leveling & aligning in orthodontics /certified fixed orthodontic courses

Leveling
And
Aligning
INDIAN DENTAL ACADEMY

Leader in continuing dental education
www.indiandentalacademy.com

The Principles In Choice Of
Leveling And Aligning Wires

The wire should provide light and
continuous force to produce the most
efficient tipping tooth movement.
Heavy forces, in contrast, are to be avoided.


2


For Mesio-distal sliding along an archwire
at least a Clearance of 0.002” is needed, and
0.004” would be ideal.

That is
For the Slot size of
Clearance needed is
Ideal wire size is

0.018”
0.022”
- 0.004” - 0.004”
0.014”
0.018”


2

It is better to position the crowns than to cause
root displacement.
Although a highly resilient wire such as
0.017” x 0.025” A-NiTi could be used during
this stage, it is not advisable
Rectangular archwire will create unnecessary
and undesirable root movements which may
delay the alignment process and increase the
possibility of root resorption.

3

Wires should have Excellent strength, Good
springiness, Long range of action and Low loaddeflection.
The titanium based NiTi and beta titanium (TMA)
wires offer a better combination of strength and
springiness than stainless steel.
NiTi is both springier and stronger in small cross
sections than beta (TMA).
For these reasons A-NiTi is particularly useful as an
initial wire in leveling and aligning.

3

Changing the diameter of a wire greatly
affects its properties.
For initial leveling and aligning, the smallest
diameter wire that has adequate strength
would be preferred.
When the diameter of a wire is doubled, the
strength increases by 8 times, the springiness
decreases by 16 times and the range decreases
by half.

3

Key points during leveling & Aligning
Forces should be kept as light as possible.
 Sagittal, vertical and lateral anchorage need
should be identified for each case.
 Lacebacks and bend backs to be used in the
initial stages to avoid unwanted tooth
movement.
 Posterior segment should be supported with
headgears / TPA in maximum anchorage
cases.


2

The Archwire
sequencing:


The Archwire sequencing:
The archwires used with the standard
edgewise appliance and during the early years
with the pre-adjusted appliance were round
and rectangular stainless steel wires.
Round wires were available in sizes .014, .
016, .018, and .020.
Rectangular wires were available in a
number of sizes, with .018x.025, .019x.025
and .0215x.025 being the most popular wires
used with the .022 bracket slot.

The Archwire Sequencing
One of the earlier attempts at producing
greater archwire flexibility was accomplished
by twisting strands of very small stainless steel
wires into what have been referred to as
multistrand wires.
These wires in sizes .015 and .017 were used
as initial wires, prior to the use of the .014
round wire, in cases with significant tooth
malalignment.

The Archwire Sequencing
The introduction of Nitinol wires provided a possible
substitute for multistrand and round wires during the
leveling and aligning stage of treatment.
Their flexibility provided for a substitution of
approximately two sizes of stainless steel wires.
Given their higher cost, their significance was therefore
considered questionable by many clinicians.
They were also mistakenly used during procedures that
required the rigidity of a rectangular stainless steel wire,
such as complete arch leveling and overbite control,
space closure, overjet reduction with intermaxillary
elastics.

The development of heat-activated nickel
titanium wires, provided a wire with
significantly greater flexibility.
As a result these wires could be used as a
substitute for three of the traditional stainless
steel wires in certain situations, which was a
significant improvement!
The normal warmth of the oral cavity allows
for significant activation of the wire and very
efficient tooth movement.

Surprisingly, patients do not seem to complain
of added discomfort, most likely due to the
light forces that are introduced.
Instead of replacing wires on a per visit basis
during leveling and aligning, a coolant can be
applied to the wire in the areas where full
bracket engagement has not been achieved and
the wire can be retied for complete
engagement.

The substitution sequence:
Traditional wires
0.015 Multistrand
0.017 Multistrand
0.014 S.S.
0.016 S.S
0.018 S.S
0.020 S.S.
0.0195 x 0.025 S.S

Heat activated wires
0.016 Thermal Niti

0.0195X0.025 Thermal Niti
0.0195 x 0.025 S.S


The substitution sequence:
This sequence has dramatically reduced chair time
and has significantly increased the efficiency of tooth
movement due to the minimizing of permanent
archwire deflection.
Because of their flexibility, there are clinical
situations where heat activated wire substitutions are
not recommended or where some stainless steel wires
should also be used.
These clinical situations can be described as follows:

Initial wires in cases with severe
malalignment of teeth:
It is a service to the patient to place a
multistrand wire as the first wire in such cases.
The permanent deflection that occurs with these
wires reduces the overall force levels and
provides for less discomfort during this initial
“experience with braces”.
Also, some wire bending in addition to the
normal arch form may be required and is easily
accomplished with multistrand wires.

Use of lacebacks for cuspid retraction
in crowded extraction cases:
The use of lacebacks minimizes the tipping of
the cuspids into the extraction sites.
However, with the continued use of flexible
heat-activated wires, some tipping can occur.
To reduce this possibility, an .018 or .020
stainless steel wire should be used as early as
possible when using lacebacks.

Use of open coil spring in the anterior or posterior
segments to create space for blocked out teeth
Because of the flexibility of heat-activated wires,
the use of open coil springs on these wires can
cause significant distortions in arch form.
Thus, open coil springs should not be used until .
018 or .020 round wires are in place.


Complete arch leveling and overbite control:
While heat-activated wires are excellent for
individual tooth alignment, they are not
effective for complete arch leveling and
subsequent bite opening.
Hence, the transition from even the rectangular
heat-activated wire to the rectangular stainless
steel wire is sometimes impossible.
An .020 round wire is often required prior to the
use of the rectangular stainless steel wire.

Torque control
 While rectangular heat-activated wires do
initiate the process of torque control, this
difficult tooth movement is best completed
with a rectangular stainless steel wire.




The introduction of heat-activated wires has
provided a beneficial substitute for a number of
traditional stainless steel wires and can
dramatically improve the efficiency of orthodontic
treatment.



This substitution is, however, beneficial for initial
tooth alignment procedures only.



Their excellent flexibility can actually be
detrimental in a number of other clinical situations
as described above.



It is important that the orthodontist separate the
situations that require archwire flexibility from
those in which archwire rigidity.

Deep Overbite


Deep Overbite
Although moderate deep overbite cases get
corrected as a result of routine leveling and
aligning procedures, the severe deep overbite
cases require different corrective procedures.
Deep overbite can be divided into two types.
1. True deep bite
2. Pseudo deep bite

2

Deep Overbite
1. True deep overbite- Is mostly due to the
infra eruption of posterior teeth.
2. Pseudo deep overbite- Is due to the supra
eruption of anterior teeth.
A majority of cases will be due to the
combination of both.


3

Modalities Of Treatment In
Deep Overbite Correction
1.
2.
3.
4.
5.

Extrusion or Uprighting of posterior teeth.
True intrusion of upper and lower anteriors.
Increasing the inclination of upper and lower
anteriors.
Combination of extrusion of molars and
intrusion of incisors.
Combination of two or more of the above
procedures.

Extrusion or Uprighting of posterior teeth:Indication:
 Patients with a horizontal growth pattern,
 Growing individuals
 True deep overbite cases.
Methods:
 Anterior bite plane.
 Including II molars in the arch setup
 Sweep in the archwire.

Proclination of upper and lower anteriors:Indication:
 This can be done only if the soft tissue
profile permits it or in cases with
retroclined anteriors.
Methods:
 Not using lacebacks and bendbacks.
 Use of open coil spring between
retroclined teeth and posterior teeth.

4

In patients with vertical skeletal growth
pattern any extrusion of posterior segment is
going to swing the mandible backwards
worsening the situation.
 In such cases, bite should be opened by true
intrusion of upper and lower anteriors.



2

True intrusion of
upper and lower anteriors:Indication:
 Bite opening by true intrusion although can
be used in both grown and growing
individuals, it is effective in growing
individuals.
 True intrusion of incisors is indicated in
cases of pseudo deep bite where the incisors
are supra erupted.

2

True intrusion of
upper and lower anteriors:Methods:
 Utility arches.
 Burstone Intrusion arches.
 Three piece intrusive arch


3

Utility Arches
This has multiple uses in various stages of
orthodontic treatment.
 This wire has been developed according to
biomechanical principles described by
Burstone and refined for incorporation into
Bioprogressive therapy by Ricketts.



2

Utility Arches
Although it is a complete arch extending
across both buccal segments,the utility arch
engages only the two molars and four
incisors.
 It is commonly known as 2 x 4 appliance
(Two by Four appliance).



2

Burstone Intrusion arches.
Originally proposed by Burstone, these
springs are made of 0.017” x 0.025” TMA
wire.
 The upper and lower arches have to be
leveled and aligned and a rigid stainless
steel wire, preferably of 0.017” x 0.025”
dimension should be engaged.



The anchor molars are reinforced with a TPA
in the upper and a lingual holding arch in the
lower arch.
The intrusion springs are made from 0.017” x
0.025” TMA wire without a helix or 0.017” x
0.025” stainless steel wire with a helix so that
the forces can be made optimal for intrusion.

The wire is bent gingivally, mesial to the
molar tube and then a helix is formed.
The mesial end of the spring is bent into a
hook and is engaged onto the main archwire
distal to the lateral incisors which, according
to Burstone, is the approximate centre of
resistance of the four incisors.
The mesial end of the spring lies passively at
the height of the mucobuccal fold and the
spring is activated by pulling the hook down
and engaging it onto the archwire.

Three piece intrusive arch
It consists of the following parts:
 The

posterior anchorage unit
 The anterior segment with posterior extension
 Intrusion cantilevers


The anterior segment is bent gingivally distal
to the laterals and then bent horizontally
creating a step of approximately 3mm.
The distal part extends posteriorly to the distal
end of the canine bracket where it is formed
into a hook.
The anterior segment should be made of
0.021” x 0.025” stainless steel wire to prevent
side effects created by bending of the wire
during force application.

The intrusion cantilever is fabricated from
0.017” x 0.025” TMA. The wire is bent
gingivally mesial to the molar tube and a helix
is formed.
The mesial end of the cantilever is bent into a
hook. The cantilever is then activated by
making a bend mesial to the helix at the molar
tube, such that the anterior end with the hook
lies passively in the vestibule.

This is then brought down and engaged onto the
horizontal portion of the anterior segment.
This allows further distal placement of the intrusive
force, i.e., lateral to the lateral incisor, so that the
resultant forces are made to pass through the centre
of resistance of the anterior teeth.
An elastic chain can be attached to the hook to
facilitate simultaneous intrusion and retraction or to
redirect the forces more parallel to the long axis of
the incisors.

Suggestion
The general guidelines in leveling and
aligning have been presented here. However,
every patient is unique and should be treated
by those methods most suitable for him.


Thank you
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