MBT wire sequence during orthodontic alignment and leveling is discussed

1. MBT WIRE SEQUENCING
DURING TOOTH
LEVELING AND ALIGNING
Prof dr Maher Fouda
Mansoura Egypt

2. Reference

3. Page 297
Case report

4. Molar relationship was 4 mm
Class II on the right and 2 mm
Class II on the left. All the teeth
were developing normally,
except the upper left third
molar. Arch form was assessed
as
ovoid. It was decided to manage
the case on a non-extraction
basis, with upper anterior
torque and lower incisor enamel
reduction.

5. Standard metal brackets were
used with .016 HANT wires to
commence tooth alignment.
The patient was asked to wear
a
combination headgear during
evenings and nights. Lower
enamel reduction was delayed
until correct upper and lower
incisor torque had been
achieved, which would reveal
the
amount of reduction necessary.

7. After 3 months of
treatment, upper and lower
rectangular
HANT wires are in place.
After 6 months of treatment, steel
.019/.025 rectangular wires
were placed. The patient was asked
to wear a right side Class
II elastic (lOOgm) to commence
correction of the right side
occlusion and the midlines.
Archwires were placed flat,
without additional torque.

8. Subsequently, after 9 months of
treatment, additional torque
was added to the upper wire
It became clear that lower enamel reduction was needed.
Separation and then enamel reduction of lower
incisors was carried out after 10 months of treatment, and
first molar bands and upper canine brackets were
repositioned.
Upper and lower rectangular HANT wires were used for 1
month to re-level and align after enamel reduction and
bracket repositioning,

11. Normal settling
methods were
used, with lower
bonded and
upper removable
retainers.

13. Historical background
Round and rectangular
steel archwires were used
with the
standard edgewise
appliance and during the
early years with
the preadjusled
appliance. Round steel
wires were used in
sizes .014, .016, .018, and
.020.

14. Rectangular steel wires were
available in a number of sizes,
with .018/025, .019/.025, and
.0215/.025 being the most
popular wires used with the .022
bracket slot. The authors
prefer the .022 slot over the .018
slot, primarily because of
the rigidity needed in the
archwire during space closure
with
sliding mechanics.

15. The .014, .016, .018, and then .020
round wire sequence
was used by the authors, followed
by the .019/.025
rectangular steel wire . This wire
allows for efficient
sliding mechanics, unlike the
larger .0215/.025 wire, which
creates excess friction during
space closure. Also, the
.019/.025 rectangular wire shows
less deflection than the
more flexible .018/.025 wire.
Round and rectangular steel wires were used during
the early years w i th the preadjusted appliance.

16. One of the early
attempts at producing
archwires with
greater flexibility
involved twisting
together strands of
very
small stainless steel
wires . These were
referred to as
multistrand wires.
Multistrand wires
were produced to
introduce
greater flexibility.
They are currently
used as initial
wires in
cases w i th
significant tooth
malalignment.

17. These wires, in
sizes .015 and
.0175, were
used as initial
wires, prior to
the use of the
.014 round steel
wire, in cases
with significant
tooth
malalignment.
Multistrand wires were produced to
introduce
greater flexibility. They are currently
used as initial wires in
cases w i th significant tooth
malalignment.
placement of initial
.015 multistrand upper and lower
aligning wires.
Low-angle Class 11/1 malocclusion

18. Recommended sequencing
The introduction of nickel-
titanium wires provided a
possible
substitute for multistrand and
steel round wires during the
leveling and aligning stages of
treatment. One nickel titanium
wire could be used in place of
approximately two sizes of
stainless steel wires.
The initial arch wire 0.016” NiTi was placed on both
upper and lower arches .

19. However, given their higher cost,
their
significance was 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, overbite
control, space closure, and
overjet reduction with inter-
maxillary elastics.

20. The development of copper
nickel-titanium wires, referred
to as 'heat-activated' wires,
provided wires 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.

21. Instead of replacing wires on a
per visit basis during leveling
and aligning, a coolant could be
applied to the heat-activated
nickel-titanium (HAN'T) wire in
the areas where full bracket
engagement had not been
achieved, and the wire could be
retied for complete engagement.

22. The normal warmth of the
oral cavity produced significant
activation of the wire-and very
efficient tooth movement.
Surprisingly, patients did not
seem
to complain of added
discomfort, probably because
of the
light forces that were
introduced.

23. The archwire sequence
shown has been
employed by the
authors. It has
significantly reduced
chairside time and
increased the efficiency
of tooth
movement, owing to the
minimizing of
permanent archwire
deflection.
In some cases, the authors can follow
sequence B to complete a treatment with
very efficient mechanics and few archwire
changes. However, in many treatments it is
necessary to use some wires from the more
traditional sequence A,

24. Heat activated superelastic
NiTi archwires (Nickel
Titanium)
Body-Heat-Activated Nickel
Titanium (ca 37°)
Extremely easy to ligate with
lower ligating forces
Transforms to a super elastic
state inside the mouth
Offering gentle continuous
tooth-moving force

25. HE AT-ACTIVATED NICKEL-
TITANIUM
(HANT) OR STAINLESS
STEEL?
Because of their flexibilily, there are
clinical situalions where
heat-activated wires are not
recommended, or where some
stainless sleel wires should also be
used. These clinical
situations are described below:
.Mid-sized
brackets were placed wiih a .014
sectional steel upper wire,
and a .016 lower round HANT
wire lo commence tooth
movements.

26. • Initial wires in cases with severe
malalignirient 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
produces less discomfort during the
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.
Upper archwire
was .016 HANT. Lower archwire was .015 mullislrand, with
offset bends for the buccally placed lower canines. The upper
left canine bracket was lassoed with a module.

27. When using lacebacks for cuspid
retraction in crowded
extraction cases. The use of
lacebacks minimizes the
tipping of the cuspids into the
extraction sites. However,
with prolonged use of flexible
heat-activated wires, some
tipping can occur. To reduce this
possibility, a .018 or .020
stainless steel wire should be used
as early as possible
when using lacebacks.
Lacebacks are
routinely used to
assist control of
canine crowns in
premolar
extraction cases,
and in some
nonextraction
cases.
:Canine
retraction with
Mulligan bypass
arch

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

29. For 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.
The opening wires were
.016 HANT to
an ovoid arch form.
The .016 HANT wires in the
ovoid form were followed by
.019/.025 rectangular IIANT
wires, with the selected
tapered
arch form.
The .019/.025 rectangular HANT wires were followed by
.019/.025 rectangular stainless steel wires, with tapered arch
form, and with soldered hooks.

30. Hence, the
transition from even
the rectangular heat-
activated wires
to the rectangular
stainless sleel wire is
sometimes
impossible. A .020
round steel wire is
often required
before the
rectangular stainless
steel wire.
The opening upper arch wire was .0175 multistrand, with a
bend in the upper left central incisor region to reduce force.
This was replaced 1 month later by a .016 HANTwire. During
the first 2 months, a .016 HANTwire was used in the lower
arch. The lower left first molar band was repositioned at the
second adjustment visit.
At 2 months, upper
and lower rectangular HANT wires
were placed,

31. For torque control.
Rectangular heat-
activated wires
commence the process
of torque control, but
this difficult
tooth movement is best
completed by using a
rectangular
stainless steel wire.
Standard metal brackets
were used with .016 HANT
wires to
commence tooth alignment.
Molar relationship was 4 mm
Class II on the right and 2 mm
Class II on the left.
After 3 months of treatment,
upper and lower rectangular
HANT wires are in place.
After 6 months of treatment, .steel
.019/.025 rectangular wires
were placed. The patient was
asked to wear a right side Class
II elastic (lOOgm) to commence
correction of the right side
occlusion and the midlines.

32. • For the treatment stages
of space closure and
overjet
reduction. The major
tooth movements that
occur during
these stages of treatment
require the rigidity of a
rectangular stainless sleel
wire, as opposed to the
flexibility
of a heat-activated wire.
Closing loop archwires
were part of traditional
edgewise treatment
mechanics. They were
individually made
for each patient, and had a
limited range of action
before the
omega loop came into
contact with the molar
tube.
A lower type one
active tieback. This
shows minimal
activation of the
elastomeric, and
slightly more
stretching could
be used.

33. In summary, 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.

34. It is important
that the
orthodontist
separates the
situations that
require
archwire
flexibility from
those in which
archwire
rigidity is
needed.
upper and lower rectangular
HANT wires are in
place,

35. CLINICAL PROCEDURES IN LEVELING AND
ALIGNING - IMPROVING PATIENT
COMFORT AND ACCEPTANCE
At the start of treatment, every
effort should be made to
ensure that discomfort and
inconvenience for patients are
minimized. This will normally be
their first experience of
orthodontic treatment, and there
are opportunities for the
orthodontic team to make it a
good experience.
The initial
lower archwire was .016
IIANT,

36. For many cases, the opening wires will
be .016 HANT, but
if there are major tooth
malalignmenis, a multistrand .015
wire is preferable. Bends can be
introduced into .015
multistrand wires, and these reduce
the force applied to the
teeth at the outset (Case JN, p. 120 and
Case DO, p. 208).
The opening wires should not be tied in
tightly. Plastic
sleeving should be used lo make
lengthy stretches of archwire
more comfortable.
.016
HANT
ARCH
WIRE
a .015
Multist
rand
arch
wire

37. As leveling and alignment
progresses, there will be a switch
into rectangular HANT wires. This
can typically follow directly
from the .016 round HANT in many
cases. The rectangular
HANT wires are most useful and
patient-friendly, and the
switch is therefore seldom
accompanied by discomfort. Any
brackets which are wrongly
positioned should be repositioned
at the rectangular HANT wire
stage, or earlier.
Commencing
upper and
lower arch
wires were
.016 HANT.
the molars are
half a unit Class
II bilaterally. The
lower midline was
1 mm to the right.
The initial .016
HANT wires were
followed by
rectangular
.017/.025 HANT
wires.

38. The patient should be
given proper
instruction on the use
of wax and mild
analgesics A good
supply of wax
should be provided,
and it should be made
clear that most
discomfort will
disappear after the
first few days.
In this very crowded
Class I case, the first
premolars
had previously been
extracted. The upper
right lateral incisor
was in crossbite, and
there was 2 mm of
displacement at
terminal closure
Initial alignment was
commenced with a
.015
multistrand upper
archwire and a .016
HANT lower archwire.
A
band with an eyelet
was placed on the
upper right lateral
incisor. This was
loosely tied.

39. Archwire ends
should be
carefully turned
in, and
particular
care is needed
with
multistrand
wires.
Multistrand wires may be
carefully turned into a
small circle distal to the
molar tube to create a
bendback.
Bendbacks are possible
when using .016 HANT
wires,
providing the terminal 3
mm is flamed and
quenched in cold
water before placement
of the archwire.

40. Steel and HANT
wireends
should be flamed
and quenched, to
allow accurate
turning in, and
also ease of
removal at the
first adjus
tment
appointment.
Molar hooks
should be turned
in .
It is helpful to flame the end of all archwires,
except
steel rectangular and multistrand wires, and
then quench them
in cold water before placement. This allows
accurate bendbacks.
Steel and HANT wires should have the
terminal 3
mm flamed and quenched before placement.
The softened end of the archwire can easily
be
turned in to form a bendback. The softening
facilitates removal
of the archwire at the subsequent adjustment
visit.

41. Two months later. The upper right
lateral incisor
bracket was not inverted because
the root position of this tooth
was good, and special torque
control was not required. A
multistrand wire was used t o
continue tooth leveling and
aligning in the upper, with a .014
round steel wire in the lower.
After 4 months of treatment, it
was possible to place
upper and lower rectangular
.019/.025 HANT wires. These
very
effective wires were used for
several months, changing
elastomeric modules and re-
tying as necessary.

42. Much can be made of selecting
colored modules at the first
visit, for those patients who
like the idea of colors. There is
a
colored module culture among
some groups of youngsters.
Self-ligaiing brackets may be
an inevitable
development in the future, but
this will be a concern for
many younger patients, who
look forward to choosing
colors
at each visit.
Here the case is seen at completion of tooth leveling
and aligning. Steel rectangular wires, .019/025 in dimension
and of ovoid arch form, are passively engaged in a correctly
placed preadjusted .022 bracket system.
The case after settling and appliance removal. Good
tooth f i t was assisted by the large size of the upper lateral
incisors.

43. It is correct to have a senior assistant make a follow-up
phone call a few days after placement of the initial
appliances .This will show that the practice is concerned to
know that all is going well, and it is a chance to offer advice
and encouragement. During this call, the patient or parent
will often raise minor queries, which are important to them,
although they 'didn't want to bother the doctor'.

44. Although there have been many technical advances in
orthodontics, there is a continuing need to ensure good
patient cooperation, in order to reach treatment goals. Care
and consideration from the outset will provide a sound basis
for the treatment relationship. This should lead on to better
cooperation in many cases.