure Tweed or Bioprogressive
technique
0.022” – more wire selection,
proper torque control in posteriors,
stabilizing arches as anchor units and
orthognathic surgery.
Bracket type
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65. Extra torque in the maxillary incisors (5° more
than normal).
Less -ve torque in the upper canines to offset the
reciprocal effect of building more +ve torque
into the incisors.
Canines have 20
more distal tip and 20
mesial
rotation, because they are being retracted in
most treatment.
Maxillary Prescription
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66. "Super Torque":
Set of maxillary anteriors for cases like Class
II, div 2, where an extreme amount of torque
may be needed.
Mesial rotation of the upper first molars, due
to the 0° rotation brackets on those teeth.
Minimizes the tooth-size discrepancy created by
taking out only two bicuspid.
Maxillary Prescription
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67. The buccal segments are distally uprighted to 00
.
The bicuspids are rotated 20
mesially to offset the
rotation that accompanies distal traction.
The molars have 140
distal rotation (twice the
amount found on the non-orthodontic normals)
and 140
buccal root torque (50
more than
normal).
Maxillary Prescription
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68. Mandibular Prescription
Incisor brackets are the same as the non-
orthodontic normals.
The canines have 70
mesial tip and 20
distal
rotation.
The entire buccal segment has a 30
distal tip from
normal and a 40
distal rotation – settle more
mesially than the uppers and simultaneously
rotate mesially, thus necessitating extra distal
rotation. www.indiandentalacademy.com
69. Mandibular Prescription
The torque in the buccal segments remains
normal, as overcorrection in this plane leads
interferences.
The two molars have exactly the same degree of
root torque since the appliance rests on the
mesiobuccal cusp (the torque measurement
for the non-orthodontic normals was taken
from the buccal groove).
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71. Bracket height
Upper Lower
Central 3.5 3.5
Lateral 3.5 3.5
Canine 4.0 4.0
1st
premolar 3.5 3.5
2nd
premolar 3.5 3.5
1st
molar 3.0 3.0
2nd
molar 2.5 3.0
Over corrects
overbite and
improves anterior
contact during
function
Levels marginal
ridges quite well
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72. In open bite cases, anterior brackets may be
placed further gingivally.
In case of long clinical crowns, all brackets may
be placed farther gingivally with use of a
uniform increase for each that is consistent
with the bracket heights listed.
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73. Accurate placement of bracket is very important
with any type of fixed appliances.
One of the unique advantages of Roth set up is
the inbuilt tip, torque, and rotation and in-out
movements.
Not only corrected but also over corrected and to
do so with few or no bends in archwire.
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75. The level anchorage system (LAS)
This system was given by Terel L Root in 1981.
It’s a system designed for those goal
oriented orthodontists, who would like to
treat efficiently to a predetermined goal.
This system quantifies the anchorage
requirements of the orthodontist problem
and thus clarify the necessary treatment step
needed to reach the goal
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76. Appliance proper
Banded or bonded edgewise appliance with built-
in tip, torque and offset and an analysis and
treatment planning chart with a step by step
treatment procedure.
Charles Tweed (1st
person) anchorage preparation
by placing tip back bends in the lower posterior
teeth.
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77. Appliance proper
Variation of tip – severity of the malocclusion.
When this anchorage preparation was used with
the standard edgewise appliance, the tip, torque
and offset bends are placed in each edgewise
arch.
Here bends were to be duplicated or increased in
succeeding arches as the case progressed.
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78. Reed Holdaway described pre-angulation,
With variation in the angulations in the Tweed
course in Tuscon.
To reduce the wire bending requirement for
anchorage preparation.
Hence, LAS could be described as utilizing a
SWA preparation as described by Holdaway.
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79. Bracket type
The level anchorage system utilizes twin
brackets for upper centrals and single
bracket (Lewis rotation brackets) for the
other teeth.
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80. Level anchorage pre adjustments
Tip:
All the maxillary anterior teeth have mesial
crown tip, centrals 40
laterals 70
canines 60
.
There is no tip in the maxillary premolars of 1st
molars, but the maxillary 2nd molars have 150
of distal crown tip.
All the mandibular anterior teeth have mesial
crown tip.
Centrals 20
laterals 20
canine 60
.
The mandibular 1st premolar has 40
of distal
crown tip.
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81. 2 choices of distal crown tip for the mandibular
buccal teeth Regular and Major. The choice
depends on the severity of malocclusion and is
determined by the use of the analysis chart.
Anchorage Values:
REGULAR MAJOR
Lower bicuspids 40
60
1st molar 60
100
2d molars 100
150
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84. Based on edgewise philosophy – developed and
introduced by Dr. RJ Wick Alexander.
“Vari” variety of brackets types used. (Twin,
Lewis and Lang).
“Simplex” KISS principle.
• Archwire fabrication is simplified, with 1st,
2nd and 3rd order effects in the brackets than
into archwire.
• Archwires are simple - pure archwire
changes, easier ligation and activation.
• Multiloop arches rarely employed.
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85. “Discipline” rather than “appliance”
the orthodontist must be knowledgeable in
edgewise mechanics and must play an active
role in the application of the appliance to the
individual patient in order that the treatment
must be successful.
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86. Philosophy
Retains 3 fundamentals of the Tweed
technique:
1. Anchorage preparation (uprighting
mandibular first molars)
2. Positioning of mandibular incisors over
basal bone
3. Orthopedic alteration with headgearwww.indiandentalacademy.com
87. Key Objective
Treat the case so that the patient ends up with
the face proportionately balanced, consistent
with his skeletal pattern.
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88. Concepts
Specified bracket system,
Pre torqued, pre angulated and specified
bracket base thickness to reflect in/out
considerations.
5 factors related to brackets:
1. Selection,
2. Height,
3. Angulation,
4. Torque, and
5. In-out. www.indiandentalacademy.com
89. Bracket types used
Twin brackets:
Maxillary Centrals and Laterals
Advantage – permit full archwire engagement.
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90. Additional tie wings for easy initial archwire
placement placed on lateral incisors.
Additional handles for placing power chains and
for ligating another teeth together.
Patient comfort.
Bracket types used
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91. Lang brackets (Dr. Howard Lang):
Used on cuspids.
Single bracket – flat rotational control wings, with
circular hole – for ligation.
Bracket types used
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92. When a Lewis or Steiner bracket
is completely tied into a
cuspid, there is a tendency to
flatten the curvature of the
archwire.
A Lang bracket avoids this effect,
while retaining the rotation
wing capability.
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93. Alexander changed the design of the long wing –
used a stiff metal for the wings, hole is smaller
and close to the base of the bracket.
Wedge shaped in profile.
When the bracket is seated properly on the
tooth, the distance between the tooth and the
gingival edge of the bracket tie wing is greater
than the distance from the tooth and the
occlusal edge of the bracket tie wing.
Ligation made simple and patient comfort is
improved.
Bracket types used
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94. Lewis bracket:
Are selected for large,
round surfaced teeth that
are not in the curve of the
arch, the bicuspids.
Also chosen for small flat
surfaced teeth
mandibular incisors.
Bracket types used
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95. Fixed-wing single bracket – sufficient interbracket
width.
Steiner wing not used instead of the fixed Lewis
wing
1. The fixed wing exerts additional force,
especially on a rectangular wire.
2. The fixed wing saves adjustment time.
3. The Lewis brackets are less sharp.
4. Less concerned with breakage.www.indiandentalacademy.com
96. Additional benefit:
Tooth that is badly rotated, the wing in the
direction of the rotation can be removed. The
bracket can then be positioned properly, with
the remaining wing serving to rotate the tooth
into proper position.
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97. Other attachment:
Twin brackets with a convertible sheath are used
on maxillary and mandibular 1st molars.
The convertible sheath is easily removed when
2nd molars are banded thus the attachments is
converted into a bracket.
Bracket types used
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98. Bracket position
On flat surfaced teeth in the mesiodistal centers.
On bicuspids and cuspids at the crest of the
contour for the rotating wings to function
optimally.
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99. Bracket Height
Basis for all other bracket height – Bicuspids
bracket height as the clinical crown height of
that tooth is so variable. Normal height is
4.5mm.
In an open bite case, deviation from the heights
of that tooth from the heights would be to
intruded the posteriors and extrude the
anterior teeth. Thus the bracket height would
be increased by 0.5 mm for anteriors and
decreased by 0.5mm for posteriors.www.indiandentalacademy.com
100. Prescriptions
Bracket in/out (1st order bends):
A system of interrelated, compensating bracket
base thickness to replace 1st order bends or
offsets.
Maxillary 1st molar brackets have 150
offsets built
into the tube that will rotate the tooth
mesiobuccally and a similar 50
offsets in the
mandibular 1st molar brackets.
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101. Prescriptions
Bracket angulation (tip or 2nd order bends):
Place the roots parallel to each other and the
crowns in their most esthetic and functional
position.
The brackets with angulations are measured to
the long axis of the crown.
The mandibular 1st molar have a -60
tip built into
promote leveling and to gain arch length as
2mm of arch length was gained by molar
uprighting.
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102. The torque values from about 50 finishing
rectangular arch wire.
This system is designed such that the results are
achieved when a 0.017 x 0.025 inch archwire is
used to fill the 0.018 inch bracket slots.
Allowing enough play permit
The rule of thumb is that 0.001 inch of play
equals about 40
of torque which can be reduced
or added.
Bracket torque
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103. 3 measurements differ in 3 major aspects.
1. The -30
on cuspids compared to the -70
to 70
eliminates the need for adjustment of the
torque during treatment.
2. No torque in the mandibular 2nd molar tubes
as omega loops are placed. When this is bent
buccally, the appropriate torque’s
automatically placed.
3. -50
of lingual crown torque in the mandibular
incisors.
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105. An evolution from the edge wise technique
introduced by Robert M Ricketts.
Development of bioprogressive set ups:
3 combinations to choose:
1. The standard progressive set up
2. Full torque bioprogressive set up
3. Triple control bioprogressive.
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106. The standard progressive set up
Torque was built into the upper incisors and all 4
canines.
Torquing of the lower buccal segment and step
bends in the arch are regulated into the
archwires.
A series of preformed arches were designed
which when placed into inventory, could be
applied in the individual situation.
In effect, the preformed pre fabricated band,
bracket and archwire inventory are designed
into a complete organized approach.www.indiandentalacademy.com
107. Full torque bioprogressive set up
Along with the incorporated torque to the upper
anterior teeth, torque was incorporated into the
lower buccal segments.
In other words, all torque requirements had been
eliminated in the wire except for the variations
needed.
This is the edgewise appliance in its purest form.
Triple control bioprogressive
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108. Considerations for Design
1. Type and severity of malocclusion:
Class II cases medially rotated upper molar,
medially tipped lower molar, forward buccal
segments and tapered upper arch – rebound –
Overcorrection.
2. General approach to mechanics:
Contracted arches in extraction cases –
detorque.
Expanded arches in non extraction cases –
torque.
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109. 3. Sizes of final arches:
For each .001 " tolerance between archwire
and slot, as much as 4° of torquing effectiveness
is lost.
Torquing - full-size continuous archwire.
4. Timing of torque control:
Torque control from the start as efficient to
bring the tooth directly to its over treated goal.
Early set-up of the posterior occlusion provides
the framework for proper buccal and anterior
tooth positions. www.indiandentalacademy.com
110. 5. Need for overcorrection:
Each tooth has an overcorrected position
that best allows for final settling. Some of these
positions relate to mechanics, others to
rebound.
6. Bracket placement:
The accuracy of bracket placement, the
compensations for occlusal interferences, and
the adaptability of the bracket bases all affect
final tooth positions, especially with direct
bonding. www.indiandentalacademy.com
111. Area to observation – upper cuspid fit with the
lower cuspid-bicuspid embrasure.
Achieved by first setting up the posterior
occlusion by rotating the upper first molar.
But it is difficult to rotate the upper first molar
without first rotating and uprighting the lower
first molar.
Therefore, the key to a Class I buccal
segment is the proper positioning of the
lower first molars.
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112. So allow the dentition to move directly toward
final positions by establishing a mandibular
occlusal table as early in treatment as possible.
The ability of certain teeth to drift into desired
locations and inability of other teeth to drift
into desired locations.
Understanding of the physiologic rebound allows
to make decisions about tooth locations when
detailing a case.
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113. Criteria for each Tooth
• Ideal orthodontic tooth position.
• Anticipated rebound and required
overcorrection.
• Appliance design features that contribute to
patient comfort, clinical simplicity, and
optimum utility.
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114. Prescription
Mandibular First Molars:
Torque Tip Rotation Thickness
Main slot – 27° – 5° 12° distal Thinnest
Auxiliary slot 0° – 5° 0°
Upper first molar - into a slight mesial tip with
the distobuccal cusp slightly past the plane of
occlusion as distal marginal ridge on the upper
first molar is shallower than the mesial
marginal ridge.www.indiandentalacademy.com
115. For distal rotation of the upper first molar – the
lower first molar must be rotated distally more
than one would expect.
The contact between the lower first and second
molars is unique. Because of the settling of the
upper first molar to the mesial, there should be
a slight opening in the contact point between
the lower first and second molars to allow the
distobuccual cusp of the upper first molar to
seat.
Prescription
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116. 2 mechanical factors for mesial rotation:
1. the pull of Class II elastics and
2. the forces used to retract anterior teeth.
Counterbalance these factors by slight over-
rotation.
Ideal distal rotation, distobuccal cusp of first
molar is rotated 1/3rd
of distance through mesial
marginal ridge of second molar.
Prescription
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117. Normally, the lower first molar will rotate slightly back
to the mesial and tip mesially, depending on upper
molar position and the muscle and inclined plane
function.
A slight distal crown tip uprights the lower molars to
allow distal seating of the upper first molar and
counteract the forces of retraction mechanics and
elastics.
The 12° distal rotation coordinates with a 15° maxillary
molar rotation to avoid conflicting inclined planes and
eliminate the need for bicuspid and molar offsets.
Prescription
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118. Maxillary First Molars
Torque Tip Rotation Thickness
Main slot -10° 0° 15° distal Thinnest
Auxiliary slot 0° 0° 0°
Prescription
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119. A line drawn through
distobuccal cusp points at the
distal of the opposite cuspid.
This rotation uses the shortest
distance across the
trapezoidal molar, with
shortest arch length in the
upper buccal segment, and
allows seating of the upper
cuspids.
Prescription
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120. 15° distal offset:
First, the tooth morphology requires some offset
for a linear archwire.
Second, the archwire leads away from the tooth
mesiodistally, and the tube's built-in rotation
must be neutral to allow proper rotation.
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121. Third, most Class II cases have mesially rotated
upper first molars that require compensation
with an overcorrected distal rotation.
Fourth, mechanics in Class II and III cases often
involve forces that rotate the upper molar
mesiolingually.
Fifth, a few degrees of offset is lost because of
archwire/slot differential.
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122. The roots be inclined slightly to the
lingual, for occlusal forces.
There is a slight distal root tip as
the upper first molars settle into a
normal Class I occlusion.
The entire upper buccal segment
should have 10° of buccal root
torque to compensate for the
occlusogingival curvature of the
crowns of these teeth.
Prescription
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123. The Auxiliary Tube:
Is offset to the buccal to avoid tissue
impingement. This allows for selective torque
and rotation of the upper first molar with initial
utility arches, and it helps in placement of
auxiliary arches.
The auxiliary tube can be used as the main arch
slot in upper first bicuspid extraction cases
where mesial rotation of the molar is desired.
Prescription
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124. Second Molars
Torque Tip Rotation Thickness
Main slot -10° 0° 12° distal Thinnest
Mandibular -27° -5° 12° distal Thinnest
Prescription
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125. In Class II cases, erupts mesially – areas of
occlusal interference, often causing
disarticulation of the condyle.
Lower second molar:
Tipped distally during treatment because it
will settle mesially as the distobuccal cusp of
the upper first molar settles into the lower first
and second molar embrasure.
Prescription
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126. Upper second molar:
When tipped back slightly and
overcorrected in its Class I position, will settle
in much the same way as the upper first molar.
The same cast tube is used for both maxillary and
mandibular second molars. Difference in
torque, correspond with that of the first molars
to allow proper positioning.
Prescription
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127. Mandibular Second Bicuspids
Torque Tip Thickness
– 17° 0° Thin
Buccal root torque symmetrical with the lower
first and second molars, because their main
cortical bone support is through the external
oblique ridge.
Bracket base be thin to accentuate the buccal
offset of the lower first molar. In extraction
cases it is helpful to have a 5° mesial tip for root
paralleling.
Prescription
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128. Mandibular First Bicuspids
Torque Tip Thickness
– 11° 0° Thin
Transition tooth of the lower arch functions as
both an anterior and a posterior tooth.
The buccal cusp seats in the distal fossa of the
upper first bicuspid.
Prescription
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129. The upper cuspid occludes with the lower first
bicuspid, the lower cuspid, and often the distal
aspect of the lower lateral incisor.
Root support of the lower first bicuspid is mainly
from the lingual.
Buccal root torque in the bracket to passively
accommodate the greater buccal crown
curvature.
Prescription
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130. Prescription
Mandibular Cuspids
Torque Tip Thickness
7° 5° Thin
Cuspid's distobuccal incline articulates with the
mesiolingual incline of the upper cuspid to
create the primary guidance for disarticulation
of the balancing side occlusion.
Therefore, the labial surface would ideally be
angled slightly outward— implying a lingual
root torque.
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131. Prescription
Also advantageous mechanically as the lower
cuspid is moved mesially or distally – especially
in extraction cases, as a tendency to detorque
both arches.
In the vertical plane, the lower cuspid should be
bracketed slightly gingivally to keep it in
contact with the upper cuspid.
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132. Prescription
Mandibular Incisors
Torque Tip Thickness
– 1° 0° Thin
Plays a role in cuspid guidance. The incisal edge
has a short mesial incline and a long, sloping
distal incline.
Allowing for a slight distal root tip of the lower
lateral incisor – stability.www.indiandentalacademy.com
133. Prescription
Bracket Height
Incisal in deep bite cases to assist in bite
opening and intrusion.
Gingival bracket placement in the buccal
segments, this helps level a deep curve of Spee.
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134. Prescription
Maxillary Bicuspids
Torque Tip Thickness
– 7° 0° Thin
If the distal marginal ridge of the upper second
bicuspid is not seated against the
mesiobuccal cusp of the lower first molar, it
is difficult to establish an anterior Class I
relationship.
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135. Prescription
As with the maxillary first molar, buccal root
torque assures that the roots can be slightly
to the lingual and supported by the dense
cortical bone of the palate particularly when
expansion is part of the treatment mechanics.
A mesial root tip of -5° in extraction cases
facilitates root paralleling.
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136. Prescription
Maxillary Cuspids
Torque Tip Thickness
7° 10° Thin
With a 134° intercanine angle, the upper cuspid
should be torqued slightly to the lingual.
The labial inclination is important in supporting
the corners of the mouth and the caninus
complex. www.indiandentalacademy.com
137. Prescription
The relationship between the upper lateral
incisor and the upper cuspid is influenced by
torque.
Torque differential to maintain integrity of the
labial surface contours.
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138. Prescription
Maxillary Incisors
Torque Tip Thickness
Lateral 14° 8° Standard
Central 22° 5° Standard
Brachyfacial – more torque is needed.
Dolichofacial need the torque to prevent
dumping during space closure.
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139. Prescription
Standard thickness:
To keep the upper lateral incisor flush with the
central incisor during the overcorrection process
and then tuck in the lateral incisor during the
retention phase.
To maintain a good contact point with the upper
cuspid, the upper lateral incisor bracket should
be slightly thicker than the upper cuspid
bracket.
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140. In this bracket system, the slot dimensions are
0.018x0.030inch compared with the standard
0.018x0.025 inch edge wise slot. This was an
evolution from the original Steiner design.
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143. Richard P McLaughlin and John Bennett in
1993.
Third generation of brackets.
Basis – mechanics and force levels should
determine the design of the bracket system
and not vice versa.
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144. Range of Brackets
1. Standard size metal brackets – control
main requirement.
2. Midsize metal brackets – less control, cases
with poor oral hygiene average to small
teeth.
3. Esthetic brackets – older patients.
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145. Shape of Bracket
Rhomboid shape:
Reduces bulk,
allows reference lines in both horizontal
and vertical planes – assists accuracy.
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146. Torque in Base
CAD factor:
Problem with earlier generation – torque in
base was not possible.
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149. Torque
Earlier torque expression:
1. Area of torque was small.
2. While using 0.19/0.025 Steel wires there is
slop of 100
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