Note: Descriptions are shown in the official language in which they were submitted.
CA 02944574 2016-10-07
SELF-LIGATING BRACKET SYSTEM WITH PASSIVE OR INTERACTIVE CLIP
Cross-Reference to Related Applications
This application is a Continuation-in-Part of International Application No.
PCT/1132015/051982, filed March 18, 2015, which claims priority to Brazilian
Application number BR 10 2014 013775 0, filed June 6, 2014. This application
also
claims priority to U.S. Provisional Application No. 62/239,114, filed October
8, 2015.
The disclosures of the prior applications are hereby incorporated in their
entirety by
reference.
Background
[001] In conventional orthodontic brackets, an archwire applies corrective
forces to
a patient's teeth in order to move them to an ideal position. The archwire may
be
received in a slot in a bracket's body and secured within the slot's walls by
an
elastomeric or steel ligature tie applied to each tooth. However, this
approach often
results in repetitive and prolonged treatment.
[002] Conversely, self-ligating brackets comprise a ligating member, such
as a clip,
for securing the archwire. One advantage of the self ligating bracket is a
much lower
friction at the slot-archwire interface. This approach allows the use of lower
force
archwires to move teeth, greatly reducing the iatrogenic potential of the
treatment.
Moreover, by eliminating elastomeric and ligature ties, the repetitive work
and the
time demanded to change the ligatures is drastically reduced.
[003] However, self-ligating brackets generally have a greater buccolingual
height,
since they must be able to accommodate the sliding and locking mechanisms of
the
clip. This feature increases the bracket's overall size, often causing
discomfort to the
patient, as well as greater visibility, which can impair aesthetics and
hygiene.
[004] Another challenge for orthodontic professionals is determining and
creating
appropriate force systems for moving teeth according to the stage of a
patient's
treatment.
[005] To create a force on the teeth, self-ligating brackets comprise a
ligating
member or clip over a slot, which is receivable for an archwire. When the
ligating
member or clip is open, the slot is exposed; closing the ligating member or
clip
retains the archwire within the slot.
[006] Often, the ligature member or clip is a sliding ligating member
capable of
=
moving within sliding channels in the bracket's body. This approach allows the
archwire to be reliably secured in a closed position with reduced operational
time.
1
CA 02944574 2016-10-07
[007] Self-ligating brackets may be passive or interactive. In passive
brackets,
clearance is provided between the four walls formed by the slot and the
archwire. In
an interactive bracket, progressively larger archwire-slot wall interaction is
provided
via use of a thicker archwire.
[008] However, there is currently a need for new technologies for improving
the
clinical management and/or functionality of self-ligating brackets, as well as
for
reducing costs and expanding the base of users.
[009] U.S. Patent No. 7,621,743 relates to a bracket with a sliding clip
that is guided
by a lateral, slightly curved sliding channel. When the bracket is in the
closed
position, the clip is held in position by bilateral outward protuberances
located in the
arms of the clip, which correspond to two concave housings in the body of the
bracket. However, the clip does not cover the entire mesial-distal width of
the
bracket slot, which hinders rotational control of the tooth. Additionally, the
curved
design of the channels increase the bracket's buccolingual height.
Furthermore, the
bracket does not allow both passive and interactive configurations in one
system.
[0010] U.S. Patent No. 5,322,435, U.S. Patent No. 6,071,119, U.S. Patent
No.
6,776,613, and U.S. Patent No. 7,335,020 also relate to self-ligating
brackets.
However, the brackets therein also do not allow both passive and interactive
configurations in one system.
Brief Description of the Drawings
[0011] FIG. 1 shows an example of a self-ligating bracket system with a
clip in a
closed position, in accordance with aspects of the present invention.
[0012] FIG. 2 shows an example of a perspective exploded view of a self-
ligating
bracket system in which the clip is removed from the system, in accordance
with
aspects of the present invention.
[0013] FIG. 3 shows an example of a lateral view of a bracket with the clip
in a
closed position and the archwire retained in the slot, in accordance with
aspects of
the present invention.
[0014] FIG. 4 shows an example of a self-ligating bracket system with the
clip in a
closed position retaining the archwire within the slot, in accordance with
aspects of
the present invention.
[0015] FIG. 5 shows an example of a perspective view of a self-ligating
bracket
system wherein the clip is in an open position exposing the slot, in
accordance with
aspects of the present invention.
2
CA 02944574 2016-10-07
[0016] FIG. 6 shows an example of a lateral view of a self-ligating bracket
system
with a passive clip in the open, retracted position, exposing the slot to
release the
archwire, in accordance with aspects of the present invention.
[0017] FIG. 7 shows an example of a self-ligating bracket system with a
passive clip
in an open position and locked to expose the slot in order to release the
archwire, in
accordance with aspects of the present invention.
[0018] FIG. 8 shows an example view showing lower tie wings and a passive
clip in
closed position, in accordance with aspects of the present invention.
[0019] FIG. 9 shows an example of a self-ligating bracket system with an
interactive
clip in the closed position retaining the archwire within the slot, in
accordance with
aspects of the present invention.
[0020] FIG. 10 shows an example of a self-ligating bracket system with an
interactive
clip removed from the system, in accordance with aspects of the present
invention.
[0021] FIG. 11 shows an example of a self-ligating bracket system with an
interactive
clip in the closed position interacting with the archwire inside the slot, in
accordance
with aspects of the present invention.
[0022] FIG. 12 shows an example of a self-ligating bracket system with an
interactive
clip in the closed position retaining the archwire inside the slot, in
accordance with
aspects of the present invention.
[0023] FIG. 13 shows an example of a self-ligating bracket system with an
interactive
clip in the open position, exposing the slot in order to release the archwire,
in
accordance with aspects of the present invention.
[0024] FIG. 14 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the open position, the clip being retracted and
locked in the
channel, and with the upper wall of the sliding channel in a retracted
position, in
accordance with aspects of the present invention.
[0025] FIG. 15 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the open position, with the upper wall of the sliding
channel in
an intermediate position, in accordance with aspects of the present invention.
[0026] FIG. 16 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the open position, with the upper wall of the sliding
channel in
an advanced position and with the archwire inside the slot, in accordance with
aspects of the present invention.
[0027] FIG. 17 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the open position exposing the slot in order to
release the
archwire, in accordance with aspects of the present invention.
3
CA 02944574 2016-10-07
[0028] FIG. 18 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the closed position interacting with the archwire
inside the
slot, in accordance with aspects of the present invention.
[0029] FIG. 19 shows an example of a self-ligating bracket system with an
interactive
clip with curved tabs in the open position, the clip being retracted and
locked in the
channel, in accordance with aspects of the present invention.
[0030] FIG. 20 shows an example of a self-ligating bracket system with an
interactive
clip with 90 bends in the closed position, in accordance with aspects of the
present
invention.
[0031] FIG. 21 shows an example of a self-ligating bracket system with an
interactive
clip with 90 bends, removed from the system, in accordance with aspects of
the
present invention.
[0032] FIG. 22 shows an example of a ligating bracket system with an
interactive clip
with 90 bends in the closed position interacting with the archwire inside the
slot, in
accordance with aspects of the present invention.
[0033] FIG. 23 shows an example of a self-ligating bracket system with an
interactive
clip with approximately 90 bends in the closed position interacting with the
archwire
inside the slot, in accordance with aspects of the present invention.
[0034] FIG. 24 shows an example of a self-ligating bracket system with an
interactive
clip with approximately 90 bends in the open position exposing the slot, in
accordance with aspects of the present invention.
[0035] FIG. 25a shows an example of a self-ligating bracket system with an
interactive clip in the open position, in accordance with aspects of the
present
invention.
[0036] FIG. 25b shows an example of a self-ligating bracket system with an
interactive clip in the open position with the clip's arms in contact with one
another, in
accordance with aspects of the present invention.
[0037] FIG. 25c shows an example of a self-ligating bracket system with a
passive
clip in the open position, in accordance with aspects of the present
invention.
[0038] FIG. 25d shows an example of a self-ligating bracket system with a
passive
clip in the open position with the clip's arms in contact with one another, in
accordance with aspects of the present invention.
[0039] FIG. 26 shows a clip in the open position with the arms of the clip
deflected
upwardly and inwardly, in accordance with aspects of the present invention.
[0040] FIG. 27 shows a clip in the closed position with the arms of the
clip parallel to
the bottom of the slot, in accordance with aspects of the present invention.
4
CA 02944574 2016-10-07
[0041] FIG. 28 shows an example of a comparison between a self-ligating
bracket
system with a passive clip (a) and with an interactive clip (b) in a closed
position
retaining the archwire within the slot, in accordance with aspects of the
present
invention.
[0042] FIG. 29 shows an example of a comparison between a medium resistance
interactive clip (a) and a high resistance interactive clip (b), in accordance
with
aspects of the present invention.
[0043] FIG. 30 shows an example of the tip of a dental instrument (for
example, a
scaler) placed between the arms of the clip, in accordance with aspects of the
present invention.
Summary and Detailed Description
[0044] Aspects of the present invention provide for a self-ligating
orthodontic bracket
system which may be useful, for example, for correcting mandibulary and
maxillary
abnormalities, and/or for repositioning teeth. Aspects provide for an
orthodontic
bracket that may be used alone or in combination with other hardware systems
to
move teeth towards their ideal positioning in a patient's mouth.
[0045] According to aspects of the present invention, the self-ligating
orthodontic
bracket system may comprise a bracket body, an archwire, a slot receivable for
an
archwire, and either a passive or interactive clip. Aspects of the present
invention
may allow for both passive and interactive configurations in the same system.
As
used herein, the term "interactive" refers to a configuration wherein the clip
is
configured to interact with an archwire retained in an archwire slot, such
that the
archwire may not move freely. As used herein, the term "passive" refers to a
configuration wherein the clip is configured to form a tube or other similar
structure
together with a slot, such that an archwire retained therein may move freely.
The
clips may not be removable from the bracket body and/or convertible between
configurations.
[0046] According to some applications, aspects of the invention may be
varied with
respect to any of the features described herein in order to produce an
appropriate
force on the archwire, thereby producing distinct levels of resistance to
archwire
sliding in the slot. For example, the resistance to archwire sliding may
correspond to
greater or lesser interference at the archwire/slot and/or archwire/clip
interfaces.
[0047] According to aspects of the present invention, the bracket body may
comprise
lower tie wings with channels therein receivable for the clip, and features
and/or
methods to move and lock the clip. According to aspects of the present
invention,
the clip may have a generally flat planar shape associated with passive clip
or have
CA 02944574 2016-10-07
radii or bends thereon, associated with an interactive clip. According to
aspects of
the present invention, the clip may also comprise arms with tabs thereon. The
arms
may extend over the slot, thereby retaining an archwire within the slot when
the clip
is in the closed position.
[0048] According to aspects of the present invention, as shown in FIG. 1,
the self-
ligating bracket system may comprise a bracket with a low profile body (9)
with a
bonding base (10) for application on the crown anatomy of a tooth. For
example, as
shown in FIGS. 2 and 3, the system may comprise at least two upper tie wings
(11)
and at least two lower tie wings (12), the lower tie wings including channels
(2)
therein capable of receiving a planar clip (4). The channels (2) may comprise
an
outer wall (2a) approximately 90 perpendicular to the bottom (2c) of the
channel (2).
The upper walls (2b) of the channel (2) may be shaped such that the lower tie
wings
appear similar to a conventional bracket and are thus familiar to the
professional. At
least in this way, the bracket body provides a familiar visual reference for
positioning
the bracket on a tooth.
[0049] The bracket may comprise a slot (13) receivable for an archwire (14)
proximal
to the upper tie wings and lower tie wings. According to some aspects, the
archwire
may be retained in the slot by a passive clip (4). As shown in FIGs. 9-19, the
clip
may be interactive and may comprise curved tabs (6). As shown in FIGs. 20-24,
the
clip may be interactive and comprise tabs located at the nnesial distal
extremities
thereof, with approximately 90 bends (8). Depending on the configuration of
the
clip, the system may be passive (1A) or interactive (1B, 1C, and 1D) using
similar or
the same overall bracket construction or similar features, thereby providing a
hybrid
system. According to aspects of the present invention, the system may
substantially
retain a similar construction with a uniform buccolingual height, regardless
of whether
the clip is interactive or passive. For example, as shown in FIG. 28, the same
or a
similar bracket body construction may be used in conjunction with the passive
and
interactive clips. The only difference between FIG. 28(a) and FIG. 28(b) is
the use of
a passive and interactive clip, respectively. In some embodiments, this
configuration
may allow the selective use of passive and interactive brackets on individual
teeth,
e.g., by alternating passive and interactive brackets in a patient's mouth by
selecting
the appropriate clips.
[0050] According to some aspects, as shown in FIG. 5, the clip (4) may
comprise a
generally "U" or a "V" cross-sectional shape, with arms (15) with planar tabs
(16) at
the ends thereof. The arms of the clip (4) may be of a sufficient width to
extend to
one or both ends of the mesial distal width of the slot (13) in the closed
position, such
that when the clip slides into each channel to the closed position, the clip
together
6
CA 02944574 2016-10-07
with the slot a tube-like or otherwise partially enclosing structure, such
that an
archwire retained therein may move freely therein when in a passive
configuration.
[0051] According to
some aspects, the clip may be manufactured in part or in whole
using a shape memory alloy and a heat treating process that allows the clip to
deflect
in three Cartesian planes of space. The clip's flexibility in three planes of
space may
be useful, for example, when the clip moves in the channels towards the lower
tie
wings in the gingival/incisal direction from the closed to the open position.
As seen in
FIG. 25, the bracket may comprise a wall (25) perpendicular to the bottom wall
of the
channel. When moving toward the open position, the arms (24) may flex and
converge towards the center (C) of the bracket, such as until the arms contact
one =
another. This action of the arms may at least partly result from the total
width of the
arms being larger than the width of the channel in some variations. In this
implementation, the clip is prevented from exiting the back of the channel,
and is thus
not removable from the bracket body.
[0052] For example, as
shown in FIGs. 26 and 27, each arm may comprise an upper
surface (P1). As shown in FIG. 26, the arms may be initially inserted into the
channel
(the position prior to full engagement of the arms also being interchangeably
referred
to herein as the "open position"). In this position, the arms may be flexed
both
upwardly and inwardly towards one another, such that the upper surface of each
of
the arms (P1) has a planar surface that is not completely parallel to the
bottom planar
surface of the slot. The clip may optionally be securely locked even when in
the
open position by interference of the arms with the top and/or side walls of
the
channel, without additional structures in or on the bracket body, channel, or
clip being
emplaced in order to hold the clip in place.
=
[0053] When moved to
the fully engaged or "closed position" (i.e., when the arms are
at least partially covering the slot), as shown in FIG. 27, the arms of the
clip may
return to their original configuration by shape memory. As seen in FIG. 27,
the arms
may thereby move downwardly and outwardly when traveling out of the channel
and
over the slot, such that the upper surfaces of each of the arms (P1) is
approximately
parallel in to the bottom planar surface of the slot upon reaching the closed
position.
Because the width of the arms is larger than the width of the channel, the
clip will not
reenter the channel after reaching the closed position without force being
applied,
such as by a user. For example, in the closed position, the clip may interface
with a
ridge on the vertical walls of the upper tie wings.
[0054] According to
some aspects, as shown in FIG. 9, the bracket (18) may
comprise an interactive clip (5) with curved tabs (6) having a radius
sufficient to
establish contact with an archwire (14) received in the slot (13) when the
clip (5) is in
7
CA 02944574 2016-10-07
the closed position. The bracket may have one or more lateral protuberances
(18)
contiguous to a central protuberance (19), which may guide the clip (5) when
moving
between the open and closed position. The clip (5) have similar features of
shape
memory and temper described above, which may allow the deflection in three
Cartesian planes, for example, when interfacing with the ridge on the vertical
walls of
the upper tie wings (11) when in the closed position and when traveling over
the
lateral protuberances (18).
[0055] According to some aspects, as shown in FIGs. 14-16, the upper wall
(20, 21,
and 22) of the lower tie wings, which form the channels, may have features
selected
so as to control the flexibility of the clip. For example, the upper wall (20)
may be
retracted in a first position, such that flexibility is at a maximum. The
upper wall may
be adjusted to an intermediate position (21) in order to create intermediate
flexibility.
The upper wall (22) may also be adjusted to the most advanced position (e.g.,
maximum extension towards the slot), such that the flexibility is at a
minimum.
[0056] According to some aspects, as shown in FIGs. 18-19, the bracket may
comprise an interactive clip (5) with curved tabs (6). The body may comprise a
recess (A) in the lower tie wings (12) for receiving for the curved tabs (6).
As shown
by FIG. 29a and 29b, the performance of the interactive bracket with the
curved tabs
may be altered, for example, by increasing the radius of the tabs of the clip.
In this
way, the resistance to sliding that the clip provides on an archwire may be
varied. In
one example, as shown in FIG. 29a, a medium resistance interactive clip may be
configured such that the clip may interact with an archwire having a height of
about
0.022" or greater, for example. As shown in FIG. 29b, a high resistance
interactive
clip may be configured such that the clip may interact with an archwire with a
height
of about 0.018" or greater, for example. According to some variations, the
pressure
applied to an archwire may increase as the curvature of the tabs increases, as
a
larger curve will provide more pressure against the archwire toward the bottom
of the
slot
[0057] According to some aspects, as shown in FIGs. 20-24, the bracket may
comprise an interactive clip (7) with shape memory and temper as discussed
above
and with mesial/distal extremities of the tabs bent approximately 900 (8)
towards the
base of the body (9). The tabs (8) may dissipate excess force created at the
interface of the clip (7) with the archwire (14) received in the slot (13),
thereby
increasing the system's resistance to archwire sliding, while repositioning
the tooth.
In this implementation, the body (9) may comprise recesses (23) on the lateral
nnesial
and distal walls of the lower twin tie wings (12) configured to house a
portion of clip
(7) when it is in the open position.
8
CA 02944574 2016-10-07
[0058] In some aspects, the same bracket may be used with any suitable
configuration of clip, thereby allowing a hybrid system having a combination
of
passive and interactive brackets. For example, it may be desirable to use
interactive
clips or a combination of interactive and passive clips during earlier phases
of
orthodontic treatment when lighter and/or smaller archwires are typically
used. When
heavier and/or larger archwires are used during later phases of treatment, it
may be
desirable to use passive clips.
[0059] According to aspects of the present invention, a planar clip may
move in the
channels of the lower tie wings, so that the clip may move from an open
position to a
closed position by moving toward upper tie wings in a direction parallel to
the
channels, until the arms and tabs of the clip extend to one or both ends of
the slot.
The total coverage of the slot by the clip may allow for better rotational
control of the
tooth, for example. In some aspects, the clip may be configured to be "self
locking,"
such that it may be secured in the closed position without ramps,
protuberances,
ridges, recesses, or the like, in the upper or lower tie wings.
[0060] As shown in Fig. 9, in some aspects, the body of the bracket may
comprise a
supporting border ridge or similarly functioning feature (9.1) in the inner
wall of the
upper tie wings, which may support the clip tabs when in the closed position.
In
some variations, the body may have one or more protuberances (19) located
between the lower tie wings, which may, for example, promote stability for the
clip
within the channels when moving between the closed and open position. For
example, in some aspects, a protuberance located between the lower tie wings
may
stabilize the clip in the horizontal and vertical directions when the clip is
travelling
between the open to closed positions, wherein the clip could otherwise stray
from an
intended sliding path and thereby cause the clip to become stuck within the
sliding
channel.
[0061] In some aspects, the body may have one or more lateral protuberances
(18),
which may serve as backstops for the clip and which may secure the clip in the
open
position by locking the clip in the open position. For example, in some
aspects, as
shown in Fig. 9, a lateral protuberance (18) may lock the clip in the closed
position as
the clip slides obliquely in a sliding plane over the lateral protuberance,
and
subsequently comes to rest in the closed position over the archwire slot. In
the
closed position, a posterior segment of the tabs (6) may be level with or
below a
=
vertical height, relative to the surface of a tooth, of the lateral
protuberance. In this
way, the lateral protuberance may at least partially lock the clip in the
closed position
and prevent the clip from sliding to the open position by masticatory forces
or
deflection of the archwire, for example. As shown in Fig. 13, in some aspects,
when
9
CA 02944574 2016-10-07
the clip is in the open position, a posterior area of the lateral protuberance
may
interact with an anterior portion of the tabs, thereby at least partially
preventing the
clip from involuntarily sliding to the closed position.
[0062] According to aspects of the present invention, the clip includes
tabs having
curvature. As shown in Fig. 19, the curvature may be in a direction generally
perpendicular to the lengthwise direction of the arms of the clip and to the
planar
direction of the bottom of the slot. According to some aspects, the lower tie
wings of
the bracket body may include one or more concave portions (A) corresponding to
the
shape of the curved tabs, the concave portions being configured to house the
curved
tabs when the clips are located in the open position. As shown in Fig. 18,
according
to some variations, when the clip is in the closed position, the curved tabs
may
interact with an archwire retained in the slot in an interactive
configuration.
[0063] As shown in Fig. 20, according to aspects of the present invention,
the clip
may comprise tabs that extend towards the bottom of the slot, thereby allowing
interactive interaction with the archwire. According to aspects of the present
invention, the tabs of the clip may be bent approximately 90 in the direction
towards
the bottom of the slot when in the assembled position. According to some
aspects,
the approximately 90 bent tabs may vary in vertical length. According to some
aspects, the tabs may comprise a vertical length of between about 0.02 mm and
0.5
mm. According to some aspects, a bent tab with a larger vertical length may
provide
greater interference at the slot/archiwre interface than tabs with a shorter
vertical
length, thereby providing more force on a retained archwire. According to some
aspects, the bracket body may have a recess configured to house the tabs when
the
clip is in the open position. For example, according to some aspects, a recess
(23)
may be configured to house approximately 90 bent clip tabs (8) as the clip
travels
between the closed and open positions. In the open position, the bent tabs (8)
may
be housed in the recesses (23), one on the mesial and the other on the distal
side of
the bracket body.
[0064] According to aspects of the present invention, the slots may have a
height
between approximately 0.018" and 0.022", for example, which may be varied.
[0065] According to aspects of the present invention, the clip may be moved
between
an open and closed position by placing a pointed instrument between the arms
of the
clip and creating a lever action toward the lower tie wings, so as to expose
the slot.
The clip may be moved to the closed position with a corresponding reverse
movement. For example, according to some aspects, as shown in Fig. 30, the tip
of
a dental instrument (for example, a scaler) may be placed between the arms of
the
CA 02944574 2016-10-07
clip, into an opening formed by the clip and the bottom slot wall. The
instrument may
then be rolled toward the incisal (in the upper dental arch) and toward
gingival (in
lower dental arch) directions in order perform a lever action motion towards
the lower
tie wings, thereby at least partially moving the clip to the open position.
According to
some aspects, the lever action motion offsets forces making the opening motion
more comfortable to the patient in comparison to pulling the clip down.
Alternatively,
the instrument may be pulled gently in the incisal (in the upper dental arch)
or the
gingival (in lower dental arch) direction in order to move the clip between
the opened
and closed position.
[0066] According to aspects of the present invention, the clip may comprise
shape
memory alloys. Examples of suitable shape memory alloys may include, but are
not
limited to, titanium and its alloys, NiTinol, CuNiTi, CoCr, heat treated
stainless steel,
and any other alloys that allow deflection in all planes of the space. The
clip may
have one or more mesial distal flexible arms comprised of shape memory alloys,
which may deflect independently of one another according to the deflection of
an
archwire received in the slot over which the clip is located. According to
some
aspects, the flexibility of the arms of the clip may minimize the collateral
effect of the
force applied by the system, such that less force is necessary to prevent or
minimize
dental movement than what is necessary in systems comprising clips not
accordance
with the present invention. According to some aspects, the force applied by
the clip
on other components of the system may vary with the material composition,
thickness, and heat treating processes of its manufacture.
[0067] According to aspects of the present invention, the buccal lingual
height of the
bracket may provide greater comfort to a patient than a bracket with a greater
buccal
lingual height. According to some aspects, the bracket may include one or more
visual guides thereon, which may function as visual cues for placement on a
tooth.
The visual guides may be used in conjunction with an instrument for aligning
the
bracket with the tooth axis, for example.
[0068] Additional advantages and novel features relating to aspects of the
present
invention will be set forth in part in the description that follows, and in
part will
become more apparent to those skilled in the art upon examination of the
following or
=
upon learning by practice thereof.
11
