U.S. patent application number 17/133475 was filed with the patent office on 2021-04-22 for insertable and prefabricated attachments for an oral appliance.
The applicant listed for this patent is Align Technology, Inc.. Invention is credited to Bruce Cam, Rohit Tanugula, Dennis Te, Crystal Tjhia.
Application Number | 20210113304 17/133475 |
Document ID | / |
Family ID | 1000005303860 |
Filed Date | 2021-04-22 |
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United States Patent
Application |
20210113304 |
Kind Code |
A1 |
Cam; Bruce ; et al. |
April 22, 2021 |
INSERTABLE AND PREFABRICATED ATTACHMENTS FOR AN ORAL APPLIANCE
Abstract
A dental appliance includes an interior shape that substantially
conforms to a dental arch of a patient, a hollow portion forming a
cavity, and an object bonded to the dental appliance and inserted
into the cavity. The object provides structural strength to the
dental appliance at a location of the hollow portion and does not
interfere with a fit of the dental appliance onto the dental arch
of the patient.
Inventors: |
Cam; Bruce; (San Jose,
CA) ; Tjhia; Crystal; (Sunnyvale, CA) ;
Tanugula; Rohit; (San Jose, CA) ; Te; Dennis;
(San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Align Technology, Inc. |
San Jose |
CA |
US |
|
|
Family ID: |
1000005303860 |
Appl. No.: |
17/133475 |
Filed: |
December 23, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15199598 |
Jun 30, 2016 |
10881487 |
|
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17133475 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B33Y 80/00 20141201;
A61C 7/36 20130101; B29C 65/16 20130101; B29C 69/001 20130101; B29C
51/268 20130101; A61F 5/566 20130101; A61C 7/08 20130101; A63B
71/085 20130101; A61C 7/14 20130101; B29C 65/08 20130101; B29C
51/00 20130101; B29C 64/112 20170801; B33Y 10/00 20141201 |
International
Class: |
A61C 7/08 20060101
A61C007/08; A61C 7/14 20060101 A61C007/14; A61C 7/36 20060101
A61C007/36; A61F 5/56 20060101 A61F005/56 |
Claims
1. A dental appliance comprising: an interior shape that
substantially conforms to a dental arch of a patient; a hollow
portion forming a cavity; and an object bonded to the dental
appliance and inserted into the cavity, wherein the object provides
structural strength to the dental appliance at a location of the
hollow portion and does not interfere with a fit of the dental
appliance onto the dental arch of the patient.
2. The dental appliance of claim 1 further comprising: a slot in
the dental appliance at a location of the hollow portion, wherein
the slot is configured to receive and retain a sphere attached to
an end of a rod.
3. The dental appliance of claim 1 further comprising: a hole or
slot in the dental appliance at a location of the hollow portion,
wherein one or more additional objects are insertable into the
cavity in the dental appliance through the hole or slot.
4. The dental appliance of claim 1, wherein the dental appliance is
configured to be worn in a mouth of the patient to alter, while the
dental appliance is worn in the mouth, contact points between a
first portion and a second portion of the dental arch of the
patient.
5. The dental appliance of claim 1, wherein the object is a
preformed object that substantially conforms to a shape or contour
of the cavity.
6. The dental appliance of claim 1, wherein the object has a first
surface that has a first shape that substantially matches first
contours of walls of the hollow portion that form the cavity, and
wherein the object has a second surface that has a second shape
that substantially matches second contours of at least a portion of
one or more teeth of the dental arch.
7. The dental appliance of claim 1, wherein the object is bonded to
the dental appliance using one or more of laser welding or
ultrasonic welding.
8. A dental appliance comprising: an interior shape that
substantially conforms to a first dental arch of a patient; a
hollow portion forming a cavity; and an object bonded to the dental
appliance and inserted into the cavity, wherein: the object
comprises a first surface shaped to fit into the cavity of the
hollow portion; the object further comprises a second surface
configured to facilitate fit of the dental appliance onto the first
dental arch of the patient; and the object corresponds to a first
feature shaped to reposition a jaw of the patient.
9. The dental appliance of claim 8 further comprising: a slot in
the dental appliance at a location of the hollow portion, wherein
the slot is configured to receive and retain a sphere attached to
an end of a rod.
10. The dental appliance of claim 8 further comprising: a hole or
slot in the dental appliance at a location of the hollow portion,
wherein one or more additional objects are insertable into the
cavity in the dental appliance through the hole or slot.
11. The dental appliance of claim 8, wherein the dental appliance
is configured to be worn in a mouth of the patient to alter, while
the dental appliance is worn in the mouth, contact points between a
first portion and a second portion of the first dental arch of the
patient.
12. The dental appliance of claim 8, wherein the object is a
preformed object that substantially conforms to a shape or contour
of the cavity.
13. The dental appliance of claim 8, wherein the first surface has
a first shape that substantially matches first contours of walls of
the hollow portion that form the cavity, and wherein the second
surface has a second shape that substantially matches second
contours of at least a portion of one or more teeth of the first
dental arch.
14. The dental appliance of claim 8, wherein the object is bonded
to the dental appliance using one or more of laser welding or
ultrasonic welding.
15. The dental appliance of claim 8, wherein the object is shaped
to engage a second feature on a second dental arch of the
patient.
16. The dental appliance of claim 8, wherein the object is
positioned on a buccal region of the dental appliance.
17. The dental appliance of claim 8, wherein the object is shaped
to provide bite stabilization to address contact between the first
dental arch and a second dental arch of the patient.
18. The dental appliance of claim 8, wherein the object is shaped
to increase bite separation between the first dental arch and a
second dental arch of the patient.
19. The dental appliance of claim 8, wherein the object is shaped
to alter one or more occlusal contacts between the first dental
arch and a second dental arch of the patient.
20. The dental appliance of claim 8, wherein the dental appliance
comprises an aligner including a plurality of tooth-receiving
cavities shaped to receive and resiliently reposition teeth on the
first dental arch.
21. A dental appliance comprising: an interior shape that
substantially conforms to a dental arch of a patient; a hollow
portion forming a cavity; and means for providing structural
strength to the dental appliance at a location of the hollow
portion without interfering with a fit of the dental appliance onto
the dental arch of the patient, wherein the means for providing
structural strength is bonded to the dental appliance.
Description
RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 15/199,598, filed Jun. 30, 2016, which is
incorporated by reference herein.
TECHNICAL FIELD
[0002] Embodiments of the present invention relate to the field of
orthodontics and dentistry and, in particular, to plastic
orthodontic aligners and other plastic shells
BACKGROUND
[0003] For some applications, shells are formed around molds to
achieve a negative of the mold. The shells are then removed from
the molds to be further used for various applications, One example
application in which a shell is formed around a mold and then later
used is corrective dentistry or orthodontic treatment. In such an
application, the mold is of a dental arch for a patient and the
shell is an aligner to be used for aligning one or more teeth of
the patient.
[0004] One challenge with molds used to form shells is the
subsequent removal of the shells from the molds. In order to ensure
that a shell will be removable from a mold without damaging or
permanently deforming the shell, the shapes and types of features
that are included in the mold may be limited. For example, features
with significant undercuts (also referred to as negative
inclination) and/or complex features may impair the removal of the
shell from the mold.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention is illustrated by way of example, and
not by way of limitation, in the figures of the accompanying
drawings.
[0006] FIG. 1A illustrates an orthodontic aligner and a mold, in
accordance with one embodiment.
[0007] FIG. 1B illustrates an orthodontic aligner and a dental
arch, in accordance with one embodiment.
[0008] FIG. 2A illustrates a cross sectional side view of a plastic
shell over a mold, in accordance with one embodiment.
[0009] FIG. 2B illustrates a cross sectional side view of the
plastic shell of FIG. 2A removed from the mold, in accordance with
one embodiment.
[0010] FIG. 2C illustrates a perspective view of a portion of the
plastic shell of FIG. 2B, in accordance with one embodiment.
[0011] FIG. 2D illustrates a cross sectional side view of the
plastic shell of FIG. 2B after a cavity of a hollow feature has
been filled by a filler, in accordance with one embodiment.
[0012] FIG. 2E illustrates a cross sectional side view of the
plastic shell of FIG. 2B after the plastic shell has been placed
over a second mold, in accordance with one embodiment.
[0013] FIG. 2F illustrates a cross sectional side view of the
plastic shell of FIG. 2B after the plastic shell has been placed
over a second mold and a cavity in a hollow feature of the plastic
shell has been filled by a filler, in accordance with one
embodiment.
[0014] FIG. 3A illustrates a mold of a dental arch and an object
that fits over the mold, in accordance with one embodiment.
[0015] FIG. 3B illustrates a cross sectional side view of a plastic
shell formed over the mold of FIG. 3A, in accordance with one
embodiment.
[0016] FIG. 3C illustrates a cross sectional side view of the
plastic shell of FIG. 3B after it is has been removed from the
mold, in accordance with one embodiment.
[0017] FIG. 4 illustrates a cross sectional side view of a plastic
shell formed over a mold similar to the mold of FIG. 3A, in
accordance with one embodiment.
[0018] FIG. 5A illustrates a cross sectional side view of
compressed mesh being placed into a cavity of a plastic shell, in
accordance with one embodiment.
[0019] FIG. 5B illustrates a cross sectional side view of an mesh
being in the cavity of the plastic shell of FIG. 5A, in accordance
with one embodiment.
[0020] FIG. 6A illustrates cross sectional views of a ball inserted
into a feature of a plastic shell, in accordance with one
embodiment.
[0021] FIG. 6B illustrates cross sectional views of a ball ended
rod into a feature of a plastic shell, in accordance with one
embodiment.
[0022] FIG. 7A illustrates views of an object inserted into a
feature of a plastic shell, in accordance with one embodiment.
[0023] FIG. 7B illustrates a cross sectional view of an object
inserted into a feature of a plastic shell, in accordance with one
embodiment.
[0024] FIG. 7C illustrates a perspective view of the object
inserted into the feature of the plastic shell of FIG. 7B, in
accordance with one embodiment.
[0025] FIG. 8A illustrates a cross sectional side view of a plastic
shell on a dental arch, in accordance with one embodiment.
[0026] FIG. 8B illustrates a cross sectional side view of pair of
plastic shells on upper and lower dental arches, in accordance with
one embodiment.
[0027] FIG. 8C illustrates a back view of an upper and lower dental
arch, in accordance with one embodiment.
[0028] FIG. 8D illustrates a back view of plastic shells on the
upper and lower dental arches of FIG. 8C, in accordance with one
embodiment.
[0029] FIG. 9 illustrates a flow diagram of one embodiment for a
method of orthodontic treatment using a sequence of aligners.
[0030] FIG. 10 illustrates a flow diagram of one embodiment for a
method of manufacturing plastic shell having hollow feature that is
at least partially filled by an object.
[0031] FIG. 11 illustrates a flow diagram of another embodiment for
a method of manufacturing plastic shell having hollow feature that
is at least partially filled by an object.
[0032] FIG. 12 illustrates a flow diagram of an embodiment for a
method of filling a cavity in a hollow feature of a plastic
shell.
[0033] FIG. 13 illustrates a block diagram of an example computing
device, in accordance with embodiments of the present
invention.
DETAILED DESCRIPTION
[0034] There are numerous orthodontic appliances that are
traditionally used to correct different patient dental conditions.
These various types of orthodontic appliances may be used to
correct different types and severities of malocclusion (defined as
abnormal alignment of the teeth and the way that the upper and
lower teeth fit together). For example, orthodontic brackets (also
known as braces) may be used with wires to correct some types of
malocclusions. Conventional plastic orthodontic aligners may also
be used to correct some types of malocclusions. However, some
malocclusions may not be treatable using braces or conventional
plastic orthodontic aligners. Additionally, some malocclusions may
be treatable, but treatment of these malocclusions using current
techniques for manufacturing plastic orthodontic aligners may
introduce undesirable tradeoffs. For example, some aligner features
for mandibular repositioning may have lower strength as compared to
a twin block. For such malocclusions, additional orthodontic
appliances that may be used on a patient include headgear,
expansion appliances (e.g., a palatal expander), spacers, bite
plates, Carrier.RTM. Distalizers.TM., functional appliances (e.g.,
an Andresen appliance, a Bionator, a Hawley retainer, a twin block,
a Herbst appliance, a Forsus appliance, etc.), and so on.
Additionally, other types of dental appliances may be used on
patients for the treatment of sleep apnea and other conditions.
[0035] Current plastic aligners may introduce tradeoffs when used
to correct malocclusions that are traditionally corrected through
the use of some of the aforementioned additional orthodontic
appliances. For example, current plastic aligners may be
susceptible to crushing when used for some geometries such as large
undercuts or complex features. Described herein are embodiments of
orthodontic aligners having features that enable the orthodontic
aligners to apply forces to correct malocclusions that would
traditionally be treated using one or more of the aforementioned
additional orthodontic appliances. These features may be hollow
features that would ordinarily be susceptible to being crushed.
Additionally, the features may have shapes (e.g., large undercuts)
that do not permit separation of the orthodontic aligner from a
mold that it is formed over at a location of the feature.
Accordingly, in embodiments cavities of the features are at least
partially filled with objects that may provide structural strength
to the features to prevent them from being crushed or otherwise
damaged. Insertion of the objects into the hollow features may
additionally or alternatively improve hygiene associated with the
plastic aligner. The objects may also provide other benefits and/or
perform other functions in addition to or instead of providing
structural strength. For example, objects of different sizes may be
inserted into holes in the features to adjust a patient's bite.
Ball ended rods (also referred to herein as rods with attached
spheres) may also be placed into holes and/or slots in the features
to control articulation of a patient's jaw. The features and
objects may also be used for numerous other purposes, such as jaw
repositioning, to create joints in the plastic aligner, to alter
mechanical properties of the plastic aligner, to alter occlusal
contacts, to treat temporomandibular joint disorder (TMD), to
enable linkages and/or locks to be applied to plastic aligners, and
so on.
[0036] An orthodontic aligner as described herein may be included
in a series of orthodontic aligners so as to provide an orthodontic
system for positioning teeth. Such an orthodontic system can
include a sequence of orthodontic aligners each including a shell
(e.g., a plastic shell) having a one or more regions shaped to
receive at least portions of teeth. The orthodontic aligners may be
successively worn by a patient to move one or more teeth from a
first arrangement to a second arrangement. One or more of the
orthodontic aligners may include hollow features that are at least
partially filled with additional objects.
[0037] Embodiments are discussed herein with regards to orthodontic
aligners. However, embodiments discussed with reference to
orthodontic aligners are also applicable to other shells that are
used for other purposes, such as orthodontic retainers, orthodontic
splints, shells to be used as night guards, shells that are to be
used to treat sleep apnea, and so on. Accordingly, it should be
understood that any reference to orthodontic aligners also applies
to other types of shells (e.g., other types of shells such as
orthodontic retainers, orthodontic splints, or other shells that
fit onto a patient's teeth but that do not reposition the patient's
teeth or jaw).
[0038] Turning now to the drawings, FIG. 1A illustrates an example
orthodontic aligner 100, which is a tooth and/or jaw repositioning
appliance that can be worn by a patient in order to achieve an
incremental repositioning of individual teeth in the jaw. The
orthodontic aligner 100 can include a shell (e.g., a translucent
polymeric shell) having teeth-receiving cavities that receive and
resiliently reposition the teeth. The orthodontic aligner 100 or
portion(s) thereof may be indirectly fabricated using a physical
model or mold 115 of a dental arch including the teeth. For
example, an orthodontic aligner can be formed using a physical mold
115 and a sheet of suitable layers of polymeric material. In some
instances, an orthodontic aligner 100 is directly fabricated, e.g.,
using rapid prototyping fabrication techniques, from a digital
model of an aligner.
[0039] One or more features 120 may be added to the mold 115 that
do not represent a patient's teeth. These may be referred to as
non-native features, and do not reflect any portion of the
patient's dental arch. The feature 120 may be added to a digital
representation of the mold 115, and the mold 115 may be fabricated
to include the feature 120. Alternatively, the mold 115 may be
fabricated without the feature 120 and the feature 120 may be
attached to the mold 115 after the mold 115 is manufactured. Many
different types of features may be added, one of which is
illustrated in FIG. 1A. Features 120 may have any imaginable shape,
size, orientation, etc. that is appropriate for insertion into a
patient's mouth.
[0040] In some embodiments, the mold 115 may be fabricated with a
registration feature. In such embodiments the feature 120 may be an
object that is attached to the mold via the registration
feature.
[0041] The orthodontic aligner 100 that is formed over the mold 115
has a shape that conforms to the mold 115. Since the mold 115 is
based on a dental arch of the patient, the orthodontic aligner 100
may also conform to and fit over the patient's dental arch. The
orthodontic aligner 100 includes a hollow feature 110 having a
size, shape, location and orientation based on the feature 120. The
hollow feature 110 may be used for many different purposes, such as
to apply forces appropriate to perform the operations of one or
more of the aforementioned additional orthodontic appliances. In
order to improve a structural strength of the hollow feature 110,
the feature 120 may detach from the mold 115 and remain inside of
the hollow feature 110 in the orthodontic aligner 100 when the
orthodontic aligner 100 is removed from the mold 115.
Alternatively, an additional object may be inserted into a cavity
in the hollow feature 110 after the orthodontic aligner 100 is
removed from the mold 115 to at least partially fill the
cavity.
[0042] FIG. 1B illustrates an orthodontic aligner 100 and a dental
arch 140 of a patient, in accordance with one embodiment. After the
orthodontic aligner 100 has been formed and an object has been
inserted into or retained in the orthodontic aligner 100, the
orthodontic aligner 100 may be positioned onto the dental arch 140
of the patient. The orthodontic aligner 100 can fit over all teeth
present in an upper or lower jaw, or less than all of the teeth.
The orthodontic aligner 100 can be designed specifically to
accommodate the teeth of the patient (e.g., the topography of the
tooth-receiving cavities matches the topography of the patient's
teeth), and may be fabricated based on positive or negative models
of the patient's teeth generated by impression, scanning, and the
like. Alternatively, the orthodontic aligner 100 can be a generic
aligner configured to receive the teeth, but not necessarily shaped
to match the topography of the patient's teeth.
[0043] In some cases, only certain teeth received by an orthodontic
aligner will be repositioned by the orthodontic aligner while other
teeth can provide a base or anchor region for holding the appliance
in place as it applies force against the tooth or teeth targeted
for repositioning. In some cases, many or most, and even all, of
the teeth will be repositioned at some point during treatment.
Teeth that are moved can also serve as a base or anchor for holding
the orthodontic aligner as it is worn by the patient. Typically, no
wires or other means will be provided for holding an aligner in
place over the teeth. In some cases, however, it may be desirable
to provide individual attachments or other anchoring elements (not
shown) on teeth with corresponding receptacles or apertures (not
shown) in the orthodontic aligner 100 so that the orthodontic
aligner can apply a selected force on the tooth.
[0044] As shown, the orthodontic aligner 100 includes a hollow
feature 110 that is at least partially filled with an object (not
shown). The object is shaped so as not to interfere with a fit of
the orthodontic aligner 100 over the dental arch of the patient. As
shown, the patient's dental arch 140 does not include the feature
120 that was used to create hollow feature 110. Instead, the dental
arch 140 includes a crown 150 of a tooth at a location
corresponding to the location of the feature 120. The object inside
of the hollow feature 110 may have a shape that conforms to a
contour of the crown 150. Alternatively, the object may be slightly
recessed into the hollow feature and may not contact the crown 150
when the orthodontic aligner 100 is positioned onto the patient's
dental arch 140.
[0045] FIGS. 2A-7C illustrate numerous examples of plastic shells
such as plastic orthodontic aligners that have hollow features with
cavities that are at least partially filled with an object. The
object may be separate from the plastic shell, but may be secured
to the plastic shell by friction, a mechanical registration
feature, a bond or weld, or other mechanism. The object may be made
of the same material as the plastic shell or of a different
material than the plastic shell. For example, the object may be a
different type of plastic from the plastic shell. The object may
also be, for example, metal, a ceramic, dental cement, a dental
composite material, a two phase polymer, epoxy, and so on. The
object may be a solid object (e.g., lacking gaps or voids), may be
a mesh (e.g., a wire mesh), or may be a frame having struts,
webbing, etc. The objects may be custom or stock prefabricated
objects or may be objects that were injected into the cavities of
the hollow features as a liquid phase and then solidified to form
the objects.
[0046] FIGS. 2A-2F illustrate various embodiments of a plastic
shell having a hollow feature that is at least partially filled
using a liquid phase material that is then cured to transform the
liquid phase material into a solid phase material. FIG. 2A
illustrates a cross sectional side view of a plastic shell 205 over
a mold 210, in accordance with one embodiment. The mold 210
includes a feature 208 that does not correspond to any region of a
patient's dental arch. FIG. 2B illustrates a cross sectional side
view of the plastic shell 205 of FIG. 2A removed from the mold 210,
in accordance with one embodiment. As shown, the plastic shell 205
includes a hollow feature 215 having a cavity 218, the hollow
feature 215 having been formed as a result of forming the plastic
shell 205 over feature 208. FIG. 2C illustrates a perspective view
of a portion of the plastic shell 205 of FIG. 2B including the
hollow feature 215, in accordance with one embodiment.
[0047] FIG. 2D illustrates a cross sectional side view of the
plastic shell 205 of FIG. 2B after the cavity 218 of the hollow
feature 215 has been filled by a filler 220, in accordance with one
embodiment. The filler 220 may be injected into the cavity 218 from
an underside of the plastic shell 205. Enough of the filler 220 may
be injected into the cavity 218 to substantially fill the cavity
218 without interfering with a fit of the plastic shell 205 onto a
patient's tooth (e.g., without interfering with the occlusal
surface of a crown underlying the hollow feature 215 when the
plastic shell 205 is worn by the patient).
[0048] The filler 220 may be a two phase material that is in a
liquid phase when injected into the cavity 218. The filler 220 may
then be cured to transform the liquid phase material into a solid
phase material. Examples of materials that may be used include a
two phase plastic, an epoxy, dental cement, a dental composite, and
so on. Depending on the material used for the filler 220, the
liquid phase material may be cured by application of heat,
ultraviolet (UV) light, air, pressure, and so on. Some materials
such as epoxy may start as two separate liquids that are mixed and
that automatically transform into a solid a predetermined amount of
time after the mixing. The cavity 218 may have a shape with one or
more undercuts, ledges, lips, knurling or other features that will
cause the filler 220 (which becomes an object when cured) to be
mechanically interlocked with the hollow feature 215. Thus, the
filler 220 may not be removable from the plastic shell 205 after
the filler 220 is transformed into the solid phase.
[0049] FIG. 2E illustrates a cross sectional side view of the
plastic shell 205 of FIG. 2B after the plastic shell 205 has been
placed over a second mold 225, in accordance with one embodiment.
In some instances it may be desirable for a shape of the object
formed in the cavity 218 of the hollow feature 215 to conform to a
contour of a tooth crown that will underlie the hollow feature 215.
Accordingly, the plastic shell 205 may be placed onto the second
mold 225.
[0050] The second mold 225 may be substantially similar to the mold
210 used to form the plastic shell 205. However, the second mold
225 may not include the feature that caused the hollow feature 215
to be formed. Instead, the second mold 225 may have the shape of a
crown at a location corresponding to the location of the feature in
the mold 210.
[0051] A hole 235 may be drilled into the hollow feature 215. The
hole 235 may terminate at the cavity 218. A syringe 238 or other
applicator may be used to inject a liquid phase material (filler)
into the cavity 218 through the hole. The liquid phase material may
be injected to fill the cavity 218. The filler may conform to a
shape of the crown of the mold 225. Thus, the object formed from
the filler after curing may conform to a contour of a tooth crown
of the patient. In one embodiment, a liner 230 is placed between
the mold 225 and the cavity 218. The liner 230 may be a non-stick
coating, a thin plastic or other liner that may be applied to the
mold 225 prior to insertion of the mold 225 into the plastic shell
205. The liner 230 may prevent the filler from bonding to the mold
225.
[0052] FIG. 2F illustrates a cross sectional side view of the
plastic shell 205 of FIG. 2B after the plastic shell 205 has been
placed over a second mold 225 and a cavity 218 in a hollow feature
215 of the plastic shell 205 has been filled by a filler 220, in
accordance with one embodiment. In the embodiment shown in FIG. 2F
an inflatable bladder 240 has been inserted into the cavity 218
prior to insertion of the mold 225 into the plastic shell 205. The
filler 220 may be injected into the inflatable bladder 240, causing
the inflatable bladder 240 to fill the cavity 218 and conform to a
shape of the cavity 218 and of a tooth crown of the mold 225. The
filler 220 may be injected through a hole similar to hole 235. By
injecting the filler 220 into the bladder 240, the filler 220 may
be prevented from leaking into regions outside of the cavity 218.
Additionally, the bladder 240 may prevent the filler 220 from
bonding to the mold 225. The inflatable bladder 240 may be a
plastic, rubber, latex, vinyl, or other material.
[0053] For the embodiments discussed with reference to FIGS. 2A-2F,
an inside of the cavity 218 may be coated with an adhesive prior to
injecting filler 220 into the cavity 218. The adhesive may be a
light curable adhesive (e.g., an epoxy that is cured using
ultraviolet light), a heat activated adhesive, a time activated
adhesive, or other type of adhesive. Alternatively, or
additionally, a laser welding or ultrasonic welding process may be
performed to bond or weld the object formed from the filler 220 to
the plastic shell 205. For example, if the filler 220 is a two
phase plastic, then the laser welding or ultrasonic welding may
melt the object and the plastic shell 205 at an interface between
the object and the plastic shell 205. Melted portions of the object
and plastic shell 205 may re-harden in a bonded or fused state.
[0054] FIGS. 3A-4 illustrate various embodiments of a plastic shell
that is formed over an object and mold and that retains that object
inside of a feature of the plastic shell when the plastic shell is
removed from the mold. FIG. 3A illustrates a mold 305 of a dental
arch and an object 310 that fits onto the mold 305, in accordance
with one embodiment. In the illustrated embodiment the object 310
is a stock (also referred to as standard or universal)
prefabricated object. The object 310 may be plastic, metal,
ceramic, carbon fiber, or other materials. Patient customization
may be satisfied using the stock object 310 by controlling the
position and orientation of the object 310 and by selecting an
appropriately sized and/or shaped prefabricated object 310. The
object 310 may be selected from a selection of numerous
prefabricated objects of varying shapes and sizes so as to form a
feature in a plastic shell formed over the mold 305 and object 310
that will perform a particular desired function (e.g., to apply a
desired force).
[0055] The mold 305 is a mold of a patient's dental arch (or a
portion of the patient's dental arch). The mold 305 may be
manufactured based on a digital model of the patient's dental arch
(e.g., printed using rapid prototyping or three-dimensional (3D)
printing) or based on an impression. The mold 305 includes one or
more registration features 315. The registration features 315 may
be added to the digital model prior to manufacturing the mold. The
registration features 315 may be automatically selected and placed
onto the digital model based on a treatment plan for the patient.
Alternatively, the registration features 315 may be selected and
placed into the digital model by a technician.
[0056] A registration feature 315 is used to register an object 310
to the mold and to retain that object 310 on the mold 305 during
the formation of a plastic shell over the mold 305 and object 310.
The object 310 may include an additional registration feature 322
that is shaped to mate with (e.g., to slide over and/or rest on)
the registration feature 315. The size and shape of the
registration feature 315 and/or registration feature 322 may be at
least partially dependent on the size and shape of the object 310
to be placed on the registration feature 315. Examples of
registration features 315, 322 include dovetail ways, grooves,
projections, flat regions (e.g., landing pads), and so on.
[0057] FIG. 3B illustrates a cross sectional side view of a plastic
shell 320 formed over the mold 305 of FIG. 3A, in accordance with
one embodiment. As shown, the plastic shell 320 is formed over the
mold 305 and over the object 310. The formation of the plastic
shell 320 over the object 310 causes the plastic shell to have a
feature 325. The feature 325 would be a hollow feature with a
cavity 330 were the object 310 to be removed from the feature 325.
Since the plastic shell is formed (e.g., thermoformed) over the
object 310, the feature has a contour that matches a shape of the
object 310.
[0058] FIG. 3C illustrates a cross sectional side view of the
plastic shell 320 of FIG. 3B after the plastic shall 320 has been
removed from the mold 305, in accordance with one embodiment. As
shown, the feature 325 of the plastic shell 320 that is formed over
the object 310 is shaped such that removal of the object 310 from
the plastic shell 320 may be difficult or unobtainable. For
example, the object 310 may be tapered in a manner that causes the
plastic shell 320 to mechanically interlock with the object 310.
The object 310 may additionally or alternatively include retentions
features such as ridges, lips, knurling, tapering, etc. to
mechanically interlock the object 310 with the plastic shell 320.
The feature retains the object 310 inside of the cavity 330 in the
feature 325 when the plastic shell 320 is removed from the mold
305. Thus, the object 310 may be a permanent part of the plastic
shell 320.
[0059] FIG. 4 illustrates a cross sectional side view of a plastic
shell 420 formed over a mold 405 similar to the mold 305 of FIG.
3A, in accordance with one embodiment. As shown, the mold 405
includes a registration feature 418. A custom shaped object 435
having another registration feature 422 is attached to the mold 405
by mating the registration feature 418 of the mold with the
registration feature 422 of the object 435. Alternatively,
registration features may not be used. A plastic shell 420 is
formed over the mold 405 and custom shaped object 435. When the
plastic shell 420 is removed from the mold 405, the object 435 may
be retained inside of a cavity 430 in a feature 425 of the plastic
shell 420.
[0060] The object 435 may have one or more custom faces 440 or
sides that are shaped to conform to a unique shape of a patient's
tooth. Thus, the object 435 may have a size and/or shape that are
determined for use on the patient. The custom shaped object 435 may
be manufactured by generating a 3D model of the custom shaped
object and then using a 3D printing or rapid prototyping process to
print the custom shaped object 435. In one embodiment, a technician
selects a stock object and a location on a 3D model of a patient's
dental arch where the object is to be placed. Processing logic may
then determine contours for one or more faces of the stock object
to convert the stock object into a custom object. Alternatively,
the custom shaped object 435 may be manually sculpted onto the mold
405. For example, a mold for the object may be filled with a
pliable material and then pressed against the mold 405 to manually
sculpt one or more faces of the custom shaped object 435.
[0061] The embodiments discussed with reference to FIGS. 3A-4 have
objects that are separate from a mold that the objects are then
attached to. Additionally or alternatively an object may be a
feature of a mold that has a breakable region. The breakable region
may break when the plastic shell is removed from the mold, and the
object may be retained inside of the plastic shell. Thus, a portion
of the mold 305 may separate from a remainder of the mold and may
be permanently retained inside of the plastic shell.
[0062] For the embodiments discussed with reference to FIGS. 3A-4,
the object 310, 435 may be coated with an adhesive prior to forming
the plastic shell 320, 420 over the object 310, 435. Alternatively,
or additionally, a laser welding or ultrasonic welding process may
be performed to bond or weld the object 310, 435 to the plastic
shell 320, 420. For example, if the object 310, 435 is a plastic,
then the laser welding or ultrasonic welding may melt the object
310, 435 and the plastic shell 320, 420 at an interface between the
object and the plastic shell. Melted portions of the object and
plastic shell may re-harden in a bonded state.
[0063] FIG. 5A illustrates a cross sectional side view of
compressed mesh 510 being placed into a cavity 515 of a plastic
shell 505, in accordance with one embodiment. The plastic shell 505
has a hollow feature 520 that may have been formed in a similar
manner as described with reference to FIGS. 2A-2B. However rather
than filling the cavity 515 in the hollow feature 520 with a
curable liquid material, the compressed mesh 510 may be inserted
into the cavity 515. The compressed mesh 510 may be compressed, for
example, by a retaining sleeve.
[0064] FIG. 5B illustrates a cross sectional side view of an
expanded mesh 525 in the cavity 515 of the plastic shell 505 of
FIG. 5A, in accordance with one embodiment. The compressed mesh 510
may be spring-loaded and under force to expand. After the
compressed mesh 510 has been inserted into the cavity 515, the mesh
may expand into expanded mesh 525. If a retaining sleeve is used to
compress the mesh, then the retaining sleeve may be removed after
the mesh is inserted into the cavity 515 to enable the mesh to
expand. The cavity 515 may be shaped to have a taper or other
retention feature that will retain the expanded mesh 525 inside of
the cavity 515. In one embodiment, the cavity 515 has a lip or
ledge 518 that retains the expanded mesh 525 within the cavity
515.
[0065] FIG. 6A illustrates cross sectional views of a sphere 620 at
an end of a rod 618 inserted into a feature 610 of a plastic shell
605, in accordance with one embodiment. The feature 610 may be a
hollow feature in some embodiments. The feature 610 may include a
hole 612 and a slot 635. The hole 612 may be sized to enable the
sphere 620 to fit into the hole 612 and may be positioned at a
first side of the feature 610. For example, the hole 612 may have
the same diameter or a slightly larger diameter than a diameter of
the sphere. The slot 635 may have a width that is approximately
equal to a thickness of the rod 618. The slot 635 may extend from
the hole 612 to a second end of the feature 610.
[0066] The sphere 620 can be inserted into the hole 612 at the
first end of the feature 610, and then the rod 618 and attached
sphere 620 be moved to the second end of the feature 610. While the
rod 618 and sphere 620 are at the second end of the feature 610,
the sphere 620 is retained within the feature 610.
[0067] The feature 610 may be formed in the plastic shell 610
according to any of the aforementioned techniques for forming a
plastic shell having a hollow feature. The hole 612 and slot 635
may then be cut into the feature after the plastic shell 605 is
formed.
[0068] In one embodiment, an object (not shown) is inserted into
the feature 610 as previously described above. The object may be a
prefabricated object that includes a hole and slot that may
substantially match the hole 612 and slot 635. By cutting the hole
612 and slot 635 into the feature 610 of the plastic shell 605,
access may be gained to the corresponding hole and slot in the
object. Alternatively, the plastic shell 610 may be thermoformed
over an object having deep recessions and a concave geometry to
cause feature 610 to be created with the hole 612 and slot 635. For
example, the object may have a hole and slot, and by thermoforming
the plastic shell 610 over the object, the plastic shell 610 may
form the feature 610 also having the hole 612 and slot 635.
[0069] In one embodiment, the feature 610 is tapered such that the
second end has a greater height than the first end that includes
the hole 612. The sphere 620 may be inserted into the feature 610
prior to the plastic shell 605 being worn by a patient. Once the
plastic shell 605 with the inserted sphere 620 is placed on the
patient's dental arch, the patient's teeth 615 may physically
prevent the sphere 620 and attached rod 618 from being removed from
the plastic shell 605.
[0070] FIG. 6B illustrates cross sectional views of a rod 630 with
attached spheres inserted into features of two plastic shells 605,
640, in accordance with one embodiment. Plastic shell 605 may be
placed over a patient's upper teeth and plastic shell 640 may be
placed over the patient's lower teeth after the spheres at the ends
of the rod have been respectively inserted into the plastic shells
605, 640. In the illustrated example, the patient's upper jaw may
be fixed, while the patient's lower jaw may be free to open and
advance but not free to retract. Thus, the rod 630 may act as a
linkage between plastic shell 605 and plastic shell 640, and may
restrict the articulation or motion of the patient's jaw.
[0071] Though FIGS. 6A-6B describe the insertion of spheres at the
end of rods into holes and/or slots in the plastic shells, at least
portions of other types of objects may also be inserted into slots
and/or holes in the plastic shells. The slots or holes may be
generally used as registration features for insertion of objects.
Such objects may have a structure or feature that mates with the
hole and/or slot that is cut into the shell. A ball ended rod as
described above is one type of joint that may be implemented. The
ball ended rod is one example of a three degree of freedom hinge
joint. Other 1 degree of freedom or 2 degree of freedom hinge
joints may also be implemented. Other types of joints to control
articulation of the jaw may also be implemented. For example, the
feature 610 may be or include a housing or socket for other joints
such as a sliding joint, a hinge joint, a friction fit joint, a
dovetail joint, a flexural joint, and so on. For a sliding joint,
the object may include a track instead of a hole and/or slot that
act as a ball socket. A 1 degree of freedom sliding joint would
allow for protrusive-retrusive motions while constraining jaw
opening. The joints may be dynamic joints or static joints. Static
joints may be configured to receive a supplementary or replaceable
feature onto the aligner. Such supplementary or replaceable
features may be mandibular advancement or jaw positioning features,
compliance indicators, or other features.
[0072] FIG. 7A illustrates views of an object 715 inserted into a
feature 705 of a plastic shell 748, in accordance with one
embodiment. The feature 705 may be formed using any of the
techniques as discussed above. After the plastic shell 748 having
the feature 705 is formed, a slot 710 is cut into the feature, such
as by laser cutting or mechanical cutting. An object 715 may then
be inserted into the feature 705 through the slot. The object may
have a particular height and/or shape to perform a desired function
with regards to a patient's mouth, jaw and/or teeth. In the
illustrated example the object 715 is a shim usable to open a
patient's bite. The object 715 may be removable from the feature
705, and another object (not shown) having a different size and/or
shape may be inserted into the slot 710. Thus, a single plastic
shell 748 may be used to perform, for example, multiple different
adjustments which traditionally might require multiple different
plastic shells.
[0073] FIG. 7B illustrates a cross sectional view of multiple
objects inserted into a feature 750 of a plastic shell 756, in
accordance with one embodiment. In the illustrated example, the
objects 760 line up with a feature 770 in another plastic shell
752. For example, plastic shell 756 may be for an upper arch of a
patient and plastic shell 752 may be for a lower arch of the
patient. The objects 760 and feature 770 may control a resting bite
position of a patient's jaw, for example. The plastic shell with
the objects 760 may be used, for example, for jaw repositioning of
a patient.
[0074] FIG. 7C illustrates a perspective view of one of the objects
760 inserted into the feature 750 of the plastic shell 756 of FIG.
7B, in accordance with one embodiment. The feature 750 may be
formed using any of the techniques as discussed above. After the
plastic shell 756 having the feature 750 is formed, a hole 755 is
cut into the feature such as by laser cutting or mechanical
cutting. An object 760 may then be inserted into the feature 750
through the hole. The object 760 may clip onto or otherwise
mechanically interlock with the feature 750. The object 760 may
have a particular length and/or shape to perform a desired function
with regards to a patient's mouth, jaw and/or teeth. The object 760
may be removable from the feature 750, and another object having a
different size and/or shape may be inserted into the hole 755.
Alternatively, or additionally, multiple objects 760 may be
inserted into and/or attached to the feature 750 (e.g., as shown in
FIG. 7B). In one embodiment, one or more of the objects 760 are
shaped to enable them to interlock with one another. A portion of
the object or objects 760 may stick out of the feature 750 in some
embodiments. Thus, a single plastic shell 756 may be used to
perform, for example, multiple different adjustments which
traditionally might require multiple different plastic shells.
[0075] In some embodiments the objects described with reference to
FIGS. 7A-7C may be attached to the plastic shells at some times and
removed from the plastic shells at other times. For example, a
patient may attach the objects to the plastic shells during the
night (e.g., before the patient goes to sleep) and remove the
objects from the plastic shells during the day (e.g., after the
patient wakes up in the morning).
[0076] The orthodontic aligners (and other plastic shells)
described herein can be used in combination with one or more
attachments mounted onto one or more of the teeth over which the
plastic shells are placed. Accordingly, the topography of the
plastic shells can be modified to accommodate the attachment (e.g.,
with a suitable receptacle for receiving the attachment). The
attachment can engage the plastic shells and/or elastics to
transmit repositioning forces to the underlying teeth.
Alternatively or in addition, the attachment can be used to retain
the plastic shell on the patient's teeth and prevent it from
inadvertently becoming dislodged. For example, teeth with no
undercuts (e.g., central teeth, lateral teeth) may benefit from an
attachment to ensure correct engagement of the plastic shell onto
the teeth, while teeth with natural undercuts (e.g., molars) may
not benefit from an attachment. The attachment can be mounted onto
any suitable portion of the tooth, such as on a buccal or lingual
surface of the tooth.
[0077] FIGS. 8A-8D illustrate plastic shells (e.g., orthodontic
aligners) having features that alter contact points between an
upper and lower dental arch of a patient. These plastic shells may
be used for bite stabilization (e.g., flat plane stabilization for
temporomandibular joint disorder (TMD), to address asymmetric
contact between teeth of a patient's upper and lower dental arch,
etc.), to increase bite separation, to reposition the jaw, to alter
occlusal contacts, and so on. These plastic shells may add
substantial volume in an inter-arch space between an upper dental
arch and a lower dental arch of a patient, which can make
manufacturing of these plastic shells challenging.
[0078] FIG. 8A illustrates a cross sectional side view of a plastic
shell 804 on a dental arch (second dental arch 808), in accordance
with one embodiment. As shown, the plastic shell 804 is being worn
on second dental arch 808 (the lower dental arch) and has an outer
surface that conforms to the contours 806 of at least some teeth in
the first dental arch 802 (the upper dental arch). An interior of
the plastic shell 804 additionally conforms to the contours 816 of
the teeth in the second dental arch 816. The plastic shell 804 may
provide equal contact points for all teeth in the first dental arch
802 and/or the second dental arch 808. Such a plastic shell 804 may
be used, for example, for TMD splints and/or anterior
deprogrammers.
[0079] To enable the plastic shell 804 to conform both to the
contours of the first arch 802 and the second arch 808, first mold
(not shown) may first be generated of the second arch 808. In one
embodiment, rather than the first mold having contours that match
the contours of the teeth in the second arch, the first mold may
have contours that correspond to the contours of the first arch 802
(the opposing arch). The first mold may have contours that conform
to a negative or inverse of the first arch 802 in one embodiment.
The plastic shell 804 may be thermoformed over the first mold to
cause an outer surface of the plastic shell 804 to match the
contours 806 of the first arch 802.
[0080] The plastic shell 804 may have a hollow feature 814 with a
cavity 812. The cavity 812 may be empty space between the teeth on
the second arch 808 and the inner surface of the plastic shell 804
when the plastic shell 804 is worn. An object 810 may be inserted
into the cavity 812 to fill the empty space. The object 810 may
have a first surface with a shape that matches contours of the
walls of the cavity 812. The object 810 may additionally have an
opposing second surface with a shape that matches the contours of
the teeth in the second arch 808.
[0081] In one embodiment, the object 810 is a preformed object that
is shaped to fit into the cavity 812. Alternatively, the object 810
may be formed from a two phase material that is injected into the
cavity 812 in a liquid phase and that is subsequently cured to
transform into a solid phase. In such an embodiment, the plastic
shell 804 may be placed onto a second mold (not shown) of the
second arch 808. The two phase material may then be injected into
the cavity through a hold in the plastic shell 804 and then cured.
Alternatively, the two phase material may be injected into the
cavity through a hole in the second mold.
[0082] In one embodiment, the first mold includes registration
features for receiving the object 810, and the object 810 is placed
onto the first mold using the registration features. The plastic
shell 804 may then be thermoformed over the first mold and the
object 810, and the object may be retained inside of the plastic
shell 804.
[0083] Any of the techniques and/or options discussed with
reference to FIGS. 1A-4 may be used to manufacture the plastic
shell 810 in embodiments.
[0084] FIG. 8B illustrates a cross sectional side view of pair of
plastic shells on upper and lower arches of a patient, in
accordance with one embodiment. In FIG. 8B a first plastic shell
824 is disposed on a first arch 822 (e.g., an upper arch). A second
plastic shell 834 is disposed on a second arch 828 (e.g., a lower
arch). The second plastic shell 834 includes a hollow feature 832
having a cavity 830. The hollow feature 832 may be, for example, a
bite ramp or an anterior guidance feature. The cavity 830 is filled
with an object 826. The second plastic shell 834 may be
manufactured using any of the techniques described herein.
[0085] FIG. 8C illustrates a back view of an upper and lower dental
arch of a patient, in accordance with one embodiment. As shown,
when the patient bites, a left side of a first dental arch 842 of
the patient and a second dental arch 844 of the patient close.
However, a right side of the first dental arch 842 and the second
dental arch 844 of the patient do not close, causing an open bit
846 on the right side.
[0086] FIG. 8D illustrates a back view of plastic shells on the
upper and lower dental arches of FIG. 8C, in accordance with one
embodiment. As shown, the first dental arch 842 includes a first
plastic shell 850 having a hollow feature 854 that bridges a gap
between the first dental arch 842 and the second dental arch 844 at
tooth 848 when the patient bites. The hollow feature 854 eliminates
the open bite 846 and balances contact points between the upper and
lower arches in posterior teeth while the first plastic shell 850
is worn. The hollow feature 854 includes a cavity 856 that is
filled with an object 852. The first plastic shell 850 may be
manufactured using any of the techniques described herein. As
shown, a second plastic shell 860 may additionally be worn over the
second dental arch 844.
[0087] FIG. 9 illustrates a flow diagram of one embodiment for a
method 900 of orthodontic treatment using a sequence of orthodontic
aligners. The method 900 can be practiced using any of the
orthodontic aligners or aligner sets described herein. In block
910, a first orthodontic aligner is applied to a patient's teeth in
order to reposition the teeth from a first tooth arrangement toward
a second tooth arrangement. The first orthodontic aligner may
include a hollow feature that is at least partially filled by an
object, as described herein above.
[0088] At block 920, a second orthodontic aligner is applied to the
patient's teeth in order to reposition the teeth from the second
tooth arrangement to a third tooth arrangement. The repositioning
of the teeth from the second arrangement to the third arrangement
may be accomplished using an additional orthodontic aligner or set
of aligners. The additional orthodontic aligner or set of aligners
may additionally include a hollow feature that is at least
partially filled by an object, as described above. Alternatively,
the second orthodontic aligner may be a standard orthodontic
aligner without a hollow feature that includes an inserted or
retained object. Accordingly, a traditional orthodontic aligner may
be used to reposition the teeth from the second arrangement to the
third arrangement.
[0089] The method 900 can be repeated using any suitable number and
combination of sequential orthodontic aligners in order to
incrementally reposition the patient's teeth from an initial
arrangement to a target arrangement. The orthodontic aligners can
be generated all at the same stage or in sets or batches (e.g., at
the beginning of a stage of the treatment), and the patient can
wear each orthodontic aligner until the pressure of each
orthodontic aligner on the teeth can no longer be felt or until the
maximum amount of expressed tooth movement for that given stage has
been achieved. Multiple different orthodontic aligners (e.g., a
set) can be designed and even fabricated prior to the patient
wearing any orthodontic aligner. After wearing an orthodontic
aligner for an appropriate period of time, the patient can replace
the current orthodontic aligner with the next orthodontic aligner
in the series until no more orthodontic aligners remain. The
orthodontic aligners are generally not affixed to the teeth and the
patient may place and replace the orthodontic aligners at any time
during the procedure (e.g., patient-removable orthodontic
aligners).
[0090] The final orthodontic aligner or several orthodontic
aligners in the series may have a geometry or geometries selected
to overcorrect the tooth arrangement. For instance, one or more
orthodontic aligners may have a geometry that would (if fully
achieved) move individual teeth beyond the tooth arrangement that
has been selected as the "final." Such over-correction may be
desirable in order to offset potential relapse after the
repositioning method has been terminated (e.g., permit movement of
individual teeth back toward their pre-corrected positions).
Over-correction may also be beneficial to speed the rate of
correction (e.g., an orthodontic aligner with a geometry that is
positioned beyond a desired intermediate or final position may
shift the individual teeth toward the position at a greater rate).
In such cases, the use of an orthodontic aligner can be terminated
before the teeth reach the positions defined by the orthodontic
aligner. Furthermore, over-correction may be deliberately applied
in order to compensate for any inaccuracies or limitations of the
orthodontic aligner.
[0091] FIG. 10 illustrates a flow diagram of one embodiment for a
method 1000 of manufacturing a plastic shell having a hollow
feature that is at least partially filled by an object. In some
embodiments, one or more operations of method 1000 are performed by
processing logic of a computing device. The processing logic may
include hardware (e.g., circuitry, dedicated logic, programmable
logic, microcode, etc.), software (e.g., instructions executed by a
processing device), firmware, or a combination thereof. For
example, one or more operations of method 1000 may be performed by
a computing device such as computing device 1301 of FIG. 13.
Additionally, some operations may be performed by a fabrication
machine based on instructions received from processing logic. Some
operations may alternately be performed by a user.
[0092] At block 1005 of method 1000, a shape is determined for a
mold of a dental arch for a patient. The shape may be determined by
digitally planning a current, intermediate or final target
arrangement of the patient's teeth, and fabricating a mold of a
dental arch that reflects that target arrangement. Alternatively,
the shape may be determined by taking an impression of a patient's
arch and generating a mold from the impression. Thus, the mold or
model can be generated from dental impressions or scanning (e.g.,
of the patient's intraoral cavity, of a positive or negative model
of the patient's intraoral cavity, or of a dental impression formed
from the patient's intraoral cavity).
[0093] Plastic shell fabrication or design can make use of one or
more physical or digital representations of the patient's teeth.
Representations of the patient's teeth can include representations
of the patient's teeth in a current arrangement, and may further
include representations of the patient's teeth repositioned in one
or more treatment stages. Treatment stages can include a desired or
target arrangement of the patient's teeth, such as a desired final
arrangement of teeth. Treatment stages can also include one or more
intermediate arrangements of teeth (e.g., planned intermediate
arrangements) representing arrangements of the patient's teeth as
the teeth progress from a first arrangement (e.g., initial
arrangement) toward a second or desired arrangement (e.g., desired
final arrangement).
[0094] In one embodiment, at block 1008 a digital representation of
a patient's teeth is received. The digital representation can
include surface topography data for the patient's intraoral cavity
(including teeth, gingival tissues, etc.). The surface topography
data can be generated by directly scanning the intraoral cavity, a
physical model (positive or negative) of the intraoral cavity, or
an impression of the intraoral cavity, using a suitable scanning
device (e.g., a handheld scanner, desktop scanner, etc.).
[0095] In one embodiment, at block 1009 one or more treatment
stages are generated based on the digital representation of the
teeth. The treatment stages can be incremental repositioning stages
of an orthodontic treatment procedure designed to move one or more
of the patient's teeth from an initial tooth arrangement to a
target arrangement. For example, the treatment stages can be
generated by determining the initial tooth arrangement indicated by
the digital representation, determining a target tooth arrangement,
and determining movement paths of one or more teeth in the initial
arrangement necessary to achieve the target tooth arrangement. The
movement path can be optimized based on minimizing the total
distance moved, preventing collisions between teeth, avoiding tooth
movements that are more difficult to achieve, or any other suitable
criteria.
[0096] One or more registration features may be added to a digital
model of the patient's dental arch for any of the stages of
treatment. The registration features may be added to enable the
mold to receive an object.
[0097] At block 1010, the mold is fabricated based on the
determined shape. This may include using a three-dimensional
virtual model of the dental arch with the included registration
features and sending instructions to a rapid prototyping machine
(e.g., a three-dimensional printer) to fabricate the mold. In one
embodiment, the mold is fabricated using a rapid prototyping
manufacturing technique. One example of a rapid prototyping
manufacturing technique is 3D printing. 3D printing includes any
layer-based additive manufacturing processes. A 3D printer may
receive an input of the 3D virtual model of the mold (e.g., as a
computer aided drafting (CAD) file or 3D printable file such as a
sterolithography (STL) file), and may use the 3D virtual model to
create the mold. 3D printing may be achieved using an additive
process, where successive layers of material are formed in
proscribed shapes. 3D printing may be performed using extrusion
deposition, granular materials binding, lamination,
photopolymerization, or other techniques.
[0098] In one embodiment, stereolithography (SLA), also known as
optical fabrication solid imaging, is used to fabricate an SLA
mold. In SLA, the mold is fabricated by successively printing thin
layers of a photo-curable material (e.g., a polymeric resin) on top
of one another. A platform rests in a bath of a liquid photopolymer
or resin just below a surface of the bath. A light source (e.g., an
ultraviolet laser) traces a pattern over the platform, curing the
photopolymer where the light source is directed, to form a first
layer of the mold. The platform is lowered incrementally, and the
light source traces a new pattern over the platform to form another
layer of the mold at each increment. This process repeats until the
mold is completely fabricated. Once all of the layers of the mold
are formed, the mold may be cleaned and cured. The manufactured
mold may include the registration features for receiving the object
that will be fit onto the mold.
[0099] At block 1012, an object is attached to the mold. The object
may correspond to any of the aforementioned objects. The object may
include a registration feature that mates with a registration
feature on the mold.
[0100] At block 1015, a plastic shell is formed over the mold and
the object. This may include sending instructions to a pressure
forming or thermoforming machine to cause a sheet of material to be
pressure formed or thermoformed over the mold to form a body of the
plastic shell. The sheet may be, for example, a sheet of plastic
(e.g., an elastic thermoplastic). To thermoform the shell over the
mold, the sheet of material may be heated to a temperature at which
the sheet becomes pliable. Pressure may concurrently be applied to
the sheet to form the now pliable sheet around the breakable mold.
Once the sheet cools, it will have a shape that conforms to the
mold. An interior shape of the plastic shell substantially conforms
to a current or future dental arch of the patient. In one
embodiment, a release agent (e.g., a non-stick material) is applied
to the mold before forming the plastic shell. This may facilitate
later removal of the mold from the plastic shell.
[0101] At block 1020, the plastic shell is removed from the object.
The object may have one or more retention features such as a taper,
slope, lip, ledge, knurling, etc. that causes the object to become
mechanically interlocked with the plastic shell after the
thermoforming process. Accordingly, the object and the plastic
shell may be removed from the mold together. The object may provide
structural strength to the plastic shell. The object does not
interfere with a fit of the plastic shell onto a dental arch of the
patient. The feature of the plastic shell that is formed over the
object may enable a force to be applied to at least one of a tooth
or a jaw of a patient while the plastic shell is worn on a dental
arch of the patient.
[0102] In one embodiment, at block 1025 laser welding or ultrasonic
welding is performed to bond or fuse the object to the plastic
shell. A power and targeting of a laser welding machine or
ultrasonic welding machine may be carefully controlled to ensure
that only a minimal amount of the object and plastic shell are
melted to ensure that a shape of the plastic shell is not degraded.
Additionally or alternatively, an adhesive may be applied to the
object prior to the thermoforming. The adhesive may act to bond the
plastic shell to the object.
[0103] In one embodiment, at block 1030 the plastic shell is cut to
form a hole and/or a slot into the plastic shell. This may include
sending instructions to a cutting machine to cause the cutting
machine to cut the plastic shell at specified coordinates. This may
permit access through the hole and/or slot to features of the
object that is retained in the plastic shell. The cutting machine
may be, for example, a laser cutter, plasma cutter or mill. The
plastic shell may also be marked and/or trimmed along a gingival
cut line.
[0104] If the plastic shell is an orthodontic aligner, for example,
a set of plastic shells can be fabricated, each shaped to
accommodate a tooth arrangement specified by one of the treatment
stages, such that the plastic shells can be sequentially worn by
the patient to incrementally reposition the teeth from the initial
arrangement to the target arrangement. The properties of the
plastic shells (e.g., characteristics of features formed in the
plastic shells and/or objects retained in or inserted into the
plastic shells) can be selected to elicit the tooth movements
specified by the corresponding treatment stage. At least some of
these properties can be determined via suitable computer software
or other digital-based approaches. The fabrication of the plastic
shells may involve creating a digital model of the plastic shells
to be used as input to a computer-controlled fabrication
system.
[0105] FIG. 11 illustrates a flow diagram of another embodiment for
a method 1100 of manufacturing a plastic shell having hollow
feature that is at least partially filled by an object. In some
embodiments, one or more operations of method 1100 are performed by
processing logic of a computing device. The processing logic may
include hardware (e.g., circuitry, dedicated logic, programmable
logic, microcode, etc.), software (e.g., instructions executed by a
processing device), firmware, or a combination thereof. For
example, one or more operations of method 1100 may be performed by
computing device such as computing device 1301 of FIG. 13.
Additionally, some operations may be performed by a fabrication
machine based on instructions received from processing logic. Some
operations may alternately be performed by a user (e.g., based on
user interaction with a mold modeling module or drafting
program).
[0106] At block 1105 of method 1100, a shape is determined for a
mold of a dental arch for a patient. The shape may be determined by
digitally planning a current, intermediate or final target
arrangement of the patient's teeth, and fabricating a mold of a
dental arch that reflects that target arrangement. Alternatively,
the shape may be determined by taking an impression of a patient's
arch and generating a mold from the impression. At block 1108, a
feature to add to the mold is determined. The feature may be
automatically determined by processing logic or may be manually
determined by a user such as a technician. The feature may be any
of the features described herein above.
[0107] At block 1110, the mold is fabricated based on the
determined shape (e.g., based on sending instructions to a rapid
prototyping machine). The mold includes the added feature. Forming
the mold may include using a three-dimensional virtual model of the
dental arch and a rapid prototyping machine (e.g., a
three-dimensional printer) to fabricate the mold.
[0108] At block 1115, a plastic shell is formed over the mold
(e.g., based on sending instructions to a thermoforming or pressure
forming machine). In one embodiment, the plastic shell is
thermoformed or pressure formed over the mold. Other exemplary
methods for fabricating plastic shells include rapid prototyping,
stereolithography, or computer numerical control (CNC) milling. The
material of the plastic shell can be translucent, such as a
translucent polymer. Alternatively, the material may have any other
desired color or colors.
[0109] At block 1120, the plastic shell is removed from the mold.
An interior shape of the plastic shell substantially conforms to a
current or future dental arch of the patient. The plastic shell
will have a hollow feature that includes a cavity with a shape,
size and location based on the feature that was added. The hollow
feature may enable a force to be applied to at least one of a tooth
or a jaw of a patient while the plastic shell is worn on a dental
arch of the patient.
[0110] At block 1122, the cavity is at least partially filled with
an object. The object has a shape that substantially conforms to a
shape or contour of the cavity. The object may provide structural
strength to the plastic shell at the location of the hollow
feature. The object does not interfere with a fit of the plastic
shell onto a dental arch of the patient. Numerous different
techniques may be used to fill (or partially fill) the cavity with
the object. In one embodiment, at block 1124 a preformed object is
inserted into the cavity. In one embodiment, a slot and/or hole are
cut into the plastic shell to permit access to the cavity. The
preformed object may then be inserted into and/or attached to the
feature of the plastic shell that includes the cavity through the
slot and/or hole. For example, a sphere attached to a rod may be
inserted into a hole cut into the feature.
[0111] In one embodiment, at block 1126 a liquid phase material is
injected into the cavity in the plastic shell and then cured. The
liquid phase material may be injected into the cavity from an
underside of the plastic shell. Alternatively, the plastic shell
may be placed onto another mold that does not include the added
feature. Instead, the other mold may include a shape of a patient's
tooth crown at a location corresponding to the location of the
feature in the initial mold. In such an embodiment, a hole may be
drilled into the feature to provide access to the cavity. The
liquid phase material may then be injected into the cavity through
the hole. Enough liquid phase material may be injected to fill the
cavity. The liquid phase material may contact the tooth crown of
the additional mold and conform to a contour of the tooth crown.
The liquid phase material may then be cured to transform the liquid
phase material into a solid phase material.
[0112] In one embodiment, at block 1130 the plastic shell is welded
to the object using one of laser welding or ultrasonic welding.
Alternatively, an adhesive may be applied to walls of the cavity
and/or to the object prior to insertion of the object into the
cavity.
[0113] FIG. 12 illustrates a flow diagram of an embodiment for a
method 1200 of filling a cavity in a hollow feature of a plastic
shell. In one embodiment, method 1200 is performed at block 1126 of
method 1100. At block 1205 of method 1200, an inflatable bladder is
inserted into a cavity in a plastic shell. At block 1208, a hole is
drilled into the plastic shell at a location of the cavity. The
hole may be drilled before or after insertion of the bladder into
the cavity.
[0114] At block 1210, the plastic shell is placed onto a second
mold that lacks a feature of an initial mold that was used to form
the plastic shell. The second mold may instead have a tooth crown
at a location corresponding to a location of the feature in the
initial mold. At block 1215, a liquid phase material is injected
into the bladder through the hole in the cavity. The bladder may
expand to a shape that conforms to a shape of the cavity and of the
tooth crown. At block 1220, the liquid phase material is then cured
to transform the liquid phase material into a solid phase
material.
[0115] FIG. 13 is a simplified block diagram of a system 1300 that
may be used in executing methods and processes described herein.
The system 1300 typically includes a computing device 1301
connected to a network 1324, a scanner 1320 and/or a fabrication
machine 1322. The computing device 1301 may be connected (e.g.,
networked) to other machines in a Local Area Network (LAN), an
intranet, an extranet, or the Internet. For example, the computing
device 1301 may be networked fabrication machine 1322, which may be
a rapid prototyping apparatus such as a 3D printer or SLA
apparatus. The computing device 1301 may operate in the capacity of
a server or a client machine in a client-server network
environment, or as a peer machine in a peer-to-peer (or
distributed) network environment. The computing device 1301 may be
a personal computer (PC), a tablet computer, a set-top box (STB), a
Personal Digital Assistant (PDA), a cellular telephone, a web
appliance, a server, a network router, switch or bridge, or any
machine capable of executing a set of instructions (sequential or
otherwise) that specify actions to be taken by that machine.
Further, while only a single machine is illustrated, the term
computing device shall also be taken to include any collection of
machines (e.g., computers) that individually or jointly execute a
set (or multiple sets) of instructions to perform any one or more
of the methodologies discussed herein.
[0116] Computing device 1301 includes at least one processing
device 1302 that communicates with one or more peripheral devices
via bus subsystem 1304. Processing device 1302 represents one or
more general-purpose processors such as a microprocessor, central
processing unit, or the like. More particularly, the processing
device 1302 may be a complex instruction set computing (CISC)
microprocessor, reduced instruction set computing (RISC)
microprocessor, very long instruction word (VLIW) microprocessor,
processor implementing other instruction sets, or processors
implementing a combination of instruction sets. Processing device
1302 may also be one or more special-purpose processing devices
such as an application specific integrated circuit (ASIC), a field
programmable gate array (FPGA), a digital signal processor (DSP),
network processor, or the like. Processing device 1302 is
configured to execute the processing logic (instructions) for
performing operations and steps discussed herein.
[0117] Peripheral devices typically connected to processing device
1302 include a storage subsystem 1306 (memory subsystem 1308 and
file storage subsystem 1314), a set of user interface input and
output devices 1318, and an interface to outside networks 1316.
This interface is shown schematically as "Network Interface" block
1316, and is coupled to corresponding interface devices in other
data processing systems via communication network interface
1324.
[0118] The user interface input devices 1318 are not limited to any
particular device, and can typically include, for example, a
keyboard, pointing device, mouse, scanner, interactive displays,
touchpad, joysticks, etc. Similarly, various user interface output
devices can be employed in a system of the invention, and can
include, for example, one or more of a printer, display (e.g.,
visual, non-visual) system/subsystem, controller, projection
device, audio output, and the like.
[0119] Storage subsystem 1306 maintains basic programming of the
computing device 1301, including computer readable media having
instructions (e.g., operating instructions, etc.), and data
constructs. The program modules discussed herein are typically
stored in storage subsystem 1306. Storage subsystem 1306 typically
includes memory subsystem 1308 and file storage subsystem 1314.
Memory subsystem 1308 typically includes a number of memories
(e.g., random access memory (RAM) 1310, read only memory (ROM)
1312, etc.) including computer readable memory for storage of fixed
instructions, instructions and data during program execution, basic
input/output system, etc. File storage subsystem 1314 provides
persistent (non-volatile) storage for program and data files, and
can include one or more removable or fixed drives or media, hard
disk, floppy disk, CD-ROM, DVD, optical drives, and the like.
[0120] The file storage subsystem 1314 may include a
machine-readable storage medium (or more specifically a
non-transitory computer-readable storage medium) on which is stored
one or more sets of instructions embodying any one or more of the
methodologies or functions described herein. A non-transitory
storage medium refers to a storage medium other than a carrier
wave. The instructions may also reside, completely or at least
partially, within the memory subsystem 1308 and/or within the
processing device 1302 during execution thereof by the computer
device 1301, the memory subsystem 1308 and the processing device
1302 also constituting computer-readable storage media.
[0121] The computer-readable storage medium may also be used to
store one or more virtual 3D models and/or a plastic shell
generation module 1350, which may perform one or more of the
operations of methods 900-1100 described with reference to FIGS.
9-11. The term "computer-readable storage medium" should be taken
to include a single medium or multiple media (e.g., a centralized
or distributed database, and/or associated caches and servers) that
store the one or more sets of instructions. The term
"computer-readable storage medium" shall also be taken to include
any medium other than a carrier wave that is capable of storing or
encoding a set of instructions for execution by the machine and
that cause the machine to perform any one or more of the
methodologies of the present invention. The term "computer-readable
storage medium" shall accordingly be taken to include, but not be
limited to, solid-state memories, and optical and magnetic
media.
[0122] One or more of the storage systems, drives, etc. may be
located at a remote location, such coupled via a server on a
network or via the internet/World Wide Web. In this context, the
term "bus subsystem" is used generically so as to include any
mechanism for letting the various components and subsystems
communicate with each other as intended and can include a variety
of suitable components/systems that would be known or recognized as
suitable for use therein. It will be recognized that various
components of the system can be, but need not necessarily be at the
same physical location, but could be connected via various
local-area or wide-area network media, transmission systems,
etc.
[0123] Scanner 1320 includes any means for obtaining a digital
representation (e.g., images, surface topography data, etc.) of a
patient's teeth (e.g., by scanning physical models of the teeth
such as casts, by scanning impressions taken of the teeth, or by
directly scanning the intraoral cavity of a patient). Scanner 1320
may receive or generate dental arch data 1321 (which may be data
usable to generate a 3D virtual model of a patient's dental arch),
and may provide such dental arch data 1321 to computing device
1301. Scanner 1320 may be located at a location remote with respect
to other components of the system and can communicate image data
and/or information to computing device 1301, for example, via
network interface 1324. Fabrication system 1322 fabricates
orthodontic aligners 1323 based on a treatment plan, including data
set information received from computing device 1301. Fabrication
machine 1322 can, for example, be located at a remote location and
receive data set information from computing device 1301 via network
interface 1324.
[0124] It is to be understood that the above description is
intended to be illustrative, and not restrictive. Many other
embodiments will be apparent upon reading and understanding the
above description. Although embodiments of the present invention
have been described with reference to specific example embodiments,
it will be recognized that the invention is not limited to the
embodiments described, but can be practiced with modification and
alteration within the spirit and scope of the appended claims.
Accordingly, the specification and drawings are to be regarded in
an illustrative sense rather than a restrictive sense. The scope of
the invention should, therefore, be determined with reference to
the appended claims, along with the full scope of equivalents to
which such claims are entitled.
* * * * *