JP4836787B2 - Methods for labeling dental work and creating dentures - Google Patents

Abstract

The invention relates to a method for aligning digitized dentures (44) displayed on a screen using an input device and a rectangular coordinate system with X, Y and Z axis (22, 24, 25). The aim of the invention is to provide a method which allows the intuitive and simple alignment of virtual models of teeth or rows of teeth or dentures within the scope of visualizing scan data and the CAD modeling of dentures. For this purpose, the Z axis of the coordinate system extends in the plane of the screen and the X axis extends perpendicularly thereto. The origin (28) of the coordinate system intersects the object displayed on the screen and the object is aligned on the screen by a maximum of five degrees of freedom.

Description

  The present invention has an X, Y, and Z axis, a rectangular coordinate system in which the Z axis and the Y axis and their intersection (the origin of the coordinate system) are on the display surface of the monitor, and the X axis is perpendicular to the display surface Based on the digitized dental work, eg a denture or at least one tooth mold, rotating about two axes perpendicular to each other and displacing along the X axis for object zooming It is related with the display method on the monitor. The present invention also relates to a method for creating a denture based on digitized data of a jaw region on which the denture is mounted.

  A standard mouse has been developed for navigation in a two-dimensional system, i.e., generally positioning the mouse arrow on a monitor or personal computer screen. Such a mouse controls two translational degrees of freedom, and in some cases, other functions are operated by auxiliary adjustment wheels.

  A complete three-dimensional alignment for moving an object or navigation for moving a camera or observer requires six degrees of freedom, ie three degrees of freedom for translational movement and three degrees of freedom for rotation. To achieve this, keyboard input and mouse movement are often combined. In that case, intuitive operation is not possible, but rather sufficient practice and a long learning time are required.

  Various input devices such as joysticks or trackballs have been developed for navigation or alignment in three-dimensional space. Although accurate navigation or alignment requires sufficient proficiency, these input devices can usually intuitively control all six degrees of freedom. The main problem in this case is an undesirable overlap of two or more directions of motion.

  In the dental field, no system is known that can perform three-dimensional alignment of a dental model with an input device that is tailored to the subject or interest of the user. Rather, it is normal to use a standard mouse.

  A method for performing orthodontic diagnosis is apparent in International Patent Publication WO-A 1998/53428. For this reason, the image of the jaw is gradually rotated around the Y and Z axes on the display surface of the monitor. In addition, zooming along the X axis is possible.

  In order to display an object at various positions on a monitor, an input device is known that can perform zooming, rotation, and movement of the object within a necessary range by using, for example, Space Mouse (registered trademark). A method for rotating a three-dimensional model around two axes perpendicular to each other is apparent from US Pat. No. 5,557,714.

From US Pat. No. 6,287,121, a method and apparatus for creating a denture part is known. Here, the dentures to be created can be displayed on the monitor.
An input keyboard for displacing an object by 6 degrees of freedom is known, for example, from European patent EP-A 1 283 495 or German patent DE-C 4405314.

  The object of the present invention is to provide an intuitive and easy alignment of dental data, in particular a virtual model of a tooth or dentition, within the framework of visualization of scan data and CAD molding of dentures. It is a problem to improve the method. In addition, based on the digitized data of the jaw area where the denture is mounted, for example, one or more residual roots, the virtual denture displayed on the monitor is easily inspected, and the desired denture is created based on this data. Is to make it possible.

Means for Solving the Problems and Effects of the Invention

The above-described problems are solved in the following manner in the method for displaying digitized dental technicians of the type mentioned at the beginning. That is, the dental technique is aligned along the T axis passing through the origin of the coordinate system on the plane extending from the X axis and the Y axis, and is moved by a maximum of 5 degrees of freedom. Rotation around (Rot _Z ), rotation around T-axis as second degree of freedom (Rot _T ), translation of object along T-axis as third degree of freedom, X-axis as fourth degree of freedom Select translation of the object along. In that case, the dental technician is aligned with respect to the coordinate system so that the origin of the coordinate system always passes through the displayed dental technician.

  According to another embodiment of the present invention, rotation about the X axis can be selected as the fifth degree of freedom, but the dental work is at most the first, second, third and fourth degrees of freedom. It is preferable to move according to the degree.

  In order to further facilitate the intuitive and simple alignment of the displayed dental work, another embodiment of the present invention is such that rotation about the T-axis is limited, i.e., generally oscillating motion is performed. It is configured as follows. In that case, the object can be rotated about the T axis by an angle α (α <360 °, in particular α ≦ 180 °).

  Furthermore, limited movement can be performed along the T-axis, and there is no problem with the display of the dental work.

  Further developing the present invention, the vertical axis of the dental technician consists of a polygonal line including a straight line connecting the center points of each part of the dental technician, for example, each part of the dental prosthesis to be created, for example, along the T axis. Due to the displacement of the dental work, only a movement along one straight line of a polygonal line passing through the origin of the coordinate system is performed. In this case, because of the displacement of the dental work along the first and second straight lines that sequentially follow the angle β (β ≠ 180 °), after the end of the displacement along the first straight line, the second Before the displacement of the dental work along the straight line, the dental work is rotated about the Z axis by an angle β, so that the direction of the course of the second straight line coincides with the course of the previous first straight line. It becomes like this.

  In contrast to an industrial three-dimensional CAD system that can display and manipulate any object--this requires all six degrees of freedom of object motion--in denture CAD casting, the present invention Based on this, the degree of freedom is simplified to 4 or 5. It is sufficient to observe the virtual crown and the treated jaw area. Surrounding areas such as the jawbone, tongue or lips are not important for dental restoration and are not digitized. Computer aided dental restoration does not take into account the roots or teeth covered with gums.

In other words, the present invention provides a method for aligning an object displayed in a coordinate system on a monitor, particularly a digitized portion of a dentition, using an input device, with a maximum of 5 degrees of freedom. In particular, they are aligned with 4 degrees of freedom. That is, 1. Rotation around the Z axis through the origin of coordinates.
2. Rotation about the vertical axis (T-axis) of the object passing through the origin of coordinates along the dentition. In that case, the rotation is particularly limited, i.e. a rocking movement takes place.
3. Translation of the object along the longitudinal axis (T-axis) of the object. Limited in that the origin of coordinates is always within the object.
4). Translation (zoom) along the X-axis from the origin of coordinates to the viewer.

  However, the origin of the coordinate system must remain at the center of the screen or roughly at the center. In that case, the Z axis coincides with the vertical axis of the dental technique unless the dental technique is rotated about the T axis.

  When displaying a large portion of a toothpick, the vertical axis (T) of the object can be formed by, for example, a broken line composed of straight lines connecting the center points of the crowns.

  In particular, the present invention relates to a method for creating a denture, for example, a bridge or a crown based on digitized data of a jaw region, for example, one or a plurality of residual roots, to which the denture is to be mounted, and calculates the denture based on the digitized data, Display on the monitor, inspect the denture displayed by moving the denture up to 5 degrees of freedom, especially 4 degrees of freedom on the monitor, evaluate the displayed denture, change if necessary, and then display And a method for creating a denture based on data corresponding to a denture that has been changed in some cases.

  In that case, pre-digitized data can be combined with callable parameters such as the thickness of the denture to be created or the cement gap between the denture and the remaining root surrounding the jaw area.

  When it is clear from the displayed examination of the denture that the denture does not match the image or the reference value, electronic casting can be performed to create a denture based on the data thus changed.

  The creation of dentures based on the digitized values and digitized values of the jaw area to which the dentures are attached, that is, the CAD-CAM method, is described in, for example, International Patent Publication WO-A-99 / 47065, and the disclosure thereof is clearly shown. Quoted.

  Of course, it is possible to display not only the denture but also the jaw area where the denture is to be covered for visual inspection on the monitor.

  Further developing the present invention, an input device used for object alignment has input units that perform object alignment separately from each other by that degree of freedom. In this case, an input device having four input units is used as the input device, and one input unit is a changeover switch for double activation of another input unit.

  Further developed, adjustment wheels are provided as single or multiple input units. A trackball that performs the functions of at least two input units can also be used as the input device.

According to a preferred embodiment, the input device includes first and second input units rotatable around at least one axis and a push button as a third input unit, and operates the first input unit. Then, when the object is operated around the first axis (T axis) and the second input unit is operated, the object is rotated around the second axis (Z axis) perpendicular to the first axis, and the third If the input unit and the first or second input unit are simultaneously operated, the object is moved along one of the above-mentioned axes, and the third operation unit and the second or first input unit are operated. An input device is used in which the display of the object is displaced perpendicular to the first and second axes (zoom) (displacement along the X axis).

  When using a trackball (sphere) as one of the input units, the similar rotation of the trackball may cause the object to rotate about the first and second axes and an axis perpendicular to these axes. it can.

  According to an alternative, the input device has an operating unit, for example an adjustment wheel, so that each one of the four object movements can be performed individually.

  The operation unit is arranged in the direction of the movement to be performed so that it can be operated intuitively. For example, rotation around the vertical axis is controlled by an adjustment wheel with a vertical rotation axis, and rotation around the longitudinal axis of the object and two translational movements are controlled by an adjustment wheel with a horizontal or nearly horizontal rotation axis.

  In that case, to reduce production costs, for example if one activation switch is used for multiple activations, one operating unit for two or three similarly oriented movements, for example rocking movement and zooming Can be used.

  In another embodiment, the two rotations are integrated by using a sphere (trackball).

  By using a sphere (trackball), rotation around the third axis can be incorporated without an auxiliary operating unit. In this case, the object motion is limited to 5 degrees of freedom.

  Furthermore, it is planned to use a standard mouse that realizes four movements by a combination of mouse movement, push button operation and adjustment wheel movement (scrolling). However, in this case, not all movements of the mouse and the operation unit correspond to the movements of the object.

  In particular, an input device is provided which allows the dental technique to move with a degree of freedom of 4 degrees. The input device includes three first adjustment wheels each having an axis substantially parallel to the operator's hand, and a fourth adjustment wheel having an axis substantially perpendicular thereto. In that case, the two first adjustment wheels can rotate about a coincident axis or an axis parallel to each other, and the remaining first adjustment wheels can rotate about an axis perpendicular to this axis. A fourth adjustment wheel is arranged between two first adjustment wheels arranged in parallel to each other and the remaining first adjustment wheel perpendicular thereto.

  By forming an input device in this connection, a one-handed operation without problems is possible, in which the dental work can be displayed on the monitor in the desired range and its alignment with the observer can be changed.

  Regardless of whether the alignment method according to the present invention is limited to 4 degrees of freedom or 5 degrees of freedom according to the application, limited object motion, particularly with respect to translational motion along the longitudinal axis (T axis) of the object In some cases, limited rotation (oscillation movement) is further performed around this axis. However, full rotation is possible at least about the vertical Z axis perpendicular to the T axis.

  Unlike industrial CAD systems, object alignment can be simplified by limiting the degrees of freedom and separating individual motions based on the present invention. Thus, those who have little or average personal computer experience can use the theory of the present invention. Thus, expensive or expensive training courses or long practice steps are not necessary. Simple intuitive operation is possible.

  Other details, advantages and features of the present invention are not only from the claims and the features found in the claims-alone and / or in combination-but also from the following description of the preferred embodiments found in the drawings. it is obvious.

  The four input devices 1, 2 and 3 to enable alignment of dentures, eg virtual models of caps 44 or dies 18 and 46, within the framework of scan data visualization or denture CAD casting. An embodiment is shown in FIGS.

  Connect to a personal computer with input devices 1, 2, 3 by operating individual input units 10, 11, 12, 13, 14, 15, 16, 32, 34, 36, or by combining their use It is possible to navigate an object, for example a jaw part or a denture 44 mold, with movement limited to 4 degrees of freedom, in some cases 5 degrees of freedom, depending on the application.

  The jaw mold 18, 46 or denture 44 can be navigated in a Cartesian coordinate system with X, Y and Z axes. In the coordinate system, the T-axis with reference numeral 20 is perpendicular to the Z-axis 22 and is in the plane where the X-axis 24 and the Y-axis 25 of the Cartesian coordinate system are stretched. Depending on the rotation of the object 18, 26, 44 around, the T-axis 20 and the Y-axis 25 will coincide or be angled with respect to each other. Apart from this, the X-axis 24, the Y-axis 25, the T-axis 20 and the Z-axis 22 emerge especially from the intersections passing through the center of the monitor, ie the coordinate origin 28.

The T-axis 20 coincides with the digitized elongated object 18 or the central axis of the mold part. The T-axis 20 ends at the boundary of the object but is displayed beyond that. When all three variants of the input devices 1, 2, 3 are used, the adjustment wheel 12 is used to move the object 18 along the T-axis 20, ie, the apparent movement of the coordinate origin 28 (Trans _T ). Is rotated. For example, the adjusting wheel 11 is rotated in the input device 1 and the adjusting wheel 14 is rotated in the input device 2 in order to enable a limited rotation or oscillating motion (Rot _T ) of about 180 ° around the T-axis 20. . In the input device 3, a sphere (trackball) 16 is rotated around a horizontal axis parallel to the center axis (T) of the digitized object.

In order to make a complete rotation (Rot _Z ) around the Z axis 22, the input wheels 1 and 2 operate the adjusting wheel 0, and the input device 3 rotates the sphere 16 about its vertical axis (Z). . Finally, the adjustment wheels 13 are used in the input devices 1 and 3 to enable zooming, that is, to translate along an axis 24 that passes through the coordinate origin 28 and is perpendicular to the axes 22, 25. In the input device 2, the adjustment wheel 14 is further rotated while the push button 15 is being pressed. In that case, the origin 28 of the coordinates remains at the center of the monitor, so that the mold part 18 will not be “invisible”.

  The input device 3 further allows rotation about the vertical axis (Z axis) and the X axis 24 orthogonal to the Y axis. For this purpose, the sphere 16 is rotated around a horizontal axis parallel to the rotation axis of the adjusting wheel 12.

Depending on the input device 1, 2 or 3, the movement limited to 4 degrees of freedom, depending on the application, i.e. full rotation about the vertical axis or Z axis 22, limited translation or zooming along the T axis 20 (Trans _T ) and, in some cases, an alignment scheme with limited rotation (oscillating motion) about the T-axis 20 is possible. Another limiting simplification condition is that the origin 28 of the coordinates is in principle the center of the monitor. Thus, the displayed objects 18, 26, 44 do not deviate from the screen cut during zooming. This movement limited to 4 degrees of freedom is realized by the input devices 1, 2 and 3 as described above. A full rotation around the Z axis 22 is achieved by manipulating the adjustment ring 10 or sphere 16 and a limited translational movement along the T axis 20 is effected by the adjustment ring 12 with a limited rotation (oscillating movement) around the T axis 20. ) Is realized by adjusting wheel 11 or adjusting wheel 14 or ball 16, and translational movement (zoom) along a plane perpendicular to the monitor surface is realized by adjusting wheel 13 or 14 while pressing push button 15.

  A particularly emphasized embodiment of the input device 1 is evident in FIG. 1A. Since the unit or number and function correspond to the input device 1 of FIG. 1, the same reference numerals are used for the same units.

  The rotating shafts of the adjusting wheels 11, 12 and 13 extend along the operator's hand, while the rotating shaft of the adjusting wheel 10 is perpendicular to these rotating shafts. Also, the two adjustment wheels—in this example, adjustment wheels 11 and 13—are arranged parallel to each other and in parallel so that they can rotate around a common axis or axes parallel to each other. Similarly, the adjusting wheel 12 having a rotating shaft extending along the operator's hand is perpendicular to the axes of the adjusting wheels 11 and 13, so that these shafts are generally at right angles. The adjusting wheel 10 is arranged between the adjusting wheels 11 and 13 arranged in parallel and the adjusting wheel 12 whose axis is rotated by 90 ° relative to the adjusting wheels 11 and 13. Since the axis of the adjusting wheel 10 passes through the intersection of the center plane on which the adjusting wheel 12 is stretched and a plane passing between the adjusting wheels 11 and 13, the adjusting wheel 10, 11, 12, 13 is well captured. The dental wheel can be moved along the T-axis by the adjusting wheel 12. The thumb is used for this purpose. The adjustment wheel 11 that can be operated with the index finger can rotate around the T-axis. A rotation around the Z axis is effected by a central adjustment wheel 10 which can also be moved with the thumb. Finally, in order to move the object along the X axis, ie the desired zoom, the adjusting wheel 13 is operated, in particular with the middle finger.

When trying to perform an exercise limited to 5 degrees of freedom according to the application, an input device comprising one trackball (sphere) and two adjustment wheels can be used. By using appropriate input units alone or in combination, rotation around the T axis, rotation around the Z axis, rotation around the X axis perpendicular to the monitor plane and the Z axis, along the T axis In other words, it is possible to perform limited translational movement along the length of the object to be navigated and translational movement (zoom) along the X axis perpendicular to the monitor plane. This can be done by using an input unit as described below.
-Rotation around the horizontal axis (T-axis) due to similar rotation of the trackball-rotation around the vertical axis (Z-axis) due to similar rotation of the trackball-axis perpendicular to horizontal and vertical due to similar rotation of the trackball Rotation around the object-limited translational movement of the object along the longitudinal or T-axis by the first adjustment ring-zooming (translational movement) along the axis perpendicular to the monitor surface by the second adjustment ring

  Another embodiment of an input device 30 is shown in FIG. 4 that allows for visualization of scan data or navigation of a virtual model of a tooth or dentition within a CAD mold casting of a denture. The mouse 30 includes a dial or adjustment ring “jog dial” 32 as a first operation unit and a rotating wheel (“scroll”) 34 or a trackball as a second operation unit surrounded by the dial or adjustment ring. A push button 36 is provided.

  Operate individual input units or use them together to limit objects, eg mold parts 18, 26 to 4 or 5 degrees of freedom, depending on the application, on a monitor connected to a personal computer coupled to a mouse It is possible to navigate with a given movement.

When the input device 30 is used to move the objects 18 and 26 along the T-axis 20, that is, the apparent movement of the coordinate origin (Trans _T ), the push button 36 and the dial or the adjustment ring 32 are used. To do. A dial or adjustment ring 34 is utilized to allow a limited rotational or oscillating motion (Rot _T ) of about 180 ° about the T-axis 20.

In order to perform a full rotation (Rot _Z ) about the Z axis 22, the rotating wheel or adjusting wheel 32 is operated. Finally, to enable zooming, i.e. to perform a translational movement along the axis 24 (X axis) perpendicular to the Z axis 22 through the coordinate origin 28, the push button 36 and the rotating or adjusting wheel 34. Are used simultaneously. In this case, since the origin 28 of the coordinates remains at the center point of the monitor, the object 18 will not be “invisible”.

  The invention for navigating a dental technician on a monitor by moving the dental technician up to 5 degrees of freedom, preferably 4 degrees of freedom, will be described in detail with reference to FIGS. In that case, the cap 44 is considered as an example of a dental prosthesis.

  In FIG. 7, the cap 44 is in an initial state. That is, the origin 28 of the coordinate system is substantially at the center of the cap 44. The Z axis that coincides with the vertical axis of the cap 44 is indicated by the reference numeral 22 as described above, and the Y axis is indicated by the reference numeral 25. The X-axis 24 passing through the origin 28 is perpendicular to the Y-axis 25 and the Z-axis 22, that is, to the plane on which the display surface of the monitor is stretched. At the initial position of the cap 44, the Y axis 25 coincides with the T axis 20 extending along the longitudinal axis of the cap 44. If the cap 44 is rotated around the Z-axis 22 as the first degree of freedom (Rot (Z)), the T-axis 20 is moved correspondingly, as is apparent from the illustration of FIG.

  In FIG. 9, as the second degree of freedom, a swinging motion (Rot (T)) around the T-axis 20 is performed. The displacement of the cap 44 along the T-axis 20 as the third degree of freedom is evident in FIG. In that case, the T-axis 20 is on the display surface and therefore coincides with the Y-axis 25. But this is not an essential feature. Finally, the displacement of the cap 44 along the X-axis 24 indicated by Zoom (X) as the fourth degree of freedom is apparent in FIG. The Y axis 25 and the T axis 20 may not coincide.

  FIG. 11 also reports that, in principle, a cap along the T-axis 20 is used to position the cap 44 relative to the origin 28 so that the origin 28 always intersects the cap 44 or the dental technician shown separately. 44 movements are performed in a limited range.

  5 and 7 to 11, the multi-element model portion 18 or cap 44 is shown. Each vertical axis extends along a straight line in which the T-axis 20 is aligned. However, as can be seen in FIG. 6, the present invention can also be implemented in a dental prosthesis or mold part, i.e. a dental technic whose longitudinal axis extends along an arc. In this figure, a multi-element model portion 46 comprising individual elements 48, 50, 52, 54, 56, 58, 60 is shown. The polygonal line 62 is aligned with the arc in which the elements 48, 50, 52, 54, 56, 58, 60 are located. On the other hand, the broken line 62 is straight lines 64, 66, 68, 70, 72. . . Consists of. The straight lines 64, 66, 68, 70, 72 are between the center points 74, 76, 78, 80, 82, 84, 86 of the elements 48, 50, 52, 54, 56, 58, 60 of the multi-element model portion 46. Go to

In order to rotate or swing the multi-element model portion 46 around the T-axis as the second degree of freedom, or to move along the T-axis as the third degree of freedom, one straight line of the broken line 62 must be coordinated. It must pass through the origin 28 of the system. At that time the linear - Specifies (T ₂ shaft in the present embodiment) straight line 66- is currently active T-axis in this example, move the multi-element model section 46 along which or rotation or rocking about its Can move. When the model portion 46 is moved along the broken line, the straight lines 62, 64, 66, 68, 70, 72 must pass through the origin 28 without fail. There is no need to rotate the model portion 46 when moving from one straight line to another. Rather, the currently effective T-axis defining the second and third degrees of freedom changes as the broken line 62 progresses. In other words, it is not necessary to align the currently valid T-axis with the previous or subsequent T-axis.

As an alternative, when moving the model portion 46 along the polygonal line 62 that defines the apparent vertical axis, the T-axis that currently passes through the origin 28 has the same angle between the X-axis or Y-axis of the coordinate system, respectively. It is possible to align the T-axis that currently passes through the origin 28. Therefore, when the model portion 46 is first moved along the straight line 66, if the break point 88 or 90 defining the straight line 64 or 68 is reached, the axis T ₁ or T ₃ determined by the straight line 64 or 68 is the preceding axis. The model portion 46 is rotated around the Z axis 22 so as to coincide with T ₂ .

  In other words, the model portion 46 is rotated around the Z-axis 22 by an angle corresponding to the angle between the straight lines 64, 66 or 66, 68. Similarly, the model portion is sequentially displaced to the origin 28 and rotated.

  Based on the present invention, it is possible to intuitively and simply align a virtual mold or virtual denture within a frame of visualization of scan data and CAD molding of a denture.

It is a theoretical block diagram of the input device which has four adjustment wheels. It is an improved block diagram of the input device of FIG. It is a theoretical block diagram of the input device which has three adjustment wheels and one changeover switch (push button). It is a principle block diagram of the input device which has one ball | bowl (trackball) and two adjustment wheels. It is a principle block diagram of another embodiment of an input device. It is a principle block diagram of the short dentition for demonstrating the alignment or the navigation system based on this invention. It is a fundamental block diagram of the bridge | bridging part from which a vertical axis | shaft consists of a broken line. Fig. 2 shows a diagram of a dental technician in the initial position. FIG. 8 shows the dental technician of FIG. 7 rotated about the Z axis. Fig. 9 shows the dental craft of Fig. 8 rotated about the T axis. Fig. 10 shows the dental craft of Fig. 9 moved along the Z axis. Fig. 8 shows the dental craft of Fig. 7 moved along the T-axis.

Claims (21)

A rectangular coordinate system having X, Y, and Z axes, the intersection of the Z and Y axes with these axes, or the origin of the coordinate system is on the display surface of the monitor, and the X axis is perpendicular to the display surface A digitized dental work, for example a denture or at least one tooth, rotating the dental work around two axes perpendicular to each other and displacing along the X axis for zooming of the dental work Or in the display method on the monitor of the mold of the jaw area where the denture is to be worn
Aligning the dental work along a T-axis that lies in the plane defined by the X-axis and Y-axis and passes through the origin of the coordinate system, and moves up to 5 degrees of freedom;
Rotation around the Z-axis (Rot _Z ) as the first degree of freedom, Rotation around the T-axis (Rot _T ) as the second degree of freedom, and the dental craft along the T-axis as the third degree of freedom. Select the translational motion, the translational motion of the dental craft along the X axis as the fourth degree of freedom,
The vertical axis of the dental technique is formed by a broken line composed of a plurality of continuous straight lines connecting two parts of the dental technique, with two adjacent straight lines forming an angle β (where β ≠ 180 °). ,
In order to displace the dental technician along the T-axis, the dental technician is displaced along a first straight line passing through the origin among a plurality of continuous straight lines forming the polygonal line,
After the displacement along the first straight line, before the displacement along the second straight line adjacent to the first straight line, the angle formed by the first and second straight lines is the dental work. rotate around the Z axis by β,
Then displacing the dental work along the second straight line passing through the origin ;
A method characterized by.   2. The method according to claim 1, wherein the dental work is moved by a maximum of first, second, third and fourth degrees of freedom. The method according to claim 1, wherein the rotation of the object about the X axis (Rot _X ) is selected as the fifth degree of freedom.   2. Method according to claim 1, characterized in that the dental work is rotated around the T-axis by a maximum angle [alpha], where [alpha] <360 [deg.], In particular [alpha] ≤180 [deg.].   The method according to claim 1, wherein the dental technique is displayed on the monitor so that the origin of the coordinate system passes through the dental technique regardless of the movement or display of the dental technique.   6. A method according to claim 1, wherein the translational movement of the object is limited along the T-axis.   7. The method according to claim 1, wherein the origin of the coordinate system is fixed on the monitor so that the origin remains at a predetermined position on the monitor regardless of the movement of the object. .   8. The method according to claim 1, wherein the coordinate origin is located at or substantially at the center of the monitor.   9. The method according to claim 1, wherein a limited rotation (second degree of freedom) about the T-axis is achieved by reciprocating the object.   10. The input device used for aligning an object on a monitor has an input unit for performing alignment of each degree of freedom of the object separately from each other. The method described in 1.   The method according to claim 7, wherein an input device having four input units is used as the input device.   12. The method according to claim 10, wherein a changeover switch for double activation of another input unit is used as the input unit.   13. A method according to any one of claims 10 to 12, characterized in that an adjustment wheel is used as the input unit or units.   14. A method according to any one of the preceding claims, characterized in that a trackball that performs the function of at least two input units is used as the input device.   When a trackball is used as one of the input units, the object is rotated about the first and second axes and about an axis perpendicular thereto by similar rotation of the trackball. The method according to any one of 7 to 14.   16. The object according to claim 7, wherein the object is moved to a degree of freedom of 4 by operating each input unit according to selection and combining the operations of the two input units. The method described in one.   In the method of creating a denture based on digitized data of the jaw area where the denture is mounted, the denture is calculated based on the digitized data, at least the denture is displayed on the monitor, and the denture is moved on the monitor by a maximum of 5 degrees of freedom. The method according to claim 1, wherein the displayed denture is evaluated, the displayed denture is changed in some cases, and then the denture is created based on data corresponding to the displayed denture.   The method according to claim 17, wherein the denture and the jaw area on which the denture is mounted are displayed on a monitor.   Combine the digitized data of the jaw area to which the denture is to be based, which is the basis for the denture calculation, with the stored parameters such as the denture thickness or the cement gap between the denture and the jaw area, and calculate the denture from the data thus obtained The method according to claim 17, wherein the method is displayed on a monitor.   20. A method according to any one of claims 17 to 19, wherein the denture displayed on the monitor is shaped by electronic modification of the data.   21. A method according to any one of claims 17 to 20, characterized in that the denture and / or jaw area is displaced on the monitor by a maximum of 4 degrees of freedom.

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