Combination anchorage technique

COMBINATIONCOMBINATION
ANCHORAGEANCHORAGE
TECHNIQUETECHNIQUE
www.indiandentalacademy.com

OVERVIEW
•Introduction
•Anchorage & Differential force
•Armamentarium
•Treatment Technique
» Extraction Treatment
» Non-extraction Treatment
» Surgical Treatment
•Modifications Of C.A.T
•Conclusionwww.indiandentalacademy.com

INTRODUCTION
The C.A.T. is a technique of
fixed appliance therapy that
utilizes the advantages of two
different fixed appliance
systems namely
1.The Begg Light-wire system &
2.The P.A.E. system,
and tries to bio-mechanically
produce what scientificallywww.indiandentalacademy.com

INTRODUCTION
The idea of a Combination system has
evolved since the 1960’s from Chun-
Hoon, through Fogel & Magill
(1963), McDowell(1967 &1969),
Kessler (1980), Thompson (1981) till
the C.A.T. by Thompson in 1988.
The C.A.T. uses two different bracket
slots through simple & efficient
means to vary (1) Anchorage (2)
Tooth movementwww.indiandentalacademy.com

ANCHORAGE &
DIFFERENTIAL FORCE
The C.A.T. does not require extra- oral
anchorage except in
•Non-extraction cases requiring
Molar Distalization
•Cases requiring orthopaedic control
of the maxilla
•Severe skeletal Cl.II problems .
The combined mechanics of C.A.T. can
develop both static & dynamic
anchorage resistance, and each is
applied at certain times in the
treatment program. This is one of the

STAGE
• I
• II
• III
• IV
TYPE OF
ANCHORAGE
• Dynamic
• Dynamic
• Dynamic/Static
• Static

• Dynamic Anchorage:
This is the complex system of
anchorage seen in the Light-wire
appliance. This is derived from :
•Anchor bends
•Wire size & design
•Elastic forces
in a complex inter-relationship
with the equally effective forces
that are developed in thewww.indiandentalacademy.com

•Static Anchorage:
Earlier only Extra-oral anchorage
was considered Static or Stationary
anchorage.In 1969, McDowell stated
that Static anchorage could be
gained through suspension of
anchor teeth in the tensed Oblique
fibre Hammock, as a result of the
reactive intrusive forces exerted by
the masticatory muscles when the
anchor teeth are being used towww.indiandentalacademy.com

The intra-oral Hammock anchorage
is often capable of totally resisting
at least half a pound of constant
mesial force in each anchor molar.
Other methods of obtaining Static
anchorage are:
(1) The use of an Anchor plate in the lower
arch that causes the mandible to remain
open very slightly into the post-freeway,
in conjunction with an upper Beggwww.indiandentalacademy.com

(2) The use of an upper Anchor bar(0.0215”
x 0.028” SS edgewise wire) in the
additional edgewise tubes of the upper
anchor molars in a Begg appliance. The
Anchor bar had a lingual crown torque
which caused the upper anchor molars to
undergo the pivotal phenomenon in the
bucco-lingual plane which was resisted
by an equal opposing intrusive derived

(3) To develop Static anchorage in the
C.A.T. in Phases III & IV, the
following are used:
•Heavier archwires
•Lingual arches
•Banding of the second molars
•Inserting a short edgewise segment
through the premolar bracket & both
molar tubes.

ARMAMENTARIUM
• Brackets
• Molar tubes
• Lock pins, ligatures, modules,
springs
• Elastics
• Archwires

BRACKETS
The current C.A.T. bracket includes
improvements from the older
combination brackets. Highlights of the
C.A.T. bracket:
• It has a 0.025” x 0.035” gingival or ribbon-arch
slot and either a 0.018” x 0.025” or a 0.022” x
0.028” straight-wire slot.
• It has an enclosed vertical slot for
uprighting/rotating springs, surgical fixation
hooks & tandem/dual archwires.
• All brackets have colour coding dots at thewww.indiandentalacademy.com

• Maxillary incisor brackets are available with
varying degrees of torque & maxillary canine
torque has been reduced to 0 deg.
• Torque in the lower premolar brackets has been
changed from 17 deg. in the 1st
premolar & 20
deg. in the 2nd
premolar , to a standard of 19 deg.
For both.
• Bracket size & contour have been reduced to
practically eliminate lip irritation & distortion
caused by occlusal interference.
• Gingival extensions have been reduced to make
placement more accurate.
• The redesigned pin slot & bracket pads have
simplified the placement & retention of pins.

MOLAR TUBES
• The 1st
molar attachments have two tubes,
a gingivally placed 0.036 inch round tube
& an incisally placed 0.018 x 0.125 inch
or a 0.022 x 0.028 inch rectangular tube.
• Triple tubes are also available for
headgears & hooks for elastics are placed
at the mesial.
• The tubes have a 7degree offset to
facilitate placement of a straight
finishing wire & also for additional molar
control. www.indiandentalacademy.com

• Conventional edgewise tubes are
currently recommended for both molars
as they are smaller occlusogingivally &
produce lesser occlusal interference
&tissue irritation than the convertible
tubes.
• The 0.018 x0.025 inch tubes are suggested
due to the availability of highly resilient
0.018 x 0.025 inch SS archwires.

BRACKET & TUBE
PLACEMENT
• In extraction cases:
– The technique for placement of brackets &
tubes is similar to that of the Straightwire
appliance.
» Molars- 3.5 mm from cusp tip
» Canines- 4mm from cusp tip
» L.incisors- 3mm from incisal tip
» C.incisors –3.5mm from incisal tip
• In NE cases:
» Mand. 1st
premolar- 4mm from cusp tip
» Canines- slightly extruded

LOCK PINS, LIGATURES,
MODULES & SPRINGS
• LOCK PINS:
• Stage I pins
• Stage II pins
• Stage III pins
• Special bypass pins
• Unicorn pins
• High hat pins
• LIGATURES:
• 0.009 inch SS wire
• MODULES & SPRINGS:
• A-lastic modules
• A-lastic thread
• Whip springs
• Rotation springs
• Rotation moduleswww.indiandentalacademy.com

ELASTICS
In the C.A.T. , elastics play an important
role in all phases of treatment but the
specific reasons for their use & the
amount of force they exert vary in each
phase.
In Phase I & II, the elastic forces will
usually be in the range of 1 ½- 3 ounces.
In Phase III & IV, the elastic forces are
increased upto 5 to 6 ounces.
According to Swain, variations in bony
resistance bet’n individuals necessitatewww.indiandentalacademy.com

ARCHWIRES
• 0.016 inch SS round
• 0.018 inch SS round
• 0.018 x 0.018 inch Niti
• Dual Flex 1
• Dual Flex 2
• 0.016 x0.022 inch Niti
• 0.017 x0.025 inch Niti &SS
• 0.018 x 0.025 inch Niti & SSwww.indiandentalacademy.com

DUAL FLEX WIRES
Dual Flex wires are multisegment wires whose SS
posterior segment is seated in the light-wire slot
& Niti anterior segment is seated in the anterior
edgewise slots.
Dual Flex wires have eliminated the use of loops
in Phase I bite-opening, allignment & retraction
mechanics.
Dual Flex 1:
Archwires with a round 0.016 inch SS
posterior segment( bite-opening & molar

• Dual Flex 2:
Archwires with a round 0.018 inch SS
posterior segment & a rectangular 0.016 x 0.022
inch Niti anterior segment from canine to
canine .
Used in cases which require heavy anterior
resistance to minimize lingual movement of
anterior teeth.
Dual Flex wires can be modified with step-up,
step-down or in- and – out bends to facilitate

THE TANDEM WIRE
TECHNIQUE
The Tandem wire technique uses two wires
in tandem , one in the straightwire slot &
the other in the lightwire slot( 0.018 inch
SS round wire in the gingival slot in
tandem with a 0.018 x 0.018 inch Niti
wire in the straightwire slot).
The rigid SS wire is called the vertical
stabilizing archwire & has bite-opening
bends to control the vertical position of
the incisors. www.indiandentalacademy.com

The tandem system acts as a superb
levelling & torquing appliance and can
be used in different combinations:
• Light-wire torquing auxillary with
mandibular tandem.
• Double tandems
• Maxillary tandem & mandibular
straight-wire.
• Tandem wire segments in premolar &
molar teeth with anterior intrusion
arches and/or lightwire bite-opening

DUALFLEX WIRES

TANDEM WIRES

LOCK PINS
Phase III pins
Phases I &II pins
Tandem, hook pins
Bypass clamp

FINISHING WIRES

• The tandem wires eliminate the
relapse of bite-closure caused by
continuous archwires.
• The rigid SS base arch creates an
intrusive force which overcomes the
extrusive force of the Niti tandem
wire therby eliminating relapse.www.indiandentalacademy.com

TREATMENT TECHNIQUE
The treatment technique is divided
into phases to facilitate the use of
light-wire or straight-wire
mechanics at specific times for
specific reasons. The phases are
often combined and/ or eliminated
because of the efficiency of the

The phases of the C.A.T. are
• Phase I (Early Organization)
• Overbite correction
• Achievement of Cl . I canine & molar
relationships
• Correction of rotations & closure of all
anterior spaces
• Treatment mechanics in the gingival slot
with Dual Flex 1 wires & Cl . II / check
elastics( 2 ½ to 3 ounces ).
• Phase I (Late Organization )
• Mechanics of early phase I is continued
• Dual Flex 1 is placed in the straight-wire

•Phase II (Consolidation ):
•Mechanics of Phase I to be continued
•Final space closure in the posterior
segments
•Dual Flex 2 wires are used in the
edgewise slots of anterior teeth & in
the gingival slots of the posterior
segments www.indiandentalacademy.com

Phase III ( Co-ordination )
• Objectives achieved in Phases I & II
are maintained
• Tandem wires are placed ( 0.018
inch SS round with 0.016 inch round
, or 0.018 inch square ,or 0.016 x
0.022 inch rectangular Niti wires )
• Cl .II elastics ( 3 to 4 oz. )

Phase IV ( Harmonization )
• Ideal finishing archwires are placed in
the edgewise slots ( ranging from 0.016 x
0.022 inch to 0.018 x 0.025 inch Niti wires
).
• If necessary , torquing auxillaries or
additional torque in the archwire are
used
• Vertical offset bends to overcome bracket
height discrepancies are usuallywww.indiandentalacademy.com

NON-EXTRACTION
TREATMENT
Non-extraction treatment with the C.A.T.
usually involves distal driving of the
maxillary molars.
Extra-oral appliances are not used unless
there is evidence of skeletal disharmony
& orthopaedic force is indicated.
In NE cases with minimal crowding,
treatment is commenced with the
archwires in the gingival tubes & slots,
which tends to automatically move the

In NE cases with adequate spaces for the
incisors, the archwires are engaged in the
edgewise slots of maxillary anterior &
all mandibular brackets, to establish
complete anchorage resistance in the
lower arch and maximum anterior
resistance in the upper arch.
Jigs, coils , or elastics are then used to
distalize the maxillary molars with wires
in the round light-wire tubes
Class II elastic forces ( 2 to 3 oz.) are used towww.indiandentalacademy.com

The distalized molars are held in
position with crimpable stops.
The canines , premolars & incisors
are tipped distally and final
finishing is done with Tandem
mechanics.

SURGICAL TREATMENT
• The C.A.T. can use either Begg or
Straightwire in pre-surgical orthodontics
• The rigid surgical splint wires can be
placed in the Straightwire slots
• Forces are light & discomfort reduced
• Extension pins of the C.A.T. are useful in
surgical fixation and also reduce oral
hygiene problems & tissue irritation.

MODIFICATIONS OF C.A.T.
The C.A.T. can be modified to treat
• Single arch problems
• Unilateral problems
• Mid-line disharmonies(if one jaw is
affected,edgewise resistance is used,& if
both jaws are affected, lightwire
resistance is used in both jaws.)
• Class III malocclusions

NON-EXTRACTION TREATMENT

MOLAR DISTALIZATION

PHASES I, II & III

PHASES III & IV

Combination anchorage technique

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