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Tackling an iatrogenic problem!!
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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Introduction• All modern mechanics have a double scale of
ladder ascendant & descendant , ascending from
experiment to the invention of causes &
descending from causes to the invention of new
experiments
• Anchorage plays a very vital role in
orthodontics. Loss of anchorage can take place
during
• Aligning, leveling and retraction stages.
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Reasons for anchor loss
during aligning
•Lower molars normally drift mesially to
occupy the lee-way space after shedding of
lower primary second molars which can be
restricted by timely placement of lingual
arch.
•Anchorage requirement in upper arch is
greater compared to lower arch
•Improper positioning of brackets.
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Reasons for anchor loss
during retraction
iatrogenic
factors
incorrect
alpha &
beta bendsexcessive forces
used during
retraction.
posterior segments
are not consolidated
during retraction.
Improper
positioning
of loop
Improper bracket
positioning
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When in doubt use
a wire applying
lighter forces
Anchorage
reinforcementUse light
Continuous
force
During
aligning….
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How to control anchorage
during leveling ?
•Using light continuous forces
•Maintain the direction of force
•Rein force anchorage
•Proper bracket positioning.
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Anchorage control during
retraction
retraction
individual
enmasse
Walking of
canine
Rein force
anchorage
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Anchorage
reinforcement
EO
high
cervi
calstraight
com
bi
IO
TPA
Nance button
Class –II elastics
Lingual archwww.indiandentalacademy.
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how to correct anchor loss ?
Anchor loss
occurs by mesial
tipping of molars
Hence distalize
molars
Extra oral
Intra oralwww.indiandentalacademy.
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Extra oral
High pull
Cervical pull
Combi pull
distalizing effect
on molars and
premolars
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Intra oral
Inter maxillary
Intra maxillary
Absolute
anchorage
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IO non compliance
appliances
Intermaxillary
Elastics
Modular appliance
Intra maxillary
Modified nance arch with NiTi coils
distalising bow Absolute
anchorage
Palatal
implantswww.indiandentalacademy.
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APPLIANCE DESIGN:
• Modular appliance is made up of 0.016x0.0 22 rectangular SS / TMA wire
• Modular appliance consists of an omega
loop touching the mesial aspect of buccal
tube and there is an upward curve in the
mesial part of the canine bracket, which
ends in a hook on the upper or gingival
part.
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•The gingival part of the hook is
helicoidally recurred with the end inward
to avoid erosion of the vestibular mucosa.
•Tip back bend of 45 degrees is given distal to omega loop .
•The wire should be cinched distal to the molar buccal tube
•The buccal segment should be contoured to prevent tissue impingement.
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APPLIANCE DESIGN
omega
loop
hook to
engage
elastics
tip back bend of 45
degreeswww.indiandentalacademy.
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•Class II elastics ( preferably blue
or green ) applying 100 – 150 gm
force are used from the hook mesial
to canine and to the lower molar
hook.
•The modular sectional arch blocks
the segment between the canine and
the upper first molar in one unit ,
which it moves in distal direction.
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BIOMECHANICS
•Based on cantilever mechanism
Mechanics
of spring
elastics
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•These mechanics can
effectively tip back an upper
molar and rotate the molar
mesial out.
•Distal end of omega loop acts
as a stop and applies the
tipping force on upper molar.www.indiandentalacademy.
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•A light class II elastic is
placed from lower arch
•Class –II elastic is effective ,
not only because of its distal
force but because a very large
moment is produced tipping
the molar distally.
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• Class – II elastics can flare the lower arch, increase the vertical and steepen the occlusal plane.
• Hence elastics are used for a short period of time.
• Because the molars tip back rapidly, only a short period of class – II elastic wear is required leading to negligible side effects
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Pre - treatment
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Pre - treatment
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Upper 5’s
lower 4’s
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Pre - surgical
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Post surgical
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Post - surgical
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Case - 3
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Case - 3
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Modular
appliance
Less time
consuming
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advantages
fixed into the
auxiliary tube
•Distalisation is brought
about in short duration
of time……..
versatile
Unilateral or bilateral
Class II
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Conclusion
If anchor loss is noticed early and timely
intervention of modular appliance is made, it saves
a lot of drudgery.
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AcknowledgementDr. E. MUNIRATNAM NAIDU,
Principal,
Dr. P. JAYA KUMAR,Vice principal,
PROF&HEAD OF DEPARTMENT,ORTHODONTICS.
STAFF MEMBERS & P.G. STUDENTSDepartment Of orthodontics
MEENAKSHI AMMAL DENTAL
COLLEGE.www.indiandentalacademy.
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