ANCHORAGE
IN
ORTHODONTICS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.indi...
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Concept
Definition & Classification
Consideration of anchorage in three planes of
space
Anchorage pl...
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Whenever a force is applied the stabilized site
from where the force is exerted is the
anchorage

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Tug of warTwo equa...
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The pegs/ stakes driven into the ground at
an angle to support the tent
The stakes are at an angle that the pull ...
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Newton & his laws of motion:
Law I: A thing at rest or in motion continues
to do so unless acted upon by an extern...
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We know that to create movement / displacement,
we must have a force acting on the body.

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For eg. Body (B) is at res...
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For every kind of movement there exist an
optimal force level, below which that
particular movement cannot be produced....
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Let us now come to oral cavity & teeth.
If an upper canine is to be retracted, with
bodily movement using a fix...
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2 bda

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As the force level is increased to 300g the
reciprocal forces also increases with greater risk
of mesial movt. of post ...
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The anchorage value of any tooth is roughly
equivalent to its root surface area

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Relationship of tooth movt. To force
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An obvious strategy for anchorage control
is to concentrate the force needed to
pr...
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Pressure in Pdl is determined by f/a.

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Tooth movt increases as pressure
increases up to a point, remains at the
same...
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309

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The optimum force for orthodontic tooth
movement is the lightest force that
produces a maximum or near maximum
respo...
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Let us consider the response of anchor teeth
(A) & teeth to be moved (M) in three
circumstances.

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In each case, the ...
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310

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In the second case(A2-M2), both are on
the plateau of the pressure response
curve. The anchor teeth can be expected
...
Defination
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The term Anchorage in orthodontics refers to
the nature & degree of resistance to
displacement offered by an...
Classification
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1. According to manner of force application
2. Acc. To jaws involved
3. Based on site of anchorage...
Manner of force application
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I. Simple Anchorage
2. Stationary Anchorage
3. Reciprocal Anchorage

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Simple Anchorage
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Dental anchorage in which manner &
application of force tends to change the axial
inclination of th...
Factors important for assessing
resistance value of an anchorage
unit( tooth)
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The part of tooth which is anchored ...
Or it can also be expressed as the approximate
root surface area.
A tooth with a larger R.S.A is more resistant to
displac...
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It is also imp. to check inclined plane
relationships & muscular forces in
assessing value of an anchorage unit.

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Am...
Stationary Anchorage
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Dental anchorage in which manner &
application of force tends to displace the
anchorage unit bo...
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310

www.indiandentalacademy.com
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This refers to the advantage that can be obtained
by pitting bodily movement of one gp. of teeth
against tipping ...
Reciprocal Anchorage
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Refers to resistance offered by two malposed
units when the dissipation of equal & opp.
forces ...
Egs of Reciprocal Anchorage

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Site of anchorage
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classification……

Intraoral Anchorage Extra oral Anchorage
Cranium (occipital or
Teeth
...
classification……

According to jaws involved
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Intramaxillary Anchorage

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All the resistance units are situated in the...
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Intermaxillary Anchorage
Anchorage in which resistance units
situated in one jaw are used to effect tooth
movement...
Class II
intermaxillary
elastics

Class III
intermaxillary
elastics
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classification……

Based on no. of anchorage units
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Single or primary anchorage
Cases wherein the resistance provided ...
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Compound Anchorage
Here the resistance provided by more
than one tooth with greater support is
used to move teeth wit...
Multiple / Reinforced Anchorage
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More than one type of resistance unit is
utilized
Refers to augmentation of ...
Three Dimensional Anchorage evaluation
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Considering anchorage in all the three
planes (sagittal, vertical & transvers...
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Horizontal anchorage control means limiting
the mesial movt. Of post. Segment while
encouraging distal movt. Of ant. Se...
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Vertical anchorage control involves limitation
of the vertical skeletal & dental development in
the post. Segments & th...
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In the transverse plane, it comprises of
maintenance of expansion procedures & the
avoidance of tipping or extrusion of...
ANCHORAGE PLANNING
Methods to increase anchorage potential
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I . By increasing the resistance to
displacement

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II. By ...
Increasing the resistance to displacement
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1. Increase the no. of teeth in the anchorage
unit ( increase root surface...
Increasing the resistance to displacement…..
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3. Cortical anchorage
Moving the roots of anchor molar into the...
Increasing the resistance to displacement…

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5. Extraoral anchorage

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6. Muscular forces can be used to
augment anchor...
Increasing the resistance to displacement…
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7. Moments generated through cantilever
springs or base intrusion arches are...
Decreasing the displacement potential
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1. Reduce forces
2. Reduce friction
3. Sequential loading

1. Reduce fo...
Decreasing the displacement potential….
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2. Reduce friction .. Using frictionless mechanics
..use of optimal cle...
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Tweed’s Classification of anchorage
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First Degree Anchorage preparation
It is applicable to all malocclusions with ...
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The degree to which anchorage should be
prepared is minimal.

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Mandibular terminal molars must always
be uprighted an...
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As a general rule, this means that the
inclination of the mandibular terminal molars
should be such that the direction ...
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Second degree anchorage preparation

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Indicated when ANB exceeds 4.5˚and facial
esthetics make it desirable to move p...
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They are accompanied by Type A, Type A
Subdivision, Type B and Type B
subdivision growth trends

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The mandibular term...
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The direction of pull of the Class II elastics
when related to the long axes of the terminal
molars should be greater t...
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Third degree or total anchorage
preparation
It is necessary in extremely severe
malocclusion in which total di...
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In these all three posterior teeth from and
including the second PM’s to and including the
terminal molars must be tipp...
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In such positions, their mesial displacement
& elongation will not be great, during the
period when prolonged and vigor...
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Conventionally Begg technique is
considered to be kind on to the anchorage
& the PEA anchorage taxing

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Begg & PEA
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Pinning of base arch wire
into anteriors generates
powerful posterior
anchorage by activating
the anchor ...
Movts of ant. are in
2 stages, tipping &
uprighting which is
kind to the anchorage
Anteriors have the
freedom to tip in bo...
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Loosing anchorage is
a definite & positive
decision

Conserving

anchorage is a definite
& positive decision

www.indi...
Anchorage considerations with PEA
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Anchorage control in PEA is very imp.
Because of the features built in the
applian...
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McLAUGHLIN & BENNETT defined
anchorage control during leveling and
aligning as "the maneuvers used to restrict
undesira...
Control of anchorage in the horizontal
plane
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Anchorage control in the ant segment

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Anchorage control in the post seg...
Anchorage control in the ant segment
In initial wires with preadjusted system,
tip built into anterior brackets increases
...
Early attempts were
made to minimize
tipping by connecting
the anterior and
posterior segments,
usually with elastic
force...
1. Lacebacks For A-P canine control
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These are .010 or .009 ligature wires which
extend from most distally banded bracke...
They restrict canines from tipping forward during
leveling & aligning.
In extraction cases, these prevented cuspid
tipping...
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Robinson investigated 57 PM Xn cases, ½
of which were treated with lace backs & ½
without.
His findings confirm t...
2. Bend backs for A-P incisor control
Bending the arch wire behind the most distally
banded molar also minimizes forward t...
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Like lacebacks, bendbacks are continued
throughout leveling & aligning archwire
sequence.

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In cases where it is nece...
Anchorage control in the post segment
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In certain cases, it may be necessary for
the upper post segments to b...
Headgears
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Extra oral force is most effective method of
post anchorage control in U arch.

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Anchorage reinforcement in...
According to the direction,
extra oral assemblies can be
grouped into:
(a) cervical – anchorage obtained from the
nape of ...
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High pull

Cervical pull

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Combi pull Headgear

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 If the LF passes below the CR of the tooth,
as in cervical traction, an extrusive
component of force will be presen...
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The combination headgear is useful in
most cases.
It minimizes the tendency for extrusion of
upper posterior teeth, ...
Palatal Bar
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Anchorage control –
Constructed of heavy .045 or .051 inch (1.1 or
1.3 mm) round wire extending from mola...
The Nance holding arch
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It extends from upper molars to the anterior
portion of the palatal vault.
A steep anterior p...
Lingual arch
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Used as space maintainers
Used for max anchorage PM Xn cases
It restricts the mesial movt. of the low...
Lip Bumper
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It transmits the lip pressure on the lower
molars & support the post anchorage.

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Muscular Anchorage

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ClassIII Elastics & headgear
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In cases with severe lower incisor crowding,
where more anchorage support is needed
that c...
Vertical anchorage control
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In case of distally tipped canines, the incisors
may be entirely bypassed, till the canin...
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Vertical control of molars in high angle
cases

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Upper 2nd molars are usually not initially
banded, to minimize extru...
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If palatal bars are used, they are designed to
lie away from the palate by approx 2mm so
that tongue can exert an...
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VHA, is essentially a
transpalatal arch with
an acrylic pad.
The VHA uses
tongue pressure to
reduce the vertical
den...
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The VHA was fabricated with banded
maxillary permanent first molars
connected with a 0.040-inch chrome
cobalt wire with...
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VHA restricts and even helps to reduce
the percentage of lower anterior vertical
face height.
Evaluation of th...
Anchorage control in transverse plane
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Inter canine width
Maintenance of intercanine width is
important for stabi...
Summary
1.
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Horizontal plane (anteroposterior)
A Control of anterior segments
Lacebacks
Bendbacks
B Control of poster...
Lower arch
Lingual arch
Class III elastics
Lip bumper

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2. Vertical plane

A Incisor control
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Avoid engaging the incisor when the
canines have negative angulations.
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Utility ar...
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Expansion if required should be achieved by
bodily movement of the posterior teeth (in
high angle cases).
Trans...
3. Lateral or transverse plane
A Maintenance of upper and lower intercanine
width.
B Correction of molar crossbite
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Rapid...
Retraction or space closure
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ANCHORAGE CLASSIFICATION
Anchorage needs of an individual treatment
plan could vary from ...
A Anchorage. This category describes the
critical maintenance of the posterior tooth
position. Seventy-five percent or mor...
C Anchorage This category describes non
critical anchorage. Seventy-five percent or
more of the space closure is achieved
...
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COMPONENTS OF FORCE SYSTEM
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Alpha Moment
This is the moment acting on the anterior
teeth (often termed anterior t...
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Horizontal Forces
These are the mesio distal forces
acting on the teeth. The distal force acting
on the anterior teet...
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Vertical Forces
There are intrusive-extrusive forces acting on
the anterior or posterior teeth. These forces
ge...
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Symmetric Space Closure – Group B
Anchorage
The requirement for space closure include
equal translation of the an...
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Maximum Posterior Anchorage – Group A
Space Closure
The biomechanical paradigm for this space
closure problem is ...
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Maximum Anterior Anchorage – Group C
Space Closure
The biomechanical principle reverses the
approach to Group A s...
In Group C space closure with a segmented Tloop, the spring is positioned closer to the
anterior segment. It is important ...
Implants as a source of anchorage
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In contemporary orthodontics Implants is the
best source of anchorage, which doesn’t ...
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Implants are defined as alloplastic devices
which are surgically inserted into or onto the
jaw bone-Boucher.

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Implan...
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Skeletal Anchorage System
(For open bite correction)
Sugawara; Umemori et al (AJO 1999;115)
They developed sk...
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Surgical Procedure

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Done under LA.

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A mucoperiosteal flap is raised in the apical
region of the 1st or 2nd mola...
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After wound healing occurs and elastic force
was applied from molar to the miniplate for
intrusion .

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Lingual crown ...
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Skeletal Anchorage System
(For deep bite correction)

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Creekmore;Eklund et al, the possibility of
skeletal anchorag...
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The elastic thread was renewed throughout
treatment,so that a continous force was
maintained 24 hrs a day.

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After 1 ...
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MiniImplant:Ryuzo kanomi; Miniimplant for
orthodontic anchorage ;(JCO 1997;31)

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The author used an implant made of...
Placement of mini-implant.
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Taken from the JCO on CD-ROM
(Copyright © 1997 JCO, Inc.), Volume 1997 Nov(763 - 767
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Placement of mini-implants for cuspid retraction.

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Placement of mini-implants for molar
intrusion.
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Conclusion
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It is very important to plan anchorage right
before hand so as to have a smooth
progression on to a prede...
References
1. Graber T.M: Orthodontics: Principles
& Practice. WB Saunders,1988
2. Profitt WR: Contemporary Orthodontics, ...
Thank you
www.indiandentalacademy.com
Leader in continuing dental education

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Anchorage in orthodontics 3 /certified fixed orthodontic courses by Indian dental academy

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  • Anchorage in orthodontics 3 /certified fixed orthodontic courses by Indian dental academy

    1. 1. ANCHORAGE IN ORTHODONTICS INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
    2. 2.          Concept Definition & Classification Consideration of anchorage in three planes of space Anchorage planning (Methods to increase anchorage potential) Tweeds concept of anchorage preparation Anchorage considerations with Begg Anchorage considerations with PEA Anchorage demand- minimum, moderate , maximum Implants as a source of anchorage www.indiandentalacademy.com
    3. 3.  Whenever a force is applied the stabilized site from where the force is exerted is the anchorage  Tug of warTwo equal sized people will pull each other together by an equal amount. A big person will pull a small one without being moved. If two or more smaller person combine the chances of pulling a big person will increase.    www.indiandentalacademy.com
    4. 4.    The pegs/ stakes driven into the ground at an angle to support the tent The stakes are at an angle that the pull of the tent ropes against the stake would not increase 90˚ The stakes driven too vertically will be pulled upward & towards the tent. www.indiandentalacademy.com
    5. 5.    Newton & his laws of motion: Law I: A thing at rest or in motion continues to do so unless acted upon by an external force Law III : Every action has an equal & opposite reaction www.indiandentalacademy.com
    6. 6.  We know that to create movement / displacement, we must have a force acting on the body.  For eg. Body (B) is at rest. Lets apply a force (F) to move it to the left. The force (F) will have to overcome the frictional force( Fr) bw the body (b) & the surface (S), the gravitational force (G), only then a particular movement will be seen.  If the force (F) is smaller in magnitude than the sum (Fr+G), then no movement will take place. www.indiandentalacademy.com
    7. 7.  For every kind of movement there exist an optimal force level, below which that particular movement cannot be produced.  So this force level is the anchorage potential of the body (B) for that particular movement www.indiandentalacademy.com
    8. 8.     Let us now come to oral cavity & teeth. If an upper canine is to be retracted, with bodily movement using a fixed appliance, the force applied to the canine is approx. 100 gm. Forces in the opp. direction varying from 67 gm on the 1st molar to 33gm on the upper 2nd PM resist this. Minimum unwanted anterior movement of the posterior teeth. www.indiandentalacademy.com
    9. 9.  2 bda www.indiandentalacademy.com
    10. 10.  As the force level is increased to 300g the reciprocal forces also increases with greater risk of mesial movt. of post teeth. www.indiandentalacademy.com
    11. 11.  The anchorage value of any tooth is roughly equivalent to its root surface area www.indiandentalacademy.com
    12. 12. Relationship of tooth movt. To force  An obvious strategy for anchorage control is to concentrate the force needed to produce tooth movt where it is desired, & to dissipate the reaction force to as many other teeth as possible, keeping the pressure in pdl of anchor teeth as low as possible. www.indiandentalacademy.com
    13. 13.  Pressure in Pdl is determined by f/a.  Tooth movt increases as pressure increases up to a point, remains at the same level up to a broader range, & then may actually decline with extremely heavy pressure. www.indiandentalacademy.com
    14. 14.  309 www.indiandentalacademy.com
    15. 15.   The optimum force for orthodontic tooth movement is the lightest force that produces a maximum or near maximum response (i.e, which brings pressure in the PDL to the edge of the nearly constant portion of the response curve). Forces greater than that , though equally effective in producing tooth movement, would be unnecessarily traumatic & stressful to the anchorage www.indiandentalacademy.com
    16. 16.  Let us consider the response of anchor teeth (A) & teeth to be moved (M) in three circumstances.  In each case, the pressure in the Pdl of (A) is less than that of (M) because there are more teeth in the anchor unit.  In the first case(A1-M1), the pressure for the teeth to be moved is optimal, where as the pressure in anchor unit is suboptimal --Anchor teeth moved less www.indiandentalacademy.com
    17. 17.  310 www.indiandentalacademy.com
    18. 18.   In the second case(A2-M2), both are on the plateau of the pressure response curve. The anchor teeth can be expected to move as much as the teeth that are desired to be moved. With extremely high force(A3-M3), the anchor teeth might move more than the teeth it was desired to move. Although this is theoretic & may not be encountered clinically. www.indiandentalacademy.com
    19. 19. Defination  The term Anchorage in orthodontics refers to the nature & degree of resistance to displacement offered by an anatomic unit when used for the purpose of effecting tooth movement www.indiandentalacademy.com
    20. 20. Classification     1. According to manner of force application 2. Acc. To jaws involved 3. Based on site of anchorage 4. Based on no. of anchorage units. www.indiandentalacademy.com
    21. 21. Manner of force application    I. Simple Anchorage 2. Stationary Anchorage 3. Reciprocal Anchorage www.indiandentalacademy.com
    22. 22. Simple Anchorage   Dental anchorage in which manner & application of force tends to change the axial inclination of the tooth or teeth that form the anchorage unit in the plane of space in which the force is being applied. Resistance of the anchorage unit to tipping is utilized to move another tooth or teeth. www.indiandentalacademy.com
    23. 23. Factors important for assessing resistance value of an anchorage unit( tooth)    The part of tooth which is anchored in the alveolar bone No. of roots Shape, size & length of each root– A triangular shaped root offers greater resistance to movement than a conical or ovoid shaped root www.indiandentalacademy.com
    24. 24. Or it can also be expressed as the approximate root surface area. A tooth with a larger R.S.A is more resistant to displacement than one with a smaller R.S.A Other factors are also involved such as -- Relation of contiguous teeth -- the forces of occlusion --The age of pt --individual tissue response variables www.indiandentalacademy.com
    25. 25.  It is also imp. to check inclined plane relationships & muscular forces in assessing value of an anchorage unit.  Amt. of force used is also imp. The forces should be below the threshold needed for movt. of post. teeth while serving light forces against the ant. teeth. www.indiandentalacademy.com
    26. 26. Stationary Anchorage   Dental anchorage in which manner & application of force tends to displace the anchorage unit bodily in the plane of space in which the force is being applied is termed Stationary anchorage. Anchorage provided by a tooth which is resisting bodily movt. Is considerably greater than one resisting tipping force www.indiandentalacademy.com
    27. 27.  310 www.indiandentalacademy.com
    28. 28.    This refers to the advantage that can be obtained by pitting bodily movement of one gp. of teeth against tipping of another. For eg. If the appliance were arranged so that the anterior teeth could tip lingualy while the posterior teeth could only move bodily, the optimum pressure for the anterior segment would be produced by abt. 1/2 as much force as if the anterior would be to be retracted bodily. This would mean that the reaction over the post teeth would be reduced by ½, so these teeth would move ½ as much. www.indiandentalacademy.com
    29. 29. Reciprocal Anchorage   Refers to resistance offered by two malposed units when the dissipation of equal & opp. forces tends to move each unit towards a more normal occlusion. Two teeth or two gp. of teeth of equal anchorage value are made to move in opp. direction. www.indiandentalacademy.com
    30. 30. Egs of Reciprocal Anchorage www.indiandentalacademy.com
    31. 31.  Site of anchorage      classification…… Intraoral Anchorage Extra oral Anchorage Cranium (occipital or Teeth parietal anchorage) Back of neck (Cervical Alveolar bone anchorage Basal bone Facial bones musculature www.indiandentalacademy.com
    32. 32. classification…… According to jaws involved  Intramaxillary Anchorage  All the resistance units are situated in the same jaw www.indiandentalacademy.com
    33. 33.    Intermaxillary Anchorage Anchorage in which resistance units situated in one jaw are used to effect tooth movement in the opposing jaw. Also termed Baker’s anchorage www.indiandentalacademy.com
    34. 34. Class II intermaxillary elastics Class III intermaxillary elastics www.indiandentalacademy.com
    35. 35. classification…… Based on no. of anchorage units   Single or primary anchorage Cases wherein the resistance provided by a single tooth with greater alveolar support is used to move another tooth with less support www.indiandentalacademy.com
    36. 36.   Compound Anchorage Here the resistance provided by more than one tooth with greater support is used to move teeth with lesser support www.indiandentalacademy.com
    37. 37. Multiple / Reinforced Anchorage      More than one type of resistance unit is utilized Refers to augmentation of anchorage by various means -- extraoral forces -- adding 2nd molars to the post unit to augment post achorage --Traspalatal arch www.indiandentalacademy.com
    38. 38. Three Dimensional Anchorage evaluation   Considering anchorage in all the three planes (sagittal, vertical & transverse) And subsequent anchorage planning is very important before initiating any tooth movements. www.indiandentalacademy.com
    39. 39.  Horizontal anchorage control means limiting the mesial movt. Of post. Segment while encouraging distal movt. Of ant. Segments.  For example, a "maximum anchorage Class II, division 1 case" is one in which no forward movement of the upper posterior segments is allowed, but preparation is made for maximum retraction of the upper anterior segment. www.indiandentalacademy.com
    40. 40.  Vertical anchorage control involves limitation of the vertical skeletal & dental development in the post. Segments & the limitation of the vertical eruption or even intrusion of the ant. Segment. www.indiandentalacademy.com
    41. 41.  In the transverse plane, it comprises of maintenance of expansion procedures & the avoidance of tipping or extrusion of posterior teeth during expansion. www.indiandentalacademy.com
    42. 42. ANCHORAGE PLANNING Methods to increase anchorage potential  I . By increasing the resistance to displacement  II. By decreasing the displacement potential www.indiandentalacademy.com
    43. 43. Increasing the resistance to displacement   1. Increase the no. of teeth in the anchorage unit ( increase root surface area) 2.Create Buccal segments The post. teeth are connected by rigid sectional arch wire(18×25, 19×25).Alternatively, in the absence of brackets a rigid sectional arch wire can be bonded to the teeth, to create a buccal segment which acts like a large multirooted tooth generating good post. anchorage. www.indiandentalacademy.com
    44. 44. Increasing the resistance to displacement…..      3. Cortical anchorage Moving the roots of anchor molar into the cortex increases their resistance to displacement. 4. Palatal , lingual arches , Nance’s button The bilateral buccal segments thus connected offer significant benefits. Incorporation of anterior vault of palate enhances post. Anchorage. www.indiandentalacademy.com
    45. 45. Increasing the resistance to displacement…  5. Extraoral anchorage  6. Muscular forces can be used to augment anchorage such as through use of lip bumper www.indiandentalacademy.com
    46. 46. Increasing the resistance to displacement…  7. Moments generated through cantilever springs or base intrusion arches are applied to anchor teeth. These create distal tipping forces, which help to resist anterior displacement of anchor units.  8. Implants, Ankylosed teeth They are perfect egs of stationary anchorage  www.indiandentalacademy.com
    47. 47. Decreasing the displacement potential      1. Reduce forces 2. Reduce friction 3. Sequential loading 1. Reduce forces ..movt. In stages ..using movements which require less force www.indiandentalacademy.com
    48. 48. Decreasing the displacement potential….     2. Reduce friction .. Using frictionless mechanics ..use of optimal clearance bw bracket & arch wire. 0.002 clearance is advocated for using sliding mechanics … Optimal leveling to reduce binding effect 3. Sequential loading …Gradual progression towards stiffer slot filling arch wires www.indiandentalacademy.com
    49. 49. www.indiandentalacademy.com
    50. 50. Tweed’s Classification of anchorage    First Degree Anchorage preparation It is applicable to all malocclusions with ANB angles ranging from 0˚ to 4˚ in which facial esthetics are good and in which total discrepancy does not exceed 10 mm. It is mainly limited o high cuspid, crossbite pseudo-Class III, and true Class III cases. www.indiandentalacademy.com
    51. 51.  The degree to which anchorage should be prepared is minimal.  Mandibular terminal molars must always be uprighted and / or maintained in such an upright position as to prevent their being elongated when Class II intermaxillary force is used www.indiandentalacademy.com
    52. 52.  As a general rule, this means that the inclination of the mandibular terminal molars should be such that the direction of pull of the intermaxillary elastic force during function will not exceed 90˚ when related to the long axis to these teeth. www.indiandentalacademy.com
    53. 53.  Second degree anchorage preparation  Indicated when ANB exceeds 4.5˚and facial esthetics make it desirable to move point B anteriorly and point A posteriorly . These cases are usually Class II in nature and require prolonged Class II intermaxillary mechanics   www.indiandentalacademy.com
    54. 54.  They are accompanied by Type A, Type A Subdivision, Type B and Type B subdivision growth trends  The mandibular terminal molars must be tipped distally so that their distal marginal ridges are at gum level. www.indiandentalacademy.com
    55. 55.  The direction of pull of the Class II elastics when related to the long axes of the terminal molars should be greater than 90˚ during function, so that the terminal molars will be further depressed rather than elongated www.indiandentalacademy.com
    56. 56.     Third degree or total anchorage preparation It is necessary in extremely severe malocclusion in which total discrepancy vary from 14 to 20 mm or more but the ANB angle does not exceed 5˚ Class I in nature, with exceedingly irregular teeth. Jigs are necessary for third degree or total anchorage preparation in the mandibular arch. www.indiandentalacademy.com
    57. 57.  In these all three posterior teeth from and including the second PM’s to and including the terminal molars must be tipped distally to anchorage preparation positions  This means that both second PM’s and first molars must be tipped to such distoaxial inclinations that the distal marginal ridges of the terminal second molars are below gum level www.indiandentalacademy.com
    58. 58.  In such positions, their mesial displacement & elongation will not be great, during the period when prolonged and vigorous intermaxillary force is being used www.indiandentalacademy.com
    59. 59.  Conventionally Begg technique is considered to be kind on to the anchorage & the PEA anchorage taxing www.indiandentalacademy.com
    60. 60. Begg & PEA   Pinning of base arch wire into anteriors generates powerful posterior anchorage by activating the anchor bend Simultaneous aligning, leveling & retraction of U/L anteriors Anchorage is to be actively created Discreet phases of aligning Levelling /& retraction of U/L anteriors, each with its anchorage considerations. www.indiandentalacademy.com
    61. 61. Movts of ant. are in 2 stages, tipping & uprighting which is kind to the anchorage Anteriors have the freedom to tip in both LL but importantly mesiodistally.  Movt of ant. Are with torque control which places strain onto the anchorage  No MD tipping freedom www.indiandentalacademy.com
    62. 62.  Loosing anchorage is a definite & positive decision Conserving anchorage is a definite & positive decision www.indiandentalacademy.com
    63. 63. Anchorage considerations with PEA   Anchorage control in PEA is very imp. Because of the features built in the appliance, which tend to procline the teeth Let us examine diff. phases of treatment, & how the anchorage can be controlled. www.indiandentalacademy.com
    64. 64.  McLAUGHLIN & BENNETT defined anchorage control during leveling and aligning as "the maneuvers used to restrict undesirable changes during the initial phase of treatment, so that leveling and aligning is achieved without key features of the malocclusion becoming worse". www.indiandentalacademy.com
    65. 65. Control of anchorage in the horizontal plane  Anchorage control in the ant segment  Anchorage control in the post segment www.indiandentalacademy.com
    66. 66. Anchorage control in the ant segment In initial wires with preadjusted system, tip built into anterior brackets increases tendency of anterior teeth to tip forward. www.indiandentalacademy.com
    67. 67. Early attempts were made to minimize tipping by connecting the anterior and posterior segments, usually with elastic forces. But this created a greater demand for anchorage control,& there was a tendency for the anterior teeth to tip and rotate distally, increasing the curve of Spee and deepening the bite. www.indiandentalacademy.com
    68. 68. 1. Lacebacks For A-P canine control  These are .010 or .009 ligature wires which extend from most distally banded bracket to the canine bracket. www.indiandentalacademy.com
    69. 69. They restrict canines from tipping forward during leveling & aligning. In extraction cases, these prevented cuspid tipping & are an effective means of distalizing the canines without the unwanted tipping. www.indiandentalacademy.com
    70. 70.    Robinson investigated 57 PM Xn cases, ½ of which were treated with lace backs & ½ without. His findings confirm that Lower canine lace backs have beneficial effect in controlling lower incisor proclination. Without lace backs, the L.I moved forward 1.4 mm, in contrast, with lace backs in place, the L.I moved 1mm distally. www.indiandentalacademy.com
    71. 71. 2. Bend backs for A-P incisor control Bending the arch wire behind the most distally banded molar also minimizes forward tipping of incisors. www.indiandentalacademy.com
    72. 72.  Like lacebacks, bendbacks are continued throughout leveling & aligning archwire sequence.  In cases where it is necessary to increase arch length, & where A-P control is not required, bendbacks should be placed1 or 2 mm distal to molar tubes. www.indiandentalacademy.com
    73. 73. Anchorage control in the post segment       In certain cases, it may be necessary for the upper post segments to be limited in their mesial movt, maintained in their position or even distalized. Headgear Palatal Bar Lingual arch Lip Bumper Class III elastics www.indiandentalacademy.com
    74. 74. Headgears  Extra oral force is most effective method of post anchorage control in U arch.  Anchorage reinforcement in vertical and anteroposterior plane in extraction cases with critical anchorage requirement www.indiandentalacademy.com
    75. 75. According to the direction, extra oral assemblies can be grouped into: (a) cervical – anchorage obtained from the nape of the neck (b) occipital – anchorage obtained from back of the head (c) parietal – the upper part of the back of the head is used as anchorage www.indiandentalacademy.com
    76. 76. www.indiandentalacademy.com
    77. 77. High pull Cervical pull www.indiandentalacademy.com
    78. 78. Combi pull Headgear www.indiandentalacademy.com
    79. 79.    If the LF passes below the CR of the tooth, as in cervical traction, an extrusive component of force will be present. If it passes above the CR of the tooth then intrusive component of force will be present. www.indiandentalacademy.com
    80. 80.   The combination headgear is useful in most cases. It minimizes the tendency for extrusion of upper posterior teeth, While simultaneously allowing effective distalization of the molar www.indiandentalacademy.com
    81. 81. Palatal Bar   Anchorage control – Constructed of heavy .045 or .051 inch (1.1 or 1.3 mm) round wire extending from molar to molar with a loop placed in the middle of the palate& the wire abt 2mm from the roof of the palate. It is soldered to the molar bands. www.indiandentalacademy.com
    82. 82. The Nance holding arch   It extends from upper molars to the anterior portion of the palatal vault. A steep anterior palatal vault has a buttressing effect so is a useful source of anchorage www.indiandentalacademy.com
    83. 83. Lingual arch    Used as space maintainers Used for max anchorage PM Xn cases It restricts the mesial movt. of the lower molars & ensures that most of the Xn space is available for anterior alignment www.indiandentalacademy.com
    84. 84. Lip Bumper  It transmits the lip pressure on the lower molars & support the post anchorage. www.indiandentalacademy.com
    85. 85. Muscular Anchorage www.indiandentalacademy.com
    86. 86. ClassIII Elastics & headgear  In cases with severe lower incisor crowding, where more anchorage support is needed that can be provided by a lingual arch alone, Class III elastics can be worn to Kobayashi tiewires in the lower canine region, at the same time as a head gear. www.indiandentalacademy.com
    87. 87. Vertical anchorage control   In case of distally tipped canines, the incisors may be entirely bypassed, till the canines are uprighted, to prevent deepening of the bite anteriorly. It is important to avoid early archwire engagement of high labial canines, so that unwanted vertical movement of laterals & PM does not occur. www.indiandentalacademy.com
    88. 88.  Vertical control of molars in high angle cases  Upper 2nd molars are usually not initially banded, to minimize extrusion of these teeth. If they reqire banding an arch wire step can be placed behind the 1st molar to avoid extrusion www.indiandentalacademy.com
    89. 89.    If palatal bars are used, they are designed to lie away from the palate by approx 2mm so that tongue can exert an intrusive force. Combination pull or high pull headgears are used. Cervical pull HG is avoided. In some cases, U/ L post bite plate in molar region is helpful to minimize extrusion of molars. www.indiandentalacademy.com
    90. 90.   VHA, is essentially a transpalatal arch with an acrylic pad. The VHA uses tongue pressure to reduce the vertical dentoalveolar development of maxillary permanent first molars. www.indiandentalacademy.com
    91. 91.  The VHA was fabricated with banded maxillary permanent first molars connected with a 0.040-inch chrome cobalt wire with a dime-size acrylic button at the sagittal and vertical level of the gingival margin of the molar bands.  Four helices were incorporated into the wire configuration for flexibility. www.indiandentalacademy.com
    92. 92.     VHA restricts and even helps to reduce the percentage of lower anterior vertical face height. Evaluation of the vertical holding appliance in treatment of high-angle patients Marcsss DeBerardinis, Tony Stretesky, Pramod Sinha, and Ram S. Nanda, Oklahoma City, Okla, AJO 2000, volume 117 www.indiandentalacademy.com
    93. 93. Anchorage control in transverse plane     Inter canine width Maintenance of intercanine width is important for stability. They should be kept as close as possible to the starting dimensions. Molar crossbites They should be corrected by bodily movt. Rather than tipping which extrudes the palatal cusps. www.indiandentalacademy.com
    94. 94. Summary 1.   Horizontal plane (anteroposterior) A Control of anterior segments Lacebacks Bendbacks B Control of posterior segments Upper arch Headgears Transpalatal arch Nance holding arch www.indiandentalacademy.com
    95. 95. Lower arch Lingual arch Class III elastics Lip bumper www.indiandentalacademy.com
    96. 96. 2. Vertical plane A Incisor control  Avoid engaging the incisor when the canines have negative angulations.  Utility arches B Molar control  Upper second molar banding to be avoided initially (in high angle cases). www.indiandentalacademy.com
    97. 97.     Expansion if required should be achieved by bodily movement of the posterior teeth (in high angle cases). Transpalatal arch should be 2-3 mm away from the palate. High pull or combi pull headgear to be used. Posterior bite planes or bite blocks www.indiandentalacademy.com
    98. 98. 3. Lateral or transverse plane A Maintenance of upper and lower intercanine width. B Correction of molar crossbite  Rapid maxillary expander,  Quad helix  Transpalatal arch. www.indiandentalacademy.com
    99. 99. Retraction or space closure   ANCHORAGE CLASSIFICATION Anchorage needs of an individual treatment plan could vary from absolutely no mesial movement of the molars/ premolars permitted (or even distal movement of the molars needed) to 100% of the space closure by mesial protraction of the posterior teeth Anchorage can be classified as: www.indiandentalacademy.com
    100. 100. A Anchorage. This category describes the critical maintenance of the posterior tooth position. Seventy-five percent or more of the extraction space is needed for anterior retraction B Anchorage This category describes relatively symmetric space closure with equal movement of the posterior and anterior teeth to close the space. This is the least difficult space closure problem www.indiandentalacademy.com
    101. 101. C Anchorage This category describes non critical anchorage. Seventy-five percent or more of the space closure is achieved through mesial movement of the posterior teeth. This could also be considered to be critical anterior anchorage . www.indiandentalacademy.com
    102. 102. www.indiandentalacademy.com
    103. 103. COMPONENTS OF FORCE SYSTEM     Alpha Moment This is the moment acting on the anterior teeth (often termed anterior torque). Beta Moment This is the moment acting on the posterior teeth Tip-back bends places mesial to the molars produce an increased beta moment www.indiandentalacademy.com
    104. 104.   Horizontal Forces These are the mesio distal forces acting on the teeth. The distal force acting on the anterior teeth always equal the mesial forces acting on the posterior teeth. www.indiandentalacademy.com
    105. 105.     Vertical Forces There are intrusive-extrusive forces acting on the anterior or posterior teeth. These forces generally result unequal alpha and beta moments. When the beta moments is greater than the alpha moments, an intrusive forces acts on the anterior teeth, if alpha moment is greater than the beta moment, then extrusive forces act on the anterior teeth while intrusive forces act on the posterior teeth. The magnitude of the vertical forces is dependent on the difference between the moments and the interbracket distance. www.indiandentalacademy.com
    106. 106.    Symmetric Space Closure – Group B Anchorage The requirement for space closure include equal translation of the anterior and posterior segments into the extraction space. Equal and opposite moments and forces are indicated. A T-loop spring centered between the anterior (canine) and posterior (molar) attachments produces this force system. www.indiandentalacademy.com
    107. 107.    Maximum Posterior Anchorage – Group A Space Closure The biomechanical paradigm for this space closure problem is to increase the posterior M/F ratio (beta M/F ratio) relative to the anterior M/F ratio (alpha M/F ratio). Utilizing the V-bend principle, the T-loop is positioned closer to the posterior attachment or the molar tube. The beta moment is greater than the alpha moment, a vertical intrusive force acts on the anterior segment. www.indiandentalacademy.com
    108. 108. www.indiandentalacademy.com
    109. 109.    Maximum Anterior Anchorage – Group C Space Closure The biomechanical principle reverses the approach to Group A space closure. The alpha (anterior) moment is increased relative to the beta (posterior) moment. The primary side effect is an extrusive force acting on the anterior teeth. The difficulty results from this extrusive force, thus deepening the overbite. www.indiandentalacademy.com
    110. 110. In Group C space closure with a segmented Tloop, the spring is positioned closer to the anterior segment. It is important that the anterior wire segment achieve full bracket engagement; otherwise, the play within the brackets reduces the effectiveness of the moment differential. www.indiandentalacademy.com
    111. 111. Implants as a source of anchorage  In contemporary orthodontics Implants is the best source of anchorage, which doesn’t rely on patient compliance.  The pioneering studies on oral implants was done by LINKOW who is rightfully called the Father of Oral Implantology www.indiandentalacademy.com
    112. 112.  Implants are defined as alloplastic devices which are surgically inserted into or onto the jaw bone-Boucher.  Implants can be used for Space Closure. They are used in the retromolar region to move teeth distally or anteriorly for mesial movement  www.indiandentalacademy.com
    113. 113.      Skeletal Anchorage System (For open bite correction) Sugawara; Umemori et al (AJO 1999;115) They developed skeletal anchorage system using Titanium plates as a source of anchorage for intruding the molars. The implants used are ‘L’ shaped Titanium implants. www.indiandentalacademy.com
    114. 114. www.indiandentalacademy.com
    115. 115.  Surgical Procedure   Done under LA.  A mucoperiosteal flap is raised in the apical region of the 1st or 2nd molar and the cortical bone is exposed.  The ‘L’ shaped miniplate is adjusted to fit the contour of the cortical bone and fixed to the bone by using screws, with long arm exposed to the oral cavity. www.indiandentalacademy.com
    116. 116.  After wound healing occurs and elastic force was applied from molar to the miniplate for intrusion .  Lingual crown torque was applied in the lingual arch to prevent the buccal flaring as the molar intrudes and after the treatment the miniplates are removed. www.indiandentalacademy.com
    117. 117.   Skeletal Anchorage System (For deep bite correction)  Creekmore;Eklund et al, the possibility of skeletal anchorage (JCO 1983;17)  They inserted a surgical vitallium bone screw just below anterior nasal spine.  Ten days after the screw was placed,a light elastic thread was tied from the head of the screw to the archwire www.indiandentalacademy.com
    118. 118.  The elastic thread was renewed throughout treatment,so that a continous force was maintained 24 hrs a day.  After 1 year they found that the maxillary CI were elevated 6mms and torqued lingually about 25 degrees. www.indiandentalacademy.com
    119. 119. www.indiandentalacademy.com
    120. 120. www.indiandentalacademy.com
    121. 121.   MiniImplant:Ryuzo kanomi; Miniimplant for orthodontic anchorage ;(JCO 1997;31)  The author used an implant made of miniscrews to fix the bone plates.  Minimplant-1.2mm in diameter 6mm in length  www.indiandentalacademy.com
    122. 122. Placement of mini-implant. www.indiandentalacademy.com
    123. 123. Taken from the JCO on CD-ROM (Copyright © 1997 JCO, Inc.), Volume 1997 Nov(763 - 767 www.indiandentalacademy.com
    124. 124. Placement of mini-implants for cuspid retraction. www.indiandentalacademy.com
    125. 125. Placement of mini-implants for molar intrusion. www.indiandentalacademy.com
    126. 126. Conclusion   It is very important to plan anchorage right before hand so as to have a smooth progression on to a predetermined optimal end result. Kind action always invoke kind reactions, so always use kind action forces to have kind reactions forces on the anchorage. www.indiandentalacademy.com
    127. 127. References 1. Graber T.M: Orthodontics: Principles & Practice. WB Saunders,1988 2. Profitt WR: Contemporary Orthodontics, Sr Louis, CV Mosby,1986 3. Robert E Moyers: Handbook of Orthodontics,Year book medical publishers,inc,1988 4. Thomas M Graber, Robert L Vanarsdall: Orthodontics current principles& techniques,Mosby year book inc,1994 5. Evaluation of the vertical holding appliance in treatment of high-angle patients Marcs DeBerardinis, Tony Stretesky, Pramod Sinha, and Ram S. Nanda, AJO 2000, volume 117 www.indiandentalacademy.com
    128. 128. Thank you www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com

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