(12) United States Patent
`US 6,334,853 B1
`(10) Patent N0.:
`(45) Date of Patent:
`Jan. 1, 2002
`Kopelman et al.
`
`USOO6334853B1
`
`(54) METHOD FOR OBTAINING A DENTAL
`OCCLUSION MAP
`
`(75)
`
`Inventors: Avi Kopelman, Ramat-Chen; Baruch
`Nissenbaum, Ramat Gan, both of (IL)
`
`(73) Assignee: Cadent LTD, Or Yehuda (IL)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21) Appl. No.:
`
`09/424,195
`
`(22) PCT Filed:
`
`May 14, 1998
`
`(86) PCT No.:
`
`PCT/IL98/00219
`
`§ 371 Date:
`
`Jun. 12, 2000
`
`§ 102(e) Date:
`
`Jun. 12, 2000
`
`(87) PCT Pub. No.: WO98/52493
`
`PCT Pub. Date: NOV. 26, 1998
`
`5,458,487 A * 10/1995 Komatsu et a1.
`5,605,459 A *
`2/1997 Kuroda et a1.
`5,730,151 A *
`3/1998 Summer et a1.
`5,977,979 A * 11/1999 Clough et a1.
`5,989,199 A * 11/1999 Cundari et a1.
`
`............... 433/71
`433/214
`600/587
`345/422
`.............. 600/587
`
`
`
`FOREIGN PATENT DOCUMENTS
`
`EP
`W0
`
`0 593 061
`WO 97/03622
`
`4/1994
`2/1997
`
`............ A61C/19/05
`
`OTHER PUBLICATIONS
`
`for PCT/IL98/00219, dated
`
`International Search Report
`Aug. 31, 1998 (2 pgs.).
`Rakoski, Thomas, et al., “Study Cast Analysis,” Color Atlas
`of Dental Medicine/Orthodontic—Diagnosis, p. 207, pub-
`lished by Thieme Medical Publishers, N. Y.
`
`* cited by examiner
`
`Primary Examiner—Robert L. Nasser
`Assistant Examiner—Charles Marmor, II
`(74) Attorney, Agent, or Firm—Fitch, Even, Tabin &
`Flannery
`
`(30)
`
`Foreign Application Priority Data
`
`(57)
`
`ABSTRACT
`
`May 22, 1997
`
`(IL)
`
`...................................................... 120892
`
`Int. Cl.7 ..................................................... A61B 5/103
`(51)
`(52) US. Cl.
`........................... 600/590; 600/587; 433/214
`(58) Field of Search ..................................... 600/587, 590;
`33/511, 512, 513; 433/68, 69, 214, 229;
`128/898
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`A method for obtaining a dental occlusion map of a three-
`dimensional Virtual computer model of teeth of upper and
`lower jaws of a mouth. The occlusion map indicates the
`distances between opposite regions on facing surfaces of
`opposite teeth of the upper and lower jaws of the mouth. The
`method includes the steps of determining the distances
`between opposite regions on opposite teeth of the upper and
`lower jaws of the mouth, and setting up a correspondence
`between the determined distances and regions on a mapping
`surface.
`
`4,799,785 A
`4,983,120 A *
`
`................ 351/212
`1/1989 Keates et a1.
`1/1991 Coleman et al.
`............... 433/24
`
`13 Claims, 4 Drawing Sheets
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`.30
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`37’
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`34
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`36”
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`32”
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`22
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`Y
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`30"
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`38"
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`'1
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`3SHAPE EXHIBIT 1001
`SSHAPE EXHIBIT 1001
`3Shape v. Align
`3Shape V. Align
`IPR2019-00153
`IPR2019—00153
`
`

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`US. Patent
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`Jan.1,2002
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`Sheet1,0f4
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`US 6,334,853 B1
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`FIG.1
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`US. Patent
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`US. Patent
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`FIG.6
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`US. Patent
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`Jan. 1, 2002
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`Sheet 4 0f4
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`FIG.8
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`FIG.9
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`US 6,334,853 B1
`
`1
`METHOD FOR OBTAINING A DENTAL
`OCCLUSION MAP
`
`FIELD OF THE INVENTION
`
`The invention relates to dental occlusion relations for the
`distances between teeth.
`
`BACKGROUND OF THE INVENTION
`
`In dental procedures in general and more specifically in
`orthodontic procedures, a model of a patient’s teeth is
`required in order
`to make treatment decisions in,
`for
`example, design of braces, crowns, bridges, etc., and to
`allow monitoring of dental procedures. Of particular impor-
`tance is a knowledge of the distance and spatial relationship
`between the teeth on opposite jaws.
`Dental procedures requiring knowledge of the position of
`teeth and the distance between teeth on opposite jaws,
`generally use models of the teeth, referred to hereinafter as
`“dental models”. Typically, plaster dental models are used,
`which are made by casting plaster into the negative impres-
`sion made by teeth in an appropriate matrix. Dental models
`can, however, be made of any convenient material.
`However, this approach has a number of major draw-
`backs. First, in the occluded state it is difficult to see the
`relation between facing surfaces of opposite teeth of the
`upper and lower jaws. Second, on moving a tooth, or adding
`a tooth, or changing the form of a tooth in the dental model,
`it
`is not possible to see if the affected tooth affects the
`occlusion. Third, the information provided by dental models
`regarding proximity of opposite teeth in opposite jaws is
`typically no more than whether certain points of opposite
`teeth make contact, or not, in the occluded state. In order to
`be able to arrive at an optimal closing of the teeth when
`changes are made to one or more of the teeth of the dental
`model, a fairly long and tiresome process of physically
`modelling the affected teeth is required in order to ensure a
`good fit between opposite teeth on opposite jaws in the
`occluded state.
`
`With the advent of powerful computers and advanced
`computer aided design techniques, it would be expected that
`three dimensional virtual dental models would help in
`alleviating the problems encountered with the plaster dental
`models. Storing a computer virtual dental model on a
`computer can be achieved “directly” by scanning and digi-
`tizing the teeth and gums, or “indirectly” by utilizing a
`plaster dental model or the negative impression. The latter
`method is disclosed in PCT Application No. PCT/IL
`96/00036, Publication No. WO 97/03622, published on Feb.
`6, 1997, hereinafter incorporated by reference. However,
`none of the existing virtual computer dental models provide
`tools relating to the distance between opposite teeth on
`opposite jaws.
`
`SUMMARY OF THE INVENTION
`
`It is the object of the present invention to provide a
`method for graphically representing the distance between
`opposite points, or regions, on the surface of opposite teeth
`of the upper and lower jaws. The proposed method exploits
`an existing three-dimensional virtual dental model obtained,
`directly or indirectly, from actual teeth and associated gums.
`The resulting graphical representation of the distance
`between opposite points, or regions, on the surface of
`opposite teeth will be termed an “occlusion map”.
`The occlusion map comprises colored regions, where
`each color corresponds to a given distance, or range of
`
`10
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`15
`
`20
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`25
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`30
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`35
`
`40
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`45
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`50
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`55
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`60
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`65
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`2
`distances, between opposite points or regions on the surface
`of opposite teeth. The occlusion map therefore provides a
`clear indication of the distance between opposite portions of
`the surfaces of opposite teeth. The term “color” used herein
`includes not only all colors and shades of colors but also
`black and white and all shades of grey between black and
`white on a grey scale.
`In accordance with the present invention there is provided
`a method for obtaining a dental occlusion map of a three-
`dimensional virtual computer model of teeth of upper and
`lower jaws of a mouth, said occlusion map indicative of
`distances between opposite regions on facing surfaces of
`opposite teeth of the upper and lower jaws of the mouth, said
`method comprising the steps of:
`(i) determining said distances between opposite regions
`on opposite teeth of the upper and lower jaws of the
`mouth; and
`(ii) setting up a correspondence between said determined
`distances and regions on a mapping surface.
`If desired, said mapping surface is a plane, whereby said
`dental occlusion map is a two-dimensional map of the
`distances between said opposite regions on said opposite
`teeth.
`Alternatively, said mapping surface is a facing surface of
`said facing surfaces of opposite teeth of the upper and lower
`jaws of the mouth.
`In accordance with one embodiment, said facing surface
`belongs to the teeth of said upper jaw, and said lower teeth
`and lower jaw are transparent.
`In accordance with another embodiment, said facing
`surface belongs to the teeth of said lower jaw, and said upper
`teeth and upper jaw are transparent.
`Preferably, said opposite regions on said facing surfaces
`of opposite teeth are colored in accordance with a given
`color scale and wherein each color corresponds to a given
`distance.
`Alternatively, said opposite regions on said facing sur-
`faces of opposite teeth are shaded in accordance with a grey
`scale and wherein each shade corresponds to a given dis-
`tance.
`
`If desired, said opposite regions on said facing surfaces of
`opposite teeth are points.
`Further if desired, said regions on said mapping surface
`comprise at least one pixel.
`By one specific application, said occlusion map only
`shows those distances that are less than one tenth of a
`millimeter.
`By another specific application, said occlusion map only
`shows those distances that are zero in value.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`the invention will now be
`For a better understanding,
`described, by way of example only, with reference to the
`accompanying drawings in which:
`FIG. 1 shows an illustrative perspective view of a virtual
`image dental model in the occluded state;
`FIG. 2 shows four opposite points in a cross-sectional
`view through an upper tooth and an opposite lower tooth
`taken in the ZY—plane at an arbitrary value of X;
`FIG. 3 shows a map onto a line of the distances between
`the four opposite pairs of points shown in FIG. 2;
`FIG. 4 shows a map onto a plane of the distances between
`four opposite pairs of points in four different parallel cross-
`sectional planes taken parallel to the ZY—plane at different
`values of X;
`FIG. 5 shows a map of the distances of FIG. 4 (on a
`smaller scale) superimposed on the outline of the plan view
`of the lower tooth in FIG. 2 looking in the negative Z
`direction;
`
`

`

`US 6,334,853 B1
`
`3
`FIG. 6 shows an occlusion map for the three posterior
`teeth on both sides of the virtual image dental model, shown
`in FIG. 1, superimposed on the outline of the plan view of
`the teeth of the lower jaw looking in the negative Z direc-
`tion;
`FIG. 7 shows a map onto a line of the distances between
`the four opposite pairs of points shown in FIG. 2, whereby
`each determined distance is mapped onto four pixels;
`FIG. 8 shows a partial cross-sectional view through an
`upper tooth and an opposite lower tooth with two opposite
`points shown, each point being surrounded by a small
`region; and
`FIG. 9 shows an illustrative example of a color code key.
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`Attention is first drawn to FIG. 1 showing an illustrative
`perspective view of a virtual image dental model 10 in the
`occluded state. Superimposed on dental model 10 is a
`rectangular Cartesian coordinate system XYZ with the
`XY—plane coinciding with the “occlusion plane”. The occlu-
`sion plane is defined as the horizontal plane through the tips
`of the buccal cusps of the premolars or the tips of the
`mesiobuccal cusps of the first molars and first premolars (see
`Thomas Rakoski, Irmtrud Jones and Thomas M. Graber.
`“Color Atlas of Dental Medicine, Orthodontic-Diagnosis,
`page 207, published by Thieme Medical Publishers, New
`York 1993). As will be described in greater detail below, the
`occlusion plane is used as a reference plane for defining a
`grid system used in the invention. Shown in the figure are
`upper jaw 12 with upper teeth 14 and lower jaw 16 with
`lower teeth 18. Shown in particular are a pair of opposite
`teeth, namely upper tooth 20 and lower tooth 22.
`FIG. 2 shows four opposite points in a cross-sectional
`view through upper tooth 20 and opposite lower tooth 22, of
`FIG. 1. The actual position at which the cross-section is
`taken is of no importance since the figure is for illustrative
`purposes only. The cross-section is taken at an arbitrary
`value along the X-axis and parallel to the ZY-plane. It should
`be noted that since teeth 20 and 22 are at the rear of the jaws
`the buccal and lingual sides of the teeth are substantially
`perpendicular to the Y-axis and therefore it is convenient to
`consider a cross-section parallel to the ZY-plane. However,
`for other teeth it may be more convenient
`to choose a
`cross-sectional plane passing through the Z-axis and making
`an arbitrary angle with the Y axis. Shown are four parallel
`grid lines 30, 32, 34 and 36. These grid lines are parallel to
`the Z-axis, or, equivalently perpendicular to the occlusion
`plane (not shown). Only four grid lines have been shown for
`illustrative simplicity. Grid lines 30, 32, 34 and 36 and the
`curve representing the cross-section of the surface of upper
`tooth 20 cross at points 30', 32', 34' and 36', respectively.
`Similarly, grid lines 30, 32, 34 and 36 and the curve
`representing the cross-section of the surface of lower tooth
`22 cross at points 30", 32", 34" and 36", respectively.
`Each of the two points of the pairs of opposite points (30',
`30"), (32', 32"), (34', 34") and (36', 36") has the same (X, Y)
`coordinates but a different Z coordinate, depending on the
`relative separation of the opposite points of each pair. It
`should be kept in mind that the cross-sectional view shown
`in the figure is obtained from virtual image dental model 10.
`Hence,
`the curves representing the cross-sections of the
`surfaces of the upper and lower teeth are actually made up
`of many discrete points. Hence, the number of parallel grid
`lines could, if desired, be equal to the number of pairs of
`points of the virtual computer model, comprising the upper
`
`4
`and lower curves representing the cross-sections of the
`surfaces of the upper and lower teeth.
`It should also be noted that only those points on opposite
`teeth which have an opposite facing point are taken into
`account for distance determinations. Apoint such as 37' on
`upper tooth 20 has no opposite point on lower tooth 22. That
`is, a grid line passing through point 37' on upper tooth 20
`will not cut the curve representing the cross-section of the
`surface of lower tooth 22. Hence, point 37' has no “facing
`partner” on lower tooth 22 which if it had, would be
`numbered 37". Similarly, point 38" on lower tooth 22 has no
`“facing partner” on upper tooth 20. Hence, points having a
`“facing partner” such as points 30', 32', 34' and 36' on the
`surface of upper tooth 20 lie on a “facing surface” of the
`surface of upper tooth 20, similarly points 30", 32", 34" and
`36" on the surface of lower tooth 22 lie on a “facing surface”
`of the surface of lower tooth 22. Clearly, points such as 37'
`on upper tooth 20 that do not have a “facing partner” on the
`surface of lower tooth 22 do not lie on the “facing surface”
`of upper tooth 20. Likewise, points such as 38" on lower
`tooth 22 that do not have a “facing partner” on the surface
`of upper tooth 20 do not lie on the “facing surface” of lower
`tooth 22.
`
`Since the coordinates of all points comprising the virtual
`image dental model are known, the distances between oppo-
`site points on the grid line can easily be determined. Let the
`distance between point I' on the surface of upper tooth 20
`and its “facing partner” point I" on the surface of lower tooth
`22, be denoted by d(I',I"), then
`
`d(131")=|Z(1')-Z(1")L
`
`where Z(I'), Z(I") are the Z coordinates of the points I', I",
`respectively. The absolute value of the difference between
`the coordinates has been taken since only the magnitude of
`the difference is of interest. For example,
`the distance
`between opposite points 30' and 30" on the upper and lower
`teeth 20 and 22, respectively, is given by
`
`d(30‘,30")=|Z(30')—Z(30")|.
`
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`In this manner the distances between the other three pairs
`of points (32' 32"), (34',34") and (36',36") are found. Each
`of the four values of distance so obtained is then related to
`
`a corresponding shade on a grey scale, or a corresponding
`color on a color scale.
`
`45
`
`As a non-binding example let the distances found corre-
`spond to colors as follows:
`d(30',30")=red, d(32',32")=orange, d(34',34")=yellow,
`and d(36',36")=blue.
`The above four distances are then represented by a map of
`colored dots, or pixels, as shown in FIG. 3. Pixel 40 is red,
`pixel 42 is orange, pixel 44 is yellow and pixel 46 is blue.
`The distance between each pixel is equal to the distance
`between each grid line in FIG. 2, and the order of the pixels
`in FIG. 3 is the same as the order as that of the corresponding
`opposite pairs of points in FIG. 2. That is,
`the distance
`d(30',30") corresponds to pixel 40, the distance d(32',32")
`corresponds to pixel 42, the distance d(34',34") corresponds
`to pixel 44 and the distance d(36',36") corresponds to pixel
`46. In other words,
`the values of the distances between
`opposite pairs of points on opposite upper and lower teeth
`are mapped onto colored pixels on a straight line with the
`distance between adjacent pixels equal
`to the distance
`between adjacent grid lines on which the adjacent pairs of
`opposite points corresponding to the adjacent pixels are
`situated. For example, the distance between pixel 40 and
`pixel 42 is equal to the distance between grid line 30 on
`
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`US 6,334,853 B1
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`5
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`which the opposite pair of points (30',30") are situated and
`grid line 32 on which the opposite pair of points (32',32") are
`situated.
`
`The process described above for generating the line of
`pixels shown in FIG. 3 is now repeated for another cross-
`section of teeth 20 and 22. Preferably, but not necessarily,
`the new cross-section is parallel to the cross-section shown
`in FIG. 2. The new cross-section is preferably, but not
`necessarily, distanced from the cross-section shown in FIG.
`2 by a distance equal to the distance between the grid lines
`shown in FIG. 2. Repeating the process described above in
`the new cross-section gives rise to a new line of colored
`pixels 50, 52. 54 and 56, representing the distances between
`four pairs of opposite points on the upper and lower teeth in
`the new cross-section.
`
`The above process is repeated for another cross-section,
`giving rise to another line of colored pixels 60, 62, 64 and
`66, and is then yet repeated for another cross-section giving
`rise to yet another line of colored pixel 70, 72, 74 and 76.
`The result of this process is shown in FIG. 4 showing a map
`of the 16 colored pixels 40, 42, .
`.
`.
`, 74, 76 onto a plane.
`Again, the distance between neighboring pixels is equal to
`the distance between neighboring grid lines on which the
`adjacent pairs of points corresponding to the adjacent pixels
`are situated.
`
`Although FIG. 4 shows a 4 by 4 matrix of pixels as
`obtained from four cross-sections of the opposite pairs of
`teeth in FIG. 2, with four grid lines in each cross-section, this
`is just an illustrative example. In general, there will be many
`more grid lines and many more cross-sections. In fact, grid
`lines can be drawn through each generating the virtual image
`dental model 10. The grid lines are all parallel to each other
`and are preferably perpendicular to the occlusion plane. It is
`in this sense that the occlusion plane acts as a reference
`plane for the grid lines, as mentioned above.
`In the illustrative example described above the number of
`cross-sections for the opposite pair of teeth 20, 22 was taken
`to be equal to the number of grid lines in the first cross-
`section chosen. However, this was done merely for illustra-
`tive purposes. In general, the matrix of pixels obtained (as
`shown in FIG. 4) will not be square. Also, since teeth are, in
`general, irregular in shape and since opposite teeth do not,
`in general, completely overlap the number of pixels per row
`will, in general, differ from row to row. For example, if the
`pixel map shown in FIG. 4 was generated from another pair
`of opposite teeth, it is quite possible that pixel 56 would be
`missing in the second row of the matrix and that, for
`example, pixel 70 in the fourth row would also be missing.
`The map of distances between pairs of opposite points on
`opposite teeth, such as that shown in FIG. 4 will be referred
`to as an “occlusion map” for the opposite pair of teeth. It is
`often convenient to superimpose an occlusion an opposite
`pair of teeth on the outline of one, or both, of the teeth of the
`pair. FIG. 5 shows the occlusion map of FIG. 4 superim-
`posed on outline 22" of the plan view of lower tooth 22
`looking in the negative Z direction. Clearly, in this case, the
`points comprising the occlusion map are mapped onto the
`facing surface of lower tooth 22. In the same manner, the
`points comprising the occlusion map can be mapped onto
`the facing surface of upper tooth 20.
`Attention is now drawn to FIG. 6, showing an occlusion
`map of the rear three teeth on both sides of the mouth
`superimposed on the outline of the plan view of the teeth of
`lower jaw 16, looking in the negative Z direction. It should
`be clear that the occlusion map could just as well have been
`superimposed on the outline of the plan view of the teeth of
`upper jaw 12 looking in the positive Z direction.
`
`6
`Furthermore, the occlusion map could be superimposed
`on the outline of the plan view of the teeth of both the upper
`and lower jaws and set side by side. This affords easy
`monitoring of dental procedures by allowing a dental
`surgeon, orthodontist or dentist
`to see the relationship
`between the surfaces of opposite teeth (i.e.
`the distances
`between opposite pairs of points on opposite teeth) with the
`jaws closed, by studying the dental occlusion map with
`respect to both the upper and lower teeth. A tooth (or teeth)
`can be fitted with a crown (or a bridge), or a tooth can be
`moved in the virtual three-dimensional computer image of
`the dental model and the influence of the change made on the
`relationship between opposite teeth on the upper and lower
`jaws can be seen by noting color changes in the dental
`occlusion map. Changes can continue to be made until a
`desired spatial relationship between opposite teeth is
`achieved. This type of procedure would clearly be very
`difficult, or almost impossible, to perform on a plaster model
`of the teeth.
`In another embodiment of the invention, the occlusion
`map is superimposed directly on the surface of the three-
`dimensional virtual image of the teeth. For example, the
`occlusion map can be superimposed on the teeth of the lower
`jaw. The lower jaw itself will be colored by some color not
`included in the occlusion map. In this embodiment,
`the
`upper jaw and teeth can either be transparent, but observable
`or not present al all. The virtual image can be rotated so that
`on “looking down” at the lower jaw through the transparent
`upper jaw,
`the occlusion map on the background of the
`surface of the lower teeth can clearly be seen. What actually
`will be seen, is very similar to the result shown in FIG. 6.
`Similarly, the procedure can be reversed and the occlusion
`map can be superimposed on the teeth of the upper jaw. In
`this case the upper jaw will be made opaque and the lower
`jaw and teeth will be transparent or not present at all. Again,
`the three-dimensional virtual image can be rotated so that on
`“looking up” at the upper jaw through the transparent lower
`jaw the occlusion map on the background of the upper teeth
`can be seen. Again, the result is similar to that shown in FIG.
`6. In both theses cases the resulting distance map will also
`be termed an “occlusion map”, since it is also a map of the
`distance between opposite teeth. The occlusion map in this
`case is not planar but takes on the topography of the surface
`of the onto which it is superimposed.
`Several embodiments of the foregoing described method
`for obtaining a dental occlusion map exist. In accordance
`with one embodiment, each determined distance d(I',I") is
`mapped onto several pixels. This is contrary to the mapping
`of each determined distance onto one pixel as illustrated in
`FIG. 3 for one cross-section and FIG. 4 for four cross-
`
`sections. For example, each determined distance d(I',I")
`could be mapped onto four pixels as shown in FIG. 7 for one
`cross-section.
`In accordance with another embodiment, each determined
`distance d(I',I") represents the distance between opposite
`pairs of surface regions on opposite teeth. FIG. 8 shows a
`partial cross sectional view through tooth 20 and lower tooth
`22 around points 32' and 32" of FIG. 2. As shown, each point
`is surrounded by a small region. Point 32' is surrounded by
`region 32'R and point 32" is surrounded by region 32"R.
`What is seen in FIG. 8 is the cross sections of regions 32'R
`and 32"R. These regions can be circular, elliptic, or irregular
`in shape. Furthermore, the points 32' and 32" do not have to
`be located at the geometric center of the regions 32'R and
`32"R. In a manner similar to that described for pairs of points
`of opposite teeth, regions having a “facing partner” such as
`regions 30'R, 32'R, 34'R and 36'R on the surface of upper tooth
`
`10
`
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`US 6,334,853 B1
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`7
`20 lie on a “facing surface” of the surface of upper tooth 20,
`similarly regions 30"R, 32"R, 34"R and 36"R on the surface
`of lower tooth 22 lie on a “facing surface” of the surface of
`lower tooth 22.
`
`The distance d(32',32") between the points 32' and 32" is
`taken to represent the distance between the regions 32R and
`32"R,
`that
`is d(32'R,32"R)=d(32',32"). For a given cross-
`section, each of the determined distances d(I'R,I"R) between
`the regions PR and I"R (e.g., 1:, 30, 32, 34 and 36, as in FIG.
`2) can then be mapped onto one pixel, as shown in FIG. 3,
`or onto several pixels, e.g. four pixels as shown in FIG. 7.
`The above two described embodiments are particularly
`useful when the grid lines are not dense, in which case the
`resulting matrix of pixels is sparse giving rise to an occlu-
`sion map of widely spaced pixels making it difficult to see
`the resulting color variation in the occlusion map.
`In practice, it is useful to provide a color code key for
`relating the colors observed in an occlusion map to the
`distances between opposite pairs of surface regions (or
`points) on opposite teeth. An illustrative example of a
`convenient color code key is shown in FIG. 9. In this
`example, color code key 90 comprises four colors 91, 92, 93
`and 94. Each color can either represent a given distance, or
`a range of distances. For example, in the former case, color
`91 may indicate 0.3 mm and color 93 may indicate a distance
`of 2 mm. Whereas in the latter case, color 91 may indicate
`the range of distances 0.3 to 2 mm and color 92 may indicate
`the range of distances 2.1 to 4 mm.
`For convenience, the color code key is placed along side
`the occlusion map, allowing the user to easily relate the
`colored regions of the occlusion map to distances.
`Although the present invention for graphically represent-
`ing the distances between opposite pairs of regions or points
`has been described with respect to teeth it is contemplated
`that the inventive technique set forth herein is usable and
`workable with respect
`to other objects having facing
`surfaces,and can without undue modification or experimen-
`tation be applied to other objects that would benefit from
`such techniques. Furthermore, the method is not bound to
`representing the distances between the surfaces of opposite
`teeth by colors (or shades of grey), albeit a very convenient
`graphical aid providing the user with an straightforward and
`clear understanding if the distance relation between the
`surfaces of opposite teeth.
`invention has been
`Therefore, although the present
`described to a certain degree of particularity, but it should be
`understood that various alterations and modifications can be
`
`made without departing from the spirit or scope of the
`invention as hereinafter claimed.
`What is claimed is:
`
`1. A method for obtaining a dental occlusion map of a
`three-dimensional virtual computer model of teeth of upper
`and lower jaws of a mouth, said occlusion map indicative of
`distances between opposite regions on facing surfaces of
`
`8
`opposite teeth of the upper and lower jaws of the mouth, said
`method comprising the steps of:
`(i) determining said distances between opposite regions
`on opposite teeth of the upper and lower jaws of the
`mouth; and
`(ii) setting up a correspondence between said determined
`distances and regions on a mapping surface.
`2. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said mapping surface is a
`plane, whereby said dental occlusion map is a two-
`dimensional map of the distances between said opposite
`regions on said opposite teeth.
`3. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said mapping surface is a
`facing surface of said facing surfaces of opposite teeth of the
`upper and lower jaws of the mouth.
`4. The method for obtaining a dental occlusion map in
`accordance with claim 3, wherein said facing surface
`belongs to the teeth of said upper jaw, and said lower teeth
`and lower jaw are transparent.
`5. The method for obtaining a dental occlusion map in
`accordance with claim 3, wherein said facing surface
`belongs to the teeth of said upper jaw, and said lower teeth
`and lower jaw are not present.
`6. The method for obtaining a dental occlusion map in
`accordance with claim 3, wherein said facing surface
`belongs to the teeth of said lower jaw, and said upper teeth
`and upper jaw are transparent.
`7. The method for obtaining a dental occlusion map in
`accordance with claim 3, wherein said facing surface
`belongs to the teeth of said lower jaw, and said upper teeth
`and upper jaw are not present.
`8. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said opposite regions on
`said facing surfaces of opposite teeth are shaded in accor-
`dance with a grey scale and wherein each shade corresponds
`to a given distance.
`9. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said opposite regions on
`said facing surfaces of opposite teeth are colored in accor-
`dance with a given color scale and wherein each color
`corresponds to a given distance.
`10. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said opposite regions on
`said facing surfaces of opposite teeth are points.
`11. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said regions on said
`mapping surface comprise at least one pixel.
`12. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said occlusion map only
`shows those distances that are less than one tenth of a
`millimeter.
`
`13. The method for obtaining a dental occlusion map in
`accordance with claim 1, wherein said occlusion map only
`shows those distances that are zero in value.
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