bracket placement,archwire progression,initial alignment, arch leveling, tooth translation and retraction, torquing and finishing

1. The
SPEED
The four steps
to using this
self-ligating
bracket system
ParadigmBy Sylvain Chamberland,
DMD, MSc
S
elf-ligating appliances were first introduced to the profession in
the 1930s by Ford and Boyd.1 Over the next 40 years, many self-
ligating designs were conceived but none resulted in any clinical or
commercial impact. In the early 1970s, G. Herbert Hanson, DDS, began
to work on the design of a new orthodontic bracket that would improve
operator efficiency and achieve greater precision and control of tooth
movement than previous designs had.
This led to the release of the SPEED bracket in the early ’80s.2 Since
then, several modifications have made clinical use easier, but the funda-
mental design remains unchanged. One of the most significant modifica-
tions was the introduction of a superelastic nickel titanium spring clip.3
Sylvain Chamberland,
The clip maintains its stiffness and exerts consistent force on ligated DMD, MSc
archwires throughout treatment, while clips made of weaker material
such as Elgiloy have shown extensive relaxation after use.4
Hanson’s design also offers the often-overlooked advantage of pro-
viding the user with a mix of so-called “passive” and “active” archwire
interaction. Enhanced cooperation between the bracket and the archwire
gives the user full 3D control over rotation, tip, and torque. Any devia-
tion of the bracket position relative to the wire will result in deflection of
the spring clip that will then seat the wire into its home position.
Bracket Placement
As with many other systems, precise bracket positioning is very
important with the SPEED system. The basic placement principles are
the same as with any straightwire edgewise appliance. The orthodontist
determines the archwire plane by locating the maximum buccal convex-
ity of the posterior teeth (Figure 1). This plane usually coincides with
placing the slot of the bracket 4 mm to 4.5 mm from the incisal edges of
the anterior teeth. A more incisal or gingival position of ± 0.5 mm may
Figure 1: Selecting the archwire plane based on maximal buccal convexity.
20 OrthodonticProductsOnline.com February 2010

2. be decided accord- rectangular NiTi
ing to the clinical archwire.
crown length. The archwire
The user should sequence of this
consider two other phase may include
parameters when .016 x .022, .020
placing the brackets: x .020, or .020 x
the long axis and .025 nickel tita-
the mesiodistal posi- nium wire (Figure
tion of the bracket. 4). Any significant
The long axis of the Figure 2: The long axis is assessed from the lingual for anterior teeth. Mesiodistal bracket-placement
placement is on the middle lobe prominence of the teeth.
anterior teeth is best errors that become
assessed using the lingual and with a panoramic view (Figure apparent should be rectified at this stage before moving
2). A meticulous bonding technique will pay dividends later into heavier stainless steel wires.
in terms of efficiency and quality of treatment. This sequence should be followed by a .020 x.025
stainless steel SPEED archwire or .021 x .021 stainless steel
Archwire Progression D-wire. The goal would be to enhance torque, achieve
A typical archwire progression may be divided into archform coordination, and obtain a flat curve of Spee.
four segments: ini- 3) Tooth trans-
tial alignment, arch lation and retrac-
levelling and torqu- tion: As mentioned
ing, tooth transla- above, en-masse
tion, and retraction retraction should
and finishing. Each be preceded by a
segment of treatment full-dimensional,
has different goals rigid archwire. This
and thus requires encourages full
different wire char- expression of the
acteristics. interaction between
1) Initial align- Figure 3: The initial archwire, a .016 Supercable, is left in place for 11 weeks. the superelastic
As unraveling occurs, the excess wire extends distally.
ment: The preferred spring clip, the arch-
wire at this stage of treatment is .016 or .018 SPEED wire, and the archwire slot. The torque prescription will be
Supercable™. Supercable contains multiple strands of expressed, and the curve of Spee will continue to flatten.
superelastic nickel titanium wire. Regardless of malalign- En-masse retraction is achieved using a dual-geometry
ment, Supercable archwire provides 3 to 5 times less force wire (Figure 5, page 24), square in the anterior (.021 x
than .014 or .016 solid nickel titanium wire.5 .021) and round in the posterior (.018 or .020). This con-
The initial phase of treatment varies significantly from figuration allows full torque control of the incisors dur-
one patient (or malocclusion) to another, but generally it is ing retraction, with significantly reduced friction in the
accomplished in 6 to 18 weeks (Figure 3). The added value posterior since the rounded part of the wire will be in the
of taking time to align teeth in first and second order is that passive zone of the spring clip/archwire configuration.
you might be able to skip a wire in the next phase. When inserted into the arch, E-Links force module
2) Arch leveling: The second phase of treatment (TP Ortho) can be attached to the first or second molars
consists of leveling the curve of Spee, coordination of according to the anchorage requirement. The force used
the archform, and torquing. This should be done with to close the extraction space is applied above the center
Figure 4: Note archform development from A at 21 weeks to C at 33 weeks. A .020 x .020 heat-activated NiTi wire is engaged 27 weeks into treat-
ment (B) followed by a .020 x .025 SPEED nickel titanium wire 6 weeks later (C).
22 OrthodonticProductsOnline.com February 2010

3. bracket’s prescription, it is necessary
to fill the archwire slot. A .021 x .021
or .020 x .025 wire has a torque loss of
about 4° to 5°, which means effective
torque of 6° to 7° in a brackets that is
Figure 5: A .021 x .021 x .018 Dual-geometry wire preangulated at 11°.8 With this data
with reversed curve of Spee and posterior toe-in. If in mind, we can conclude that active
in the maxillary arch, the preactivation bend would
accentuate the curve of Spee.
SLBs with a full-dimensional archwire
will express torque earlier than passive
SLBs. A torquing moment of at least
of resistance of the posterior unit and anterior unit in the 8 to 10 Nmm will be attained, which is enough to torque
sagittal view. The previously formed reversed curve of maxillary incisors.
Spee creates a moment that will counteract the tipping of Figure 7 shows a situation where the lateral incisors
the anterior and the posterior unit toward the extraction are in palatal position relative to the central incisors.
site. If you note that the curve of Spee is increasing while Special brackets with 0° of torque were bonded on the
closing the space, you should increase the reverse curve or lateral incisors. The canines were retracted and the lateral
reduce the force used to close the space. incisors were aligned. A rectangular nickel titanium wire
Occlusally, expansion at the molars could occur if was engaged early in treatment to initiate third-order
posterior constriction is not incorporated into the arch. In movement of the laterals, while the canines were retracted
some situations, extraction spaces close almost spontane- with an elastomeric chain. At 61 weeks, a .020 x .025
ously during alignment and initial torque correction. (See stainless wire was engaged. Note the alignment of the cin-
the maxillary arch in Figure 6.) If this occurs and there is gulum of the incisors, showing adequate root movement
only 2 or 3 mm of and torque at this
space to close, it can stage. Finishing
be done with an elas- bends and detailing
tomeric chain placed of the occlusion is
under the archwire. done with a .020 x
The closure of such .025 stainless steel
small spaces can be SPEED wire.
accomplished on The concept that
l a r g e - d i m e n s i o n Figure 6: Mandibular arch: .021 x .021 .018 preformed (reversed curve and posterior toe SPEED pioneered
in) and E-Links #5 attached from the hook to the first molar. Maxillary arch: .020 x .025
archwires such as stainless steel SPEED wire and elastomeric chain underneath the wire to closed residual 30 years ago is this:
.020 x .025 stainless extraction space. no tie wings, no liga-
steel and does not tures, single-point
require specialty mechanics or archwires. attachment, miniaturization, and full control. This is the
4) Torquing and finishing: Torque expression of paradigm. OP
self-ligating brackets (SLBs) have been compared in dif-
ferent studies. Using a .019 x .025 stainless steel wire, Sylvain Chamberland, DMD, MSc, is in private practice in
Badawi et al6 found that active SLBs started to expressed Quebec, Canada. He is a diplomate of the ABO. He can be
torque at an angle of torsion of 7.5°, while passive SLBs reached at drsylchamberland@biz.videotron.ca.
start to express the torque at a much higher angle of tor-
sion (15°). Morina et al7 found that the torquing moment
at 20° of torsion of a .019 x .025 stainless steel wire in a References for this article can be found with the
.022-slot bracket is around 8 Nmm for both passive and online version at OrthodonticProductsOnline.com.
active SLBs. To take advantage of the tip and torque of the
Figure 7: (A) The initial photo. (B) 45 weeks into treatment, a .020 x .025 NiTi wire is engaged. (C) At 61 weeks into treatment, a .020 x .025
stainless steel SPEED wire is engaged to express 3D control.
24 OrthodonticProductsOnline.com February 2010