JPWO2012004937A1 - Implant design method, implant design apparatus, and implant design program - Google Patents

Abstract

Provided is an implant design device capable of designing a dental implant into an optimal shape for each patient in accordance with the structure and condition of a patient's jawbone. In an implant design apparatus 100 for designing a dental implant using image processing by a computer, a jawbone model creation unit 111 that creates a jawbone model from jawbone data indicating the structure of a patient's jawbone, and an implant that indicates the external shape of the dental implant An implant model creating unit 112 for creating an implant model from data, a simulation unit 110 for simulating an operation of embedding a dental implant in a patient's jaw bone by being incorporated in a specified part of the jaw bone model, and the simulation And a design unit 120 for designing the dental implant from an implant model obtained by modifying and modifying the implant data according to the result of the above.

Description

  The present invention relates to an implant design method, an implant design apparatus, and an implant design program, and in particular, a method and apparatus for designing an artificial root to be embedded in a jaw bone using an image of a patient's jaw bone obtained by computer tomography, and The present invention relates to a simulation program for designing the artificial tooth root.

  Conventionally, as a dental treatment, there is an implant treatment in which an artificial tooth root (hereinafter referred to as a dental implant) is embedded for the purpose of substituting the function of a tooth for a missing portion of a tooth.

  FIG. 16 is a schematic diagram for explaining an example of the structure of a dental implant used for such an implant treatment.

  The dental implant 10 includes, for example, a cylindrical implant body (hereinafter referred to as a fixture) 11 to be embedded in a jawbone, and a post (hereinafter referred to as a fixture) fixed to a screw hole 11a formed in the fixture 11 by screwing or the like. And an upper structure (hereinafter referred to as a prosthetic crown) 13 attached to the abutment 12 with an adhesive or a screw (screw).

  By the way, in order to perform implant treatment more safely and appropriately, it is necessary to examine the condition of the bone of the jaw in detail, and the doctor in charge performs thorough examination and diagnosis by X-ray, intraoral photography, etc. The condition of the implant is examined, and the possibility of implant treatment is examined, such as whether there is a problem in the site where the dental implant is implanted and the bone mass of the site.

  In addition, the attending physician performs a close examination such as a CT scan as necessary.

  Here, CT is an abbreviation for computer tomography, and CT in a broad sense uses not only X-ray CT using X-rays but also a computer such as nuclear magnetic resonance imaging (MRI). CT is a general term for various inspection methods to obtain cross-sectional images. In general, CT is capable of grasping the condition of the body structure by irradiating the human body with X-ray irradiation and computer analysis of data obtained by X-ray irradiation. This is a device for obtaining a cross-sectional image (hereinafter referred to as a CT device). From this cross-sectional image, for example, the form, size, position, etc. of each organ of the body can be confirmed.

  Thus, computer tomography is originally a technique for obtaining a cross-sectional image (such as a circular slice) of an object, but these inspection techniques are not only used as a cross-sectional image, but also by improving the image processing technique, three-dimensional graphics. In many cases, the inspection method is not limited to the “cross section”.

  The basic principle of the CT apparatus will be briefly described.

  The CT apparatus is configured so that the X-ray source and the X-ray detector rotate around the inspection object, and the inspection object in the CT apparatus receives X-rays from all directions. The irradiated X-ray is partially absorbed and attenuated by the inspection object when passing through the inspection object, and then reaches the X-ray detector located on the opposite side of the X-ray source. The intensity of is recorded. That is, the basic data in the CT apparatus is the degree (absorption rate) indicating how much X-rays irradiated to the object from all directions around 360 degrees are absorbed in each direction.

  As a unit of the absorption rate, a unit called HU (Hounsfield unit) in which air is defined as -1000HU and water is defined as 0HU is used, and the expression of transmittance by this is expressed in particular as "CT value (CT number)". Call it.

  The CT apparatus performs a Fourier transform calculation process on the data (CT value) indicating the absorption rate by a computer to reconstruct a three-dimensional image to be inspected.

  Next, the implant treatment will be briefly described.

  FIG. 17 is a diagram for explaining the procedure of implant treatment.

  First, the attending physician examines the structure of the oral cavity, such as the patient's jawbone, using an image obtained by X-ray imaging or computed tomography (CT). At this time, the attending physician examines not only the state of the patient's tooth defect, but also the state of meshing and the joint of the jaw. Then, the dental implant 10 suitable for the patient is selected from a plurality of ready-made products having different sizes and shapes.

  When the dental implant 10 is selected, an embedding hole 50a for embedding the implant 10 is formed in the jaw bone (alveolar bone) 50 supporting the tooth 60 by a drill (FIG. 17A). Next, the fixture 11, which is an implant body, is embedded in the embedded hole 50 a formed in the jawbone 50. A thread (thread) is formed on the outer surface of the fixture 11, and the fixture 11 is screwed into an embedding hole 50 formed in the jawbone (FIG. 17B). After the implant fixture 11 is thus embedded in the jawbone, the screw hole 11a of the fixture 11 is covered with the cap 14, and the fixture 11 and the jawbone 50 are waited for adhesion (FIG. 17C). This adhesion between the fixture and the jawbone is called osseointegration, and this osseointegration takes 2 to 3 months, and in some cases about 6 months.

  Then, after confirming the state of adhesion between the fixture 11 and the jawbone 50, the cap 14 is removed, and the lower threaded portion of the abutment 12 is screwed into the screw hole 11a of the fixture 11, so that the abutment 12 is removed. Mounted on the fixture 11 (FIG. 17D). In this state, the shape of the covering (prosthetic crown) 13 is taken, the prosthetic crown 13 finished according to the shape is attached to the abutment 12, and the implant treatment is completed (FIG. 17 (e)).

  By the way, in such an implant treatment, the doctor in charge has determined the implant position of the implant body (fixture) by visual observation using a jaw bone image obtained by X-ray imaging or X-ray CT imaging, Even if the implantation position is slightly shifted, a fatal accident that damages blood vessels and nerves in the jawbone may occur.

  In view of this, it is becoming possible to simulate an implant treatment so that an implant position with higher safety can be easily set. For example, a simulation for supporting a treatment method using an image obtained by CT scan of a patient's jawbone is widely used (Patent Document 1).

  However, in the past, the most suitable dental implants of several standard shapes and sizes were selected to suit the structure of the patient's jawbone. Even if possible, it has been difficult to meet the requirement of an implant having an optimal shape that matches the jawbone structure of each patient.

  In Patent Document 2, images showing the structure of a patient's jawbone obtained by CT (Computer Tomography) are graphically superimposed on images of various dental implants having different lengths and diameters. A technique for selecting an appropriate dental implant from various dental implants is also disclosed.

Japanese Patent No. 4408430 (Japanese Patent Laid-Open No. 2007-130325) Special table 2009-537190 gazette

  As described above, a method for accurately setting the implantation position of a conventional dental implant by simulation and an image showing a structure of a patient's jaw bone obtained by CT (Computer Tomography) are available in various lengths and diameters. In the technique of selecting a suitable dental implant from among these various implants by superimposing it on images of various dental implants, dental implants of different lengths and diameters are prepared in advance. The problem that it is impossible to embed optimal dental implants suitable for various conditions and structures in the patient's jawbone remains unsolved.

  The present invention has been made to solve the above-described problems, and an implant design method capable of designing a dental implant into an optimal shape for each patient in accordance with the structure and condition of the patient's jawbone. And an implant design apparatus, and an implant design program.

  An implant design method according to the present invention is an implant design method for designing a dental implant by a computer, and includes a step of creating a jaw bone model from jaw bone data indicating a structure of a patient's jaw bone, and an external shape of the dental implant. Creating an implant model from the implant data; simulating an operation of implanting a dental implant in a patient's jawbone by incorporating the implant model into a specified portion of the jawbone model; and depending on the result of the simulation And designing the dental implant from an implant model obtained by modifying and modifying the implant data, whereby the above object is achieved.

  According to the present invention, in the implant design method, the step of performing the simulation includes an upper limit value and a lower limit of the size of the implant model based on a positional relationship between the jaw bone model and the implant model embedded in the jaw bone model. Preferably, the method includes determining a value and issuing a warning when the size of the deformed implant model is outside the range indicated by the upper limit value and the lower limit value.

  According to the present invention, in the above implant design method, the jawbone data indicating the structure of the patient's jawbone is preferably image data obtained by computer tomography of the patient's jawbone.

  According to the present invention, in the above implant design method, the computed tomography is preferably X-ray CT imaging or MRI imaging.

  According to the present invention, in the implant design method, the jawbone data indicating the structure of the patient's jawbone is image data obtained by X-ray CT imaging of the patient's jawbone, and the step of performing the simulation includes the jawbone model In the state where the fixture model is not embedded, a preoperative blood flow parameter that is a measure of the blood flow in the cancellous bone portion of the jawbone model is converted into a CT value included in the image data obtained by the X-ray CT imaging. And a postoperative blood flow parameter serving as a guide for blood flow in the cancellous bone portion of the jaw bone model in a state where the fixture model is embedded in the jaw bone model, the CT value, and the jaw bone model And deriving based on the positional relationship between the implant model and the step of issuing the warning Even if the size of the implanted implant model is within the range indicated by the upper limit value and the lower limit value, the postoperative blood flow is determined from the preoperative blood flow parameter and the postoperative blood flow parameter. When it is determined that the flow rate is lower than the flow rate, a step of issuing a warning is preferable.

  According to the present invention, in the above implant design method, the implant data used at the beginning of the simulation represents an external shape of a specific dental implant selected from a plurality of existing dental implants having different structures, sizes, and materials. Preferably, it is implant standard data.

  According to the present invention, in the implant design method, the step of creating the jaw bone model includes three-dimensional as jaw bone data indicating the structure of the patient's jaw bone by a conversion process of image data obtained by computer tomography of the patient's jaw bone. Creating a three-dimensional jaw model from the three-dimensional image data as the jaw bone data; and creating the implant model includes three steps from the three-dimensional image data as the implant data. Preferably, the method includes a step of creating a three-dimensional implant model, and the step of simulating the operation includes a step of synthesizing the three-dimensional jaw model and the three-dimensional implant model.

  According to the present invention, in the above implant design method, the dental implant includes an implant body that is embedded in the jaw bone of the patient, a post that is fixed to the implant body, and an artificial tooth that is attached to the post. Preferably it is.

  The present invention provides the implant design method, wherein the implant data includes implant body data, strut data, and three-dimensional image data that respectively determine the implant body, the struts, and the outer shape of the dental implant. The step of creating the implant model including artificial tooth data is preferably a step of creating a three-dimensional implant model from the implant body data, strut data, and artificial tooth data.

  According to the present invention, in the implant design method, the step of simulating the operation is a step of simulating a positional relationship between a boundary between a cortical bone portion and a cancellous bone portion in the jaw bone model and an implant body of the implant model. It is preferable to contain.

  According to the present invention, in the implant design method, the step of simulating the operation preferably includes a step of simulating a positional relationship between blood vessels and nerves in the jaw bone model and an implant body of the implant model.

  According to the present invention, in the implant design method, the step of simulating the surgery is based on a step of simulating the movement of the upper jaw and the lower jaw based on the jawbone model, and a simulation result of the movement of the upper jaw and the lower jaw. Preferably, the method includes a step of simulating a load applied to an implant body that supports the artificial tooth and a direction in which the load is applied when the artificial tooth is disposed in a tooth defect portion of the patient's jawbone.

  According to the present invention, in the implant design method, the step of simulating the operation determines whether the patient's jawbone is supported by the implant body based on the load applied to the implant body obtained by the load simulation. It preferably includes a step of simulating.

  An implant design apparatus according to the present invention is an implant design apparatus that designs a dental implant using image processing by a computer, and a jawbone model creation unit that creates a jawbone model from jawbone data indicating the structure of a patient's jawbone; Simulates an implant model creation unit that creates an implant model from implant data indicating the external shape of a dental implant, and an operation for embedding a dental implant in a patient's jaw bone by incorporating the implant model in a specified part of the jaw bone model And a design unit for designing the dental implant from an implant model obtained by correcting and deforming the implant data according to the result of the simulation, thereby achieving the above object. The

  An implant design program according to the present invention is a program for causing a computer to execute an implant design method for designing a dental implant, in which the computer creates a jaw bone model from jaw bone data indicating the structure of a patient's jaw bone; Creating an implant model from implant data indicating an external shape of the dental implant; simulating an operation of embedding a dental implant in a patient's jaw bone by incorporating the implant model into a specified portion of the jaw bone model; And the step of designing the dental implant from an implant model obtained by modifying and deforming the implant data according to the result of the simulation, thereby achieving the above object.

  According to the present invention, a jaw bone model is created from jaw bone data indicating the structure of a patient's jaw bone, an implant model is created from implant data indicating the external shape of a dental implant, and the implant is placed at a designated portion of the jaw bone model. Since the operation of implanting a dental implant in the patient's jawbone is simulated by incorporating the model, and the dental implant is designed from the implant model deformed by correcting the implant data according to the simulation result, the dental implant Can be designed in an optimal shape for each patient in accordance with the structure and state of the patient's jawbone.

FIG. 1 is a diagram for explaining an implant design device according to Embodiment 1 of the present invention. FIG. 1A is a CT scan device for imaging a patient's jawbone, and a patient's jawbone obtained by the CT scan device. FIG. 1B shows a basic configuration of the implant design apparatus, and FIG. 1C shows a specific configuration of the implant design apparatus. FIG. 2 is a diagram for explaining a dental implant that is a target of the implant design apparatus according to the first embodiment, and shows a state in which the dental implant is mounted on an actual patient's jawbone. FIG. 3 shows various dental implants (FIGS. (A) to (d)) as dental implants that are targets of the implant design apparatus according to the first embodiment. FIG. 4 is a diagram for explaining the flow of implant treatment using the implant design apparatus according to the first embodiment. FIG. 4 (a) shows the flow of the entire treatment, and FIG. 4 (b) shows the implant design process. (C) shows the manufacturing process of the implant. FIG. 5 is a diagram illustrating data supplied to the simulation unit 110 included in the implant design device according to the first embodiment. 6A and 6B are explanatory diagrams of a patient's jawbone model. FIG. 6A is a front view of the jawbone model, and FIG. 6B is an enlarged perspective view of the jawbone model. FIG. 7 is a view showing a state where a dental implant model is attached to a patient's jaw bone model. FIG. 7A is a view of the jaw bone model viewed from the front, and FIG. 7B is a view of the jaw bone model. It is an expansion perspective view. FIG. 8 is a diagram for explaining a simulation for making a hole for attaching a fixture to a patient's jawbone model using a drill model. FIG. 9 is a diagram illustrating a state in which a fixture model is embedded in a patient's jawbone model. FIG. 10 shows a state in which an artificial tooth model (prosthetic crown model) is attached to the patient's jawbone model (FIG. 10A), and the shape (length) of the fixture is changed in this state (FIG. 10B). And (c)). FIG. 11 is a cross-sectional view for explaining the inspection of the distance between the fixture and the nerve by changing the length of the fixture with the fixture model embedded in the patient's jawbone model. The state where it is not embedded (FIGS. (A) and (d)), the state where a long fixture is embedded (FIGS. (B) and (e)), the state where a short fixture is embedded (FIGS. (C) and (f) )). FIG. 12 is a diagram illustrating a state in which data obtained as a result of the fixture embedding simulation is displayed on the display screen. FIG. 12A illustrates a state in which a long fixture is embedded, and FIG. , Shows a short fixture embedded. FIG. 13 shows a state in which an artificial tooth model (prosthetic crown model) is attached to a patient's jaw bone model (FIG. (A)), and a state in which the angle of the fixture is changed in this state (FIGS. (B) and (c)). ). FIG. 14 is a cross-sectional view for explaining the inspection of the distance between the fixture and the nerve by changing the angle of the fixture model with the fixture model embedded in the patient's jawbone model. A state where the fixture is not embedded (FIGS. (A) and (d)), a state where the fixture is slightly inclined (FIGS. (B) and (e)), a state where the fixture is further inclined (FIGs. (C) and (f) )). FIG. 15 is a diagram for explaining an implant design apparatus according to Embodiment 2 of the present invention. FIG. 15A is an MRI imaging apparatus for imaging a patient's jaw bone, and a patient's jaw bone obtained by the MRI imaging apparatus. FIG. 15B shows a basic configuration of the implant design apparatus, and FIG. 15C shows a specific configuration of the implant design apparatus. FIG. 16 is a schematic diagram for explaining an example of the structure of a dental implant used for conventional implant treatment. FIG. 17 is a diagram for explaining a general procedure for implant treatment. The step of forming the embedding hole 50a (FIG. (A)), the step of embedding the fixture 11 (FIG. (B)), and the step of attaching the cap 14 (FIG. (C)), an abutment 12 mounting step (figure (d)), and a prosthetic crown 13 attachment step (figure (e)).

  Hereinafter, embodiments of the present invention will be described.

(Embodiment 1)
[A. Description of the configuration of the implant design device]
FIG. 1 is a diagram for explaining an implant design device according to Embodiment 1 of the present invention. FIG. 1A is a CT scan device for imaging a patient's jawbone, and a patient's jawbone obtained by the CT scan device. FIG. 1B shows a basic configuration of the implant design apparatus, and FIG. 1C shows a specific configuration of the implant design apparatus.

  As shown in FIG. 1A, an implant design apparatus 100 according to the first embodiment is an apparatus for designing a dental implant using image data Dah obtained by imaging a patient's jaw bone with a CT scanning apparatus 80. It is. Here, the CT scanning device 80 is a CT device described in the prior art, that is, the human body and the like are subjected to X-ray irradiation and computer analysis of data obtained by the X-ray irradiation. It is the same as the apparatus which obtains the cross-sectional image which can grasp a state.

  This implant design apparatus 100 is a processor 100a for designing a dental implant by simulating an operation of implanting a dental implant in a patient's jawbone, a storage device 100b for storing various data, and the implant design apparatus 100 by a user. A user interface 100c for operation and an output unit 100d for outputting the contents of data processing in the processor 100a are provided, and these are connected to each other via a data bus Db. Here, the user interface 100c includes an operation unit 114 such as a keyboard and a mouse. The output unit 100d includes a display unit 116, a printer (not shown), a voice output unit (not shown), and the like that display the contents of data processing inside the processor 100a.

  Specifically, the storage device 100b of the implant design device 100 includes a jaw bone data storage unit 101 that stores image data Dah indicating the structure of the jaw bone obtained by imaging the patient's jaw bone with the CT scanning device 80, and And an implant standard data storage unit 102 for storing implant standard data SDip indicating the outer shapes of a plurality of prepared dental implants having different structures.

  The processor 100a of the implant design device 100 is programmed to simulate dental surgery and design a dental implant, and is based on jaw bone data Dah indicating the structure of the patient's jaw bone from the jaw bone data storage unit 101. The jaw model Mip (see FIG. 5) based on the jaw bone model creation unit 111 for creating the jaw model Mah (see FIG. 5) and the implant standard data SDip indicating the external shape of the dental implant from the implant standard data storage unit 102 And an implant model creation unit 112 for creating Further, the processor 100a of the implant design apparatus 100 incorporates an implant model Mip into a specified site of the jawbone model Mah, and simulates an operation of implanting a dental implant in the patient's jawbone, and a result of the simulation. The design unit 120 for designing a dental implant from the implant model MMip modified and deformed by the implant model Mip indicated by the implant standard data SDip and the display unit 116 for displaying simulation results and input information are displayed on the jaw bone model Mah. And a display control unit 115 for controlling the display unit 116 so that a state in which the implant model Mip is incorporated in the designated site is displayed.

  Here, the implant model creation unit 112 is configured to modify and deform the implant model Mip indicated by the implant standard data SDip in accordance with the instruction signal Osg indicating the simulation result from the simulation unit 110 to generate the implant model MMip. ing. Further, the jawbone data Dah stored in the jawbone data storage unit 101 is obtained by X-ray CT imaging, but the jawbone data stored in the jawbone data storage unit 101 may be obtained by MRI imaging. Often, image data obtained by computed tomography of the patient's jawbone is preferred. For example, the jaw bone data is two-dimensional image data showing an image of a longitudinal section of a jaw bone along the tooth arrangement direction or an image of a longitudinal section perpendicular to the tooth arrangement direction, and more preferably, the structure of the jaw bone is three-dimensional. 3D image data as shown.

  If the jawbone data Dah stored in the jawbone data storage unit 101 is a two-dimensional image obtained by computer tomography of the patient's jawbone, the jawbone model creation unit 111 performs conversion processing of the two-dimensional image data. By having an image processing unit that creates three-dimensional image data indicating the structure of the patient's jawbone and creating a three-dimensional jawbone model from the three-dimensional image data as the jawbone data, the simulation unit 110 Can supply three-dimensional image data as image data indicating the structure of the patient's jawbone.

  The implant standard data storage unit 102 stores implant standard data SDip indicating the external shapes of a plurality of dental implants having different structures, sizes, and materials. The implant model creation unit 112 stores a plurality of dentists. Implant standard data SDip indicating the external shape of a specific dental implant selected by the attending physician from among the dental implants is supplied as initial implant data.

  The implant model creation unit 112 is configured to create a three-dimensional implant model Mip from the three-dimensional image data as the initial implant data. Therefore, in this embodiment, the simulation unit 110 includes a synthesis processing unit (not shown) that synthesizes images of these models so that the 3D implant model Mip is incorporated in the 3D jaw model Mah. Implant surgery simulation is performed by incorporating a three-dimensional implant model Mip into the three-dimensional jaw model Mah.

  2 and 3 are views for explaining an example of a dental implant designed by the implant design apparatus according to Embodiment 1, and FIG. 2 shows a state in which a predetermined dental implant is mounted on a jaw bone of a patient. ing. FIG. 3 shows another example of the structure of a dental implant (FIGS. 3A to 3D).

  The dental implant 20 includes an implant body (hereinafter also referred to as a fixture) 21 to be implanted in a patient's jawbone 30 and a post (hereinafter also referred to as an abutment) 22 fixed to the fixture 21 by screwing or the like. And an upper structure (hereinafter also referred to as a prosthetic crown) 23 fixed to the abutment 22 with an adhesive or the like.

  Here, the jawbone 30 of the patient has a structure in which the inner cancellous bone 31 is covered with the outer cortical bone 32 and the cortical bone 32 is further covered with the gum 33. A nerve Sp and a blood vessel Bv are disposed inside the cancellous bone 31. In the figure, Bp is an interface between the cancellous bone 31 and the cortical bone 32.

  Further, dental implants have various structures as shown in FIGS. 3 (a) to 3 (d).

  For example, FIG. 3A shows a fixture IPa that is embedded in a narrow portion of the jawbone such as an anterior tooth as an example of the fixture of the implant. FIG. 3B shows a fixture IPb in which threads (threads) Sr are formed in portions other than the upper end and the lower end. Further, FIG. 3C shows a substantially cylindrical fixture IPc, and FIG. 3D shows an implant body IPd in which a fixture part and an abutment part are integrally formed.

  In the first embodiment, as shown in FIG. 2, a case where the abutment 22 is thin and a dental implant 20 of a type in which bacteria are difficult to enter from between the abutment and the gingiva is customized and designed for a patient. explain.

  In this case, the implant standard data SDip supplied as the initial implant data from the implant standard data storage unit 102 to the implant model creation unit 112 includes an implant body (fixture) 21 and a column (abutment) 22 constituting the dental implant 20. , And 3D image data representing the outer shape of the superstructure (prosthetic crown) 23, respectively, include implant body data, strut data, and superstructure data. The implant model creation unit 112 also includes a fixture model 21a, an abutment model 22a, and a superstructure model (prosthetic crown model) 23a from the implant body data, strut data, and superstructure data. Create a Mip.

  In the first embodiment, the simulation unit 110, as shown in FIG. 9, includes the boundary Bp between the cortical bone portion 32a and the cancellous bone portion 31a in the jawbone model 30a, and the implant body (fixture model) 21a of the implant model. The positional relationship between the blood vessel Bv or the nerve Sp in the jawbone model Mah and the implant body (fixture model) 21a of the implant model Mip is output as a simulation result (instruction signal Osg). Output.

  In the first embodiment, the simulation unit 110 determines the ideal position of the prosthetic crown (implant superstructure) at the tooth defect portion of the patient's jawbone based on the jawbone model Mah (see FIG. 5). Simulation, movement simulation simulating the movement of the maxilla and mandible based on the jawbone model Mah, Based on the load simulation that simulates the magnitude and direction of the load applied to the implant body (fixture) that supports the prosthetic crown, and the load applied to the implant body obtained by the load simulation, the implant body To simulate whether the patient's jawbone can be supported Deployment and is intended to perform. Here, in the position simulation, as the ideal position of the prosthetic crown, the position in the tooth arrangement direction in the tooth defect part, the position in the horizontal direction orthogonal to the tooth arrangement direction in the tooth defect part, and the tooth The position in the height direction of the tooth at the missing portion is determined.

  Furthermore, the simulation unit 110 of the first embodiment has a function (design support function) for assisting the design of the implant by simulation as follows.

  That is, the simulation unit 110 determines the upper limit value and the lower limit value of the size of the implant model based on the positional relationship between the jaw bone model and the implant model embedded in the jaw bone model, and the deformation. When the size of the implant model is outside the range indicated by the upper limit value and the lower limit value, a process for issuing a warning is performed.

  Specifically, a user (for example, a physician in charge) has a tooth defect portion A of the patient's jawbone model Mah displayed on the display unit 116 of the implant design device (computer) 100 (see FIGS. 6A and 6B). When the implant standard data SDip stored in the implant standard data storage unit 102 is selected according to the size of the implant, the superstructure model (prosthetic crown model) 23a indicated by the selected implant standard data SDip is a tooth of the jawbone model Mah. It arrange | positions at the defect | deletion part A (refer FIG. 7 (a) and (b)). Thereafter, the optimum position and the optimum size of the prosthetic crown model 23a are determined by the user operation in accordance with the spacing between adjacent teeth in the tooth defect portion A of the jawbone model Mah and the size of those teeth. At this time, the user determines an ideal position and size of the prosthetic crown model 23a within a range in which there is no warning from the simulation unit 110.

  Thereafter, the user inserts the fixture model 21a in the patient's jaw bone model Mah displayed on the display unit 116 based on the ideal position of the prosthetic crown model 23a determined for the model Mah, and The direction (angle in the horizontal plane and the vertical plane) of the abutment model 22a is determined.

  Further, based on the insertion position of the fixture model 21a and the direction of the abutment model 22a, the user determines the fixture according to the boundary position between the cortical bone portion 32a and the cancellous bone portion 31a in the jawbone model 30a. The maximum possible design value as the thickness of the fixture is determined, and the minimum possible design value as the thickness of the fixture is determined based on the load on the fixture.

  Further, based on the positional relationship between the position of the nerve Sp or blood vessel Bv (see FIG. 9) in the jawbone model 30a and the fixture model 21a, the maximum possible design value as the fixture length is determined, and the cancellous bone The necessary length of the fixture in the cancellous bone portion is determined based on the CT value which is an index of the bone density of the bone. In other words, the fixture and the cancellous bone adhere to each other after the fixture is implanted, and the fixture is firmly bonded to the jawbone. However, the support strength at the cancellous bone varies depending on the bone density of the cancellous bone. In other words, the minimum necessary length of the fixture is determined by the bone density of the cancellous bone.

  In addition, the simulation unit 110 obtains preoperative blood flow parameters that serve as a guide for blood flow in the cancellous bone portion of the jaw bone model in a state where the fixture model is not embedded in the jaw bone model by the X-ray CT imaging. And a postoperative blood flow parameter that serves as a guide for blood flow in the cancellous bone portion of the jaw bone model in a state where the fixture model is embedded in the jaw bone model. May be performed on the basis of the CT value and the positional relationship between the jawbone model and the implant model. In this case, the process for issuing the warning may be performed even if the deformed implant model has a size within the range indicated by the upper limit value and the lower limit value. Therefore, when it is determined that the blood flow after the operation is lower than the blood flow before the operation, it is preferable to be configured to issue a warning.

  Here, the preoperative blood flow parameter, that is, the preoperative blood flow parameter, which is a measure of the blood flow in the cancellous bone portion without the fixture embedded, is the tooth arrangement direction of the area occupied by the cancellous bone in the jawbone. Calculated based on the area (cross-sectional area of the cancellous bone region) perpendicular to the CT, CT value, and blood vessel distribution. However, the cross-sectional area of the cancellous bone region is obtained in the range from the upper end of the cancellous bone region to the depth reached by the fixture.

  In addition, postoperative blood flow parameters, and postoperative blood flow parameters that serve as a measure of blood flow in the cancellous bone with the fixture embedded, are perpendicular to the tooth arrangement direction in the area occupied by the cancellous bone in the jawbone. It is calculated based on the cross-sectional area (cross-sectional area of the cancellous bone region), CT value, and blood vessel distribution. However, it is assumed that the cross-sectional area of the cancellous bone region is obtained in a range from the upper end of the cancellous bone region to the fixture embedding depth.

  Here, the CT value is a measure of the moisture content in the tissue taken by X-ray CT, and the CT value obtained by X-ray CT of the bone portion is a measure of bone density. At the same time, it can be used as a blood flow parameter serving as an index of blood flow.

  Further, the design support function of the simulation unit includes a function for instructing the display control unit 115 to display an upper limit value and a lower limit value as design guidelines and an alarm on the display unit 116 as follows. It is out.

  Specifically, FIG. 12 shows a state in which the simulation result is displayed on the display unit.

  In FIGS. 12A and 12B, F is a screen for displaying the simulation result, and Dg and Dn are a graph display portion and a numerical value display area of the screen F.

  The numerical value display portion Dn includes first to sixth numerical value display areas Dn1 to Dn6.

  For example, in the first numerical value display area Dn1, the maximum design value possible as the thickness of the fixture is displayed based on the boundary position Bp (see FIG. 2) between the cortical bone and the cancellous bone in the jawbone 30. In the second numerical value display area Dn2, the minimum design value possible as the thickness of the fixture is displayed based on the load related to the fixture.

  The third numerical value display area Dn3 displays the maximum possible design value as the fixture length based on the position of the nerve Sp or blood vessel Bv (see FIGS. 2 and 9) in the jawbone 30. In the fourth numerical value display area Dn4, the necessary length of the fixture in the cancellous bone portion is displayed based on the CT value as an index of the bone density of the cancellous bone.

In the fifth and sixth numerical value display areas Dn5 and Dn6, blood flow parameters serving as a measure of the amount of blood flow in the jawbone are displayed. That is, in the fifth numerical value display area Dn5, preoperative blood flow parameters serving as a guide for blood flow in the cancellous bone portion without the fixture being embedded are displayed. In addition, in the sixth numerical value display area Dn6, a postoperative blood flow parameter serving as a guide for blood flow in the cancellous bone portion in a state where the fixture is embedded is displayed.
[B. Description of operation of implant design device]
Next, the operation of the implant design apparatus according to the first embodiment will be described along with the flow of implant treatment.

  FIG. 4 is a diagram for explaining the flow of implant treatment using the implant design apparatus according to the first embodiment, FIG. 4 (a) shows the flow of the entire implant treatment, and FIG. 4 (b) is for dental use. An implant design process is shown, and FIG. 4C shows a manufacturing process of a dental implant.

  First, when performing an implant treatment, a dental state is diagnosed in advance (procedure P1).

  Periodontal disease (alveolar pyorrhea) is a disease in which the alveolar bone (the part that supports the bones and roots inside the gingiva) is destroyed. If implant treatment is performed without treating periodontal disease, Bacterial infections can occur in the embedded surrounding tissue, and if the surrounding tissue of the dental implant suffers from periodontal disease, the dental implant will fall off as well as the natural teeth come off.

  Furthermore, it is necessary to check the patient's engagement when performing the implant treatment.

  At present, dental implant troubles are often caused by abnormal force applied by poor biting rather than infection.

  In particular, it may cause problems in the implant due to bruxism and clenching, which is called a parafunction, and it is very important to check the meshing before implant treatment.

  Next, the treatment plan based on the diagnosis is explained to the patient (procedure P2).

  For example, if you have tooth decay on another tooth or have periodontal disease, the implant treatment cannot be performed immediately. Therefore, the dental treatment of the surrounding teeth and the treatment of periodontal disease (alveolar pyorrhea) before the implant treatment. Explain that it is necessary to perform bone regeneration treatment for patients who have insufficient bone mass.

  Subsequently, the dental implant 20 is designed using the implant design device 100 of the first embodiment (procedure P3). The implant design process (procedure P3) includes a fixture design process (procedure P3a), an abutment design process (procedure P3b), and a superstructure design process (procedure P3c). In addition, a surgical jig used for implant surgery is also designed in accordance with the designed dental implant (procedure P5).

  For example, as shown in FIG. 8, the surgical jig used for implant surgery includes a cutting edge of a drill DT for forming an implant mounting hole in the jawbone, a surgical guide SG for guiding the cutting edge of the drill during the operation, and the like. .

  Subsequently, manufacture of the designed dental implant 20 (procedure P4) and manufacture of a surgical jig (procedure P6) are performed. The implant manufacturing process (procedure P4) includes a fixture manufacturing process (procedure P4a), an abutment manufacturing process (procedure P4b), and a superstructure manufacturing process (procedure P4c).

  Thereafter, an implant operation is performed in which the manufactured dental implant 20 is embedded in the patient's jawbone using a surgical jig manufactured accordingly.

  Hereinafter, a method for designing an implant using the implant design apparatus according to the first embodiment will be described.

  In the implant design apparatus 100 according to the first embodiment, jaw bone data Dah indicating the structure of a patient's jaw bone obtained by imaging the patient's jaw bone by X-ray CT scan in advance is stored in the jaw bone data storage unit 101. The implant standard data storage unit 102 of the implant design apparatus 100 stores implant standard data SDip indicating the external shapes of various dental implants having different structures, sizes, materials, and the like.

  When the doctor in charge (user) inputs the type of dental implant desired by the patient from the operation unit 114, the patient's doctor can use the various implant standard data stored in the implant standard data storage unit 102 of the implant design device 100 to determine the patient's type. The implant standard data SDip of the dental implant corresponding to the desired material, color (artificial tooth color), etc. is selected. At this time, based on the implant standard data SDip, a plurality of standard dental implants having the same color and material but different sizes such as diameter and length are displayed on the display unit 116.

  Next, the attending physician operates, by operating the operation unit 114, the dental implants that are predicted to be appropriate from the structure of the patient's jaw bone, such as the examination results, in advance, for a plurality of standardized dentistries with different displayed sizes. When an implant is selected from among the implant implants, implant standard data SDip indicating the outer shape of one standard dental implant is supplied from the implant standard data storage unit 102 to the implant model creation unit 112 as initial implant data. The implant standard data SDip includes fixture shape data, abutment shape data, and prosthetic crown shape data.

  The implant model creation unit 112 creates an implant model Mip including a fixture model 21a, an abutment model 22a, and a prosthetic crown model 23a shown in FIG. 5 based on the implant standard data SDip.

  At this time, the jawbone model creation unit 111 receives the jawbone data Dah from the jawbone data storage unit 101 and generates the jawbone model Mah shown in FIG. Here, a three-dimensional model is used as each of these models. However, the model is not necessarily limited to a three-dimensional model, and a model showing a structure of a longitudinal section along a tooth arrangement direction and a longitudinal section perpendicular to the tooth arrangement direction. A model indicating the structure may be used.

  These models are synthesized by the simulation unit 110 to perform a simulation of an operation for implanting a dental implant in a patient's jawbone.

  Specifically, as shown in FIGS. 6A and 6B, the simulation unit 110 receives the jawbone data Dah and generates a jawbone model Mah.

  At this time, the superstructure model (prosthetic crown model) 23a indicated by the selected implant standard data SDip is arranged in the tooth defect portion A of the jawbone model Mah (see FIGS. 7A and 7B). Thereafter, the optimum position and the optimum size of the prosthetic crown model 23a are determined by the user operation in accordance with the spacing between adjacent teeth in the tooth defect portion A of the jawbone model Mah and the size of those teeth. At this time, the position and size of the prosthetic crown model 23a are changed by a user operation in a state where the jawbone model Mah and the prosthetic crown model 23a are superimposed on the screen of the display unit 116. The user determines an ideal position and size of the prosthetic crown model 23a within a range where no warning is given from the simulation unit 110.

  Thereafter, based on the ideal position of the prosthetic crown model 23a determined with respect to the jawbone model Mah by the user's operation, the insertion position of the fixture model 21a and the direction of the abutment model 22a (horizontal and vertical) The angle in the plane) is determined.

  For example, depending on the distance between the fulcrum P of the jaw and the tooth loss location A, the prosthetic crown model 23a of the selected dental implant implant model is arranged at the loss location A as shown in FIGS. 7 (a) and 7 (b). When this is done, the magnitude and direction of the load applied to the prosthetic crown model 23a are simulated.

  Based on the result of this load simulation, the direction in which the abutment 22 is raised from the fixture 21 is determined according to the ideal position and size of the prosthetic crown model 23a, and the angle of the fixture 21 that fixes the abutment 22 is determined. decide.

  Specifically, as shown in FIG. 10A, in the state where the prosthetic crown model 23a is embedded in the tooth defect portion A of the patient's jawbone model Mah, the fixture model 21a is further activated. Incorporated into the jawbone model Mah along the direction (FIG. 10B). In this state, as shown in FIGS. 11 (b) and 11 (e), the nerve Sp and the fixture model 21a are close to each other. Therefore, as shown in FIGS. By operating the unit 114, a command signal is sent to the implant model creation unit 112 via the input control unit 113, and the implant standard as initial implant data is shortened to the implant model creation unit 112 so that the length of the fixture model 21a is shortened. The data SDip is changed. Thereby, the length of the fixture model 21a optimum for the patient's jawbone is determined.

  11A and 11D show a state where the fixture model is not embedded in the jawbone model (corresponding to FIG. 10A). 11 (a) to 11 (c) show vertical cross-sectional structures perpendicular to the tooth arrangement direction as a jaw bone structural model, and FIGS. 11 (d) to 11 (f) show jaw bone structural models. The structure of the longitudinal section along the arrangement direction of teeth is shown.

  Further, the thickness of the fixture model 21a is determined based on the result of the load simulation, and the stress distribution when the fixture model 21a having the determined thickness is embedded in the jawbone model Mah is obtained. This stress distribution is a distribution generated when the maximum load is applied to the fixture due to the meshing of the upper and lower teeth.

  In FIG. 12A, a stress distribution generated around the fixture model 21a of the jawbone model Mah when the diameter of the fixture model 21a embedded in the jawbone model Mah is thin is shown by a graph G1. FIG. 12B shows a stress distribution generated in the periphery of the fixture model 21a of the jawbone model Mah in a graph G2 when the diameter of the fixture model 21a embedded in the jawbone model Mah is thick.

  Based on this simulation result, the thickness of the fixture model 21a optimum for the patient's jawbone is determined by changing the implant standard data SDip as the initial implant data by the user operation, as described above.

  FIG. 13 and FIG. 14 show how the angle of embedding of the fixture model 21a is changed by the arrangement of the nerves Sp in the jawbone model.

  For example, as shown in FIG. 13A, in a state where the prosthetic crown model 23a is embedded in the jawbone model Mah of the patient, the fixture model 21a is further incorporated into the jawbone model Mah along the direction in which the abutment is raised. (FIG. 13B). In this state, as shown in FIGS. 14B and 14E, the nerve Sp and the fixture model 21a are close to each other. Therefore, as shown in FIGS. 14C and 14F, the fixture is operated by the user operation. The tea model 21a is deformed so that its posture is inclined more obliquely.

  FIGS. 14A and 14D show a state in which the fixture model is not embedded.

  Further, as shown in FIG. 2, threads (threads) are formed on the outer peripheral surface of the fixture 21 by changing the pitch between the upper portion 211 and the lower portion 222. The thread pitch is narrower than the lower part, and the screw depth is the same at the upper and lower parts.

  Therefore, depending on the result of the load simulation and the thickness of the cortical bone 32 and cancellous bone 31, the strength against the internal stress and load is appropriately set by the pitch and depth of the upper thread and lower thread of the fixture model. You can also

  Furthermore, the simulation unit 110 is equipped with a function (design support function) that supports the user's implant design, and this design support function will be described with reference to FIG.

  The numerical value display part Dn of the display screen F of the display part 116 includes first to sixth numerical value display areas Dn1 to Dn6, and the following numerical values are respectively displayed.

  For example, in the first numerical value display area Dn1, the maximum design value possible as the thickness of the fixture is displayed based on the boundary position Bp (see FIG. 2) between the cortical bone and the cancellous bone in the jawbone 30. In the second numerical value display area Dn2, the minimum design value possible as the thickness of the fixture is displayed based on the load applied to the fixture.

  In the third numerical value display area Dn3, the maximum possible design value as the length of the fixture is based on the position of the nerve Sp, blood vessel Bv, etc. (see FIGS. 2 and 9) in the jawbone 30. In the fourth numerical display area Dn4, the necessary length of the fixture in the cancellous bone portion is displayed based on the CT value as an index of the bone density of the cancellous bone.

  In the fifth and sixth numerical value display areas Dn5 and Dn6, blood flow parameters serving as a measure of the amount of blood flow in the jawbone are displayed. In the fifth numerical display area Dn5, preoperative blood flow parameters serving as a guide for the blood flow in the cancellous bone portion without the fixture being embedded are displayed, and in the sixth numerical display area Dn6, the fixture is displayed. A postoperative blood flow parameter that is a measure of blood flow in the cancellous bone portion in a state in which is embedded is displayed.

  Then, the processor 100a of the implant design device, when the length and thickness of the fixture is set outside the range between the maximum value and the minimum value by the user operation, or the length and thickness of the fixture Is set between the maximum value and the minimum value, when the simulation unit 110 determines that the postoperative blood flow parameter is smaller than the preoperative blood flow parameter, a warning display on the display screen or a sound is displayed. Outputs an alarm signal for issuing an alarm.

  And the design part 120 designs a dental implant based on the patient's optimal implant model calculated | required by the simulation of an implant as mentioned above.

  In this case, the dental implant will be designed as an implant body, an abutment and a superstructure.

  In addition, the design unit 120 designs a surgical jig used in an implant operation from the optimal implant model of the patient obtained by the implant simulation as described above.

  As described above, in the present embodiment, in the implant design apparatus 100 that designs a dental implant using image processing by a computer, a jawbone model creation unit 111 that creates a jawbone model from jawbone data indicating the structure of a patient's jawbone, Implant model creation unit 112 for creating an implant model from implant data indicating the outer shape of the dental implant, and a simulation of embedding a dental implant in a patient's jaw bone by incorporating the implant model into a specified part of the jaw bone model And a design unit 120 for designing the dental implant from an implant model obtained by modifying and modifying the implant data in accordance with the simulation result. It can be designed for optimal shape for each patient in accordance with the structure and conditions.

  In addition, since the simulation unit 110 has a function (design support function) for supporting the implant design by the user, the length and thickness of the fixture are set between the maximum value and the minimum value by a user operation. Even when the length and thickness of the fixture are set between the maximum value and the minimum value, the simulation unit 110 sets the postoperative blood flow parameter as the preoperative blood flow. When it is determined that the parameter is smaller than the parameter, a warning is displayed on the display screen or a voice alarm is issued, so that a more reliable implant can be designed with less effort.

  In the first embodiment, since the surgical jig is designed based on the shape data of the designed implant simultaneously with the design of the implant, preparation for the implant operation can be performed in a short time.

  In the first embodiment, it is assumed that the jaw bone data Dah stored in the jaw bone data storage unit 101 is obtained by X-ray CT imaging, and the CT value obtained by X-ray CT imaging of the bone portion is used as the blood flow rate. Although it is used as a blood flow parameter as an index, it is assumed that jaw bone data stored in the jaw bone data storage unit 101 is obtained by MRI imaging, and blood flow volume is diagnosed using a perfusion weighted image obtained by this MRI imaging. You may do it.

Hereinafter, as Embodiment 2 of the present invention, an implant design apparatus for diagnosing blood flow using a perfusion weighted image that is image data obtained by MRI imaging will be described.
(Embodiment 2)
FIG. 15 is a diagram for explaining an implant design apparatus according to Embodiment 2 of the present invention. FIG. 15A is an MRI imaging apparatus for imaging a patient's jaw bone, and a patient's jaw bone obtained by the MRI imaging apparatus. FIG. 15B shows a basic configuration of the implant design apparatus, and FIG. 15C shows a specific configuration of the implant design apparatus.

  The implant design apparatus 200 according to the second embodiment uses image data Dahm obtained by imaging the patient's jawbone with the MRI imaging apparatus 90 as data indicating the structure of the patient's jawbone, and applies the dental implant to the patient's jawbone. The simulation of the implantation operation is different from the implant design apparatus of the first embodiment in that blood flow is diagnosed using a perfusion weighted image obtained from the image data Dahm obtained by MRI imaging.

  That is, the implant design apparatus 200 according to the second embodiment uses an MRI instead of the simulation unit 110 and the jawbone model creation unit 111 that receive the image data Dah obtained by X-ray CT imaging in the implant design apparatus 100 according to the first embodiment. A simulation unit 210 and a jawbone model creation unit 211 that receive image data Dahm obtained by imaging are provided, and other configurations are the same as those of the implant design device 200 of the first embodiment. Moreover, in the simulation part 210 of this Embodiment 2, it replaces with the postoperative blood flow parameter and the preoperative blood flow parameter in the said Embodiment 1, and changes the postoperative blood flow volume and the preoperative blood flow volume obtained from the information of a perfusion emphasis image. Used.

  In the following, MRI (magnetic resonance imaging) will be briefly described. In addition to the configurations of the simulation unit 110 and the jawbone model creation unit 111 of the first embodiment, the simulation unit 210 and the jawbone model creation unit 211 have a configuration that enables simulation of an implant model based on a perfusion-emphasized image. It is.

  By the way, MRI is a method in which information inside a living body is converted into an image using a nuclear magnetic resonance (NMR) phenomenon. In this method, an image that looks similar to X-ray CT imaging is obtained as a tomographic image, but is an imaging method that focuses on the physical properties of a substance that is completely different from X-ray CT imaging. A lot of information that cannot be obtained is obtained, and the principle of MRI is as follows.

  In the first place, nuclei whose atoms and mass numbers are not even among the nuclei that constitute atoms with electrons have the properties of magnets due to their nuclear spins, but the magnetization directions of each nuclear spin are disjoint and as a whole Does not generate magnetization. In this state, when a (strong) static magnetic field is applied from the outside, the magnetization direction of the nuclear spin is slightly aligned with the direction in which the magnetic field is applied. Thereby, magnetization is performed in the direction in which a magnetic field is applied as a whole.

  The direction of the nuclear magnetization is precession (similar to the swing motion of the top) with the static magnetic field as the axis by applying a high-frequency pulse voltage of a specific frequency. If the application is stopped, the original state is gradually restored.

  Here, in the process (relaxation phenomenon) until the application of the pulse voltage is stopped to return to the steady state, the return speed varies depending on each tissue of the human body. In nuclear magnetic resonance imaging, the difference in return in each tissue is imaged by signal processing to create a three-dimensional image of the human body.

  It is possible to reflect the behavior of all nuclei that have the properties of a magnet by nuclear spins in the image data. Of the atoms contained in the human body, those that have the properties of a magnet are hydrogen. Since the content is extremely small except for, in medical MRI, image data is acquired from the behavior of atomic nuclei of hydrogen atoms.

  Therefore, since there is a blood vessel in a portion where water is unevenly distributed in a tissue such as cancellous bone, information indicating the blood flow rate can be extracted from image data obtained by MRI imaging. In particular, a perfusion weighted image is used as an image for diagnosing blood flow.

  Next, the operation will be described.

  Specifically, a method for designing an implant using the implant design apparatus according to the second embodiment will be described.

  In the implant design apparatus 200 according to the second embodiment, jaw bone data Dham indicating the structure of the patient's jaw bone obtained by photographing the patient's jaw bone with the MRI imaging apparatus 90 in advance is stored in the jaw bone data storage unit 101. The implant standard data storage unit 102 of the implant design apparatus 200 stores implant standard data SDip indicating the external shapes of various dental implants having different structures, sizes, materials, etc., as in the first embodiment. Yes.

  When the doctor in charge (user) inputs the type of dental implant desired by the patient from the operation unit 114, the patient's doctor can select from the various implant standard data stored in the implant standard data storage unit 102 of the implant design device 200. The dental implant standard data SDip is selected as desired. At this time, based on the implant standard data SDip, a plurality of standard dental implants having the same color and material but different sizes such as diameter and length are displayed on the display unit 116.

  Next, the doctor in charge uses the operation unit 114 to operate a plurality of standardized dental implants with different displayed sizes for dental implants that are predicted to be appropriate based on examination results (for example, the structure of the patient's jawbone). When one of the implants is selected, implant standard data SDip indicating the outer shape of one standard dental implant is supplied from the implant standard data storage unit 102 to the implant model creation unit 112 as initial implant data. The implant standard data SDip includes fixture shape data, abutment shape data, and prosthetic crown shape data.

  The implant model creation unit 112 creates an implant model Mip (see FIG. 5) including a fixture model 21a, an abutment model 22a, and a prosthetic crown model 23a based on the implant standard data SDip.

  At this time, the jawbone model creation unit 211 receives the jawbone data Dahm from the jawbone data storage unit 101 and generates a jawbone model Mah. Here, a three-dimensional model is used as each of these models, but it is not necessarily limited to a three-dimensional model.

  These models are synthesized by the simulation unit 210, and a simulation of an operation for implanting a dental implant in a patient's jawbone is performed in the same manner as in the first embodiment.

  However, in the second embodiment, since the jaw bone data Dahm is obtained by MRI imaging, the blood flow around the tooth defect portion A of the jaw bone model is displayed on the screen of the display unit 116, for example, red. A perfusion emphasized image indicated by shading is displayed.

  Therefore, in the implant design apparatus 200 according to the second embodiment, when performing a simulation for obtaining an optimal implant model of a patient, the doctor in charge can determine the shape and position of the fixture model based on the perfusion weighted image.

  In the second embodiment, as in the first embodiment, the prosthetic crown model 23a is optimized in accordance with the spacing between adjacent teeth in the tooth defect portion A of the jawbone model Mah and the size of the teeth. A process for determining the position and the optimum size, a process for determining the insertion position of the fixture model 21a, the direction of the abutment model 22a, and the like based on the ideal position of the prosthetic crown model 23a; Processing for determining the thickness is performed.

  In the second embodiment, the blood flow rate around the tooth defect portion A of the jaw bone model is an important element in designing the implant, and stem cells are carried around the implant by the blood flow rate. This is because the amount of stem cells is determined, and the more stem cells, the more the bone growth is promoted and the better the osseointegration between the implant and the cancellous and cortical bone.

  As described above, in the second embodiment, in the implant design apparatus 200 for designing a dental implant using image processing by a computer, a jaw bone model is created from jaw bone data obtained by MRI imaging showing the structure of a patient's jaw bone. A jaw bone model creation unit 211, an implant model creation unit 112 that creates an implant model from implant data indicating the external shape of the dental implant, and a patient's jaw bone that is incorporated into the implant model at a designated site of the jaw bone model. Since it includes a simulation unit 210 that simulates an operation for implanting a dental implant, and a design unit 120 that designs the dental implant from an implant model obtained by modifying and modifying the implant data according to the simulation result. Dentistry The implant can be designed to optimum shape for each patient in accordance with the structure and condition of the patient's jawbone.

  In addition, since the simulation unit 210 is equipped with a function (design support function) that supports the implant design by the user, the length and thickness of the fixture are set between the maximum value and the minimum value by a user operation. Even when the length and thickness of the fixture are set between the maximum value and the minimum value, the simulation unit 210 determines that the postoperative blood flow is higher than the preoperative blood flow. When it is determined that the size is small, a warning display on the display screen or a voice warning is issued, so that a more reliable implant design can be performed with less effort.

  In the second embodiment, since the surgical jig is designed based on the shape data of the designed implant simultaneously with the design of the implant, preparation for the implant operation can be performed in a short time.

  Further, in the second embodiment, image data Dahm obtained by MRI imaging of the patient's jaw bone is used as data indicating the structure of the patient's jaw bone, and this MRI is performed in the operation simulation of implanting a dental implant in the patient's jaw bone. Since blood flow is diagnosed based on perfusion-weighted images obtained from image data Dahm obtained by imaging, blood flow around the implant around the jaw bone is secured, bone growth around the implant is promoted, and good osseo integration There is an effect that can be realized at an early stage.

  The implant design device 100 or 200 according to the first or second embodiment can be realized by a normal personal computer having a processor, a storage device, a user interface (input operation unit), and an output unit. By installing the implant design program, the implant design apparatus 100 or 200 can be realized on a personal computer.

  In such an implant design program, basically, a computer creates a jaw model from jaw bone data indicating the structure of the patient's jaw bone, and an implant model from the implant data indicating the external shape of the dental implant. Simulating an operation of implanting a dental implant in a patient's jaw bone by incorporating the implant model into a specified site of the jaw bone model, and modifying the implant data according to the result of the simulation And a step of designing the dental implant from the deformed implant model.

  Moreover, such an implant design apparatus can be constructed by storing such a program in a computer-readable recording medium and reading it into a computer as necessary. Here, the computer-readable recording medium is an optical disk, a hard disk, or the like. Further, the program is not limited to being stored in a recording medium, but may be stored in a predetermined server on the Internet. In this case, the program is downloaded from a predetermined server on the Internet via a communication line. can do.

  In the first and second embodiments, the simulation units 110 and 210 have the function of assisting the design of the implant by simulation (design support function). However, the simulation units 110 and 210 have the functions described above. It may not have a function to assist the design of the implant by simulation.

  The present invention relates to a method and apparatus for designing a dental implant to be embedded in a jaw bone using a three-dimensional image obtained by computer tomography of the patient's jaw bone. Therefore, it is possible to provide a method and apparatus that can be designed into an optimal shape for each patient.

20 Dental implant 21 Implant body (fixture)
21a Fixture model 22 Strut (Abutment)
22a Abutment model 23 Superstructure (artificial tooth or prosthetic crown)
23a prosthetic crown model 30 patient's jaw bone 31 cancellous bone 32 cortical bone 33 gingiva 80 CT scanning device 90 MRI imaging device 100, 200 implant design device 100a processor 100b storage device 100c user interface 100d output unit 101 jaw bone data storage unit 102 implant standard data Storage unit 110, 210 Simulation unit 111 Jaw bone model creation unit 112 Implant model creation unit 113 Input control unit 114 Operation unit 115 Display control unit 116 Display unit 120 Design unit Dah Jaw bone data Db Data bus Mah Jaw bone model Mip Implant model MDip Implant deformation data SDip implant standard data

Claims (15)

An implant design method for designing a dental implant by a computer,
Creating a jawbone model from jawbone data representing the structure of the patient's jawbone;
Creating an implant model from implant data indicating the external shape of the dental implant;
Simulating the operation of implanting a dental implant in a patient's jawbone by incorporating the implant model at a specified site of the jawbone model;
Designing the dental implant from an implant model obtained by modifying and modifying the implant data in accordance with the result of the simulation. The implant design method according to claim 1,
The step of performing the simulation includes:
Determining an upper limit value and a lower limit value of the size of the implant model based on a positional relationship between the jaw bone model and the implant model embedded in the jaw bone model;
And issuing a warning when the size of the deformed implant model is outside the range indicated by the upper limit value and the lower limit value. The implant design method according to claim 2,
The jaw design method, wherein the jawbone data indicating the structure of the patient's jawbone is image data obtained by computer tomography of the patient's jawbone. The implant design method according to claim 3,
The computed tomography is an X-ray CT imaging or MRI imaging method for implant design. The implant design method according to claim 4,
Jaw bone data indicating the structure of the patient's jawbone is image data obtained by X-ray CT imaging of the patient's jawbone;
The step of performing the simulation includes:
Preoperative blood flow parameters that serve as a guide for blood flow in the cancellous bone portion of the jaw bone model in a state where the fixture model is not embedded in the jaw bone model are included in the image data obtained by the X-ray CT imaging. Deriving based on CT values;
In the state where the fixture model is embedded in the jawbone model, the postoperative blood flow parameter which is a measure of the blood flow in the cancellous bone portion of the jawbone model, the CT value, and the position of the jawbone model and the implant model Deriving based on relationships,
The step of issuing the warning is based on the preoperative blood flow parameter and the postoperative blood flow parameter, even if the deformed implant model has a size within the range indicated by the upper limit value and the lower limit value. An implant design method, which is a step of issuing a warning when it is determined that the subsequent blood flow is lower than the pre-operative blood flow. The implant design method according to claim 2 or 5,
The implant design method, wherein the implant data used at the beginning of the simulation is implant standard data representing an external shape of a specific dental implant selected from a plurality of existing dental implants having different structures, sizes, and materials. The implant design method according to claim 3 or 5,
The step of creating the jawbone model includes
Creating three-dimensional image data as jawbone data indicating the structure of the patient's jawbone by a conversion process of image data obtained by computer tomography of the patient's jawbone;
Creating a three-dimensional jaw bone model from the three-dimensional image data as the jaw bone data,
Creating the implant model comprises:
Creating a 3D implant model from 3D image data as the implant data;
The step of simulating the surgery includes
An implant design method including the step of synthesizing the three-dimensional jaw model and the three-dimensional implant model. The implant design method according to claim 2 or 7,
The dental implant is
An implant body that is implanted in the patient's jawbone;
A strut secured to the implant body;
An implant design method comprising an artificial tooth attached to the support. The implant design method according to claim 8,
The implant data includes implant body data, strut data, and artificial tooth data as three-dimensional image data that respectively determines the outer shape of the implant body, the struts, and the artificial teeth that constitute the dental implant.
The implant design method is a step of creating a three-dimensional implant model from the implant body data, strut data, and artificial tooth data. The implant design method according to claim 2 or 5,
The step of simulating the surgery includes
An implant design method comprising simulating a positional relationship between a boundary between a cortical bone portion and a cancellous bone portion in the jaw bone model and an implant body of the implant model. The implant design method according to claim 2 or 5,
The step of simulating the surgery includes
An implant design method comprising simulating a positional relationship between blood vessels and nerves in the jawbone model and an implant body of the implant model. The implant design method according to claim 9,
The step of simulating the surgery includes
Simulating upper and lower jaw movements based on the jawbone model;
Based on the simulation results of the movement of the upper jaw and the lower jaw, the load applied to the implant body that supports the artificial tooth and the direction in which the load is applied are simulated when an artificial tooth is placed in the tooth defect portion of the jaw bone of the patient. And an implant design method. The implant design method according to claim 12,
The step of simulating the operation includes a step of simulating whether or not a patient's jawbone can be supported by the implant body based on a load applied to the implant body obtained by the simulation of the load. . An implant design apparatus for designing a dental implant using image processing by a computer,
A jawbone model creation unit that creates a jawbone model from jawbone data indicating the structure of the patient's jawbone;
An implant model creation unit for creating an implant model from implant data indicating the external shape of a dental implant;
A simulation unit for simulating a surgical operation in which a dental implant is embedded in a patient's jawbone by being incorporated in the implant model at a specified site of the jawbone model;
An implant design apparatus comprising: a design unit that designs the dental implant from an implant model obtained by modifying and deforming the implant data according to a result of the simulation. A program for causing a computer to execute an implant design method for designing a dental implant,
The computer
Creating a jawbone model from jawbone data representing the structure of the patient's jawbone;
Creating an implant model from implant data indicating the external shape of the dental implant;
Simulating the operation of implanting a dental implant into a patient's jawbone by incorporating it into the implant model at a specified site of the jawbone model;
And a step of designing the dental implant from an implant model obtained by modifying and modifying the implant data in accordance with a result of the simulation.

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