Evolution of orthodontic brackets

Evolution of Orthodontic
Brackets
www.indiandentalacademy.com

1. INTRODUCTION
2. CLASSIFICATION
3. EVOLUTION & BRACKET DESIGN
• Brackets of historical perspective
– Angles 'E' Arch Appliance - 1907
– Calvin Case Appl - 1908
– Pin & Tube Appl - 1910
– Robbinson Appl - 1915
– Angles Ribbon Arch Appl - 1916
• Begg brackets and modifications
– Begg's Appliance - 1929-30
– Begg Chun Hoon - 1960
• Edgewise brackets and modifications
– Angles Edgewise Appl – 1925
– Griffin Appliance - 1930
– Twin Wire Appliances by Johnson - 1931
– Tweed - Merrifield edgewise appl - 1960
– Andrews S. W.A – 1976
– Roth modification – 1979

j)
– Modified Edge Wise Brackets
– 1) Alexander sved bracket 1937
– 2) Siamese twin bracket by swain (Twin bracket)
– 3) Lewis bracket
– 4) Steiners bracket
– 5) Broussard bracket
• Combinations of edgewise and begg
– Universal appliance by Atkinson - 1931-37
– Multiphase attachment by Bowles - 1953
– Tip edge appliance by P .C. Kesling - 1980
– Roots level anchorage system - 1981
– Combination anchorage Tech - 1981 – 88, Dr.Thomson
– Alexander vari simplex – 1983

• Newer brackets
– Self-ligating brackets
– Active, passive
– Speed
– Activa
– Damon
– Edgelok
– Time
– Ceramic brackets
– Lingual orthodontics, Craven Kruz - 1975

Classification of brackets

Types of bracket based on material used
Metals
Ceramics
Plastics

Bracket can be also classified, according
to the type of slot
Ribbon arch slot
Edgewise bracket
Combination

Classification based on mode of
attachment to tooth
Weldable bracket
Bondable bracket
• Self Cure
• Light Cure

Dr. Andrews classification of brackets
Non programmed
Partially programmed
Fully programmed

Dr. Andrews Extractional series bracket
classification
Minimum translation brackets
Medium translation brackets
Maximum translation brackets

Based On Bracket Design [torque
incorporation]
Torque in Face
Torque in base
Self locking
Passive self ligation
Active self ligation

Based on Friction produced by bracket &
archwire
Maximum Friction
Medium Friction
Minimum Friction

Metals
Stainless steel – commonest
Gold – oldest
Titanium – in cases of nickel hypersensitivity
Stainless steel bracket coated with a microthin layer of
Zirconia nitride to impart a gold colour

Ceramics
Esthetic alternative to brackets
Types
• Monocrystalline
• Poly crystalline
• Zirconia [ceramic] bracket
Advantages
• Excellent colour fidelity
• Stain resistance
• Strength

Disadvantages
• Fracture tendency
• Fracture enamel during debonding
• The manufactures of these brackets have tried to
improve bracket characteristics to facilitate easier de-
bonding
• These changes have included a shift from the purely
chemical retention mechanism of resin bonding to the
bracket base to a totally mechanical mode of bonding for
the poly crystalline brackets
• New design of bracket (ceramic) has metal slot reducing
the friction
• Another feature of this appliance is the ease of
debonding via a vertical scribe line placed in the base of
the bracket

Plastics
In an attempt to create an esthetic bracket with lower frictional
resistance and easier debonding features than ceramics a
variety of new, ceramic reinforced plastic brackets with or
without metal slot inserts have been introduced
Poly Carbonate
Plexiglass Bracket

Disadvantages
Discoloration
Fragility
Breakage under stress
Plastic brackets can deform because of compression from
ligation and thus binding of the wire higher frictional
resistances were recorded than stainless steel brackets

RECENT IMPROVEMENTS
Reinforcement of plastic brackets
– Precision- made stainless steel slot inserts
– Ceramic material fillers (15-30%)
Metal slot reinforcement of plastic brackets
appears to strength the matrix adequately so
that torque can be applied at the same level as
with metal brackets

Ceramics- reinforced composite brackets
without a metal slot insert have been shown to
have fairly low fractional characteristics compared
ceramic & metal brackets.
Hence, newly introduced ceramic-reinforced
plastic brackets are suitable for clinical
use because they are
– Colour stable
– Have lower friction
– Have the structural integrity transmit orthodontic
forces out distorting (strength)

Manufacturing

Brackets made by milling are too expensive and at the same
time too prone to human error, in comparison with those made
with the help of molds
The dramatic step forward made by Unitek by milling a one-
piece attachment on the lathe (Dynalock) has opened new
horizons, several companies following suit and coming up later
with one-piece brackets
This has opened the door to one-piece brackets made by
casting (Ortho-Organizers, San Macros, Calif.)
sintering (the partial welding together of metal particles
below their melting point)
metal injection molding (MIM)

Casting
While casting has long been a mainstay for "A" Company, -
first ones to build-in identification marks and torque in the
base, as well as to use more corrosion resistant alloys
the company has not extended the process to one-piece
appliances, fearing retention problems - building in a rough,
high-surface area on the base side of the bracket while
rendering the bracket side smooth and shiny is quite difficult,
considering the minute size of the appliance

Sintering uses only metal powders, which are melted
as such in molds
MIM
adds to these, various thermoplastic polymers, lubricants,
and other additives, which are subsequently pyrolyzed and
gasified
To compensate for the shrinking that occurs, the molds have
to be larger than the parts
the operation is quite sophisticated and requires the use of
computer-aided design, along with computer-numerical
controlled machines tools
The resulting built-in accuracy and microstructural
homogeneity, if not plagued by pores, leads to appliances
having superior mechanical and chemical properties
(brackets made of powders have been found to have a
smaller corrosion rate than both the cast and the cold
worked ones)

Cast,one-piece bracket with built-
in base and power arm
(Edgeway from Ortho-
Organizers, San Macros,
Calif.)

Brackets showing opposite
working principles

Brackets showing different
orientations

History

Angles contributions
It is difficult to imagine that there was a period in
orthodontics before the invention of brackets
Yet this was the situation when angle developed and
perfected treatment procedures with his "E" arch, which
expanded the dental arches but provided no axial tooth
control
During this time he (Dr. Angle) advocated the pretreatment
extraction of teeth and devised methods to close extraction
spaces Sans brackets
However, till 1907 there were no practical means to upright
the tipped teeth
Afterward angle moved away from extraction and started
arch expansion techniques with a series of appliances, that
would provide total control of the axial inclinations of all the
teeth

Case’s appliance
Case appliance which was reported in 1908, used for
moving roots
Pin tube appliance
Introduced by angle in 1910 to overcome the weak point in
his "E -arch i.e. lack of axial control
Permitted axial control in all directions but permitted only
limited mesio-distal crown tip
Few consider appliance system as pro type of modern
bracket system, others reject

The Pin &Tube appliance(1912)

Robinson’s appliance
In 1915 Dr. R.D. Robinson presented a system for painless
and positive tooth movements
He was dissatisfied with the complexity of the pin and tube
appliance and the extreme pressures associated with an
expansion arch and steel ligatures
He developed a technique and appliance that utilized light
forces with constant control of the roots of the teeth

Ribbon arch
Ribbon arch designed by angle in 1916
To overcome two of the main problems of the P & T
appliances
1. Arch wire placement
2. Mesiodistal movement
As a means to hold the tooth upright he devised cleats, that
could be soldered to the arch wire to contact the sides of the
ribbon arch bracket
Necessitates soldering
New cleats unsightly
Different locations to move the tooth along the arch wire

Ribbon arch appliance (1915)

Begg

Modified Ribbon arch brackets or Begg
appliance
In 1928 P.R. Begg returned to his native Adelaide
Followed Angles Ribbon arch appliances, with non extraction
technique faithfully. He was dissatisfied with treatment results
In early 1930s introduced Begg Bracket by modifying Ribbon
arch bracket

Begg Chun Hoon
Introduced in the 1960s
Consisted of a begg slot and an edgewise slot
Chun hoon

Edgewise

Edge wise bracket system
A solution to all his problems was his "latest and best
orthodontic mechanism" which was introduced in 1925.
Brackets were initially referred as open face or tie bracket
Presently referred to as the edgewise bracket or appliance
This nomenclature originally was intended only to designate
the new horizontal plane of the rectangular arch wire
Main advantage - positive control of the positions of teeth in
all three planes of space

Evolution of edgewise
brackets
Original bracket – soft
gold .022 x .028 inch
slot

Griffin appliance
In 1930s Dr. E.M. Griffin developed a resilient arch
assemblage
Center sections of the brackets were soldered to the arch
wire, preventing free tipping and sliding of the teeth on the
wire
Lingual arch wires were also employed

Twin wire appliance -Johnson (1930)
The twin - wire appliance consists of a pair of steel wires
0.010 or 0.011 inch x 0.022 inch in diameter placed in S.
Steel end tubes which fits into a lock type of bracket
The cap and channel bracket is most commonly used with
the twin-wire mechanism
Eliminates the time-consuming task of tying ligatures and
exhibits a high degree of efficiency
In correcting irregularities of the anterior teeth, the bracket
slides along the twin-wire and permits the teeth to be aligned
In using this bracket, an archwire can be removed and
replaced within three minutes

Twin arch

Cap and channel bracket

The original bracket, as designed by Dr. Johnson, was
welded parallel to the incisal edge of the band
Today, brackets can be obtained with any angulation
desired
In the future, it is anticipated that these brackets will be
available with torqued channels
Angulated brackets with torque would greatly enhance the
efficiency of the twin-wire arch and the .011 x .022 flat-wire
arch
Not efficient in translation and in paralleling roots
Twin wire philosophy
More physiologic tooth movement could be obtained than
with one heavy wire
The twin wire attachments and bracket permit rapid
reduction of rotations with relatively little discomfort to the
patients

Twin wire appliance in place

Angles edge wise bracket
Was a soft gold bracket with 0.022x0.028 slot that was
readily deformed by the forces of occlusion and by tying
ligature wires to the bracket
Width 0.050 inch
Because of narrow width involved, the bracket itself was
ineffective for tooth rotation
Angle devised soldered gold eyelets to be placed in
appropriate positions on the orthodontic band

Sved’s Appliance (1937)
Alexander Sved believed that the edgewise bracket was too
restrictive and provided little interbracket distance for arch
wire flexing
Next step in the development of the present day edge wise
bracket began with the use of two brackets on a single tooth
The brackets were spaced so they would effect rotation of
the tooth
Disadvantage
Extreme care had to be taken, however, that slots of the
brackets were in perfect alignment otherwise, the archwire
could not be seated into both brackets
Modified edgewise brackets

Twin brackets
To overcome above problem twin bracket system came into
the picture
two brackets on one base
“Siamese twin brackets” by Swain
space between two brackets was .050 inch (equal to width
of one bracket )
Advantage
• Effective rotational control without the use of auxiliary
eyelet ties
• Used only on the upper central incisor and on molar
teeth (initially)

Twin brackets

Success with the early Siamese twin bracket prompted the
development of Siamese bracket that were not as wide as
the original
Terminology was gradually changed and the name was
shortened to "Twin brackets" only
With development of twin brackets of various widths, their
use was not restricted to any tooth of the oral cavity
There are 4 sizes of twin brackets
• 1. Extra wide
• 2. Standard
• 3. Intermediate
• 4. Junior
This original Siamese twin bracket was about the same width
as extra wide twin bracket available today

Curved base twin bracket
curved bases to confirm to the
curvatures of the canines &
premolars

Although terminology varies among manufacturers, a wide
range of sizes is available
Another early development was the evolution of a solid
bracket that was approximately twice as wide as the original
edge wise bracket
Called as posterior bracket, approximately width was - 0.100
and although designed to be used on molar teeth
It has gained popularity for use on practically all teeth

Advantages of Siamese twin brackets
• Rotational control effectively (prevents relapse)
• Greater axial control
• Positive control i.e, means that once the tooth has been
rotated mere the tying of the bracket ligature wire
maintains the tooth in corrected positions
• Curved design some deflection of the bracket from the
base is present, but this has been controlled to a
considerable degree in the manufacturing process and is
no longer considered as impairment the bracket

Disadvantages
Decreased interbracket span [the length of the arch wire
between bracket]
The bracket itself, of course, does not effect tooth rotation it
merely makes possible the deflection of the archwire over a
broader surface of the tooth, enabling arch wire to
accomplish the rotation

Lewis bracket
During the development of the twin bracket, another
approach to the problem of efficient tooth rotation was
developed by Lewis in 1950
He soldered auxiliary rotation arms (rigid) that abutted
against the bracket itself and thus offered a lever arm to
deflect the archwire and rotate the tooth
The present Lewis rotation bracket is a one-piece bracket
with integral rotation wings
It is equivalent to the original edge wise (0.050) bracket but
with the tooth rotation deficiencies of the latter overcome,
while "single width" feature is maintained

Lewis bracket

Curved base Lewis
bracket

Advantages
Allows greater contact with the band or bonding pad
Prevents food trapping around the wing
A refinement in the Lewis bracket has been the
incorporation of a 0.20x0.20 inch vertical slot, making
possible use of uprighting springs to correct, axial inclination
if needed
Desired tooth rotation is possible it also possible to
overcorrect positions
Increased IB span - don't decrease the IB span therefore do
not interfere with occluso-gingival deflections of the arch
wire
Do not interfere with the activation of closing loops, 2nd
order bends and other archwire fabrications that slide freely
past the rotational wing

Steiner bracket
This bracket incorporated flexible rotational arms and
therefore did not rely entirely on the resiliency of the
archwire for tooth rotation
The flexibility of the arms of the bracket also afforded a
rotational effect
Advantages
Easy to tie and is quite efficient for tooth rotation
Disadvantages
Flexible arms may be deformed - need readjustment

Broussard bracket
Designed by Garford Broussard for use in the
Broussard technique
This modification of edge wise bracket has been the
addition of a 0.0185 x 0.046 vertical slot to accept a
double 0.018 inch auxiliary wire
Broussard two force technique - the Broussard two
force technique works on the philosophy -
passive force - the main arch wire will establish and maintain
harmony, symmetry and arch co-ordination
active force - the removable auxiliary springs provide force for tooth
movemen
Garford Broussard Bracket
• A conventional edge wise slot of 0.018 x 0.025 or 0.022 X 0.028
• An additional vertical slot is added with slot size 0.018 x 0.046

Other bracket modifications
Burstone’s modification
Burstone modified the canine bracket by adding a vertical
tube for the insertion of retraction assemblies
He also designed a 2nd premolar bracket with an auxiliary
tube
Combination or convertible brackets
Designed for use on first molar
They function as tubes until the 2nd molar are banded, at
which time removal of the metal tabs converts them into
brackets

In Burstone’s segmented arch
technique the attachment used
for the cuspid is the Burstone’s
Cuspid Bracket
This bracket consists of the
basic 0.022" x 0.028" slot plus
a 0.017" x 0.025" vertical or
horizontal auxiliary tube
When placing this bracket on
the tooth, auxiliary tubes are
always placed gingivally
Burstone cuspid bracket
with either vertical tube or
an orthos horizontal tube

Shapes of brackets now
obsolete

Tweed - Merrifield edgewise appliance (in
1960s)
Pure edgewise bracket without any tip, torque or any
variations in thickness in the brackets with neutral slot
Slot size - 0.022
Anterior teeth - Single, double width breath of 0.022
Premolar - Intermediate single width
Molar - Twin brackets
2nd molar - 0.022 tubes with mesial hook
Brackets with mesh foils welded on bands
Each bracket and tube is placed at right angles to the long
axis of the tooth
Based on sequential differential straight force technique

Andrew’s appliance
What is an appliance?
Defined as the basic components that are attached to the
teeth i.e. the bracket, the tubes and other attachments
Most of the adjustments that required highly complicated
archwire bends can be eliminated if some of the treatment is
"Built into the appliance". The ultimate degree of
sophistication in this approach was introduced by Lawrence
Andrew with his straight wire appliance [SWA]
Before reaching the present state of modification in bracket
system (as in S.W.A. Tech.), there were number of minor
changes had been carried out in past
In 1929 - Angle angulated bracket and tubes to effect tipping
movement

In 1952 - Holdaway described three uses of bracket
angulation
• As an aid in paralleling roots adjacent to extraction spaces
• As a method of settings up posterior anchorage units into the
tipped back or anchorage prepared positions
• And as a mans of obtaining correct axial inclination or “artistic”
positioning
1960 - Ivan Lee, suggested torqued slot
1963 - Jarabak described the use of torqued brackets and
also angulated for the upper anterior
1960 - Manufacturers raised base of brackets for laterals
1976 - Andrews S.W.A.
1979 - Roth modification
1983 - Alexander vari simplex
1994 - Andreiko developed individualized system Elan's
orthos using computer system aided manufacturing

Need for a modifying bracket of edgewise
• 1. Design short comings of standard edge wise
• 2. Bracket base are perpendicular is to bracket stems
• 3. Bracket bases are not contoured occluso-gingivally
• 4. Slots are not angulated
• 5. Stems of bracket are of equal prominence
• 6. Maxillary molar offset not built in

Classification of bracket
• Non programmed brackets
• Semi programmed brackets
– Eg: Alexander Hilgers
– Burstone
• Fully programmed brackets
– Eg: Andrews S.W.A
– Roths appliance

Extraction series brackets of Andrews
[Based on how much tooth has to be moved]
Andrews suggested a wide range of brackets as further
development of the "S.W.A"
These contained variations in Tip, Torque and rotation,
designed to meet the needs of individual cases
In particular they were recommended to counteract tip and
rotation changes during tooth movement when treating
extraction cases

Bracket types
1. Minimum translation brackets
It is recommended for the tooth which has to translated
2mm or less
Two types of them are
• 2° counter mesio-distal tip and a power arm added to
distogingival tie wing for distal translation of tooth
• 2° subtracted if translation is to be mesial since and power
arm added to mesiogingival tie wing

2. Medium translation bracket
It is recommended for the tooth which has to be translated
more than 2mm but not more than 4mm.
3° degree of counter mesiodistal tip added or subtracted
4° degree of counter rotation is incorporated.
Maxillary 1st molar translational bracket has, in addition to
counter M-D tip and counter rotations, 5° of counter
buccolingual tip added to the standard amount of positive
intention
Power arm added

3. Maximum translation brackets
It is recommended for the tooth which has to translated for
more than 4mm
4° of counter M-D tip is added or subtracted
6° of counter rotation is incorporated
Maxillary 1st molar translation bracket in addition to M-D
tip and counter rotation 6° of counter bucco-lingual tip
added to the standard around of positive inclination
Power arm is usually added to these brackets
Later Andrew modified brackets for particular ANB angle
cases which may require different torqueand tip values to
compensate skeletal malrelation

Roth / MBT

Roth 12 8 -2 -7 -7 -14 -
14
Andrews 7 3 -7 -7 -7 -9 -9
Andrews -1 -1 -11 -
17
-22 -30 -
33
Roth -1 -1 -11 -
17
-22 -30 -
30
MBT
MBT
17 10 -7, 0,
+7
-7 -7 -14 -14
-6 -6 -6, 0,
+6
-
12
-17 -20 -10

Worldwide distribution of
main prescriptions

Combination of Begg and Edgewise

Begg-edgewise diagnosis-determined totally
individualized orthodontic technique
offers the capacity to employ selected principles and features of
Begg and edgewise mechanisms in specific situations in which
they are most advantageous – Hocevar - 1985
Brackets
The brackets are narrow, single-width (0.050 inch or 1.3
mm) edgewise1 brackets with 0.022 inch (height) x 0.028
inch (faciolingual depth) horizontal arch wire slots
On the lingual side of the bracket (that is, against the band
or bonding pad) is a 0.020 x 0.020 inch vertical slot
The arch wire slots are ''torqued" (cut at such angles to the
brackets that they will be oriented parallel to the plane of the
arch when the teeth are positioned properly)

BEDDTIOT bracket on universal
bonding pad

Since the slope of the surface of any particular tooth varies
among patients, the operator should exercise judgment in
the selection of appropriate brackets
Except for torque, the brackets are all identical –
interchangeable
Placed with its torque-indicator groove gingival, a bracket
provides lingual root torque
With the groove occlusal, it provides lingual crown torque
The standard torques make up a set with a smooth
progression— 0°, 5°, 10°, 15°, and 20° - an appropriate
bracket is available for most situations

Cross section of bracket with 200
lingual crown torque on
mandibular second premolar

Appropriate torques for
"average" teeth in "average"
cases. Variation on these
"typical" torques is the rule
rather than the exception

The brackets are small in all dimensions to ensure optimal
appearance and minimal lip and cheek irritation
This also lessens occlusal interference, enamel surface
involved in bonding, and problems with gingival proximity
and oral hygiene
Narrow brackets have long, resilient spans of arch wire
between them— a great advantage over twin bracket
edgewise
The vertical slot has many potential uses
• It can accommodate ligatures, elastic hooks, rotation devices,
and various other auxiliaries, uprighting springs
• Turned 90° (so it is horizontal), it can serve as a miniature
buccal tube – partially erupted teeth

A, Acute bends are required to
engage a wire in twin
brackets on malaligned
teeth
B, The wire is deformed much
less in the engagement of
narrow brackets in the same
situation; the force level is
much more gentle, and the
degree of deflection is more
likely to be within the elastic
range of the wire

Rotation-control uprighting springs
in place on the canines and an
older style uprighting spring
placed on the mandibular
premolar

If oriented horizontally, the "vertical"
slot of the bracket can serve as
a miniature buccal tube to gain
control of partially erupted or
impacted second molars. The
attachment's size facilitates
avoidance of occlusion. It also
allows bonding where only a
small area of tooth surface has
emerged

Universal Appliance
Universal appliance described by Dr. Atkinson as a
"Prescription appliance"
Components of universal appliances are
Universal bracket: Only a main part of this appliance given
by or introduced by Dr. Atkinson in 1929 and described its
feature in his article entitled "the strategy - of orthodontic
treatment" in 1937
Lingual arch
Removable plate
Extraoral headgear
Many other adjuncts

Universal bracket
Designed by Dr. Spencer Atkinson
A combination of the edgewise principle and Angle's ribbon
arch - control in three planes of space
A very popular Universal bracket is called the "double action
bracket“ - two transverse slots
The gingival or horizontal slot, into which an .008" up to an .
014" round wire may be fitted, opens buccally - controls the
mesiodistal inclinations and serves as a fulcrum for labio-
lingual movements
Incisal slot is vertical opens incisally - round wires from .008"
to .016“, flat wires from .008" x .020" up to .015" x .028".
Controls the tooth bucco-lingually and also controls
rotations. Both slots allow the tooth to move bodily during
retraction

Two popular varieties of Universal
bracket. The ''double action bracket''
(left) and the "root torquing bracket"
(right)

Both the gingival and the incisal wires are locked into the
bracket by a single lock pin
This bracket has a precurved base for better adaptation and
is available in two sizes, a long one with a body height of .
150" and a short one of .125".
A variation of this bracket is the "root torquing bracket“.
Have tabs that permit extra ligation for severe rotations,
extra leverage, and better support for the archwires. Used
mainly for wide teeth or severely rotated teeth. It also comes
in two sizes and has a precurved base.
There are other variations of the Universal bracket, but they
all have the same basic principle.

A "double action bracket" with the
gingival round wire and the
incisal flat wire secured in place
by a brass lock pin

Multiphase attachment
Introduced by Bowles in 1953
Bowles states that the multiphase, designed to effect
standardization of most philosophies, yet maintain the
unique characteristics of labiolingual, twin wire, universal,
differential light forces and edgewise techniques, may be
described as the common denominator
In the multiphase technique a single anterior bracket is
usually used with a choice of a molar width bracket or
different widths of twin multiphase brackets available, as
with the edge wise
The ingenious bracket design accommodates all currently
used gauzes of wires, singly or in combination
Routine use of it with almost all techniques mentioned
above, gives us freedom of modification of mechanotherapy
as the treatment progresses and the individual preferences
of the operator, levels a high layers of versatility to the
appliance

Bowles multiphase attachment

Tip -edge appliance
Introduced by P.C. Kesling
Edge wise type bracket with unique arch wire slot
Diagonally opposed surfaces of the edgewise slot has been
chamfered
This permits initial predetermined direction of tipping, which
is controlled in both direction and degree
Since this bracket permits tipping yet also provides
edgewise control, it is referred to as "'Tip-edge" bracket

Internal design of tip edge bracket
Crown tipping control surface
Root uprighting control surfaces
Vertical and torque control ridges or pivots
Rotational control surface
Initial bite opening and A-P correction are accomplished with
vertical and horizontal forces from 0.016 inch round high
tensile archwire and [1 / 2 Ounces Elastics]
This appliances system is preadjusted in 3-dimensions, the
tip, edge slot permits the use of straight arch wires in the
majority of cases since both extraction and non extraction
The bracket is designed to provide all the benefits of
differential tooth movements and predetermined degrees of
final crown tip and torque

Slot size - 0.022 x 0.028
Have central ridge, uprighthing - surface and tipping
surfaces
Vertical slot - 0.020 x 0.020
Accepts rotating / uprighting springs power pins, jigs etc
Both the gingival and incisal ends are chamfered to facilitate
the insertion of auxiliaries from either direction
The in out compensation - eliminates the need for lateral
bicuspid or molar offsets
Torque built in the base
Tip built in the face
Lateral extensions of the brackets behind the archwire
provide maximum rotational control even when the tooth is
tipped therefore bracket can be narrow for maximum
esthetics - lateral extensions are hidden behind the arch
wire

Features
Through the creation of a new edge wise slot configuration,
it is possible to provide for differential (Beg) tooth
movements and yet maintain final predetermined control of
each tooth
In combination with unique elastomeric ties, molar torquing
flaps and standard auxiliaries, treatment of both extraction
and non extraction and cases can be completed with two or
three sets of plain arch wires using light intraoral forces

Advantages
Automatic M-D tip control
Increased Interbracket distance (in both vertical and
horizontal plane)
Eliminates considered torque of the conventional edge –
wise appliance, thus less interferences in bite opening and
dental midline shifts
Improved anchorage

Root’s level anchorage system [1981]
Developed by Terrell. L. Root
The level anchorage system is a complete, orthodontic
treatment designed for those goal oriented orthodontists
who could like to treat efficiently to a predetermined goal and
reach that goal on a routine basis
It consists of a bonded or banded edgewise appliance with
built-in tip, torque and offset and an analysis and treatment
planning chart with a step-by-step treatment procedure for
seven different extraction and non extraction choices

Level Anchorage system
"J" hooks attached to the archwire

The level anchorage system could be described as utilizing
a S.W.A with an anchorage preparation described by
holdaway
Distal tipping included in the molar tubes that automatically
provide anchorage prepared positions to the molars
The level anchorage system has taken new materials such
as NITINOL WIRE & new manufacturing abilities such as
accurate steel casting of appliances to provide a completely
preadjusted appliance

The combination anchorage technique [cat] by
Thompson [1981]
Begg & S.W.A appliances amalgamation
Purpose is to utilize the advantages of these mechanics to
the fullest
In the combination bracket design (1981), the lower 3rd of
the bracket was a 256 Begg bracket and the upper 2/3rd
was 0.018 “0.025” S.W.A. slot with in and out,
preangulations and pretorque values
However the original bracket proved to be bulky, weak and
esthetically unattractive

Tipping is possible because of the
tapered slot in the Begg
bracket

Problems with
• Pinning
• Rotations
• slot closure
occlusal interferences were problematic

Bracket design
Gingival slot - Closely resembles a true Begg Ribbon Arch
type[0.022 x 0.035]
• Maximum speed & maximum tipping
• Minimum pain, least amount of friction
• Maximum effectiveness for auxiliaries springs
Straight Wire Slot [0.022 x 0.028]
• Facilitates optimum three dimensional edge wise treatment
• In out compensation, tip & torque built in to the slot

Bracket positioning and angulation

Four-stage torque

Additional
• An enclosed vertical slot also incorporated in to the
bracket for use with uprighting or retaining springs,
elastic or surgical fixation hooks and for attachment of
the tandem arch wires
• Colour - coding dots
– Maxillary - red
– Mandibular - blue

Alexander Vari – simplex
Utilizes various brackets for various teeth andto meet various
requirements – hence Vari – variety – according to requirement
to simplify treatment - simplex

Twin Brackets
Used on large, flat-surfaced
teeth (namely, maxillary
central and lateral incisors)
The flat surfaces of these
teeth permit full arch wire
engagement in the twin
brackets
There is little trouble tying the
wire into these brackets
because of their ease of
accessibility
Bracket Selection
Twin Brackets are Convenient for Ligating
Teeth Together & Placing Hooks

• This bracket consists of the
basic 0.022" x 0.028" slot plus a
0.017" x 0.025" vertical or
horizontal auxiliary tube
• When placing this bracket on
the tooth, auxiliary tubes are
always placed gingivally
Ball hooks for elastic placement
are usually placed on lateral
incisor brackets.
The brackets allow for 5 to 6
mm of inter-bracket width,
which is sufficient for flexibility,
rotational control, and torquing.
Also, these brackets are smooth
and minimize irritation on labial
tissues

Lang Brackets
Originally developed by Dr.
Howard Lang
Used on large, round-
surfaced teeth at the corners
of the arch i.e. maxillary &
mandibular cuspids
The pad is contoured, which
fits on most cuspids

The straight wing eliminates interference with complete arch wire
engagement. Thus, the bracket is easily ligated and inter-bracket
width is maximized
The wings can easily be activated for rotational control
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.
Lewis Lang

Twin brackets on cuspids are not the brackets of
choice because
They decrease the inter-bracket width, making it more difficult
to ligate & control rotations
It is often impossible to get full- bracket engagement on these
teeth early in treatment and
They can interfere with opposing cusps on occlusion (actually
often causing cusp attrition)

Lewis Brackets
Used on round-surfaced teeth not located at the corners of
the arches (maxillary and mandibular bicuspids) as well as
small, flat-surfaced teeth (mandibular incisors
The Lewis bracket is a fixed-wing single bracket that again
contributes positively to the concept of increased inter-bracket
width. The wings provide a distinct advantage in having a
built-in auxiliary for rotational control, much in the same
fashion as those on the Lang bracket
Lewis Brackets

The design of the bracket is wedge shaped which puts the tie
wing closer to the tooth occlusally and far out gingivally
This makes it easy to tie
To use as hooks for elastics
To keep clean and
Often in this technique, up & down elastics on posterior teeth are
used for settling, and this wedge shape is excellent for that purpose

An additional benefit offered by the single bracket with wings is
that, on a 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

Specifications of the Appliance
Bracket Height
Bracket height in this Discipline, as in any other technique, is
extremely important in the construction of the appliance
Bicuspid bracket height (x) is the key because its clinical crown
height is so variable
Other bracket heights are calculated in relation to x

Maxillary Arch
Centrals X
Laterals X – 0.5mm
Cuspids X + 0.5mm
Bicuspids X
1st Molars X – 0.5mm
2nd Molars X – 1.0mm
Mandibular Arch
Centrals X – 0.5mm
Laterals X – 0.5mm
Cuspids X + 0.5mm
Bicuspids X
1st Molars X – 0.5mm

Bracket Angulation
To allow the roots to be properly positioned at the end of
the treatment, care is taken during the bracket
placement to ensure that the brackets are placed
parallel to the long axis of the clinical crowns
Maxillary Arch Mandibular Arch
Centrals 3° 5°
Laterals 6° 8°
Cuspids 6° 10°
Bicuspids and
Molars 0° 0°
Centrals 2° 2°
Laterals 2° 2°
Cuspids 6° 6°
Bicuspids 0° 0°
1st Molars – 6° – 6°
2nd Molars 0° 0°
Banding
(Incisal edge
Reference)
Bonding
(Long axis
Reference)
Banding
(Incisal edge
Reference)
Bonding
(Long axis
Reference)

Bracket Torques
The torque prescriptions used in this technique are derived
from measurement of the torques in the rectangular
archwires used to finish well treated orthodontic cases
Maxillary Arch
Centrals 14°
Laterals 7°
Cuspids – 3°
Bicuspids – 7°
Molars – 10°
Mandibular Arch
Incisors – 5°
Cuspids – 7°
1st Bicuspids – 11°
2nd Bicuspids – 17°
1st Molars – 22°
2nd Molars 0° or – 27°

These measurements differ from commonly used torques in
three major respects
• The -3º torque on the max cuspids compared to
extremes of +7º to -7º in other appliances, eliminates the
need for adjusting the torque later in the treatment
• No torque is placed in the mandibular second molar
tubes, because of the use of omega stops, which are
always bent out to avoid impingement on gingival tissue
& to avoid food trap. This automatically incorporates
torque in the wire
• -5 º of lingual crown torque or labial root torque in the
mandibular incisors

Evolution of orthodontic brackets

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