WO2011073436A1

WO2011073436A1 - Device and method for intraoral 3d data acquisition

Info

Publication number: WO2011073436A1
Application number: PCT/EP2010/070166
Authority: WO
Inventors: Albert Mehl; Thomas Schneider
Original assignee: Universität Zürich
Priority date: 2009-12-17
Filing date: 2010-12-17
Publication date: 2011-06-23
Also published as: DE112010004857B4; DE112010004857A5

Abstract

The invention relates to a device for measuring jaws and parts thereof and to a corresponding measuring method. Further possible uses of the device according to the invention include intraoral drainage for intraoral images and other dental treatment and diagnostic methods.

Description

Device and method for intraoral 3D data acquisition

The present invention relates to a device for measuring pines and parts thereof and a corresponding surveying method. Jaw. Further

Uses of the device of the invention include intraoral draining in intraoral shots and other dental treatment and diagnostic procedures.

State of the art

Tooth surfaces can be scanned three-dimensionally with different measuring systems. Intraoral measuring systems are e.g. in EP 1 984 785 and US 4,575,805. It is also known that various methods measure mandibular movements in all degrees of freedom. US Pat. No. 6,152,731 describes a method for digitizing the tooth surfaces of the upper and lower jaw and relating them to one another via joint axes. It is also known according to the patent DE 35 74 340, to measure lower jaw movements in all degrees of freedom and to record the position data by means of arithmetic unit. In addition, this publication describes how to determine three-dimensional measuring points in the area of the tooth surfaces by means of a stylus tip. DE 102 18 435 finally presents a method for determining the positions of the lower jaw and upper jaw in relation to the position of the electronic registration system which records the jaw joint movements. For this purpose, a bite plate or bite fork is used which has markings which in a known position, for example, to a magnetic receiving plate for the

Measuring sensors stand. If the impressions of the tooth surfaces are measured together with the markings, the desired assignment is obtained.

Disadvantages of the prior art and object of the invention

For the production of functional and long-lasting dental restorations or dentures, it is important to be able to simulate the individual jaw movements and identify interfering contacts. Also, one would like for diagnostic and therapeutic purposes analyze functional disorders during chewing and generally during jaw movements.

For this purpose, a whole series of different jaw movement registration systems is used. Basically, electronic or digital records have significant advantages in terms of accuracy and temporal motion resolution over conventional mechanical recording systems. So far, however, in all described and known methods, the problem is to determine the position of the measuring sensor in relation to the tooth surfaces or jaw sections of the lower jaw and the upper jaw in a simple and precise manner. For example, the indirect impression taken by the bite fork or bite plate with markings, as described in DE 102 18 435, the disadvantage that they must be supplemented usually by further impressions, be it an additional intraoral measurement or the extraoral measurement of plaster models, and these Jaw model data must be registered with the data of the impressions on the bite fork. At the same time, the bite fork must then be removed for the recording of the movement and the measuring sensors have to be newly attached to the lower jaw, which requires additional positioning. Furthermore, the sole one

Determining the position by manually picking up striking reference points using feeler pins is too inaccurate and can lead to errors of several millimeters when calculating the joint parameters. Overall, all the methods and equipment described so far are too susceptible to measurement inaccuracies and the overall implementation too time consuming. This is contrary to a wider dissemination of such methods in practice. From the point of view of the best possible care, it would be necessary to determine and use the individual parameters of the temporomandibular joints as standard in a large part of all restorations to be performed. In the future, the focus will be on direct 3D data acquisition using intraoral measurements. This can then be won

Immediately display movement parameters and values virtually for diagnostic purposes and incorporate them into the CAD calculations of dental restorations or dentures. However, one must also in the context of the entire process to a high overall

Pay attention to impression accuracy, which can not yet be considered sufficient for total jaw recordings (Mehl A, Ender A, Mörman W, Attin Th: Accuracy Testing of a New Intraoral 3D Camera, Int J Comput Dent 12, 1 1 -28 (2009)) , As a rule, intraoral detection systems are used which, due to the limited accessibility in the mouth and the resulting sizes of optics or measuring systems, can only partially detect the tooth surfaces. Downstream data processing makes it possible to combine the individual 3D images into an overall view using existing overlapping areas. This process is known in the art and is referred to as registration or matching. This process is the more accurate, the more structurally the surfaces to be overlaid and the larger the overlapping surface areas are. Especially in the anterior region, however, both conditions can only be met to a very limited extent. Therefore it can be there too

Overlay errors occur that continue into the posterior region.

The present invention is therefore based on the object of providing an intraoral system for SD data acquisition, in particular of teeth, jaw elements and whole jaw and of jaw movements, which overcomes the above-mentioned disadvantages of known methods and devices therefor.

The solution to this problem is to provide the embodiments of the present invention, as characterized in the claims and in the

Description will be explained in more detail.

By the present invention can without tags, without additional

Position determinations and immediately in time the intraoral optical impression and the high-precision registration of temporomandibular joint movements are performed. At the same time an improvement and simplification of the optical impression of whole pines or larger jaw sections can be achieved.

Summary of the invention

In particular, the present invention provides a device for measuring pines or parts thereof and / or for intra-oral draining, comprising a frame with bearing elements for attachment to the jaw, the

bearing elements

at least two intra-lateral bearing elements facing each other and configured to apply a force to each other,

a middle intraoral located between the two intraoral bearing elements

Bearing member adapted to exert a force on the jaw, which is aligned substantially transverse to the force of the two intraoral bearing elements, and

at least one further bearing element which preferably acts extraorally on the upper or lower jaw and which is designed to support the frame under the lower jaw front teeth or above the upper jaw front teeth in relation to the jaw,

include. The device according to the invention preferably has one or more extraoral holders for a measuring device (s) or measuring sensor system, the holder (s) being / is rigidly connected to the device. More preferred is / are at the /

Holder (s) one or more measuring devices extraorally attached to the lower or upper jaw.

Preferably, the lateral intraoral bearing elements are spreading apart

Clamps are arranged, which surround the contour of the jaw at least partially, wherein the bearing elements are formed to cooperate with teeth of the jaw and wherein the brackets are arranged on the jaw to be movable or resilient (see for example Fig. 1, 2, 3, 6, 7, 15-17).

Furthermore, it is inventively preferred to arrange the middle intraoral bearing element in a holder such that it is mounted on the jaw to be movable and / or rotatable so that it interacts with teeth of the jaw.

Preferably, in the device according to the invention, the relative position of the lateral and middle intraoral bearing elements to each other adjustable and fastened. In the device according to the invention, it is further preferred to arrange the further bearing element on the frame displaceable below or above the lateral and middle intraoral bearing elements.

In the aforementioned embodiments, it is further preferred to apply a spring force to the lateral and / or middle intraoral bearing elements and / or the further bearing element.

According to a preferred embodiment of the present device, the lateral intraoral bearing elements and / or the middle intraoral bearing element are designed as conical tips which engage between the teeth. Alternatively, it is also possible to form the lateral and / or middle intraoral bearing elements as at the tooth contours at least partially adapted conditions.

Preferably, the further, preferably extra-oral bearing element is designed as a chin rest.

Furthermore, it is preferred according to the invention for the intraoral bearing elements and / or the further, preferably extraoral, bearing element to be interchangeable. In a further preferred embodiment of the device according to the invention intraoral holders for measuring sensors, which are preferably rigidly connected to the device, and / or structured, preferably intra-oral, reference markers are provided.

Preferably, the components of the device are at least partially for

Weight reduction of a, preferably fiber-reinforced, plastic and / or made of aluminum. In a further embodiment of the device, parts of the device, at least in the relevant radiation or viewing areas, consist of materials which have a

Having radiopacity in the form that at least parts of this device in conventional X-rays, in 3D X-ray images (DVT, CT) or magnetic resonance imaging (MRI) can be seen without this larger areas of the rows of teeth are covered.

The device according to the invention is in particular for

- Creation of a three-dimensional dataset of jaw models or sections of pines;

- recording of jaw movements;

Registration of 3D volume data from the DVT, CT or MRT to the intraorally measured jaw model data, and / or

- intraoral drainage for intraoral or dental treatment. Another object of the present invention is a method for measuring a jaw or parts thereof, comprising the steps

- captive and shake-free attachment of the above-described

Device of a jaw on a lower or upper jaw;

- Measuring at least a portion of the lower and / or upper jaw by one or more measuring device (s), wherein the measuring device (s) at the same time at least part of the device with parts of the row of teeth (s) of the lower and / or upper jaw detected / capture ;and

- Creating a three-dimensional record of at least the part of the lower or upper jaw

includes. According to the invention, the measuring device (s) can be attached to the device, and / or they can be guided separately from the device.

In a particularly preferred embodiment of the inventive method is from the position of one or more structured reference marker (s), the /

(preferably intraorally) may be provided on the device for fixing the measuring device, and / or one and more part (s) of the device determines the position of the measuring device mounted on the device via a holder. In particular, in the method, a dynamic three-dimensional jaw model is created by the optical measuring device or measuring sensor system detecting the relative movement of the lower or upper jaw.

According to a further preferred embodiment of the method according to the invention, the device is attachable to the lower or upper jaw by intraoral bearing elements with teeth of the lower or upper jaw cooperate by applying a holding force and another, for example. Extraoral bearing element on the face in the

Jaw environment supports to fix the intraoral bearing elements in a plane untiltable.

According to the invention, the measuring device (s) used for measuring the jaw or parts thereof or in the device according to the invention can, for example, comprise one or more optical sensors, ultrasonic sensors, motion sensors, pressure sensors and combinations thereof.

In a further embodiment of the method, additional 3D data sets are created by means of DVT, CT and / or MRT and these data records are registered with the intraorally measured data records. Detailed Description of the Preferred Embodiments

It is thus provided according to the invention that a device is fixed to the rows of teeth so that they are stable for the possible applications described

Basis is, for example, a stable and shake-free mounting a measuring electronics allowed, can not be moved or slipped through the soft tissue or allows the positioning of cotton rolls for draining. It is important that this device a trouble and obstacle-free biting of the lower jaw and Mandible allows and even with the movements of the two jaws is not an obstacle to each other. This means that at least the closing bite position and the limit movements under tooth contact such as laterotrusion, mediotrusion and protrusion in a diagnostically and functionally relevant area are possible without restriction. As an indication, it can be assumed that, starting from the habitual intercuspation, it is an area of about 5 mm in the aforementioned movements. It also follows that the relevant free chewing movements and

Mouth opening movements also experienced no significant restrictions. The fixation is carried out by support over three bearing elements (hereinafter also called "pads") on the row of teeth.

The difficulty is to achieve an attachment that works without impression compounds, adhesives or other materials such as composite. Therefore, a fourth support (or a fourth support member) e.g. provided on the chin to stiffen the entire system.

In FIGS. 1 to 5 an embodiment of the device according to the invention is shown for this purpose. A significant advantage is that attachment is very fast, only a very small portion of the tooth surface is covered for optical impression, and the entire device is immediately reusable for the next patient. This is primarily ensured by the fact that the one support, preferably the support in the incisal area (3), by a screw or clamping (spring) device (6) is attached. The other two editions, preferably in the left and right

Posterior region (1, 2) can contribute to attachment by either spring tension (spring band) (1 1, 12) or screwing devices (15) (e.g., Figures 1 and 6). It should be ensured that a certain freedom of positioning of the individual pads is present so that the device can be used for the largest possible number of patients, each with different teeth and tooth sizes.

According to the invention, in the method, parts of the device (eg parts of 8, 9, 11, 12, 11 1) are preferably detected together with the teeth on the individual optical recordings. On the one hand, this serves to draw conclusions about the positioning of the measuring sensor electronics from the position of certain elements or element parts of the device, if their mutual position is known by the component geometries. On the other hand, this improves the registration of the intraoral single images into an overall 3D model, and thus makes jaw imaging faster and more accurate. According to the invention, it is possible to improve the requirements for optical detection and registration by providing certain surface parts of the device or also the entire device with a structure and coating suitable for the optical measurement or by attaching additional elements which comprise them

Have prerequisites (see also below). The distance of one or some of these elements from the teeth is usually chosen so that with a single shot, parts of these elements and parts of the tooth surfaces can be detected simultaneously. On the other hand, a certain distance should be maintained in order to cover as few surface areas of the teeth in the optical recordings. These

Distances also depend on the measuring fields of the measuring systems used intraorally and must be designed accordingly. Figures 1 to 7 show this implementation, Figures 1 1 to 13, the situation in the data sets.

According to the invention, the coupling of an extra-oral measuring sensor system is e.g. intended for the recording of jaw movements or for the determination of position of any kind. In order to be able to calculate or derive the exact position of the measuring sensor system from the intraoral recordings, it is a prerequisite that element parts of the device which were detected by the SD measurement are in a clearly stable position relative to the coupling unit of the measuring sensor system (7). This can, as shown in Figures 1 and 6, e.g. via a torsion-free stable rod (9) which is connected on one side firmly to the element (8) and on the other side to a receiving plate (7) for the measuring unit (see, eg, FIGS. 1, 2, 6, 7 , 15-17).

The measuring unit can be mounted only in a clearly defined position, from which any further individual sensor position can be calculated (see FIGS. 9 and 10). In the end result, e.g. alone from the position of the element (8) or the two arms (1 1, 12) or the possibly applied thereon elements clearly the position of the measuring sensor in relation to the teeth in the mandibular arch are determined (see also Figures 1 1 to 14) , It is also provided according to the invention to use the extra-oral holder in order, for example, to also fix measuring devices for the intraoral measurement or to use it as a support for support (for example Sirona BlueCam measuring camera). This can also be done via pivoting or Schaniervorrichtungen that allow a guided movement of the intraoral measuring device. Furthermore, it should be noted that also a manual support of the intraoral measuring units in general on the inventive

Device is possible. It is further provided according to the invention to extend the method explicitly to the use of intraoral sensors, which are connected in a defined manner with the device (indirect position determination) or whose position is also detected directly by means of intraoral 3D measurement. This can be, for example, small cameras, lasers,

Ultrasonic sensors or motion sensors that record the movements or the distance at any time to the respective antagonist jaw. Furthermore, these may also be pressure sensors which determine the load during chewing or the occlusal contact points. A spatial assignment of the individual measured values to the 3D spatial data of the tooth surfaces is again clearly possible with the aid of the device.

According to the invention it is further preferred if parts or elements of the device are provided, which in a spatially fixed and unique position to the

Coupling units of the measuring sensors (indirectly) or to the measuring sensors themselves (directly) are located and this relation does not change independently of the application and the situation of the jaw (size, toothing etc).

Furthermore, in the context of the method according to the invention, the position of the measuring sensors can be calculated directly from the intraoral 3D image. This is preferably done by software programs that look for known structures / elements in the 3D image, register these structures / elements to each other, and thus control the positions of other elements of the device, such as the device. the coupling unit of

Measuring sensors can calculate. Of course, the manual clicking of

Reference structures and the interactive evaluation of the 3D coordinates possible, but this is more time consuming than with automatic procedures.

Embodiments of the measuring sensors which may be coupled to the device are e.g. optical measuring systems (transit time measurement, triangulation, strip projection, color measurement, etc.), ultrasound systems, motion sensors, pressure sensors, etc. In order to achieve a certain range of contact points under the aspect of individual differences of the rows of teeth, it is preferably proposed a

To integrate hinge device (14) so that the one support (3) and / or the other two supports (1, 2) have a certain rotational freedom, which is stiffened when tightening the screw or fixing the entire system again. Possible

Embodiments are shown in Figures 6 and 7. Preferably, the two other conditions are additionally fixed by a screw device, wherein an eccentric at non-symmetrical support points allows a certain positioning flexibility of the support points (Fig. 6 and 7). It is inventively provided a further embodiment such that the fourth support element (4) by a sliding mechanism (9) can be easily, quickly and safely stabilized in position. In Fig. 2 it can be seen how this can be implemented. By squeezing two spring bands, the rod (5) can slide, releasing the current position of the rod is fixed. Another solution with the same result is the use of a spring-loaded "tab" which engages the grooves ground on a surface of a bar By pressing, for example, a button, the tab can be lifted against the spring tension and the bar can be moved By releasing the button, the rod is fixed again by the rider.Similar further solutions can be imagined, which are subsumed in the claim under the umbrella term of the spring-sliding mechanism.

The intraoral supports or bearing elements can be designed differently. In well-toothed jaw situation, a conical shape has proved to be very suitable (see Fig. 3, 10, 1 1). This allows intervening in the interdental space and thus allows the best possible, in all three directions limited fixation.

At the same time the contact surface is very small, so that hardly a worth mentioning

Loss of information occurs when taking up the buccal surfaces through an intraoral camera. Preferably, the support cone made of Teflon or other tooth-friendly material with a slightly roughened surface and rounded tip. The inclination of the cones preferably goes up slightly to optimally fit the interdental papilla

"To snuggle" and not to hurt.

Is in the field of conditions, for example a prepared, carious or fractured tooth, so that a larger open approximal space is available, it is recommended the use of pads or bearing elements, which can be fixed in the cervical area of the teeth at or slightly below the gingiva. Preferred are forms for this purpose

proposed, as they are known from rubber dam clamps, but are used in the device only on the Bukkaiseite the tooth. It is also possible that the device includes a mechanism to exchange and combine the pads as needed. This can either be with Screw connections are made or by spring-loaded "rider" rails.Other conventional designs are familiar to a person skilled in the art.

It is preferable to attach the extraoral bearing element or the extraoral support to the chin, in order to increase the distance to the other supports and to enable a simple and rapid fixation. In order to avoid soft tissue squeezing and at the same time to stabilize the support as well as possible, it is therefore advantageous to provide a large support surface. This support element is preferably made

Plastic / hard rubber and possibly softer surface designed.

In order to influence the free movements of the lower jaw as little as possible, a weight-saving construction of the device is preferably provided. This can e.g. using glass fiber reinforced elements, aluminum parts, recesses and

Hollow molds on non-loaded parts etc. take place.

In the intraoral measurement of the rows of teeth according to the present

Claims are shown in addition to the soft tissues and tooth surfaces and shares of the device in the three-dimensional data set. For various purposes, it may therefore be useful to at least partially remove these portions of the device. This can e.g. automatically by software. By

Knowing the individual components of the device you can search this in the record and then calculate out. Defects in the background or on the tooth surfaces can be closed by interpolation. Another possibility is to make additional intra-oral recordings of the areas obscured by the device after removal of the device and then to add these to the data set.

Among the uses of the described methods and devices is the use for the measurement of jaw movements and the detection of the

TMJ parameters, the creation of a three-dimensional data set of

Tooth surfaces by intraoral scanning systems and draining at the

Surveying or other dental treatment and diagnostic procedures. When draining, it is also provided according to the invention to use the device in the way in which attached to this other other devices (eg suckers, brackets, wire frames, etc.), the other soft tissues such as cheeks, tongue, lips, etc. hold and or absorb oral fluid. Also for other diagnostic purposes or position determinations elements can be attached to the device according to the invention, which are suitable for the corresponding purposes (eg for rails and Drilling templates, Lego bricks, balls, X-ray opaque materials for wax-ups, backward-planing etc).

Furthermore, it is provided in the invention to use the device for registering 2D or 3D data sets from other imaging diagnostic methods with the intraoral measurement data sets. The diagnostic imaging techniques may be conventional X-ray images, volume data sets from DVT (digital volume tomography), any type of computed tomography (CT), or magnetic resonance imaging (MRI). The device is preferably designed so that it at least partially

However, the materials that are recognized in the special imaging procedures, but the structures that serve as a superposition surface to the intraoral 3D surface data sets or are relevant for diagnostic or therapeutic purposes, not shaded or overlaid with artifacts. By including the device, both data sets can thus be superimposed (registered) in a simpler and more accurate manner on the basis of the structures of the device, and thus the information can be increased.

Claims

claims

1 . Apparatus for measuring pines or parts thereof or for intraoral

Draining, comprising a frame with bearing elements (1, 2, 3, 4) for attachment to the jaw, the bearing elements (1, 2, 3, 4)

- At least two intra-oral lateral bearing elements (1, 2), the one another

opposed and trained to exert force upon each other,

a medial intraoral bearing element (3) disposed between the two intraoral bearing elements and configured to exert a force on the jaw substantially transverse to the force of the two intraoral abutments

Bearing elements is aligned, and

at least one further bearing element (4), which is designed to support the frame below the mandibular anterior teeth or above the maxillary anterior teeth relative to the jaw,

include.

2. Device according to claim 1, wherein one or more extra-oral support (s) (7) are provided for one or more measuring devices which are rigid with the

Device are connected.

3. A device according to claim 2, wherein on the / the holder (s) (7) one or more measuring device (s) are attached to the device extraoral against the lower or upper jaw.

4. Device according to one of the preceding claims, wherein the lateral intraoral bearing elements (1, 2) are arranged on itself aufspreizenden brackets which surround the contour of the jaw at least partially, wherein the bearing elements

(1, 2) are adapted to cooperate with teeth of the jaw and wherein the brackets are arranged to be movable on the jaw.

5. Device according to one of the preceding claims, wherein the central intraoral bearing element (3) in a holder (6) is arranged so that it is mounted on the jaw to move and / or rotatable to cooperate with the teeth of the jaw.

6. Apparatus according to claim 4 or 5, wherein the relative position of the lateral and / or middle intraoral bearing elements (1, 2, 3) to each other adjustable and can be fastened.

7. Device according to one of the preceding claims, wherein the further bearing element (4) on the frame slidably below or above the intraoral bearing elements (1, 2, 3) is arranged.

8. Apparatus according to claim 6 or 7, wherein the lateral and / or middle intraoral bearing elements (1, 2, 3) and / or the further bearing element (4) can be acted upon by a spring force.

9. Device according to one of the preceding claims, wherein the lateral and / or middle intraoral bearing elements (1, 2, 3) are designed as conical tips, which engage between the teeth.

10. Device according to one of claims 1 to 8, wherein the lateral and / or middle intraoral bearing elements (1, 2, 3) are formed as at the tooth contours at least partially adapted pads.

1 1. Device according to one of the preceding claims, wherein the further

Bearing element (4) acts extraorally on the lower or upper jaw.

12. The device according to claim 1 1, wherein the extraoral bearing element (4) is designed as a chin rest.

13. Device according to one of claims 1 to 12, wherein the bearing elements (1, 2 3, 4) are interchangeable.

14. Device according to one of the preceding claims, wherein one or

several intraoral holders are provided for measuring sensors.

15. The apparatus of claim 14, wherein the holder (s) is rigidly connected to the device / are.

16. Device according to one of the preceding claims, in which, preferably intraoral, structured reference markers (8) are provided.

17. Device according to one of the preceding claims, wherein the

Components of the device are at least partially made of a, preferably fiber-reinforced plastic and / or made of aluminum.

18. Device according to one of the preceding claims, wherein the components of the device consist, at least in the relevant radiation or viewing areas of materials having a radiolucency in the form that at least parts of this device in conventional radiographs, in SD x-ray images (DVT, CT) or magnetic resonance images (MRI) are recognizable without covering larger areas of the rows of teeth.

19. Use of the device according to claims 1 to 18 for

- Creation of a three-dimensional dataset of jaw models or

Sections of pine trees;

- recording of jaw movements;

- Intraoral draining during intraoral or dental treatment.

20. A method for measuring a jaw or parts thereof, comprising the steps

- captive and shake-free attachment of a device according to claim 1 to 18 on a lower or upper jaw;

- Measuring the at least part of the lower and / or upper jaw by one or more measuring device (s), wherein the measuring device (s) simultaneously detected at least part of the device with parts of the row of teeth (s) of the lower and / or upper jaw detected and

- Creating a three-dimensional record of at least the part of the lower and / or upper jaw

includes.

21. The method of claim 20, wherein a dynamic three-dimensional

Jaw model is created by the measuring device (s) detected / detected the relative movement of the lower or upper jaw to the opposite upper or lower jaw.

22. The method of claim 20 or 21, wherein at least one measuring device via a holder (7) is attached to the device.

23. The method of claim 22, wherein the position of the measuring device is determined from the position of one or more structured reference markers (s) (8) or / and parts of the device.

24. The method according to any one of claims 20 to 23, wherein the device is attachable to the lower or upper jaw by intraoral bearing elements (1, 2, 3) with teeth of the lower or upper jaw under application of a holding force

cooperate and another bearing element (4) is supported on the face in the jaw environment to fix the intraoral bearing elements (1, 2, 3) in a plane tilted.

25. The method of claim 20, wherein the measuring device comprises one or more optical sensors, ultrasonic sensors, motion sensors, pressure sensors and combinations thereof.