U.S. patent application number 12/710948 was filed with the patent office on 2010-06-17 for designing a bracket alignment device.
This patent application is currently assigned to GeoDigm Corporation. Invention is credited to Michael C. MARSHALL.
Application Number | 20100151405 12/710948 |
Document ID | / |
Family ID | 39763066 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100151405 |
Kind Code |
A1 |
MARSHALL; Michael C. |
June 17, 2010 |
DESIGNING A BRACKET ALIGNMENT DEVICE
Abstract
A method includes obtaining an electronic model image
representing teeth of a patient; determining a desired bracket
arrangement for one or more brackets on the teeth; designing an
electronic model image of an alignment device based in part on the
desired bracket arrangement; and fabricating the alignment device
based on the electronic model image of the alignment device. The
desired bracket arrangement includes a surface location, a tip
orientation, and a torque orientation of each bracket. The
alignment device defines at least one slot through which a bracket
can be placed at a surface location and an orientation indicator to
indicate a desired tip orientation and a desired torque orientation
of each bracket.
Inventors: |
MARSHALL; Michael C.; (Prior
Lake, MN) |
Correspondence
Address: |
MERCHANT & GOULD PC
P.O. BOX 2903
MINNEAPOLIS
MN
55402-0903
US
|
Assignee: |
GeoDigm Corporation
Chanhassen
MN
|
Family ID: |
39763066 |
Appl. No.: |
12/710948 |
Filed: |
February 23, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11893985 |
Aug 17, 2007 |
7690917 |
|
|
12710948 |
|
|
|
|
60838653 |
Aug 17, 2006 |
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Current U.S.
Class: |
433/24 |
Current CPC
Class: |
A61C 7/146 20130101;
A61C 7/00 20130101; A61C 7/002 20130101; B33Y 80/00 20141201 |
Class at
Publication: |
433/24 |
International
Class: |
A61C 7/12 20060101
A61C007/12 |
Claims
1. A method comprising: obtaining an electronic model image
representing teeth of a patient; determining a desired bracket
arrangement for a plurality of brackets on the teeth of the
electronic model image when the teeth are arranged in desired
positions, the desired bracket arrangement including a surface
location, a tip orientation, and a torque orientation of each
bracket; designing an electronic model image of an alignment device
based in part on the electronic model image of the teeth of the
patient and on the desired bracket arrangement, the electronic
model image of the alignment device defining at least one slot
through which a bracket can be placed at a surface location and an
orientation indicator to indicate a desired tip orientation and a
desired torque orientation; and fabricating the alignment device
based on the electronic model image of the alignment device.
2. The method of claim 1, wherein determining the desired bracket
arrangement further comprises determining the desired bracket
arrangement within six degrees of freedom.
3. The method of claim 1, further comprising using the fabricated
alignment device to properly position one or more brackets on the
teeth of a patient.
4. The method of claim 3, wherein using the fabricated alignment
device comprises: coupling the alignment device to a dental cast of
the patient; placing a plurality of brackets through the slots
defined by the alignment device and onto surface locations; and
arranging each of the plurality of brackets according to the
desired tip orientation and the desired torque orientation of the
bracket; and producing an indirect bonding tray using the plurality
of brackets.
5. The method of claim 3, wherein using the fabricated alignment
device comprises fitting an alignment tool within a slot defined by
each bracket and within an alignment channel defined by the
alignment device simultaneously.
6. The method of claim 1, further comprising manipulating the
electronic model image to plan a course of treatment for shifting
the teeth into the desired positions.
7. The method of claim 1, wherein obtaining an electronic model
image representing teeth of a patient comprises: obtaining a dental
cast representing the teeth of the patient; scanning the dental
cast to obtain spatial data representing the teeth of the patient;
and generating the electronic model image representing teeth of a
patient based on the obtained spatial data.
8. A system comprising: a three-dimensional scanner configured to
obtain spatial data corresponding to a dental cast, the dental cast
representing teeth of a patient; a computing system coupled to the
three-dimensional scanner, the computing system configured to
generate an electronic model image representing the teeth of the
patient based on the spatial data obtained by the scanner, the
computing system also configured to generate an electronic model
image of an alignment device, the alignment device configured to
facilitate positioning one or more brackets according to a desired
surface location, a desired tip orientation, and a desired torque;
and a prototyping device coupled to the computing system, the
prototyping device configured to fabricate the alignment device
based on the electronic model images of the alignment device.
9. The system of claim 8, wherein the computing system is also
configured to enable display, manipulation, storage, and
transmission of the electronic model images.
10. The system of claim 8, wherein the computing system is also
configured to enable a user to manipulating the electronic model
image representing the teeth of the patient to plan a course of
treatment for shifting the teeth into desired positions.
11. The system of claim 8, wherein the three-dimensional scanner is
a line-scanner.
12. The system of claim 8, wherein the prototyping device is
configured to print the alignment device in wax.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional Application of U.S.
application Ser. No. 11/893,985, filed on Aug. 17, 2007, which
claims the benefit of U.S. Provisional Application Ser. No.
60/838,653, filed Aug. 17, 2006, and which applications are
incorporated herein by reference. A claim of priority to all, to
the extent appropriate is made.
TECHNICAL FIELD
[0002] The invention relates generally to a method, system, and
device for positioning brackets on teeth; and, more particularly,
to bracket alignment devices, and systems and methods for producing
and utilizing the same.
BACKGROUND
[0003] Brackets are typically bonded to teeth for the purpose of
orthodontic treatment. One method of securing the brackets to the
teeth of a patient includes applying adhesive to the brackets and
manually placing the brackets directly on the patient's teeth.
Another method involves manually placing the brackets on a dental
model of the patient's teeth, transferring the brackets from the
dental model to a bonding tray, and then transferring the brackets
from the tray to the correct locations on the patient's teeth. This
latter method is commonly known as indirect bonding. While indirect
bonding generally provides an accurate location of the brackets
based on the bracket positions on the model, dental technicians
must still position the brackets onto the model by manually
estimating or "eyeballing" the correct positions. Such techniques,
therefore, are prone to human error.
[0004] There arises a need in the art to provide systems and
methods for accurately securing brackets onto desired positions on
a patient's teeth.
SUMMARY
[0005] The present invention provides for devices, systems, and
methods for securing brackets to the correct locations, and in the
correct orientations, on a patient's teeth. In particular, the
invention relates to bracket location and alignment devices, and
systems and methods of designing, fabricating and utilizing the
same.
[0006] In general, a dental/orthodontic professional plans a course
of treatment for shifting one or more teeth of the patient into
desired positions based on manipulation of electronic model images
of the patient's teeth. Desired locations for brackets are
determined using the electronic models. In a preferred embodiment,
the desired locations are determined based on the desired positions
of the teeth post-treatment.
[0007] An electronic model of an alignment device can be designed
based on the electronic model images of the patient's teeth and the
desired bracket locations. The alignment device can be fabricated
based on the electronic model and used to properly position the
brackets, either directly or indirectly, on the teeth of the
patient.
[0008] The alignment device generally defines a body and at least
one slot through which a bracket can be placed at a surface
location. The alignment device also includes an orientation
indicator to denote a desired tip orientation and a desired torque
orientation of the bracket. Typically, the orientation indicator is
coupled to the body adjacent the slot. The alignment device can
also include an alignment tool configured to align the bracket with
the orientation indicator when the bracket is positioned at the
location on the surface through the slot.
[0009] According to one aspect, the alignment device is configured
to aid in securing brackets to a dental cast to aid with indirect
bonding. Such an alignment device typically includes an alignment
tool to aid in positioning the brackets.
[0010] According to another aspect, the alignment device is
configured to aid in directly bonding brackets to a patient's
teeth. Such an alignment device typically includes fingers
configured to retain one or more brackets in a fixed position.
[0011] In a preferred alignment method, an electronic model image
representing the teeth of a patient is obtained; and a desired
bracket arrangement is determined for one or more brackets on the
teeth of the electronic model image. The desired bracket
arrangement includes a surface location, a tip orientation, and a
torque orientation of each bracket. The method also includes
designing an electronic model image of an alignment device based in
part on the desired bracket arrangement; and fabricating the
alignment device based on the electronic model image.
[0012] In a preferred embodiment, the alignment system can include
a three-dimensional scanner; a computing system; and a rapid
prototyping device. The scanner digitizes one or more dental casts
to generate electronic model images of the dental casts. The
computing system enables display, manipulation, storage, and
transmission of the electronic model images. The computing system
also enables the user to design an electronic model of an alignment
device configured to aid in properly locating and aligning the
brackets on the patient's teeth. The rapid prototyping device
enables fabrication of the alignment device based on the electronic
model.
[0013] While the invention will be described with respect to
preferred embodiment configurations and with respect to particular
devices used therein, it will be understood that the invention is
not to be construed as limited in any manner by either such
configuration or components described herein. Also, while the
particular types of scanning devices, computing devices, and
fabrication devices used in the preferred embodiment are described
herein, it will be understood that such particular components are
not to be construed in a limiting manner. Instead, the
functionality of those devices should be appreciated. These and
other variations of the invention will become apparent to those
skilled in the art upon a more detailed description of the
invention.
[0014] The advantages and features which characterize the invention
are pointed out with particularity in the claims annexed hereto and
forming a part hereof. For a better understanding of the invention,
however, reference should be had to the drawing which forms a part
hereof and to the accompanying descriptive matter, in which there
is illustrated and described a preferred embodiment of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Referring to the drawing, wherein like numerals represent
like parts throughout the several views:
[0016] FIG. 1 illustrates an operational flow for a process for
creating an alignment device according to one embodiment of the
present disclosure;
[0017] FIG. 2 is a perspective view of an electronic model
representing the dental arches of the mandible and the maxilla
according to one embodiment of the present disclosure;
[0018] FIG. 3 is a front view of teeth arranged in pre-treatment
positions according to one embodiment of the present
disclosure;
[0019] FIG. 4 is a front view of teeth arranged in post-treatment
positions according to one embodiment of the present
disclosure;
[0020] FIG. 5 illustrates an example design and production system
on which example processes of the present disclosure can be
executed according to one embodiment of the present disclosure;
[0021] FIG. 6 illustrates an operational flow for implementing the
plan operation of the creation process of FIG. 1;
[0022] FIG. 7A is a front view of a tooth showing the arc over
which the tooth can tip is a mesial or distal direction according
to one embodiment of the present disclosure;
[0023] FIG. 7B is a front view of a tooth showing how the tooth can
rotate according to one embodiment of the present disclosure;
[0024] FIG. 8 is a front perspective view of a tooth showing how
the arc over which the tooth can torque in a facial or lingual
direction according to one embodiment of the present
disclosure;
[0025] FIG. 9 is a front perspective view of a bracket according to
one embodiment of the present disclosure;
[0026] FIG. 10 illustrates an operation flow for an example process
for determining the desired positions of brackets on teeth in a
post-treatment position according to one embodiment of the present
disclosure;
[0027] FIG. 11 is a front view of brackets arranged into desired
positions on teeth arranged in post-treatment positions according
to one embodiment of the present disclosure;
[0028] FIG. 12 illustrates the normal vector of a bracket mounted
to a post-treatment tooth relative to a generally horizontal plane
according to one embodiment of the present disclosure;
[0029] FIG. 13 illustrates the torque orientation of the bracket of
FIG. 12 relative to the normal vector of the tooth according to one
embodiment of the present disclosure;
[0030] FIG. 14 illustrates an operation flow for an example process
for determining the desired positions of brackets on a
pre-treatment arrangement of teeth according to one embodiment of
the present disclosure;
[0031] FIG. 15 is a front view of brackets mounted to teeth
arranged in pre-treatment positions according to one embodiment of
the present disclosure;
[0032] FIG. 16 illustrates the torque orientation of a bracket
mounted to a pre-treatment tooth relative to the normal vector of
the tooth according to one embodiment of the present
disclosure;
[0033] FIG. 17 illustrates an operation flow for a generation
process of an electronic model of an alignment device according to
one embodiment of the present disclosure;
[0034] FIG. 18 is a front view of a first alignment device mounted
to teeth arranged in pre-treatment positions according to one
embodiment of the present disclosure;
[0035] FIG. 19 is a front view of a bracket positioned relative to
another type of first alignment device according to one embodiment
of the present disclosure;
[0036] FIG. 20 is a cross-sectional view of a first alignment
device taken along the line 20-20 of FIG. 19 according to one
embodiment of the present disclosure;
[0037] FIG. 21 illustrates an example operation flow for an
alignment process using a fabricated first alignment device to
position a bracket according to one embodiment of the present
disclosure;
[0038] FIG. 22 is a partial, front perspective view of a bracket
positioned within the recess of the alignment device of FIG. 19
according to one embodiment of the present invention;
[0039] FIG. 23 is a front, perspective view of an alignment tool
engaging a bracket and an orientation indicator of the alignment
device of FIG. 19 in which the body of the alignment device has
been removed for clarity;
[0040] FIG. 24 is a front view of an example second alignment
device including features that are examples of inventive aspects in
accordance with the principles of the present disclosure;
[0041] FIG. 25 is a front view of the second alignment device of
FIG. 24 holding a bracket to a tooth according to one embodiment of
the present disclosure;
[0042] FIG. 26 illustrates an operation flow for a bracket
securement process by which one or more brackets can be secured to
teeth using the second alignment device according to one embodiment
of the present disclosure;
[0043] FIG. 27 is a front view of three brackets coupled to a
second alignment device configured to mount to three teeth
according to one embodiment of the present disclosure;
[0044] FIG. 28 shows the brackets and second alignment device of
FIG. 27 mounted to three teeth; and
[0045] FIG. 29 illustrates three teeth on which brackets are
mounted in desired pre-treatment positions according to one
embodiment of the present disclosure.
DETAILED DESCRIPTION
[0046] The present disclosure provides for an alignment device for
securing brackets to desired locations, and in desired
orientations, on a patient's teeth to implement a course of
treatment planned by a dental/orthodontic professional. In
particular, the disclosure relates to bracket alignment devices and
systems and methods for creating and using the same.
[0047] Referring to the figures in general, the professional can
plan a course of treatment for a patient using one or more
electronic models 100 of the patient's dentition. FIG. 1
illustrates an operational flow for a process 1000 for creating one
example of an alignment device. The process 1000 begins at start
operation 1005 and proceeds to obtain operation 1010. The obtain
operation 1010 acquires an electronic model 100 of the patient's
dentition (e.g., see FIG. 2).
[0048] The electronic model 100 generally represents the teeth 110
of the patient in a pre-treatment arrangement (e.g., see FIG. 3).
In some embodiments, the electronic model 100 represents the teeth
110 located on one of the mandible 102 and the maxilla 104 of the
patient. In other embodiments, however, the electronic model 100
can represent the teeth 110 located on both the mandible 102 and
the maxilla 104. In certain embodiments, the electronic model 100
is formed from a polygonal mesh. In a preferred embodiment, the
electronic model 100 is formed from a triangular polygonal mesh. In
other embodiments, however, other types of electronic models, such
as voxel-based models, can be used.
[0049] In some embodiments, the obtain operation 1010 acquires the
electronic model 100 by scanning a dental cast of the patient's
dentition to obtain spatial data representing the teeth 110 of the
patient and generating the electronic model 100 based on the
obtained spatial data. In other embodiments, the obtain operation
1010 acquires the electronic model 100 by directly scanning the
teeth 110 of the patient or by scanning a bite impression. In still
other embodiments, however, the obtain operation 1010 can receive
the electronic model 100 from a secondary source.
[0050] A plan operation 1015 shifts the teeth 110 of the electronic
model 100 from the pre-treatment arrangement into desired positions
in a post-treatment arrangement (e.g., see FIG. 4). For clarity,
teeth arranged in a post-treatment arrangement will be designated
as 110'. A position operation 1020 selects desired locations for
brackets 150 (see FIG. 9) along the surface of the post-treatment
arrangement of the teeth 110' of the electronic model 100 (see FIG.
11). One example process for selecting the desired bracket
locations will be discussed in more detail herein with reference to
FIG. 10.
[0051] When the desired bracket positions are known for the
post-treatment arrangement of teeth 110', a determine operation
1025 determines desired bracket locations for the pre-treatment
arrangement of the teeth 110 (e.g., see FIG. 15). Next, a design
operation 1030 generates an electronic model of an alignment device
(e.g., see FIGS. 19 and 24). In general, the electronic model of
the alignment device is based on the desired bracket positions for
the pre-treatment arrangement of the patient's teeth 110. In
certain embodiments, the electronic model of the alignment device
is also generated based on desired post-treatment positions of the
teeth 110' of the electronic model 100. More details regarding
example alignment devices will be provided herein with reference to
FIGS. 17-29.
[0052] Still referring to FIG. 1, a fabricate operation 1035
produces an alignment device based on the electronic model of the
alignment device. In certain embodiments, the fabricate operation
1035 prints out the alignment device on a rapid prototyping
machine. In other embodiments, however, the fabricate operation
1035 can produce the alignment device using any desired fabrication
process. The fabricated alignment device can be used to properly
position the brackets 150. The process ends at stop operation
1040.
[0053] FIG. 5 illustrates an example design and production system
200 on which example processes of the present disclosure can be
executed. In general, the system 200 includes a computing system
220 and a fabrication device 270 coupled to the computing system
220. The computing system 220 is configured to implement at least
the design operation 1030 of FIG. 1. In a preferred embodiment, the
computing system 220 is configured to implement the plan, position,
determine, and design operations 1010-1030. The fabrication device
270 is configured to implement the fabricate operation 1035 of FIG.
1 to produce (e.g., print) objects based on the electronic models
generated by the computing system 220.
[0054] One example of the computing system 220 includes a processor
unit 222, read only memory (ROM) 224, random access memory (RAM)
228, and a system bus 230 that couples various system components
including the RAM 228 to the processor unit 222. The system bus 230
may be any of several types of bus structures including a memory
bus or memory controller, a peripheral bus and a local bus using
any of a variety of bus architectures. A basic input/output system
226 (BIOS) is stored in ROM 224. The BIOS 226 contains basic
routines that help transfer information between elements within the
computing system 220.
[0055] The computing system 220 further includes a hard disk drive
232 for reading from and writing to a hard disk, a magnetic disk
drive (not shown) for reading from or writing to a removable
magnetic disk, and an optical disk drive 234 for reading from or
writing to a removable optical disk, such as a CD-ROM, DVD, or
other type of optical media. The hard disk drive 232, magnetic disk
drive, and optical disk drive 234 can be connected to the system
bus 230 by a hard disk drive interface (not shown), a magnetic disk
drive interface (not shown), and an optical drive interface (not
shown), respectively. The drives and their associated
computer-readable media provide nonvolatile storage of computer
readable instructions, data structures, programs, and other data
for the computing system 220.
[0056] Although the exemplary environment described herein employs
a hard disk drive 232, a removable magnetic disk, and removable
optical disk drive 234, other types of computer-readable media
capable of storing data can be used in the exemplary system.
Examples of these other types of computer-readable mediums that can
be used in the exemplary operating environment include magnetic
cassettes, flash memory cards, digital video disks, and Bernoulli
cartridges.
[0057] A number of program modules may be stored on the ROM 224,
RAM 228, hard disk drive 232, magnetic disk drive, or optical disk
drive 234, including an operating system 236, one or more
application programs 238, other program modules, and program (e.g.,
application) data 240.
[0058] A user may enter commands and information into the computing
system 220 through input devices 242, such as a keyboard, touch
screen, and/or mouse (or other pointing device). Examples of other
input devices may include a microphone, joystick, game pad,
satellite dish, and document scanner. These and other input devices
are often connected to the processing unit 222 through an I/O port
interface 244 that is coupled to the system bus 230. Nevertheless,
these input devices 242 also may be connected by other interfaces,
such as a parallel port, game port, or a universal serial bus
(USB). A monitor 246 or other type of display device is also
connected to the system bus 230 via an interface, such as a video
adapter 248. In addition to the display device 246, computing
systems typically include other peripheral output devices (not
shown), such as speakers and document printers.
[0059] The computing system 220 may operate in a networked
environment using logical connections to one or more remote
computers. Examples of remote computers include personal computers,
servers, routers, network PC's, peer devices and other common
network nodes, and typically include many or all of the elements
described above relative to the computing system 220. In certain
embodiments, the network connections can include a local area
network (LAN) or a wide area network (WAN). Such networking
environments are commonplace in offices, enterprise-wide computer
networks, intranets, and the Internet 250.
[0060] When used in a WAN networking environment, the computing
system 220 typically includes a modem 252 or other means for
establishing communications over the wide area network, such as the
Internet 250. The modem 252, which may be internal or external, can
be connected to the system bus 230 via the I/O port interface 244.
When used in a LAN networking environment, the computing system 220
is connected to the local network 254 through a network interface
or adapter 256. In a networked environment, program modules
depicted relative to the computing system 220, or portions thereof,
may be stored in the remote memory storage device. It will be
appreciated that the network connections shown are exemplary and
other means of establishing a communications link between the
computers may be used.
[0061] In certain embodiments, the fabrication device 270 includes
a rapid prototyping machine configured to print wax patterns.
Examples of such a rapid prototyping machine are the SLA.RTM.
systems produced by 3D Systems of Rock Hill, S.C. However, any type
of fabrication device 270 may be used without deviating from the
spirit and scope of the disclosure. In certain embodiments, the
fabrication device 270 can be connected to the computing system 220
via an appropriate interface 258.
[0062] The interface 258 can connected to the bus 230 such that the
electronic model data may be retrieved from the appropriate or
desired memory location. In some embodiments, the interface 258
converts the electronic models generated on the computing system
220 to a format readable by the fabrication device 270. In one
example embodiment, the interface 258 converts the electronic model
to an STL file. The converted file can be transmitted to the
fabrication device 270 using a direct line connection or using a
networked connection described above.
[0063] In certain embodiments, the design and production system 200
also includes a scanner 210 configured to implement the obtain
operation 1010 of FIG. 1. For example, a three-dimensional scanner
210 can be coupled to the computing system 220 via an appropriate
scanner interface 260. The scanner interface 260 is connected to
the bus 230 such that the scanned data may be stored in the
appropriate or desired memory location, manipulated by the CPU 222,
displayed on the display device 246, etc. Preferred scanners
include a laser line scanner arranged and configured for scanning
line study casts (e.g., plaster casts), such as the dental scanner
manufactured by GeoDigm Corporation of Minnesota. The operation and
scanning methodology used by such a line scanner is generally
described in U.S. Pat. No. 6,217,334. However, any suitable scanner
210 may be used and a number of other methodologies might be
employed to generate the scanned image data.
[0064] Portions of the preferred embodiment constructed in
accordance with the principles of the present invention utilize a
computer and are described herein as implemented by logical
operations performed by a computer. The logical operations of these
various computer implemented processes are generally performed
either (1) as a sequence of computer implemented steps or program
modules running on a computing system and/or (2) as interconnected
machine modules or hardware logic within the computing system. The
implementation is a matter of choice dependent on the performance
requirements of the computing system implementing the invention.
Accordingly, the logical operations making up the embodiments of
the invention described herein can be variously referred to as
operations, steps, or modules.
[0065] Referring now to FIG. 6, an example process 1100 for
implementing the plan operation 1015 of FIG. 1 is disclosed. The
process 1100 begins at start operation 1105 and proceeds to a
display operation 1110. The display operation 1110 displays at
least a portion of the electronic model 100 of the patient's
dentition in a pre-treatment arrangement (e.g., see FIG. 3). A
manipulate operation 1115 then shifts each individual tooth 110 to
a desired position (e.g., see FIG. 4). In certain embodiments,
shifting a tooth 110 includes modifying the rotation, the tip
orientation, and/or the torque orientation of the tooth 110. In an
embodiment, the tooth 110 can be shifted about six degrees of
freedom.
[0066] FIGS. 7(A-B) are front views and FIG. 8 is a front
perspective view of an example tooth 110. As shown in FIG. 7A,
modifying the tip orientation (i.e., yaw) of the tooth 110 includes
tilting the tooth 110 in either a mesial direction or a distal
direction along a first arc O.sub.T. Rotating the tooth 110
includes turning the tooth 110 about an axis of rotation A.sub.R to
move one side of the tooth in a buccal/labial direction and the
other side of the tooth in a lingual direction as shown in FIG. 7B.
As shown in FIG. 8, modifying the torque orientation (i.e., pitch)
of the tooth 110 includes tilting the tooth 110 in either a lingual
direction or a facial direction along a second arc O.sub.Q.
[0067] When the teeth have been arranged into a desired
post-treatment arrangement, a position operation 1120 determines a
position on the surface of one or more teeth 110' in the electronic
model 100 for an electronic model of a bracket 150 (FIG. 9). In
general, the position of the bracket 150 includes at least four
components: an occlusal-apical component OA; a medial-distal
component MD; a tip orientation .theta.1; and a torque orientation
.theta.2. The process 1100 ends at stop module 1125.
[0068] Referring to FIG. 9, one example of a bracket 150 configured
to mount to a tooth 110' is shown. The bracket 150 includes a front
151, a back 153, a first side 157, and a second side 159. The front
151 of the bracket 150 includes a recess 152 defined between a
first section 154 and a second section 156. In general, the recess
is configured to receive an arch wire. An arch wire is a wire that
extends around a dental arch and couples to the recess 152 of each
bracket 150 along the dental arch. The recess 152 extends in a
substantially linear path from the first side 157 to the second
side 159. The first and second sections 154, 156 each include
indicia 158 indicating an approximate midpoint between the first
side 157 and the second side 159.
[0069] Referring now to FIG. 10, an example process 1200 for
determining the desired positions of brackets 150 on teeth 110' is
disclosed. The process 1200 begins at start operation 1205 and
proceeds to a first select operation 1210. The first select
operation 1210 determines an occlusal-apical position OA of each
tooth 110' (see FIG. 11). The occlusal-apical position OA specifies
the position of the bracket 150 on the clinical crown between the
occlusal surface of the tooth 110' and the gingival border.
[0070] In a preferred embodiment, the first select operation 1210
determines the occlusal-apical position OA of each bracket 150 by
determining an arch wire path H (see FIG. 11). Typically, the path
H followed by the arch wire at the end of the treatment extends
along a generally horizontal plane P.sub.H that cuts through the
clinical crown of each tooth 110' (see FIG. 11). In some
embodiments, the generally horizontal plane P.sub.H is
substantially parallel to the Frankfort horizontal plane. In other
embodiments, the plane P.sub.H is curved to follow the curve of
Wilson and/or the curve or Spee.
[0071] A second select operation 1215 determines a medial-distal
position MD for each bracket 150. In certain embodiments, the
mesial-distal component MD refers to a distance from the bracket
150 to either the mesial or the distal side of the tooth 110'. In a
preferred embodiment, the mesial-distal component MD refers to the
distance from the indicia 158 (FIG. 9) of the bracket 150 to one of
the sides of the tooth 110'. Typically, a bracket 150 is generally
centered between the mesial side and the distal side of the tooth
110'.
[0072] A third select operation 1220 determines a tip orientation
.theta..sub.1 of each bracket 150. The tip orientation
.theta..sub.1 refers to the degree to which each bracket 150 tilts
along the arc O.sub.T (FIG. 7) of the tooth 110'. For example, in
one embodiment, the tip orientation indicates the angle
.theta..sub.1 between a line extending along the recess 152 of the
bracket 150 and the substantially horizontal plane P.sub.H.
Typically, when the brackets 150 are mounted on teeth 110' arranged
in a post-treatment position, the tip orientation .theta..sub.1
should approach or equal zero (see FIG. 11).
[0073] A fourth select operation 1225 determines a torque
orientation .theta..sub.2 of each bracket 150. The torque
orientation .theta..sub.2 refers to the degree to which a normal
vector N.sub.B (FIG. 13) of each bracket 150 tilts along the arc
O.sub.Q (FIG. 8) of the tooth 110' relative to the normal vector
N.sub.T of each tooth 110' (FIG. 13). The torque orientation
.theta..sub.2 of the bracket 150 can be adjusted by modifying the
amount and placement of adhesive 130 (FIG. 12). Typically, when the
brackets 150 are mounted on teeth 110' arranged in a post-treatment
position, the normal vector NB of the bracket 150 should be
generally parallel to the substantially horizontal plane P.sub.H
(e.g., see FIG. 12). The process 1200 ends at stop operation
1230.
[0074] A fifth select operation 1230 determines a rotational
orientation about an axis .theta..sub.R of each bracket 150. The
rotational orientation refers to the arrangement of the bracket 150
about the axis of rotation .theta..sub.R, which is generally
parallel with the axis of rotation A.sub.R of the corresponding
tooth 110 (see FIG. 7B). Adjusting the rotational orientation of a
bracket 150 adjusts how the sides of the bracket 150 interact with
the corresponding tooth 110. For example, rotating the bracket 150
in a first direction can raise a first side of the bracket off the
tooth 110 and press an opposite side of the bracket onto the tooth
110.
[0075] Referring now to FIGS. 14-16, desired bracket positions on
the pre-treatment arrangement of teeth 110 can be determined based
on the selected bracket positions on the post-treatment arrangement
of teeth 110'. FIG. 14 illustrates an example process 1300 for
determining the desired positions of brackets 150 on a
pre-treatment arrangement of teeth 110. The process 1300 begins at
start operation 1305 and proceeds to a first formation operation
1310. The first formation operation 1310 creates at least a first
transformation matrix to describe the shift in position of the
teeth 110 of the electronic model 100 from the pre-treatment
arrangement to the post-treatment arrangement. In one embodiment,
the first formation operation 1310 generates at least a first
transformation matrix for each tooth 110.
[0076] In general, the first transformation matrix represents the
transition in space of one or more teeth 110 in the electronic
model 100. In a preferred embodiment, the transformation matrix is
generated as a four-by-four identity matrix created based on known
algorithms. As the teeth 110 are manipulated from a pre-treatment
position to a post-treatment position, the first transformation
matrix is updated such that multiplying the first matrix by the
positions of the teeth 110 in the pre-treatment configuration will
produce the post-manipulation positions of the teeth 110.
[0077] A second formation operation 1315 creates a second
transformation matrix (i.e., an inverse matrix). The second
transformation matrix represents the transition of the teeth 110
from the post-treatment arrangement to the pre-treatment
arrangement. In one embodiment, the second transformation matrix is
generated based on the first transformation matrix according to
known algorithms. In another embodiment, the second transformation
matrix is formed prior to manipulating the teeth 110 and is updated
along with the first matrix as the teeth are manipulated.
[0078] A transform operation 1320 applies the second set of
transformation matrices to the bracket positions of the
post-treatment teeth 110' to obtain desired pre-treatment bracket
positions. A display operation 1325 renders electronic models of
the brackets 150 in the pre-treatment positions and superimposes
the brackets 150 on a pre-treatment arrangement of the teeth 110
(See FIG. 15). The process ends at stop operation 1330. Further
information regarding the formation and use of transformation
matrices can be found in the U.S. application Ser. No. 11/231,064
entitled "System and Method for Determining Condyle Displacement
Utilizing Electronic Models of Dental Impressions Having a Common
Coordinate System," filed Sep. 19, 2005, the disclosure of which is
hereby incorporated by reference.
[0079] Referring now to FIGS. 17-20, electronic models of alignment
devices can be designed to facilitate accurate placement of
brackets into the desired pre-treatment positions. One example
alignment device is illustrated in FIGS. 17-23. FIG. 17 illustrates
an operation flow for a generation process 1400 for creating an
electronic model 300 of an alignment device 310. The generation
process 1400 begins at a start operation 1405 and proceeds to a
mounting operation 1410. The mounting operation 1410 superimposes
electronic models of brackets 150 into desired pre-treatment
positions on the electronic model 100 of the patient's teeth 110
(e.g., see FIG. 15).
[0080] A generate operation 1415 creates an electronic model 300 of
a body 312 of an alignment device 310 configured to mount over one
or more teeth 110 of the electronic model 100. In general, the
generate operation 1415 forms the body 312 to extend from the front
of a tooth 110, over the occlusal surface of the tooth 110, and
partially over the back of the tooth 110 (e.g., see FIG. 20). In a
preferred embodiment, the body 312 is configured to extend
continuously away from the surface of the tooth 110 without
undercuts, thereby facilitating mounting of the alignment device
310 on the tooth 110 (e.g., see FIG. 20).
[0081] In some embodiments, the body 312 is configured to mount
over substantially all of the teeth 110 in the dental arch of
either the mandible or the maxilla. In other embodiments, the body
312 is configured to mount over only one tooth 110 (e.g., see FIG.
19). For clarity, FIG. 18 illustrates an electronic model 300 of an
alignment device 310 configured to mount over three adjacent teeth.
The model 300 is shown superimposed over electronic models of a
first tooth 112, a second tooth 114, and a third tooth 116.
[0082] A slot operation 1420 defines one or more openings 314 in
the body 312 (FIG. 18). Each of the openings 314 is configured to
enable placement of a bracket 150 through the slot 314 and onto the
surface of the tooth 110. Typically, the body 312 defines an
opening 314 for each tooth 110 to which the body 312 is configured
to couple. In the example shown in FIG. 18, the body 312 defines
three openings 314.
[0083] A first design operation 1425 creates at least one
orientation indicator 320 on the body 312 adjacent each opening
314. In general, the orientation indicator 320 is configured to
indicate a desired occlusal-apical position OA, a desire tip
orientation .theta..sub.1, and a desired torque orientation
.theta..sub.2 at which a bracket 150 should be mounted to a tooth
110 through each opening 314. In certain embodiments, the first
design operation 1425 includes forming a first member 324 and a
second member 326 to protrude from the body 312 (FIG. 19). The
first member 324 is spaced from the second member 326 to form a
channel 322 therebetween (see FIG. 20).
[0084] In certain embodiments, the members 324, 326 and the channel
322 are configured to align with the sections 154, 156 and the
recess 152, respectively, of each bracket 150. Aligning the channel
322 with the recess 152 includes positioning the members 324, 326
to form the channel at the occlusal-apical position OA of the
bracket recess 152. Furthermore, aligning the members 324, 326 with
the sections 154, 156 includes positioning the members 324, 326 at
the same tilt orientation .theta..sub.1 or tip orientation
.theta..sub.2 as sections 154, 156 of the bracket 150 when the
bracket 150 is positioned in a post-treatment arrangement. By so
aligning the orientation indicator 320 of the alignment device 310,
the orientation indicator 320 of a fabricated alignment device 310
can provide guidance in determining the desired position of a
bracket 150 on a physical tooth 110.
[0085] In some embodiments, the first design operation 1425 forms
the orientation indicator 320 to extend the entire length between
the slot openings 314 defined by the body 312 (e.g., see FIG. 18).
In other embodiments, the first design operation 1425 forms an
orientation indicator 320 to extend a relatively short distance
away from each slot opening 314 (e.g., see FIG. 19). In such an
embodiment, the first design operation 1425 can form an orientation
indicator 320 on either side of an opening 314 (FIG. 19) or on only
one side of each opening 314.
[0086] From the first design operation 1425, the process 1400 can
either end at stop operation 1435 or can proceed to a second design
operation 1430. The second design operation 1430 forms a
mesial-distal indicator 318 on the body 312 (FIG. 19). In general,
the second design operation 1430 forms the mesial-distal indicator
318 to align with the midpoint indicia 158 of the bracket 150 when
the bracket 150 is properly positioned on the tooth 110. In a
preferred embodiment, the mesial-distal indicator 318 includes a
notch defined in the body 312 above the slot 314. The generation
process 1400 ends at stop operation 1435.
[0087] An alignment device 310 can be fabricated based on the
electronic model 300. In certain embodiments, the electronic model
300 of the alignment device 310 (or data obtained from the
electronic model 300) can be forwarded from the computing system
220 on which the model 300 was generated to a fabrication device
270 (FIG. 5). The fabrication device 270 produces a physical
alignment device 310. For example, the fabrication device 270 can
rapidly print the alignment device 310 from at least one of wax,
thermoplastic, ceramic, rubber, and metal. In one embodiment, the
alignment device 310 is fabricated from a bio-compatible material,
such as an ABS material.
[0088] FIG. 21 illustrates an example operational flow for an
alignment process 1500 using a fabricated alignment device 310 to
position a bracket 150 on a surface. For example, the alignment
device 310 can facilitate positioning a bracket 150 on a dental
cast representing the teeth of a patient. In other embodiments, the
alignment device 310 can also facilitate positioning a bracket 150
on a tooth 110 of a patient. The alignment device 310 enables the
bracket to be positioned along six degrees of movement.
[0089] The alignment process 1500 begins at a start operation 1505
and proceeds to a mounting operation 1510. The mounting operation
1510 positions the alignment device 310 on one or more teeth 110 of
the patient (i.e., or on physical representations of the teeth).
The teeth 110 are typically arranged in the pre-treatment position
(see FIG. 18). An apply operation 1515 administers adhesive 130
(FIG. 22) to the back 153 of a bracket 150. The adhesive 130 is
applied to secure the bracket 150 to the tooth 110. Examples of
adhesive 130 include resin, resin-based adhesive, composite cement,
glass ionomer, and polycarboxylate. When a bracket 150 is mounted
to a physical representation of a tooth, the adhesive holding the
bracket 150 to the representation solidifies on the bracket 150 to
form a custom pad (see reference number 130 in FIGS. 12 and 13) and
is eventually mounted to the actual tooth 110 of the patient as
part of the bracket 150.
[0090] A load operation 1520 mounts the bracket 150 to the tooth
surface using the adhesive 130 (see FIG. 22). The general
occlusal-apical position O.sub.A, mesial-distal position MD,
rotational orientation, tip orientation .theta..sub.1, and torque
orientation .theta..sub.2 can be estimated by a user. For example,
the user can align the recess 152 and the indicia 158 on the
bracket 150 with the channel 322 and the mesial-distal indicator
318 on the indicator 310 by sight. In an alternative embodiment,
the load operation 1520 can mount the bracket 150 by loading the
bracket 150 onto an alignment tool 350 and pressing the back 153 of
the bracket 150 against the tooth surface through the opening 314
in the alignment device 310.
[0091] A secure operation 1525 fine-tunes the position of the
bracket 150 on the tooth surface along the six degrees of freedom
by inserting an alignment tool 350 into both the recess 152 and the
channel 322 (see FIG. 23). For example, inserting the tool 350 also
adjusts the torque orientation O.sub.2 of the bracket 150 to match
the torque orientation of the channel 322. Light pressure can be
applied to the bracket 150 via the tool 350 to hold the bracket 150
in place while the adhesive 160 sets or cures. The alignment
process ends at stop module 1530. If the brackets 150 were aligned
on physical representations of the teeth instead of the patient's
actual teeth, then the brackets 150 can be used in forming an
indirect bonding tray for loading the brackets 150 onto the actual
teeth.
[0092] FIG. 23 illustrates one example of an alignment tool 350
engaging a bracket 150 and an orientation indicator 320. The
alignment tool 350 includes an engagement member 352 and a handle
354. The engagement member 352 has a length sufficient to extend at
least partially across the bracket 150 and at least partially
across the orientation member 320. The engagement member 352 also
has a transverse cross-section shaped to enable the engagement
member 352 to be received within the recess 152 defined in the
bracket 150 and within the channel 322 of the alignment device
310.
[0093] Referring now to FIGS. 24-29, a second embodiment of an
alignment device 410 is disclosed. In one embodiment, the second
alignment device 410 can be configured to mount multiple brackets
150 directly to a patient's teeth 110 simultaneously, thereby
reducing the amount of time a patient must spend having the
brackets 150 installed during the clinical bonding process (e.g.,
see FIG. 28). In another embodiment, the second alignment device
410 can be configured to mount a single bracket 150 directly to a
single tooth 110 (e.g., see FIG. 25). In other embodiments,
however, the second alignment device 410 can be used to mount one
or more brackets 150 to a dental cast for use in indirect
bonding.
[0094] The second alignment device 410 includes a body 412 defining
an opening 414 (see FIG. 24). The second alignment device 410 also
includes an orientation indicator 420 enabling a user to couple a
brackets 150 into a desired position within each opening 414 of the
second alignment device 410. In certain embodiments, the
orientation indicator 420 includes one or more fingers 422
protruding into the opening 414 from the body 412. In a preferred
embodiment, the alignment device 410 includes three fingers 422.
Each finger 422 can have a fingertip configured to engage (e.g., be
received within) a notch or recess in the bracket 150.
[0095] In the example shown in FIG. 25, the recess 152 of each
bracket 150 is retained in a desired occlusal-apical position, tip
orientation, and tilt orientation by a first fingertip 424 coupled
to a finger 422 extending from one side of the opening 414 and by a
second fingertip 426 coupled to a finger 422 extending from the
opposite side of the opening 414 (see FIG. 25). In other
embodiments, however, the brackets recess 152 can be supported
using only one fingertip 424. A third fingertip 428 can retain the
bracket 150 in a desired mesial-distal position by engaging the
indicia 158 of the bracket 150 (see FIG. 25).
[0096] In general, the fingertips 424, 426, 428 are sized to
securely engage and retain the bracket 150. As shown in FIG. 25,
the fingertips 424, 426 and the fingertip 428 can have
substantially the same dimensions of the recess 152 and the indicia
158, respectively. For example, in some embodiments, each of
fingertips 424 and 426 is configured to extend along substantially
half of the bracket recess 152. In other embodiments, however, each
of the fingertips 424 and 426 extends only partially along the
bracket recess 152.
[0097] The second alignment device 410 can be fabricated from an
electronic model using a rapid prototyping machine. For example,
the alignment device 410 can be printed from the same materials
disclosed above with respect to fabrication of the first alignment
device 310. This prototyping technique, however, is meant to be
illustrative only and other suitable fabrication techniques can
also be used.
[0098] FIG. 26 illustrates an operation flow for a bracket
securement process 1600 by which one or more brackets 150 can be
secured to teeth using the second alignment device 410. FIGS. 27-29
illustrate the results of different steps in the process 1600. The
securement process 1600 begins at start operation 1605 and proceeds
to an arrange operation 1610. The arrange operation 1610 couples
one or more brackets 150 to the second alignment device 410.
[0099] FIG. 27 illustrates the result of the arrange operation
1610. As shown in FIG. 27, the second alignment device 410 includes
a body 412 configured to mount over three teeth 110. Three brackets
150 are coupled to fingers 422 protruding from the body 412 of the
second alignment device 410. Fingertips 424, 426 engage the
recesses 152 of the brackets 150 and fingertips 428 engage the
indicia notches 158 of the brackets 150.
[0100] An apply operation 1615 administers adhesive (not shown)
either to the back 153 of the brackets 150 or to the surface of the
teeth 110. In another embodiment, adhesive can be applied to both
the brackets 150 and the teeth 110. A mount operation 1620 couples
the alignment device 410 to the teeth 110 of the patient (i.e., or
to the physical representation of the teeth 110). When a bracket
150 is mounted to a physical representation of a tooth, the
adhesive holding the bracket 150 to the representation solidifies
on the bracket 150 to form a custom pad (see reference number 130
in FIGS. 12 and 13) and is eventually mounted to the actual tooth
110 of the patient as part of the bracket 150.
[0101] FIG. 28 illustrates the result of the mount operation 1620.
The second alignment device 410 is coupled to the three teeth 110
of the patient. The brackets 150 are held at desired positions on
the teeth. In particular, each bracket 150 is retained at a desired
occlusal-apical position, a desired mesial-distal position, a
desired tip orientation, and a desired torque orientation. In other
embodiments, the mount operation 1620 can mount the alignment
device 410 on the teeth 110 before the arrange operation 1610
couples the brackets 150 to the alignment device 410.
[0102] A retain operation 1625 holds the brackets 150 to the teeth
110 for a sufficient amount of time to enable the adhesive to set
or cure. When the brackets 150 are bound to the teeth 110 with
sufficient strength, a remove operation 1630 detaches the fingers
422 from the brackets 150. For example, in one embodiment, the
fingers 422 are resilient and the remove operation 1630 bends the
fingers 422 away from the brackets. In another embodiment, the
remove operation 1630 pulls the alignment device 410 away from the
front 151 of the brackets 150. The securement process 1600 ends at
stop operation 1635.
[0103] FIG. 29 shows the brackets 150 secured to the teeth 110
arranged in a pre-treatment position. The brackets 150 shown are
ready to receive an arch wire or to otherwise begin treatment.
[0104] Although embodiments of the present disclosure have been
described with respect to digitizing a dental cast of a patient, it
should be appreciated that the principles of the present disclosure
can also be applied to a digitized impression or a direct scan of
the dentition of a patient. In the former case, a computer can
invert the scanned impression to provide a positive image of the
patient's teeth.
[0105] The foregoing description of the exemplary embodiments of
the invention has been presented for the purposes of illustration
and description. They are not intended to be exhaustive or to limit
the invention to the precise forms disclosed. Many modifications
and variations are possible in light of the above teaching. It is
intended that the scope of the invention be limited not with this
detailed description, but rather by the claims appended hereto.
* * * * *