selection of preformed archwires during the alignment stage of preadjusted orthodontic fixed appliance is presented

1. Selection of orthodontic
preformed archwires
during the alignment stage
of preadjusted fixed
appliance
Presented by
prof dr Maher Fouda
Mansoura Egypt

2. This lecture was
uploaded on the
slideshare in addition to
several undergraduate
and postgraduate
orthodontic lectures .

3. Stages of Straight Wire
Technique
1. Leveling and aligning.
2. Overbite reduction.
3. Overjet reduction and
space closure.
4. Finishing and occlusal
detailing.

4. Let us take into
our consideration
the following
important points :

5. Point 1: alignment is
the lining
up of teeth of an arch in
order to achieve normal
contact point
relationships.

6. Round flexible
archwires are
needed to
provide a gentle
continuous force
that is flexible
enough to
engage the
brackets on the
misaligned teeth

7. NiTi and
CuNiTi are
the round
flexible
archwires
that are
considered.

8. Point 2: It is beneficial to place
the brackets slightly in the
direction of the rotation to aid in
their correction.

9. Point 3: Alignment is
achieved by crown tipping
without root movement
alignment with NiTi arch-wires from 0.014-in
through to 0.018-in

10. Point 4 : Avoiding flexible
rectangular wires during alignment
to prevent round tripping of the
anterior teeth.

11. It is not necessary or even
advisable to use flexible
rectangular archwires for
initial alignment, as they may
place untoward forces on
root apices, potentially
causing greater patient
discomfort.

12. using flexible rectangular archwires
for initial alignment, may also cause
damage to the root apices and, as labial
crown torque will begin to express in the
maxillary incisors, potentially facilitating a
loss of posterior anchorage

13. Point 5 : archwire sleeve protecting tubing
or Mulligans bypass arch is used during
alignment stage in cases of severe incisor
crowding until space is available for their
alignment TO PREVENT ROUND TRIPING
MOVEMENT OF THE INCISORS .
Archwire sleeve protecting tubing Mulligan bypass arch

14. 0.022 x 0.028”
slot MBT
appliance was
used in this case.
Posterior leveling
and aligning was
initially done with
round 0.014 and
0.016 Niti wires.

15. . 0.018SS archwire was used
to make the Mulligan’s
bypass arch. It was placed
from canine to molars
bilaterally bypassing
incisors. E-chain was placed
from the molar tube to
canine hook with the force
of 100g . Individual canine
retraction is carried about
for 4 months and the
anteriors were allowed to
decrowd itself with
driftodontics

16. Point 6 : Avoiding
roller coaster
effect .

17. Roller coaster effect
also known as
vertical bowing
effect occurs when a
tooth ( e.g high and
labially placed
canine ) is brought
into the arch using a
light wire
Avoid roller coaster effect
A) Straight wire mechanics used
for canine extrusion.
B) Note the side effects on the lateral incisor
and first premolar, which made the conditions
of the case worse

18. loss of arch
length,
reduced
space in the
canine region
The net result is that
the adjacent teeth
will dip in and as a
result the eruption
space is compromise
Avoid
roller
coaster
effect
roller
coaster
effect

19. Five examples of
mechanics used
to extrude a
canine. (1) An
open coil spring
between the
lateral incisor and
premolar on 0.016-
inch stainless steel
wire maintains the
space while
preventing the
adjacent teeth
from tipping
Avoid roller coaster effect

20. .
(2) A cantilever
with a V-bend can
be used to move
the canine down.
The cantilever
should be
attached to the
canine with a
ligature at only
one point to avoid
unwanted moment.
Avoid roller coaster effect

21. (3)
Reciprocal
anchorage
to level
maxillary
and
mandibular
canines
with an up-
and-down
elastic.
Avoid roller coaster effect

22. (4) An
auxiliary
0.014 or
0.016 NiTi
wire can be
used along
with a
rectangular
SS main
archwire to
bring the
high
canine
down.
Avoid roller coaster effect

23. (5)A box loop: When
used for canine
alignment,
it is constructed of
.017" x .025" TMA.
The activation of the
box loop depends on
the
desired position of
the canine in both
the sagittal
and horizontal
planes of space
Avoid roller coaster effect

24. Canine retraction: In
this extraction case
avoid retracting
canines on flexible
archwires.
Teeth tended to tip and
rotate into the
extraction sites when
the chains were
overstretched, with
associated bite
deepening.
Avoid roller coaster effect

25. The clinician needs to recognize
the signs of excess force, such
as tissue blanching, patient
discomfort, and unwanted tooth
movements (for example roller
coaster effect), and take steps
to avoid these.

26. prestretching the elastic chain
SHOUD BE DONE before using
to minimize the effect of abrupt
force decay in the first hours of
use .
Point 7 : Due to the continuing
deterioration of the force of the
power chain during use

28. Point 8: avoid
too frequent
archwire changes.

29. Essentially
there is a
need for the
orthodontist
to use thin,
flexible wires
early on,
with minimal
Deflection.

30. During leveling
with straight
wire, tooth
tipping might
create
premature
contacts
between
antagonist
teeth and
cause the bite
to open.

31. Initial flexible archwires tend to migrate
laterally along the dental arch
The wire will protrude from one side
while simultaneously coming out of
the opposite side molar tube

32. a–c Mechanical irritation of the mucosa caused by a continuous wire that has slipped
distally. The protruding wire part can cause considerable soft-tissue irritation
On the side that the wire is
protruding, it may cause ulceration
of the soft tissues, sometimes
leading to considerable patient
discomfort

33. Such unwanted
archwire
migration may
be prevented by
placing a stop
on the wire
between two
brackets that
are relatively
close together. Dimples positioned between the
centrals are designed to help with
accurate placement during ligation
MASEL
DIMPLED ARCHWIRES FROM 3M: AN
EXCELLENT CHOICE

34. Bendistal pliers is used to make v
bend in the archwire between the
central incisors to prevent its shift

35. Some wires
have crimpable
stops on them,
referred to as
crimpable split
tubes, which
just need to be
crimped into
the required
position .
3 Crimpable split tubes,
which may be crimped
onto the archwire with
Weingart pliers.

36. Alternatively, a
small bead of
flowable
composite resin,
known as a
composite stop,
may be run onto
the archwire in an
interbracket span
and light cured .

37. Neither of these
manoeuvres is
necessary if the
archwire is
either cinched or
bend backs are
placed distal to
the terminal
molars Cinchback of Nitinol
archwire

38. Bendback :If the
archwire is
bendback
immediately behind
the tube on the
most distally
bonded molar, this
serves to minimise
forward tipping of
incisors.

39. Bendback :In cases
where it is
necessary to
increase arch length
during levelling and
aligning and where
the A/P incisor
control is not
required, bend back
should be placed 1
or 2 mm distal to
the molar tube

40. In some patients,
particularly those
with deep bites,
well-interdigitated
occlusion and
potentially strong
jaw musculature,
the interdigitation
of the dental
occlusion
itself may be a
hindrance to initial
alignment. class II DIV 2

41. In such
situations, the
posterior teeth
may be
separated just
beyond the
resting vertical
dimension and
freeway space. The effect of ‘opening the bite’. Further
eruption of the incisors is limited while the
molars are encouraged to erupt to reduce the
overbite.
An upper removable appliance with a flat anterior
bite plane. The posterior teeth are out of occlusion,
providing space for eruption. The levelling effect
can be increased by placing a lower fixed appliance.

42. Such temporary bite
opening may be
achieved by placing a
removable clip-over
anterior bite plane,
bonding a composite
resin anterior bite
plane or
Acrylic
bite
plane
over an
acetate
.
Fixed
bite
plane
Bite ramps bonded to the upper central
incisors.
bite opening turbo
props bonded
palatal to the
maxillary central
incisors .

43. bite opening turbo props bonded palatal to
the maxillary central incisors .

44. Anterior bite opening turbos (turbo props).

45. Anterior bite opening
with a removable or
fixed bite plane permits
vertical clearance to
bond the mandibular
arch and permits easier
levelling of the
mandibular dental arch.
However, if there is an
increased incisor overjet,
posterior bite opening
may be required.
Posterior disclusion.
Fixed bite plane in mouth.
Patient with anterior deep bite

46. This may be
achieved also by
placing glass
ionomer cement
over the occlusal
surfaces of the
posterior molars,
usually the upper
molars, which makes
their subsequent
removal easier .

47. Glass ionomer cement bonded to (a)
occlusal surfaces of maxillary molars or (b)
mandibular molars, to open the anterior
bite.

48. With this latter
posterior bite opening
approach, it is
important that the
mandibular dental
arch
is bonded in order to
avoid uncontrolled
overeruption of
the mandibular
incisors

49. Point 9 :
There is no certain arch
wire sequence that
clinicians have to go
by.

50. Point 10 : Heat activated
wires could be used as a
substitute for three of the
traditional stainless steel
wires in certain situations,
which was a significant
improvement.

51. Point 11: Nitinol Heat-Activated
wire is a thermally activated
super-elastic archwire.
It is the easiest of Nitinol wires
to engage, and it delivers light
continuous
forces that effectively move
teeth with minimal discomfort
to the patient.

52. Orthodontic Niti heat - activated arch wire
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

53. heat-
activated/thermal
NiTi wires are soft
and pliable at
room temperature,
which permits
easier insertion
into the bracket
slots. As the wire
warms to mouth
temperature, the
wire becomes
more “active.”

54. The development
of copper nickel-
titanium wires,
referred to as
'heat-activated'
wires, provided
wires with
significantly
greater flexibility. initial .016 HANT wire was followed
by a rectangular HANT wire
MBT

55. 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.
initial .016 HANT wire was
followed by a rectangular HANT
wire and then a .019/.025
rectangular steel wire.
MBT

56. 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.
Rectangular HANT wires are very effective in
achieving tooth movements of this type in
this region. They give good control and do not
distort in response to masticatory forces
MBT

57. Point 12 : Multi-Strand Stainless
Steel archwires
have low stiffness and can be used
for initial leveling and aligning stage
in orthodontics. However, due to
their lower elastic limit they can be
readily deformed if acted upon by
any other force such as food

58. Multi-Strand Archwires
3-strand wires are three
twisted strands of fine, round
Type 302SS that forma single
wire to provide light force,
good flexibility, and resiliency.

59. Point 13 : Nitinol could
replace multistrand
arch wires in the
alignment stage

60. Nickel Titanium archwire
Nickel-titanium
(NiTi) wires are
preferred by
clinicians because
compared to
stainless steel
wires, they have a
wider working
range and higher
springback
properties.
Maxillary and mandibular .016
nickel‐titanium
arch wires have been placed. A
sectional .016 × .022 β‐titanium
wire was placed on the maxillary
right molar to canine for
retraction of the canine.

61. The introduction of
nickel-titanium
wires provided a
possible
substitute for
multistrand and
steel round wires
during the
leveling and aligning
stages of treatment.
A .014 nickel‐titanium arch wire was placed
on the
maxillary arch
multistrand and steel round wires

62. POINT 14: One nickel
titanium
wire could be used in
place of approximately
two sizes of
stainless steel wires.

63. Point 15 : superelastic
Nitinol is better than
conventional Nitinol
wire is that engagement
of the displaced tooth is
readily achievable

64. Point 16 :
superelastic NiTi archwires
deliver a nearly light
constant force over a span
of activations—ideally those
that occur between office
visits and rapid tooth
movement results

65. Point 17 : Superelastic
Niti wire causes more
discomfort for the
patient comparing to
heat activated Niti.

66. every
clinician is
different
and has
their own
preferred
archwire
sequence.

67. The next
archwire
cannot be
placed
until the
previous
archwire has
been engaged
to all the
teeth.

68. The next
archwire
cannot be
placed
until the
previous
archwire has
been engaged
to all the
teeth.

69. Point 18 :Archwire
sequence with standard
edgewise appliance used
stainless steel for
alignment ; case report :

70. Point 19 : It is not
advisable to use NiTi
archwires from different
brands on the same
patient as the size may
vary by brand.

71. Treatment involved the
extraction of first
premolars in the upper
and lower arch to
correct the
proclination and
maintain angle’s Class-I
molar relation.
Treatment started with
the placement of
0.022Ë•
standard
edgewise brackets and
molar tubes (Victory
series, 3M, UNITEK,
Monrovia, CA, USA
Angles Class I molar and canine relation
Treatment began with the leveling and
alignment with well-coordinated 0.016Ë•
and
0.018Ë •
stainless steel (S.S.) arch wires

72. Treatment began
with the leveling
and alignment with
well-coordinated
0.016Ë•
and
0.018Ë •
stainless
steel (S.S.) arch
wires with molar
stops, progressive
tip back bends and
curve of spee wire in
the upper and
reverse curve of
spee wire in the
lower arch .
Angles Class I molar and canine relation

73. Individual canine
retraction was
started and
finished with an
elastic chain on
0.018” stainless
steel wire with tip
backs. Care was
taken to put a light
force to avoid
tipping of canine
Angles Class I molar and canine relation,

74. After canine retraction,
0.019 × 0.025Ë•
S.S. T loop
archwires with
progressive tip back bends
were placed in both
arches . Progressive buccal
root torque was placed in
the lower posterior
segment, progressive
lingual root torque in the
upper posterior segment
and lingual root torque in
the upper and lower
anterior segment.
Angles Class I molar and canine relation,

75. Patient was recalled
every 6 weeks for
reactivation of loops
and to check the
progress. Finishing
was performed on
0.016x0.022” S.S.
archwires with tip
backs and artistic
positioning bends
Angles Class I molar and canine relation,

76. Point 20: Archwires
sequence with the
preadjusted fixed
applaince ; case
reports:

77. Sizes used in this stage of
treatment:
●● 0.012 in., considered in very
crowded cases
●● 0.013 in., considered in very
crowded cases
●● 0.014 in.
●● 0.016 in., considered if unable
to engage 0.018 in.
●● 0.018 in.
Examples of archwire sequence

78. alignment in the maxillary and
mandibular dental arches was
achieved by a 0.016-in thermal
nickel-titanium wire. In the
mandibular arch, the space
closure started with lacebacks
on the right and left sides .
Then, leveling was obtained in
both arches with 0.019 x
0.025-in thermal nickel
titanium wires. Maxillary and
mandibular 0.019 x 0.025-in
stainless steel rectangular
archwires and power chain
were used to close the
extraction spaces .
archwire sequence CASE REPORT
alignment was achieved by a 0.016-in thermal
nickel-titanium wire
leveling was obtained with 0.019 x 0.025-in
thermal nickel titanium wires
0.019 x 0.025-in stainless steel rectangular
archwires and power chain were used to close
the extraction spaces .

79. After the initial wire,
0.014 NiTi, 0.016
NiTi, followed by
0.016×0.022” NiTi
wire were placed for
the sequential
leveling. Stainless
steel wire of
016×022” in upper
and lower arch was
used for final
leveling.
ARCH WIRES SEQUENCE
Alignment and leveling was done with, 0.014
NiTi, 0.016 NiTi, followed by 0.016×0.022”
NiTi and finally 16x22 st st

80. orthodontic treatment
was initiated with a 022
MBT appliance and 0.16
heat activated (HA)
nickel-titanium (NiTi)
archwires. After 20 weeks,
rectangular 19 × 25 HA NiTi
archwires were placed for
further alignment and
leveling. Initial space
closure with carried out
with rectangular stainless
steel (SS) wires with loops
Archwires sequence
Alignment was done with 0.16 heat activated
(HA) nickel-titanium (NiTi) archwires and
rectangular 19 × 25 HA NiTi archwires
Initial space closure with carried out with
rectangular stainless steel (SS) wires with
loops

81. The alignment and the leveling phases were performed using
the following sequence: 0.014- and 0.016-in nickel titanium
arches, and 0.018- and 0.020-in stainless steel arches
The distalization of the canines was performed using the
0.020-in stainless steel archwire
Distalization rate of maxillary canines in an alveolus filled
with leukocyte-platelet–rich fibrin in adults:
A randomized controlled clinical split-mouth trial
Case report
ARCH WIRES SEQUENCE

82. class I molar relationship bilaterally, missing
left maxillary lateral incisor, upper right peg
lateral incisor, and gap between the teeth in
the upper front region
ARCH WIRES SEQUENCE

83. 0.018″ ss wire followed
by 0:019 × 0:025″ ss wire
was placed to level and
express the prescription
of the bracket
ARCH WIRES SEQUENCE
The arches were
aligned using the
following sequence of
archwires: 0.014″ NiTi
and 0.016″ NiTi

84. Leveling and alignment
were started on maxillo-
mandibular dentition with
the use of 0.014-inch nickel-
titanium wire. After
completion initial
alignment, the wires
replaced into 0.016×0.022
stainless steel archwires
and upper and lower
canines on both sides were
started to retract with
elastic chains. Then,
0.016×0.022-inch stainless
steel wires were used for an
anterior retraction phase
Leveling and alignment were with the use of
0.014-inch nickel-titanium wire then 16x22 st
st for retraction

85. The archwire sequence shown has been
employed by the MBT. It has significantly reduced
chairside time and increased the efficiency of tooth
movement, owing the minimizing of permanent
archwire deflection .
The MBT system ARCHWIRE SEQUENCE

86. MBT prescription for tip and torque
Archwires sequence
The MBT system
Initial aligning
.014 or .016 heat-activated nickel
titanium
Leveling
.019 x .025 heat-activated nickel
titanium
Working
.019 x .025 stainless steel with hooks
Finishing
.019 x .025 beta titanium
Settling
.019 x .025 braided stainless steeL

87. Lower force than solid stainless steel archwires
8-Braid wires are made of eight fine, equal-sized
wires braided tightly and rolled to the most popular
square and rectangle wire sizes. 8-Braid Stainless
Steel archwires combine low tooth-moving forces
with high resiliency. Great for aligning and finishing.
Resists fraying when cut.

88. MBT 0.022
preadjusted
appliance was
bonded (ceramic
brackets in
anteriors and
metal brackets in
posteriors)
Case report
ARCHWIRE SEQUENCE
levelling alignment was initiated. Wire
sequence followed was 0.014“ Niti,
0.016” Niti, 0.016x0.022 Niti, 0.017x
0.025 ss, and 0.019x0.025 ss

89. Archwires sequence
Initial leveling and alignment
were performed using a round
0.014-inch nickel-titanium
archwire (NiTi) and canines’
laceback , followed by
0.016-inch NiTi and then 0.016 ×
0.016-inch NiTi
Case report
canine retraction started on 0.016
× 0.022-inch SS archwire using
power chain
After canine retraction, the upper
and lower incisors were leveled and
aligned, and then the midline was
corrected and
were retracted using rectangular SS
0.016 × 0.022-inch SS archwire with
T-loop in both arches that was
activated by cinch back the wire
every 3 weeks.
finishing and detailing using
0.017 × 0.025-inch titanium
molybdenum alloy archwire
(TMA) and 0.017 × 0.025-inch
SS.

90. Archwires sequence
Preadjusted MBT
brackets, slot
0.022 × 0.028-in were
used. Brackets were
firstly placed in the
maxillary arch . Leveling
and alignment was
achieved with 0.014-in,
0.016-in, 0.020-in,
0.017 × 0.025-in, and
0.019 × 0.025-in nickel-
titanium (NiTi)
archwires. Then, a
0.018 × 0.025-in
stainless steel archwire
was placed.

91. Complete bonding &
banding in both
maxillary and
mandibular arch was
done, using MBT-
0.022X0.028”slot.
Initially a 0.012” NiTi
wire was used which
was followed by
0.014 , 0.016”,
0.018”, 0.020” Niti
archwires following
sequence A of MBT.
Case report

92. After 6 months of
alignment and
leveling NiTi round
wires were
discontinued.
Retraction and closure
of existing spaces was
then started by use of
0.019” x 0.025”
rectangular NiTi
followed by 0.019” x
0.025” rectangular
stainless steel wires.
Case report

93. Retraction and closure of
existing spaces was done
with the help of Elastomeric
chains delivering light
continuous forces and
replaced after every 4 weeks
due to force decay and
reduction in its activity.
Finally light settling elastics
were given with rectangular
steel wires in lower arch and
0.012” light NiTi wire in
upper arch for settling .
Case report

94. Point 21 : it is important to
select prefabricated NiTi
archwires that are similar to
the patient arch form to
minimize changes and
reduce possible relapse .

95. Point 22 : It is
generally advised to
maintain the patient
arch
form during fixed
orthodontic treatment.

96. No single
arch form is
unique to
any of the
Angle’s class
of
malocclusion

98. Arch Form
Changes
to arch form
during
treatment
may result in
instability
and
subsequent
relapse

99. Arch Form
With this in mind,
3M provides
three distinct
arch forms that
reconcile the
variation
in anterior
curvature, inter-
cuspid width,
inter-molar width
and the curvature
from the cuspid
to the
second molars.

100. Tapered Arch Form:
Among the
three, this arch
form offers the
narrowest
inter-cuspid
width.

101. Tapered Arch Form:
This form is
especially ideal for
patients with
narrow arch forms
and gingival
recession in the
area of the cuspids
and bicuspids
(most frequently
found among
adults).

102. Tapered Arch
Form: Another
useful application
of this arch form
is in cases of
partial treatment
of only one arch,
as it will help
reduce the
occurrence of
expansion in the
treated arch

103. Ovoid Arch Form: With
an inter-cuspid width
between the other two
forms, this form is
intended, when
employed with the
retention and settling
steps , to maintain a
stable arch form post-
treatment.

104. Square Arch
Form: This
arch form is
especially
practical for
patients with
broad natural
arch forms.

105. Square Arch Form:
It can also be
applied early
in treatment in
cases that
require buccal
uprighting of
the lower
posterior
segments and
upper arch
expansion.

106. Square Arch
Form: If over-
expansion
occurs, it is
possible to
change to the
Ovoid arch
forms later in
treatment.

107. Arch Form,
Particularly
the Mandibular
Arch,
Cannot Be
Permanently
Altered with
Appliance
Therapy

108. Treatment
should be
directed
toward
maintaining the
arch form
presented by
the
malocclusion
as much as
possible.

109. In a clinical
situation,
orthodontists
should select the
most appropriate
archwire for the
patient arch form
and treatment
plan to align and
level the teeth.
Selecting the archwire
on the pretreatment
model

110. This selection is
sometimes
neglected as
the
orthodontists
might assume
that light NiTi
archwires will
not alter
archwidth.
Maxillary
archforms.
(A) Narrow.
(B) Ovoid.
(C) Square

111. Preserving
the arch
form also
affects
stability of
the
treatment
results.
Selecting the archwire on the
pretreatment model by adapting the
archwire on the incisal edges and cusp
tips of the teeth

112. There is ample
evidence in the
literature that
expansion in the
lower arch,
particularly in the
canine region is
unstable, and
little or no
evidence to the
contrary.
Pretreatment
Posttreatment
after 10-year retention.

113. When the lower
arch is rolled in
lingually, as occurs
in most palatal
expansion cases
and many deep
bite cases, then
buccal uprighting
in the lower arch
is indicated for
stability

114. Alignment using larger arch form

115. The intercanine
width of each
patient is
determined by
muscular balance,
and any
1: intermolar width; 2:
intercanine width; 3: molar
depth; 4: canine depth.
unintended
expansion in this
region could
cause instability

116. Orthodontic
archwires play a significant role in expansion of
the
dental arch.

117. The preformed
arch wires are
not
easily
customizable
and may
contribute to
arch form
development
during early
stages of
treatment.

118. Pre-
formed NiTi
archwires are
available in various
shapes
and sizes, and their
average intercanine
width could
exceed the natural
mandibular
intercanine width by
almost 6 mm.

119. Thus, it is
important to
select prefabri-
cated NiTi
archwires that
are similar to
the patient arch
form to
minimize
changes and
reduce possible
relapse.
Template
with
maxillary
and
mandibular
arch forms

120. The
therapeutic
arch form
should be de-
signed by
considering
the original
arch form of
the
patient and
treatment
objectives.
Ricketts pentamorphic arch
form template

121. Most orthodontists
selected archwires
subjectively by
visual assessment of
the adaptation of
the archwires to the
facial axis or facial
surface of the teeth,
incisal edges and
cusp tips, or the
facial portion of the
proximal contacts.
Contoured nickel-
titanium arch
superimposed on
a model.

122. Archform analysis
The maxillary
arch width in
the premolar
and molar
regions should
be assessed to
determine, if it
is narrow,
normal or
broad.

123. Archform analysis
These values
depend on the
combined
mesiodistal
widths of the
four upper
incisors (SI).

124. Archform analysis
The values
thus
obtained
indicate
the ideal
values of
premolar
and molar
widths..

125. Archform analysis
The actual
measured values of
the interpremolar
(mesial occlusal pit
of first premolars
on either side) and
intermolar (mesial
occlusal pit of first
molar on either
side) widths are
compared to the
ideal values to
conclude whether
the arch is narrow,
normal or broad.

126. Point 23:
determine whether
the lower arch has a
tapered, square, or
ovoid form .

127. Clear
templates can
be used to
assess the
patient's
lower model
at the start of
treatment.

128. Arch form control early in
treatment
It is recommended that
all round wires be
stocked in ovoid form
only . this helps to limit
inventory. The opening
wires will normally be
.015 or ,0175 multistrand,
.016 HANT, or sometimes
.014 steel. These may all
be used in ovoid form,
with no customizing.

129. Arch form control early
in treatment
The manufatcured shape
of rectangular HANT wires
cannot be customized. It
is therefore necessary to
stock them in tapered,
square, and ovoid form,
because (like the heavier
round wires) they should
be used in the
approximate form for the
patient, as determined
using the clear templates.

130. Arch form control early
in treatment
Rectangular HANT
wires may be in place
for several months, and
they do influence the
patient's arch form,
especially in the
important canine
region. If not used in
the appropriate
tapered, square, or
ovoid shape, they can
cause undesirable
changes in the patient's
starting arch form