U.S. patent application number 11/990661 was filed with the patent office on 2009-12-10 for dental analysis method and system.
This patent application is currently assigned to 9104-6516 Quebec Inc. Invention is credited to Alain Methot.
Application Number | 20090306939 11/990661 |
Document ID | / |
Family ID | 37757922 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090306939 |
Kind Code |
A1 |
Methot; Alain |
December 10, 2009 |
Dental analysis method and system
Abstract
A dental analysis system and method for designing the dentition
of a patient, comprising the steps of: providing a visual
representation of the dentition, inputting a value representative
of the number of teeth on a side of the dentition, inputting at
least two quantities taken from a group consisting of a ratio, an
inter-teeth distance and a central incisor width, computing the
position of the teeth within the dentition by applying a
mathematical function to the value representative of the number of
teeth on a side of the dentition and the at least two quantities
and juxtaposing positioning lines over the visual representation of
the dentition, the positioning lines indicating the position of the
teeth as computed.
Inventors: |
Methot; Alain; (Lorraine,
CA) |
Correspondence
Address: |
POLSINELLI SHUGHART PC
700 W. 47TH STREET, SUITE 1000
KANSAS CITY
MO
64112-1802
US
|
Assignee: |
9104-6516 Quebec Inc
Lorraine
CA
|
Family ID: |
37757922 |
Appl. No.: |
11/990661 |
Filed: |
August 21, 2006 |
PCT Filed: |
August 21, 2006 |
PCT NO: |
PCT/CA2006/001374 |
371 Date: |
January 16, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60709460 |
Aug 19, 2005 |
|
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|
60748196 |
Dec 8, 2005 |
|
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Current U.S.
Class: |
703/1 ;
703/2 |
Current CPC
Class: |
A61C 13/0004 20130101;
A61C 19/04 20130101; A61C 7/002 20130101; G16H 20/40 20180101 |
Class at
Publication: |
703/1 ;
703/2 |
International
Class: |
G06F 17/50 20060101
G06F017/50; G06F 17/10 20060101 G06F017/10 |
Claims
1. A method for designing the dentition of a patient, comprising
the steps of: a. inputting a value representative of the number of
teeth on each side of the dentition; b. inputting at least two
quantities taken from a group consisting of a ratio, an inter-molar
distance and a central incisor width; and c. computing the position
of the teeth within the patients dentition by applying a
mathematical function to the value representative of the number of
teeth on each side of the dentition and the at least two
quantities.
2. A method according to claim 1, wherein the value representative
of the number of teeth on each side of the dentition is a number
between 3 and 10.
3. A method according to claim 1, wherein the position of the teeth
within the dentition is a measure of a visible width of each teeth
as seen from a frontal view of the dentition.
4. A method according to claim 1, further comprising the step of:
d. displaying positioning lines corresponding to the position of
the teeth.
5. A method according to claim 1, further comprising the step of:
d. printing positioning lines corresponding to the position of the
teeth.
6. A method for designing the dentition of a patient, comprising
the steps of: a. providing a visual representation of the
dentition; b. inputting a value representative of the number of
teeth on a side of the dentition; c. inputting at least two
quantities taken from a group consisting of a ratio, an inter-teeth
distance and a central incisor width; d. computing the position of
the teeth within the dentition by applying a mathematical function
to the value representative of the number of teeth on a side of the
dentition and the at least two quantities; and e. juxtaposing
positioning lines over the visual representation of the dentition,
the positioning lines indicating the position of the teeth as
computed in step d.
7. A method according to claim 6, wherein the value representative
of the number of teeth on a side of the dentition is a number
between 3 and 10.
8. A method according to claim 6, wherein the position of the teeth
within the dentition is a measure of a visible width of each teeth
as seen from a frontal view of the dentition.
9. A method according to claim 6, wherein the visual representation
of the dentition is taken from a group consisting of a 2D digital
image of the dentition, a 3D digital image of the dentition, a
digital picture of a patient's dentition, a digital image of
virtual diagnostic wax up and a digital picture of a diagnostic wax
up.
10. A method according to claim 6, further comprising the step of:
f. printing the results of step e.
11. A method according to claim 6, wherein step d. also computes a
missing quantity taken from a group consisting of a ratio, an inter
teeth distance and a central incisor width.
12. A method according to claim 11, further comprising the step of:
f. outputting the missing quantity.
13. A method according to claim 6, wherein the positioning lines
are generally parallel to an axis defined by the length of the
teeth.
14. A method according to claim 6, wherein the positioning lines
are angled with respect to an axis defined by the length of the
teeth.
15. A method according to claim 14, further comprising the step of:
f. adjusting the angle of at least one of the positioning
lines.
16. A system for designing the dentition of a patient, comprising:
means for providing a visual representation of the dentition; means
for inputting a value representative of the number of teeth on a
side of the dentition; means for inputting at least two quantities
taken from a group consisting of a ratio, an inter-teeth distance
and a central incisor width; means for computing the position of
the teeth within the dentition by applying a mathematical function
to the value representative of the number of teeth on a side of the
dentition and the at least two quantities; and means for displaying
positioning lines over the visual representation of the dentition,
the positioning lines indicating the position of the teeth as
computed in step d.
17. A system according to claim 16, wherein the visual
representation of the dentition is taken from a group consisting of
a 2D digital image of the dentition, a 3D digital image of the
dentition, a digital picture of a patient's dentition, a digital
image of virtual diagnostic wax up and a digital picture of a
diagnostic wax up.
18. A method according to claim 16, further comprising means for
printing the positioning lines.
19. A system according to claim 16, wherein the computing means
computes a missing quantity taken from a group consisting of a
ratio, an inter teeth distance and a central incisor width.
20. A system according to claim 19, wherein the displaying means
displays the missing quantity.
21. A system according to claim 16, wherein the positioning lines
are generally parallel to an axis defined by the length of the
teeth.
22. A method according to claim 16, wherein the positioning lines
are angled with respect to an axis defined by the length of the
teeth.
23. A method according to claim 22, further comprising means for
adjusting the angle of at least one of the positioning lines.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of U.S. provisional
patent application No. 60/709,460 filed Aug. 19, 2005 and No.
60/748,196 filed Dec. 8, 2005; which are hereby incorporated by
reference.
TECHNICAL FIELD
[0002] The present invention relates to a dental analysis method
and system. More specifically, the present invention relates to an
analysis method and system for the evaluation, planning and
modification of the dentition of a patient.
BACKGROUND
[0003] In the study of what is considered "beautiful", in nature,
human features, architecture, art, etc., it was discovered that
there is a common principle at work. This common principle is the
universal recognition of pleasant proportions. People have an
inherent ability to recognize that an art object has good or bad
proportions, or that a person's torso compared to his/her legs
looks too long, or too short and out of proportion. This universal
common principle thread of proportion, known since antiquity, is
referred to the Golden Proportion or Divine Proportion.
[0004] Human beauty is also governed by the Golden Proportion.
Squares based The Golden Proportion have been used to define the
ideal location of the pupils and outside corners of the mouth.
Lines based on the Golden Proportion have been used to define, for
example, the ideal positioning of the nose, the tip of the nose,
the inside of the nostrils, the two rises of the upper lip, the
inner points of the ear, the distance from the upper lip to the
bottom of the chin, as well as the width of the nose, the distance
between the eyes and eye brows and the distance from the pupils to
the tip of the nose.
[0005] The Golden Proportion has also been used to study the human
dentition. The four front teeth, from central incisor to premolar
constitute the most significant part of the dentition and they are
in the proportion to each other following the Golden Proportion.
This phenomenon has been combined in a grid which may be used to
assist in perfecting the aesthetics of the front teeth. However,
such grid may be used only for the front four teeth and in some
instances the front six teeth but with mitigated results.
Accordingly, there is a need for a modified
[0006] In the present specification, there is described embodiments
of a method and system designed to overcome the above-described
limitations of the conventional techniques.
SUMMARY
[0007] The present invention relates to a method and system for
designing the dentition of a patient, comprising the steps of:
[0008] inputting a value representative of the number of teeth on
each side of the dentition; [0009] inputting at least two
quantities taken from a group consisting of a ratio, an inter-molar
distance and a central incisor width; and [0010] computing the
position of the teeth within the patient's dentition by applying a
mathematical function to the value representative of the number of
teeth on each side of the dentition and the at least two
quantities.
[0011] The present invention also relates to a method and system
for designing the dentition of a patient, comprising the steps of:
[0012] providing a visual representation of the dentition; [0013]
inputting a value representative of the number of teeth on a side
of the dentition; [0014] inputting at least two quantities taken
from a group consisting of a ratio, an inter-teeth distance and a
central incisor width; [0015] computing the position of the teeth
within the dentition by applying a mathematical function to the
value representative of the number of teeth on a side of the
dentition and the at least two quantities; and [0016] juxtaposing
positioning lines over the visual representation of the dentition,
the positioning lines indicating the position of the teeth as
computed in step d.
[0017] The present invention further relates to a method and system
for designing the dentition of a patient as described above,
further comprising the steps of adjusting the angle of at least one
of the positioning lines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A non-limitative illustrative embodiment of the invention
will now be described by way of example only with reference to the
accompanying drawings, in which:
[0019] FIG. 1 is a schematic diagram illustrating the Golden
Proportion concept;
[0020] FIG. 2 is a front view illustration of the upper teeth of an
individual;
[0021] FIG. 3 is a front view image of the smile of an individual
on which are superimposed positioning lines following a Golden
Proportion with a ratio of 1:1.618;
[0022] FIG. 4 is a front view image of the smile of an individual
on which are superimposed positioning lines following the modified
Golden Proportion with a ratio of 1:1.367;
[0023] FIGS. 5A and 5B are front views of an image of the smile of
an individual on which are superimposed angled positioning
lines;
[0024] FIG. 6 is a front view image of the smile of an individual
on which are superimposed two measurement reference points;
[0025] FIG. 7 is a front view image of the smile of an individual
on which is superimposed a measuring rule;
[0026] FIG. 8 is a front view image of the smile of an individual
on which are superimposed positioning lines following a modified
Golden Proportion with a ratio of 1:1.367 and a measuring rule;
[0027] FIG. 9 is a front view image of the dentition of a virtual
diagnostic wax-up on which are superimposed positioning lines
following a modified Golden Proportion with a ratio of 1:1.367;
[0028] FIG. 10 is a front view image of the dentition of a virtual
diagnostic wax-up on which are superimposed angled positioning
lines following a modified Golden Proportion with a ratio of
1:1.367;
[0029] FIG. 11 is a plan view of a diagnostic grid used for
laboratory work on which are superimposed positioning lines
following a modified Golden Proportion with a ratio of 1:1.38;
[0030] FIG. 12 is a front view image of the smile of a diagnostic
wax-up positioned on top of a diagnostic grid on which are
superimposed positioning lines following a modified Golden
Proportion with a ratio of 1:1.38;
[0031] FIG. 13 is a front view image of the dentition of a
diagnostic wax-up positioned on top of a diagnostic grid on which
are superimposed positioning lines following a modified Golden
Proportion with a ratio of 1:1.38 and a common diagnostic grid on
which are superimposed positioning lines following a Golden
Proportion with a ratio of 1:1.618;
[0032] FIG. 14 is a plan view of an alternative diagnostic grid for
use in an individual's mouth on which are superimposed positioning
lines following a modified Golden Proportion with a ratio of
1:1.38;
[0033] FIG. 15 is a front view image of the smile of an individual
with the alternative diagnostic grid, on which are superimposed
positioning lines following a modified Golden Proportion with a
ratio of 1:1.38, positioned between his or her upper and lower
teeth;
[0034] FIG. 16 is a front view illustration of a modified Golden
Proportion gauge having three points mechanically following a
Golden Proportion with a ratio of 1:1.38;
[0035] FIG. 17 is a front view image of the dentition of an
individual to which is applied a modified Golden Proportion gauge
having three points mechanically following a modified Golden
Proportion with a ratio of 1:1.367;
[0036] FIGS. 18A, 18B and 18C are bottom views of the upper teeth
of an individual on which are superimposed positioning lines with
an associated inter-molar distance;
[0037] FIG. 19 is a flow diagram depicting the modified Golden
Proportion calculator process;
[0038] FIG. 20 is a flow diagram depicting teeth position computing
step of the modified Golden Proportion calculator process of FIG.
19;
[0039] FIG. 21 is an example of a modified Golden Proportion
calculator interface; and
[0040] FIG. 22 is a front view image of the smile of an individual
having received corrective crowns following the modified Golden
Proportion shown in FIG. 21.
DETAILED DESCRIPTION
[0041] Generally stated, the non-limitative illustrative embodiment
of the present invention provides a method and system for the
evaluation, planning and modification of the dentition of an
individual, such as, for example, a patient, by the application of
generally vertical lines, hereby referred to as "positioning
lines", following a modified Golden Proportion, which may be
determined either explicitly or implicitly from measurements such
as, for example, central incisor width and inter-molar distance,
onto the dentition of the patient in order to determine "ideal"
positioning of the patient's teeth. In one embodiment, the
resulting positioning lines may be applied to 2D or 3D digital
images, X-rays, computed tomography (CT) scans, etc., of the
patient's dentition or may be included as part of a modeling or
re-modeling software to dispose the teeth when creating, for
example, ceramic teeth, orthodontic molds, dentures, etc. In a
further embodiment, the positioning lines may be angled at a
specific angle in order to address an occlusion condition or for
aesthetical considerations.
Golden Proportion
[0042] The Golden Proportion, or Divine Proportion, represents a
ratio of 1:1.618. It has been used in a multitude of applications
and is well known in the art. Briefly speaking, referring to FIG. 1
the Golden Proportion may be expressed as:
AB CB = CB A C = 1. 6 1 8. Equation 1 ##EQU00001##
[0043] For example, if the distance AB is 10 mm, then the distance
AC will be 3.82 mm and CB will be 6.18 mm.
Dentition
[0044] Referring to FIG. 2, the dentition (10) generally comprises
the central incisor (11), the lateral incisor (12), the canine
(13), the first premolar (14), the second premolar (15) and the
first molar (16). The second (17) and third (18) molars are usually
not visible in the smile. It is to be understood that for the
purpose of clarity FIG. 2 only shows the left side of the dentition
(10), the right side being symmetrical.
[0045] For the sake of clarity, from thereon reference will be made
to the positioning lines on either the left side or the right side
of the dentition (10) but it is to be understood that by virtue of
symmetry, the same comments apply to the positioning lines on other
side of the dentition (10).
Application of the Golden Proportion
[0046] Referring to FIG. 3, there is shown a front view image of a
patient's dentition (10) on which is applied the Golden Proportion
(ratio of 1:1.618) with seven positioning lines, resulting in a
center positioning line (26) and six side positioning lines (25,
24, 23, 22, 21, 20) on one side of the dentition (10). The center
positioning line (26) is positioned at the center of the dentition
(10) and the last side positioning line (20) is positioned by the
user such that the second positioning line (25) is positioned
between the central incisor (11) and the lateral incisor (12). Once
the first (26) and last positioning lines (20) are positioned, the
remaining side positioning lines (25, 24, 23, 22, 21) are computed
using the Golden Proportion with a ratio of 1:1.618. As may be seen
in FIG. 3, the position of the central incisor (11) and the lateral
incisor (12) generally correspond to side positioning lines (25)
and (24), respectively, but the position of the canine (13) does
not fit with side positioning line (23), the side positioning line
(23) actually passing in the middle of the canine (13).
Application of the Modified Golden Proportion
[0047] Referring now to FIG. 4, there is shown an image of the
patient's smile on which is applied the modified Golden Proportion
(ratio of 1:1.367) with seven positioning lines, resulting in a
center positioning line (6) and six side positioning lines (5, 4,
3, 2, 1, 0) on one side of the dentition (10). The center
positioning line (6) is fixed at the center of the dentition (10)
and the last side positioning line (0) is positioned by the user,
advantageously on the buccal face of the first molar (16), the
remaining side positioning lines (5, 4, 3, 2, 1) being computed
using the modified Golden Proportion with a ratio of 1:1.367. As
may be seen in FIG. 4, the position of the central incisor (11),
the lateral incisor (12), the canine (13) and the first premolar
(14) generally correspond to side positioning lines (5), (4), (3)
and (2), respectively. In an idealized view, shown in FIG. 9, it
may be seen that the modified Golden Proportion may be used to
position the central incisor (11), the lateral incisor (12), the
canine (13), the first premolar (14), the second premolar (15) and
the first molar (16) on a virtual wax-up of a patient using side
positioning lines (5), (4), (3), (2), (1) and (0), respectively.
Furthermore, referring to FIG. 12, the modified Golden Proportion
may be used with a real wax-up of the patient, which in turn is
used to create, for example, crowns for the patient. Thus, in this
illustrative embodiment, using the modified Golden Proportion, 12
front teeth (six on each side) of the dentition (10) were
positioned instead of only four, as seen in FIG. 3. It is to be
understood that the same technique described above using seven
positioning lines for the positioning of 12 front teeth may also be
extended to, for example, nine positioning lines permitting the
positioning of 16 teeth. The number of teeth visible in the smile
may vary from patient to patient depending on the physiognomy of
the patient.
[0048] Although in a modified Golden Proportion with a ratio of
1:1.367 was used in FIG. 4, it is to be understood that it may vary
depending on the physiognomy of the patient or the desired
aesthetical effect. Common ratio values may be, for example, from
1:1.250 to 1:1.500, though more commonly from 1:1.360 and 1:1.400,
and with rare occurrences from 1:1.500 and 1:1.618. It should also
be understood that when using software tools, such as the modified
Golden Proportion calculator which will be introduced further on,
the modified Golden Proportion ratio is not limited to three
decimals and may vary in precision depending on the application.
For example, FIG. 19 shows an interface (200) for a modified Golden
Proportion calculator in which the modified Golden Proportion ratio
(208) is precise up to 13 decimals, i.e. 1.3876540544138.
Computing the Position of the Side Positioning Lines
[0049] As mentioned above, the central positioning line (6) is
placed in the center of the smile and dentition (10) and the last
side positioning line (0) is positioned by the user, advantageously
on the buccal face of the first molar (16), the remaining side
positioning lines (5, 4, 3, 2, 1) being computed using the modified
Golden Proportion for a given ratio. The side positioning lines (5,
4, 3, 2, 1) may be computed as follows:
P(i)=P(i-1)-D/F.sub.i,i=1 to n-2; Equation 2
[0050] where [0051] n is the number of positioning lines; [0052]
P(i) is the position of positioning line(i), i=0 to n-1; [0053]
P(0) and P(n-1) are given; [0054] D is the distance between
positioning lines (0) and (n-1), i.e. [P(0)-P(n-1)];
[0054] F 1 = j = 0 n - 2 R j ; Equation 3 F 1 = F i - 1 / R ; and
Equation 4 ##EQU00002## [0055] R is the ratio of the modified
Golden Proportion;
[0056] which in the context of FIG. 4 translates to:
P(1)=P(0)-D/F.sub.1;
P(2)=P(1)-D/F.sub.2;
P(3)=P(2)-D/F.sub.3;
P(4)=P(3)-D/F.sub.4; and
P(5)=P(4)-D/F.sub.5;
[0057] where: [0058] R, P(0) and P(6) are given; [0059]
D=P(0)-P(6); and [0060]
F.sub.1=R.sup.0+R.sup.1+R.sup.2+R.sup.3+R.sup.4+R.sup.5.
[0061] It is to be understood that, as a result of symmetry,
Equations 2 to 4 may be adapted for computing the position of
positioning lines on the other side of the smile or dentition (10).
Furthermore, it is also to be understood that the positioning of
side positioning line (0) may be either dependent or independent of
the positioning of its corresponding positioning line (00) (see
FIG. 4) on the other side of the smile or dentition (10). This is
to account for the fact that smiles may not always be perfectly
symmetrical or that an image of the patient may not always be
perfectly centered.
[0062] In an alternative embodiments, shown in FIGS. 5A and 5B, the
positioning lines (6', 5', 4', 3', 2', 1', 0') may have
corresponding angles (.theta..sub.6, .theta..sub.5, .theta..sub.4,
.theta..sub.3, .theta..sub.2, .theta..sub.1, .theta..sub.0) while
positioning lines (6'', 5'', 4'', 3'', 2'', 1'', 0'') may have
corresponding angles (.tau..sub.6, .tau..sub.5, .tau..sub.4,
.tau..sub.3, .tau..sub.2, .tau..sub.1, .tau..sub.0) in order to
better conform to the natural positioning of the teeth, to address
a certain condition such as, for example, occlusion, or for
aesthetical reasons. For example, angles of 0, 1.00, 2.00, 2.50,
3.75, 4.40 and 4.50 degrees may be used for angles (.theta..sub.6,
.theta..sub.5, .theta..sub.4, .theta..sub.3, .theta..sub.2,
.theta..sub.1, .theta..sub.0), respectively. It is to be understood
that other angles and that a combination of angles .theta. and
.tau. may also be used.
Measurements
[0063] In order to facilitate the work of the practitioner,
reference points (51, 52) on the image of the patient may be
identified, as shown in FIG. 6, and the distance (53) separating
them inputted into the system, as shown in FIG. 7. In the example
of FIGS. 6 and 7, the reference points (51, 52) are positioned at
the center of the left and right pupils, respectively, and their
distance (53) of 61 mm inputted as a reference. Therefore, using
this reference, the measurement of various features on the image of
the patient may be computed by relating the inputted distance (53)
to the number of pixels between the two reference points (51, 52).
For example, as shown in FIG. 8, the patients inter-molar distance
(54) may be computed using the system, in this example the
inter-molar distance (54) being 52 mm. In this example, the
inter-molar distance is the distance between the buccal faces of
the left and right first upper molars (see FIG. 18A for the
identification of the first upper molars (116, 16)).
Virtual Diagnostic Wax-Up
[0064] Referring to FIG. 9, the practitioner may use the
measurement of the inter-molar distance (54) to create a virtual
diagnostic wax-up (100) using the positioning lines (6, 5, 4, 3, 2,
1, 0) as guidelines as to the size and positioning of the teeth
(11, 12, 13, 14, 15, 16). In an alternative embodiment, shown in
FIG. 10, angled positioning lines (6', 5', 4', 3', 2', 1', 0') may
also be used. It is to be understood that although not shown,
angled positioning lines (6'', 5'', 4'', 3'', 2'', 1'', 0''), as
illustrated in FIG. 5B, may also be used.
[0065] The virtual diagnostic wax-up (100) may then be superimposed
on the image of the patient and properly scaled so as to be able to
view its appearance as a replacement to the patients dentition
(10). If the practitioner wishes to make changes to the virtual
diagnostic wax-up (100) he may make measurements directly on the
image.
[0066] Once the practitioner is satisfied with the aesthetics of
the virtual diagnostic wax-up (100), he may then use the
measurements thus obtained to create a real diagnostic wax-up.
[0067] It is to be understood that the virtual diagnostic wax-up
(100) and the modified Golden Proportion may be included as part of
a CAD CAM, modeling or re-modeling software using, for example, 2D
or 3D models, X-Rays or CT scans of a patient's mouth to dispose
the teeth when creating, for example, ceramic teeth, orthodontic
molds, dentures, etc.
Real Diagnostic Wax-Up
[0068] The practitioner may use an image of the real diagnostic
wax-up, such as the one shown in FIG. 12, and superimpose it on the
image of the patient, properly scaled according to the inter-molar
distance (54) measured on the image of the patient, in order to
view the real wax-up in the patient mouth. It is to be understood
that real diagnostic wax-up created by other processes such as, for
example, laboratory work, may be so viewed, not only those created
from the virtual diagnostic wax-up.
Diagnostic Grid
[0069] Referring to FIG. 11, there is shown a plan view of a
diagnostic grid (110) on which is applied the modified Golden
Proportion (ratio of 1:1.38) with seven positioning lines,
resulting in a center positioning line (6) and six side positioning
lines (5, 4, 3, 2, 1, 0). The diagnostic grid (110) may be made of
a material such as, for example, plastic, paper, cardboard,
plasticized paper, metal, etc.
[0070] Referring now to FIG. 12, a diagnostic wax-up (120) may be
positioned on top of the diagnostic grid (110) and the positioning
lines (6, 5, 4, 3, 2, 1, 0) may be used as guidelines as to the
size and positioning of the teeth (11, 12, 13, 14, 15, 16) of the
diagnostic wax-up (120). The diagnostic grid (110) may also be
used, for quality control, to diagnose a case, to verify a
diagnostic wax-up (120) created from measurements obtained from the
virtual diagnostic wax-up (100), from measurements obtained from
the image of the patient such as shown in FIG. 8, measurements
obtained directly on the patient or from model casts of his
teeth.
[0071] Referring to FIG. 13, there is shown, for comparison
purposes, the wax-up (120) and diagnostic grid (110) of FIG. 12,
the diagnostic grid (110) following a modified Golden Proportion
ratio of 1:1.38, under which is placed a conventional diagnostic
grid (130) following a standard Golden Proportion ratio of 1:1.618.
As it may be observed, the first three positioning lines (6, 5, 4)
of diagnostic grid (110) and the first three positioning lines (36,
35, 34) of conventional diagnostic grid (130) generally correspond
to the positioning of the central incisor (11) and the lateral
incisor (12). However, it may also be observed that the remaining
positioning lines (3, 2, 1, 0) of diagnostic grid (110) generally
correspond to the positioning of the canine (13), the first
premolar (14), the second premolar (15) and the first molar (16)
while the remaining positioning lines (33, 32, 31, 30) of
conventional diagnostic grid (130) do not at all.
[0072] In an alternative embodiment shown in FIG. 14, a diagnostic
grid (140), following a modified Golden Proportion ratio of 1:1.38,
may have a configuration and dimensions suited for insertion in the
mouth of a patient. Referring now to FIG. 15, the practitioner may
position the diagnostic grid (140) between the upper (142) and
lower (144) teeth of a patient and use positioning lines (6, 5, 4,
3, 2, 1, 0) as guidelines as to the positioning of the teeth (11,
12, 13, 14, 15, 16). The practitioner may then establish a
diagnostic regarding the dentition (10) of the patient.
[0073] In a further alternative embodiment, the diagnostic grid
(140) may have some sort of handle or protuberance at the front
(not shown) so as to permit easy insertion and removal of the
diagnostic grid (140) from the patient's mouth.
[0074] In typical applications the diagnostic grids (110, 140) may
be created with a specific central incisor (11) width, i.e.
distance between positioning lines (6) and (5), and a specific
modified Golden Proportion ratio, the placement of the other
positioning lines (4, 3, 2, 1, 0) being set using the selected
modified Golden Proportion ratio and central incisor (11) width.
For example, the width of the central incisor (11) may typically
vary from 7.5 mm to 10 mm in increments of 0.5 mm and the modified
Golden Proportion ratio may vary from 1:1.36 to 1:1.42 in
increments of 0.01, it is understood that more precise in paper. It
is to be understood, however, that other values may be used for the
central incisor (11) as well as other modified Golden Proportion
ratios as previously disclosed. It is to be understood that the
above described diagnostic grids are based on the width of the
central incisor (11) and a given ratio and that more precise
diagnostic grids may be created by using a modified Golden
Proportion calculator, which will be described further below. These
more precise diagnostic grids may also be printed directly on
paper, as will be seen below.
Modified Golden Proportion Gauge
[0075] Referring to FIG. 16, there is shown a modified Golden
Proportion gauge (150) which mechanically follows a modified Golden
Proportion ratio of 1:1.38 with two points, resulting in a center
point (151) and two side points (152, 153). The modified Golden
Proportion gauge (150) may be made of a material such as, for
example, plastic or metal. It is to be understood, however, that
the modified Golden Proportion gauge (150) may follow other
modified Golden Proportion ratios as previously disclosed. In an
alternate embodiment the modified Golden Proportion gauge (150) may
be adjustable so as to permit the selection of a desired modified
Golden Proportion ratio, for example from 1:1.25 to 1:1.50 in 0.01
increments. It is to be understood that other ratio values and
increments may be used as well, for example the possible selection
of modified Golden Proportion ratio may be from 1:1.20 up to
1:1.618.
[0076] Referring now to FIG. 17, the practitioner may position the
center point (151) and the first side point (152) on each side of
the central incisor (11) of a patient, either directly on the
patient's smile or on a photograph of the patient's smile, and use
the second side point (153) as a guideline as to the size and
positioning of the lateral incisor (12). It is to be understood
that the same process may be used on the lateral incisor (12) to
obtain a guideline as to the size and positioning of the canine
(13), and similarly for the first premolar (14), the second
premolar (15) and the first molar (16) (not shown). It in also to
be understood that in an alternative embodiment the modified Golden
Proportion gauge (150) may have more than three points.
Modified Golden Proportion Calculator
[0077] As previously mentioned, the modified Golden Proportion may
be included as part of a modeling and/or re-modeling software or
system using, for example, 2D or 3D models, images, X-Rays or CT
scans of a patient's mouth to dispose the teeth when creating, for
example, ceramic teeth, orthodontic molds, dentures, etc.
[0078] To this end, with reference to FIG. 4, Equations 2, 3 and 4
may be adapted and incorporated into a modeling and/or re-modeling
software or system to calculate the position of side positioning
lines (5, 4, 3, 2, 1, 0) from information inputted by the user of
the software or system and position them onto a 2D or 3D model,
image, X-Ray or CT scan of a patient's mouth, or even print them on
some supporting media. In particular, the position of the side
positioning lines (5, 4, 3, 2, 1, 0) may be computed from inputting
at least two quantities such as, for example, a ratio, i.e.
modified Golden Proportion ratio, an inter-molar distance and a
central incisor width. The various quantities may be inputted
either from a user interface, such as, for example, a keyboard, a
configuration file, by dragging and positioning the positioning
lines (6, 5, 4, 3, 2, 1, 0) or by using some software tool or
interface.
[0079] The molars used for the measurement of the inter-molar
distance may vary depending on the number of positioning lines
used, i.e. depending on the number of teeth that may be seen in the
smile of the patient. For example, referring to FIGS. 18A, 18B and
18C, in the case where six positioning lines (5, 4, 3, 2, 1, 0) are
used (FIG. 18A) the inter-molar distance (95) is taken between the
two second premolars (15, 115), in the case where seven positioning
lines (6, 5, 4, 3, 2, 1, 0) are used (FIG. 18B), the inter-molar
distance (96) is taken between the two first molars (16, 116) and
in the case where eight positioning lines (7, 6, 5, 4, 3, 2, 1, 0)
are used (FIG. 18C), the inter-molar distance (97) is taken between
the two second molars (17, 117). In another example (not shown),
four or five positioning lines may be used, in which case the
inter-molar distance would be taken between the canine and first
premolars, respectively.
[0080] It is to be noted, however, that although reference will be
made to FIG. 18B, in which there are seven positioning lines (6, 5,
4, 3, 2, 1, 0), this is for illustrative purpose only and the
following discussion may similarly apply to other numbers of
positioning lines. Accordingly, for the sake of clarity, the
discussion will focus on the use of seven positioning lines (6, 5,
4, 3, 2, 1, 0) while the procedures will be presented such as to be
applicable to varying numbers of positioning lines.
[0081] In a first non-restrictive embodiment, the position of the
side positioning lines (5, 4, 3, 2, 1, 0), referred to as
LinePosition(i) where i is the numeral identifying the positioning
line, may be calculated from inputting a modified Golden Proportion
ratio, referred to as Ratio, and an inter-molar distance (96),
referred to as InterMolarDistance and applying the procedure
"CentralIncisorWidth". It is to be understood that in the example
of FIG. 18B with seven positioning lines, the variable #OfLines,
which represents the number of positioning lines, will be equal to
seven. As for the inter-molar distance (96), it will be measured
between the two second molars (16, 116). It should be noted that in
addition to calculating the position of the side positioning lines
(5, 4, 3, 2, 1, 0), the procedure also provides the central incisor
width.
TABLE-US-00001 Calculate central incisor width CentralIncisorWidth
(Ratio, #OfLines, InterMolarDistance) LinePosition (#OfLines - 1) =
InterMolarDistance / 2 LinePosition (0) = 0 Constant (1) =
GetFirstPhi (Ratio, #OfLines - 2) For i = 2 to #OfLines - 2
Constant (i) = Contant (i-1) / Ratio Next i For i = 1 to #OfLines -
2 LinePosition (i) = (LinePosition (#OfLines - 1) - LinePosition
(0)) / Constant (i) - LinePosition (i-1) Next i CentralIncisorWidth
= LinePosition (i-1) - LinePosition (i-2) RETURN
CentralIncisorWidth GetFirstPhi (Ratio, #OfLines-2) For n = 1 to
#OfLines - 2 GetFirstPhi = GetFirstPhi + (Ratio {circumflex over (
)} n) Next n GetFirstPhi = GetFirstPhi + 1 RETURN GetFirstPhi
[0082] In a second non-restrictive embodiment, the position of the
side positioning lines (5, 4, 3, 2, 1, 0), referred to as
LinePosition(i) where i is the numeral of the positioning line, may
be calculated from inputting a modified Golden Proportion ratio,
referred to as Ratio, and a central incisor (11) width, referred to
as CentralIncisorWidth, and applying the procedure
"InterMolarDistance". It is to be understood that in the example of
FIG. 18B with seven positioning lines, the variable #OfLines, which
represents the number of positioning lines, will be equal to seven.
It should be noted that in addition to calculating the position of
the side positioning lines (5, 4, 3, 2, 1, 0), the procedure also
provides the inter-molar distance (96), which is the distance
between the two second molars (16, 116).
TABLE-US-00002 Calculate Inter-molar distance InterMolarDistance
(Ratio, #OfLines, CentralIncisorWidth) LinePosition (#OfLines - 1)
= 0 LinePosition (#OfLines - 2) = LinePosition (#OfLines - 1) -
CentralIncisorWidth Calc ( ) For i = #OfLines - 1 to 0 step -1
LinePosition (i) = LinePosition (i) - LinePosition (0) Next i
InterMolarDistance = LinePosition (#OfLines - 1) * 2 RETURN
InterMolarDistance Calc ( ) For i = #OfLines - 1 to 2 step -1
LinePosition (i-2) = LinePosition (i-1) - (LinePosition (i) -
LinePosition (i-1)) / Ratio Next i
[0083] In a third non-restrictive embodiment, the position of the
side positioning lines (5, 4, 3, 2, 1, 0), referred to as
LinePosition(i) where i is the numeral of the positioning line, may
be calculated from inputting a central incisor (11) width, referred
to as CentralIncisorWidth, and an inter-molar distance (97),
referred to as InterMolarDistance, and applying the procedure
"Ratio". It is to be understood that in the example of FIG. 18B
with seven positioning lines, the variable #OfLines, which
represents the number of positioning lines, will be equal to seven.
It should be noted that in addition to calculating the position of
the side positioning lines (5, 4, 3, 2, 1, 0), the procedure also
provides the corresponding modified Golden Proportion ratio.
TABLE-US-00003 Calculate ratio Ratio (InterMolarDistance, #OfLines,
CentralIncisorWidth) LinePosition (#OfLines - 1) =
InterMolarDistance / 2 LinePosition (#OfLines - 2) = LinePosition
(#OfLines - 1) - CentralIncisorWidth Ratio = 1 Calc ( ) p = ratio /
2 For n = 1 to 100 If LinePosition (0) < 0 Then Ratio = Ratio +
p Else Ratio = Ratio - p End If Calc ( ) p = p / 2 Next n RETURN
Ratio
[0084] It is to be understood that in the loop "For n=1 to 100",
during the calculation of the modified Golden Proportion ratio, the
number of times the loop is executed, namely 100, may vary
depending on the desired precision of the result and as such, the
number of times the loop is executed may be more or less than
100.
[0085] Referring now to FIG. 19, there is shown a flow diagram of
the modified Golden Proportion calculator process. The steps
composing the process are indicated by blocks 302 to 310.
[0086] The process starts at block 302, where a visual
representation of the dentition is provided. Then, at block 304, a
value representative of the number of teeth on a side of the
dentition is inputted, this value will be used to determine the
number of positioning lines, i.e. number of teeth plus one, and
between which teeth the inter-molar distance is to be measured.
[0087] At block 306, at least two quantities taken from a group
consisting of a ratio, an inter molar distance (also referred to as
inter-teeth distance because, depending on the value inputted at
block 304, the measurement may not necessarily be taken between
molars as explained previously) and a central incisor width are
inputted.
[0088] At block 308, the process computes the position of the
positioning lines, which are used to determine the position of the
teeth within the dentition, by applying a mathematical function to
the value representative of the number of teeth inputted at block
304 and the quantifies inputted at block 306. The mathematical
function will be further detailed below.
[0089] Finally, at block 310, the positioning lines computed at
block 308 are juxtaposed over the visual representation of the
dentition.
[0090] Referring to FIG. 20, there is shown flow diagram depicting
teeth position computing of block 308 of the modified Golden
Proportion calculator process described above. The steps composing
the process are indicated by blocks 402 to 410.
[0091] At block 402, the process verifies if a central incisor
width was inputted. If a central incisor width was not inputted,
the process executes, at block 404, the CentralIncisorWidth
procedure and then proceeds to block 310 of FIG. 19. If a central
incisor width was inputted, the process proceeds to block 406.
[0092] At block 406, the process verifies if an inter-molar
distance was inputted. If an inter-molar distance was not inputted,
the process executes, at block 408, the InterMolarDistance
procedure and then proceeds to block 310 of FIG. 19. If an
inter-molar distance was inputted, the process proceeds to block
410.
[0093] At block 410, the process executes the Ratio procedure and
then proceeds to block 310 of FIG. 19.
[0094] Referring to FIG. 21, there is shown an example of an
interface (500) that may be used with the modified Golden
Proportion calculator. A first (502), second (504), third (506) and
fourth (508) input boxes may be used to enter the number of lines
to be displayed (#OfLines), the central incisor width
(CentralIncisorWidth), the inter-molar distance
(InterMolarDistance) and the modified Golden Proportion ratio
(Ratio), respectively. As discussed previously, after the number of
lines has been entered in input box (502), which may also be in the
form of a scroll down menu, at least two of input boxes (504),
(506) and (508) must be filled, i.e. two out of the central incisor
width, inter-molar distance and modified Golden Proportion ratio
must be entered.
[0095] To activate the modified Golden Proportion calculator, the
activation buttons (505), (507) and (509) corresponding the missing
quantity is selected. For example, if the central incisor width
(504) and inter-molar distance (506) are entered, then activation
button (509) is selected. The modified Golden Proportion calculator
will then use the Ratio procedure to calculate the position of the
side positioning lines (5, 4, 3, 2, 1, 0) as well as the Modified
Golden Proportion ratio, which is then displayed in input box
(208). It is to be understood that procedures CentralIncisorWidth
and InterMolarDistance are similarly used when activation buttons
(505) and (507) are selected, respectively.
[0096] The positioning lines (6, 5, 4, 3, 2, 1, 0) may then be
displayed (510) on the modified Golden Proportion calculator
interface (500) and/or on an image of the patient's dentition (10),
as shown in FIG. 22. Furthermore, the interface (500) may have
various options such as, for example, the ability to print the
positioning lines (6, 5, 4, 3, 2, 1, 0) on a sheet of paper or to
create, for example, diagnostic grids such as shown in FIGS. 11 and
14, by selecting the print button (512).
[0097] Referring back to FIG. 20, there is shown an example of
possible values obtained from the modified Golden Proportion
calculator with seven lines (Input box 502), a central incisor
width of 8.25 mm (input box 504), an inter-molar distance of 52 mm
(input box 506) and a modified Golden Proportion ratio of
1.3676540544138 (input box 508). The resulting positioning lines
(6, 5, 4, 3, 2, 1, 0) are displayed (510) on the modified Golden
Proportion calculator interface (500).
[0098] Referring now to FIG. 22, there is shown representation of a
image of the dentition (10) of a patient having received corrective
crowns following the modified Golden Proportion calculator values
displayed in the interface (500) of FIG. 21. It may be observed
that the corrected positions of the central incisor (11), lateral
incisor (12), canine (13), first premolar (14), second premolar
(15) and first molar (16) are now generally in accordance with the
corresponding center positioning line (6) and six side positioning
lines (5, 4, 3, 2, 1, 0).
[0099] It is to be understood that the disclosed non-limitative
illustrative embodiments may be used for assisting in various
dental works such as, for example, surgery, fabrication and
positioning of implants, fabrication of ceramic facings and crowns,
fabrication of dentures, orthodontic molds, partial and complete
prostheses, etc.
[0100] Although the present invention has been described by way of
an illustrative embodiment and example thereof, it should be noted
that it will be apparent to persons skilled in the art that
modifications may be applied to the present particular embodiment
without departing from the scope of the present invention.
* * * * *