JP2008194107A - Three-dimensional characteristic measuring and displaying apparatus for dental use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical coherence tomographic apparatus applicable for dental fields. <P>SOLUTION: The three-dimensional characteristic measuring and displaying apparatus with a data arithmetic part measures tissues or artificial compositions in a jaw oral cavity area of a living body and combines data of contact points or contact surfaces of upper and lower occlusal surfaces with any one of data of the shapes of tooth surfaces out of occlusion, data of the shapes of occlusal surfaces being occluded covering occlusal motions and tomographic data containing occlusal surfaces of upper and lower faced teeth being occluded covering occlusal motions and occluded faces of the upper and lower faced teeth occluded covering occlusal motions to compute and display with the arithmetic part and furthermore, data of the shapes of tooth surfaces out of occlusion separately acquired, not by the arithmetic operation with the three-dimensional superior characteristic measuring and displaying apparatus are displayed simultaneously. Thus, the surface shapes of the oral cavity tissues, the shapes of occlusal surfaces and the state of occlusion are measured and displayed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention measures the surface and internal characteristics of a living organism as characteristic values in a three-dimensional space, performs arithmetic processing on the measurement data in a calculation unit, and displays them on a two-dimensional or three-dimensional screen or printed matter. The present invention relates to a new function of a measuring / display device applied to the dental field. Specific examples of the three-dimensional upper characteristic measurement / display apparatus include an X-ray CT apparatus, an MRI apparatus, a three-dimensional ultrasonic image diagnosis apparatus, a PET apparatus, a SPECT apparatus, an optical CT apparatus, and an optical coherence tomography apparatus. Further, the present invention generally relates to a new function of a dental image capturing apparatus represented by a camera that captures an intraoral image.

Conventionally, an X-ray imaging apparatus, an intraoral camera, a dental camera, X-ray CT, MRI, and the like have been used for imaging a jaw and mouth region in dental diagnosis. Recently, inventions that apply optical coherence tomography to dentistry have been devised.
An image obtained by the X-ray imaging apparatus is merely a transmission image, and information on the X-ray traveling direction of the measurement target is detected by being superimposed. Therefore, it is impossible to know the internal structure of the measurement object three-dimensionally. Also, because X-rays are harmful to the human body, the annual exposure dose is determined, and only qualified surgeons can handle the device, and only in rooms surrounded by shielding materials such as lead and lead glass. I can not use it.

Since the intraoral camera images only the surface of the intraoral tissue, internal information such as teeth cannot be obtained. X-ray CT is harmful to the human body as well as an X-ray imaging apparatus, has low resolution, and is large and expensive. MRI has poor resolution, the apparatus is large and expensive, and the internal structure of teeth without moisture cannot be photographed.
By the way, for X-ray CT apparatus, MRI apparatus, PET, SPECT, 3D ultrasound diagnostic equipment and optical coherence tomography apparatus, the surface and internal characteristics of living organisms are measured as characteristic values in 3D space. The data is processed in the calculation unit and displayed on a 2D or 3D screen or printed matter, and includes not only the three-dimensional shape / structure information inside the organism, but also the composition, presence / absence / degree of progression, etc. Information can be displayed in the same manner, and it is used as a very useful device.

In particular, an optical coherence tomography apparatus (hereinafter referred to as an OCT apparatus) is harmless to the human body and can obtain three-dimensional information of a measured object with high resolution, so that it is applied in the field of ophthalmology such as tomographic measurement of the cornea and the retina. Has been. Note that OCT is an abbreviation for Optical coherence tomography. The OCT apparatus is sometimes called an optical coherence tomography apparatus. In the dental field as well, inventions that apply the OCT apparatus have been made. (See Patent Documents 1 to 4 and Utility Model Documents 1 to 4)
Here, the basic configuration of the OCT apparatus will be described.
(Basic configuration of OCT system, explanation of basic terms and operating principle)

An embodiment of a dental OCT apparatus according to the present invention will be described with reference to FIG. In FIG. 1, a temporally low coherent or coherent light source 1, a fiber coupler 2a (light splitting unit / interference unit), a reference mirror 3, a photodetector 4 (light detecting unit), and a computer 5 (calculating unit). ) Is shown as a basic configuration of the OCT apparatus.
In this basic configuration, light from the light source to the fiber coupler is light source light, light from the fiber coupler to the reference mirror, reflected from the reference mirror and returned to the fiber coupler again, reference light, and light from the fiber coupler to the object T to be measured The measurement light and the light reflected from each part of the measured object and returning to the fiber coupler are referred to as z-direction object reflection light, and the light from the fiber coupler to the light detector 4 and the light source 1 is referred to as interference light.
In this basic configuration, the light source light emitted from the light source reaches the fiber coupler and branches into two systems of reference light and measurement light. The reference light is specularly reflected by the reference mirror 3 and returns to the fiber coupler, and the measurement light is measured. Reflected / scattered / transmitted action from each part of the body, backscattered light that is part of it is reflected as z-direction object reflected light (each measured object in the z direction converted on the time axis in the basic configuration) It returns to the fiber coupler again while carrying backscattering coefficient information. The reference light returning to the fiber coupler and the z-direction object reflected light interfere with each other by the fiber coupler, and are branched and emitted toward the light source 1 and the photodetector 4 as interference light. The intensity of the interference light is detected by the photodetector 4, the interference light intensity is input to the computer 5 and measured and analyzed on the time axis, and the backscattering coefficient information of each part of the object, that is, the information of each part of the object is displayed. is there. Although the z-direction object reflected light carries object information on the waveform as an electromagnetic wave, the optical waveform is too fast to occur and there is no photodetector that can be measured directly on the time axis, but it interferes with the reference light. By doing so, the backscattering characteristic information of each part of the measurement object is converted into a change in the intensity of light, so that the detection on the time axis can be performed by the photodetector.

For convenience of explanation, the measurement object is shifted in the z direction, which is the traveling direction of the measurement light, in the x direction that constitutes a so-called B mode tomographic cross section, and the position of each B mode fault. Thus, the y direction, which is a shifting direction for obtaining three-dimensional measured object information called a C mode, is defined as orthogonal coordinate axes as shown in FIG. In order to obtain information in each of the x, y, and z directions, galvanometer mirrors 8-1-2 for scanning the measurement light beam in the x direction and the y direction are used. The means for obtaining information in the z-axis direction includes a reference mirror driving method for driving the reference mirror 3 in the optical axis direction, and a diffraction grating placed on the output side of the lens 7-6 to diffract time-axis information in the z-axis direction. Spectral domain method (converted to spatial axis information in the diffraction direction of the grating, and using a one- or two-dimensional imaging device such as a CCD as the photodetector 4 to reconstruct time axis information, that is, z-axis direction information on the computer 5 ( The conventional Fourier domain method can be used. Further, a swept source method (new Fourier domain method) that uses a variable wavelength light source as the light source 1 and does not use a diffraction grating is applied to a dental OCT apparatus as z-direction information acquisition means. This is in principle equivalent to the spectral domain method, and the Fourier transform operation is performed with the light source light instead of the interference light.
In addition to this, the basic configuration of the OCT apparatus using the fiber coupler 2a is to collimate or condense the optical fibers 6-1 to 4-4 used for input / output of light to / from the fiber coupler, light source light / reference light / interference light. Lenses 7-1 to 5 and 7-7, and an objective lens 7-6 for collecting the measurement light and collimating the object reflected light in the z direction are required. In addition, the structure using a beam splitter instead of a fiber coupler is also considered. In this case, the optical fibers 6-1 to 6-4 are not necessarily required, but the light source 1, the beam splitter, the reference mirror 3, the objective lens 7-6, and the photodetector 5 need to be optically appropriately arranged, and are compactly arranged. For this reason, mirrors are used in various places, and in some cases, optical fibers are used partially. However, the basic configuration is only a difference between using a fiber coupler 2a or a beam splitter as a member for performing interference, and in principle. The configuration is the same.
A unit including at least the measurement light and the z-direction object reflected light guiding unit and the objective lens 7-7 (not including the measurement target T) is a probe unit U2, and at least a light source control output / light detection A unit including the input from the unit 4 and the computer 5 is referred to as a PC unit U3, and a unit including at least the light source 1, the fiber coupler 2a, the reference mirror 3, and the photodetector 4 is referred to as an OCT unit U1.

With such an OCT apparatus, a high-resolution image inside the living body can be obtained in a non-destructive and non-contact manner. Regarding the application of the OCT apparatus to the dental field, examples in which a tomogram of a tooth is photographed using the OCT apparatus are disclosed (see, for example, Patent Documents 1 to 5 and Non-Patent Documents 1 to 9).
Among these prior arts, Patent Documents 1 to 3 describe how to incorporate optical coherence tomography into conventional dental equipment when applying to dentistry, and for measurement using optical fiber cables or power / signal lines. In this example, the position and direction of the probe are freely set, and in particular, how the scanning in the depth direction is performed in the probe and how the measurement light is emitted from the probe are mentioned. Patent Document 4 discloses Fourier domain optical coherence tomography that scans the wavelength of a light source, and mentions the wavelength range, the configuration of the probe, and the like. Further, for utility model documents 1 to 4, proposals have been made to incorporate a probe into a dental handpiece. Also, Non-Patent Documents 1 to 9 report on imaging performance when optical coherence tomography is applied to dentistry.
On the other hand, the present invention devised a new function added when optical coherence tomography is applied to dentistry. Such a new function is applied to a general three-dimensional characteristic measurement / display apparatus including an OCT apparatus. There is no conventional example.

JP 2004-344260A JP 2004-344262A JP 2004-347380A JP 2006-191937 A Utility model registration No. 3118718 Utility model registration No. 3118823 Utility model registration No. 3118824 Utility model registration No. 31188839 Laser Research October 2003 Issue: Technology Development of Optical Coherence Tomography Centered on Medical Care Journalof Biomedical Optics, October 2002, Vol.7 No.4: Imagingcaries lesions and lesion progression with polarization sensitive opticalcoherence tomography APPLIEDOPTICS, Vol.37, No.16, 1 June 1998: Imaging of hard-and soft-tissue structureIn the oral cavity by optical coherence tomography OPTICSEXPRESS, Vol.3, No.6,14 September 1998: Dental OCT OPTICSEXPRESS, Vol. 3, No. 6, 14 September 1998: In vivo OCT Imaging of hard and softtissue of the oral cavity Proceedings of 2004 Annual Meeting of the Optical Society of Japan, 5aF6, Dental Sample Measurement by Fourier Domain Optical Coherence Tomography 2005 Annual Meeting of the Optical Society of Japan, 24pE5, Application of Spectral Coherence Tomography to 3D Dental Measurement PhotonicsWest 2006, 6079-66, In-Vivo three dimensional Fourier-Domain Optical Coherence Tomography for soft and hard oral tissue measurements PhotonicsWest 2006, 6137-03, Assessment of dental-caries using optical coherencetomography

  An object of the present invention is to provide a new function that has not been obtained in the past when a three-dimensional characteristic measurement / display device, in particular, an OCT device is applied to dentistry. This new function is to measure the surface shape and occlusal surface shape, especially to measure the contact state between the upper and lower jaws and the occlusal tooth occlusal surface in the occlusal state and the occlusal movement state. The correction is to correct the image of the OCT apparatus to the actual size, and to estimate the refractive index distribution of each part of the oral tissue.

The basic means for solving the present invention is a tissue in an artificial oral cavity region or an artificial composition of the oral cavity region of a living body, and has a data calculation unit, and the surface shape of the oral tissue and the occlusal surface shape A three-dimensional characteristic measurement / display device that measures and displays the occlusal state, the shape data of the tooth surface not in the occlusal state, the shape data of the upper and lower occlusal surfaces in the occlusal state including the occlusal movement state, and the occlusion including the occlusal movement state Either at least one of the tomographic data including the occlusal surface of the upper and lower paired teeth in the state, the contact point or contact line of the upper and lower occlusal surface or the data of the contact surface is calculated and displayed by the calculation unit, or further, It is to simultaneously display the shape data of the tooth surface which is not in the occlusal state, which is obtained separately regardless of the generation of the calculation by the three-dimensional characteristic measurement / display device.
Further, the present invention relates to a dental OCT apparatus that uses a tissue in an oral cavity region of a living body or an artificial composition in the oral cavity region of a living body as a measurement object, and uses a light source and light source light emitted from the light source as a reference mirror. Interference of light splitting into reference light to be radiated and measurement light to be radiated on the measurement object, and interference light by causing the measurement light reflected by the measurement object and the reference light reflected by the reference mirror to interfere with each other And a light detection unit that measures interference light, and in a method in which the light source simultaneously generates light in a certain wavelength band, diffraction that splits interference light between the interference light and the light detection unit according to the wavelength In a system in which a grating and a light detection unit using a one-dimensional or two-dimensional imaging device are formed, and the light source temporally scans light in a certain wavelength band, a light detection unit using one or two light detection elements is provided. And the light detector measures By performing Fourier transform or inverse Fourier transform on the intensity at each stage of the wavelength of the interference light, reflection characteristic data indicating the position and reflection intensity of the measurement light reflected by the measurement object is generated, and an image of the measurement object is obtained. The above means is applied to a dental OCT apparatus provided with a calculation unit to be generated.
Further, in the OCT apparatus, the refractive index distribution is estimated from two or more data obtained by photographing the same part from different directions, or an actual size image is calculated and generated.
Further, in the measurement of the tooth in the occlusal state or the occlusal movement state, the occlusal surface shape data is extracted and output, and two or more data obtained by photographing the same part from different directions are used. Then, the surface shape and the occlusal surface shape are measured and displayed by correcting the image to the actual size.

  According to the present invention, it is possible to bring about a new function that has not been obtained conventionally. This new function is to measure the surface shape, occlusal surface shape and occlusal state, especially to measure the contact state between the upper and lower jaws and the occlusal teeth in the occlusal state and occlusal movement state. This is to correct the image of the OCT apparatus undergoing deformation to the actual size, and to estimate the refractive index distribution of each part of the oral tissue.

  Among the three-dimensional characteristic measurement / display devices, the basic configuration in the best mode according to the present invention is a dental OCT device that uses a tissue in an oral cavity region of a living body or an artificial composition of the oral cavity region as a measurement object. A light splitting unit that divides light source light emitted from the light source into reference light for irradiating a reference mirror and measurement light for irradiating the measurement object; and the measurement light reflected by the measurement object; In the system comprising: an interference unit that interferes with the reference light reflected by the reference mirror to make interference light; and a light detection unit that measures the interference light, wherein the light source simultaneously generates light of a certain wavelength band A diffraction grating for separating the interference light according to the wavelength and a light detection unit by a one-dimensional or two-dimensional imaging device are formed between the interference light and the light detection unit, and the light source temporally transmits light in a certain wavelength band. In the scanning method, the light detector is A light detection unit is formed by one or two light detection elements, and based on the interference light measured by the light detection unit, the intensity at each stage of the changing wavelength of the interference light measured by the light detection unit is Fourier transformed. A dental OCT apparatus including a calculation unit that generates reflection characteristic data representing a position and reflection intensity of the measurement light reflected by the measurement object by performing transformation or inverse Fourier transform, and generates an image of the measurement object It is to be. Specifically, in the background art, a basic configuration as shown in FIG. 1 is necessary.

In addition to the basic configuration, with regard to claim 1, the shape data of the tooth surface not in the occlusal state, the shape data of the occlusal surface including the occlusal motion state, the upper and lower occlusal surfaces in the occlusal state including the occlusal motion state At least one of the tomographic data including the occlusal surfaces of the upper and lower mating teeth in the occlusal state including the shape and the occlusal movement state, the contact point of the upper and lower occlusal surfaces or the data of the contact surface is calculated by the calculation unit and displayed. In addition, the surface shape of the oral tissue, the occlusal surface shape, and the occlusal state can be measured and displayed by simultaneously displaying the shape data of the tooth surface that is not in the occlusal state, which is obtained separately regardless of the operation generation by the dental OCT apparatus. It is characterized by doing.
(Embodiment 1 relating to claims 1 and 2: Extraction of surface shape data) As a specific mode, a method of extracting surface shape data (remaining one-dimensional (height) data on two-dimensional space coordinates) will be described. .

The data of the OCT apparatus is calculated and calculated as one-dimensional backscattering characteristic data on the three-dimensional position coordinate value. Regarding the depth data z in the measurement light direction in the three-dimensional position coordinate axis data, the measurement light is first The surface data z that enters the object to be measured is the same as the actual data, but for the internal data, the depth z of interest from a certain position determined in the irradiation optical system of the surface or measurement light Until the refractive index is integrated with the depth z as a variable. This is called an optical distance. This is a distance calculated based on the principle of [speed] × [time] = [distance], considering the light speed as the vacuum light speed (= light speed in the air). This is because the OCT apparatus measures and analyzes light interference as a phenomenon on the time axis (the phenomenon on the time axis in the Fourier domain method is eventually converted to the frequency axis). There is a reason for that.

[Optical distance] = [Velocity of vacuum] x [Elapsed time]
= [Refractive index] x [speed of light in measured object] x [elapsed time]
= [Refractive index] x [Actual distance of measured object]
Therefore, the actual distance is stretched by the refractive index. However, since the speed of light in the atmosphere is almost equal to the speed of light in vacuum (refractive index is 1), the shape of the image due to reflection or scattering at the point where the measurement light first enters the object to be measured is It is equal to the shape. Until the measurement light enters the object to be measured, except for noise and special cases (involvement of transparent protective material for preventing infection), no reflection or scattering occurs. Therefore, in the computer 5 (calculation unit), OCT The same x value from all the data (x value, y value, z value, scattering coefficient ν) × (number of z direction data) × (number of x direction data) × (number of y direction data) obtained as data・ The value of (z value, scattering coefficient ν) × (number of data in the z direction) in the y value is taken, and the depth at which the scattering coefficient first exceeds a certain level when viewed from the smaller z value (that is, shallower) Data that is z0 and (z0 value) corresponding to (x value, y value) can be used as surface shape data that first reflects the measurement light from the OCT apparatus of the measurement object. The above-described method for extracting the surface shape data in the OCT apparatus is the same in the three-dimensional ultrasonic image diagnostic apparatus. That is, in the three-dimensional ultrasonic diagnostic imaging apparatus, an ultrasonic wave is used instead of the measurement light, and the ultrasonic wave propagation speed and the refractive index are used instead of the reflected ultrasonic wave and the light velocity instead of the backscattered light. Replace with the reciprocal. Instead of the velocity of light in the atmosphere, when the measured ultrasonic wave or reflected ultrasonic wave passes through the atmosphere, when using an ultrasonic conductor for the ultrasonic velocity in the atmosphere, the ultrasonic velocity of the ultrasonic conductor is changed. Replace it. When the probe directly contacts the measurement object, the probe shape is the surface shape of the subject (including the case where the subject is deformed into the probe shape). First, if the image data of the subject is not deformed with respect to the surface shape data like X-ray CT or MRI (the progress speed of the X-ray or magnetic field used for the measuring means does not change or can be ignored), The surface may be defined as a surface composed of a set of points where a change in characteristics appears.

Next, although it is the surface shape of the tooth including the occlusal surface which is not in the occlusal state, in the case of the OCT apparatus, it can be extracted by the above method by measuring the measurement direction from the direction facing the occlusal surface. It is impossible to extract the surface condition of the tooth in the shadow due to the shadow of the tooth itself or the corresponding tooth. Therefore, attention is paid to the fact that the contact area of the occlusion can be regarded as being in contact with a point or line even if it is in contact with a point, line, or surface. That is, attention is paid to the fact that a space without backscattering, that is, a space with zero backscattering intensity, is three-dimensionally distributed around the occlusal contact portion. A space where the backscattering intensity is zero is extracted, and is identified as a hollow space sandwiched between occlusal surfaces. By this distinction, the surface shape data of the occlusal surface of the tooth in the occlusal state can be used as a boundary between the hollow space and the other portion. Even in the three-dimensional ultrasonic diagnostic imaging apparatus and other three-dimensional characteristic measurement / display apparatuses, the boundary is the surface if the object to be measured is distinguished as a space that does not exist.
In this way, it is preferable that the state where the upper and lower teeth are in contact with each other in the occlusal state is measured by the OCT apparatus, and the non-occlusion state is displayed separately from the hollow space together with the occlusal surface shape data measured by the OCT apparatus. is there. By displaying in this way, it can be made easy to visually confirm which is in contact. The occlusal surface shape data measured in the non-occlusion state may be data measured and extracted by a method other than OCT, such as X-ray CT and optical CT.

Examples of these display methods will be described next. Since the surface shape data is a three-dimensional image and is difficult to illustrate on the text, it will be described in text.
1. In the form of 3D shape display (contour display, contour display (grayscale display), bird's eye view display, mesh display, etc.) of 3D occlusal surface data in a non-occlusion state viewed from a specific direction, the far side as viewed from the same direction An image cut out at an appropriate plane is displayed. When this data is occlusal surface shape data that does not depend on the three-dimensional characteristic measurement / display device, the cut occlusal surface edge and the occlusal surface data behind it are displayed, but the three-dimensional characteristic measurement / display device is displayed. In addition to the occlusal surface shape data and the occlusal surface data behind the occlusal surface shape data, cross-sectional tomographic data cut out may also be displayed.
2. 3D occlusal surface data in occlusal state 3D occlusal surface data in the non-occlusion state are arranged or superimposed to display and scan a tomographic image in the depth direction by the 3D upper characteristic measurement / display device, and the occlusal surface data at the back from the corresponding depth position Only the display is displayed and the previous display is cut off.
Furthermore, it is more preferable to extract the shape of the occlusal surfaces of the upper and lower teeth in the occlusal state, and to configure and display based on the occlusal surface shape data measured in the non-occlusal state. To extract the shape of the occlusal surfaces of the upper and lower teeth in the occlusal state, first, extract the feature shape (feature point or feature line or feature structure) in the occlusal surface shape data measured in the non-occlusion state, and similarly 3D Feature shape (line data or line data) that traces significant changes in the scattering coefficient from the four-dimensional data (x value, y value, z value, scattering coefficient ν) of the upper characteristic measurement / display device By extracting the above feature point data, surface data or feature line / feature point data on surface data, feature surface / feature line / feature point data on solid data), and pattern matching the feature shape from this To get. Trace data and feature points / feature lines / feature surface data may be extracted using Hough transform or the like. In this case, the measurement of the three-dimensional characteristic measurement / display device is measured with a certain angle direction with respect to the occlusal surface as the measurement light direction (for example, in the case of a molar, from the buccal side direction from the substantially horizontal direction to the occlusal surface. In addition, it is also preferable to determine the position and direction, such as taking the x direction as the tooth axis direction and the y direction as the dentition direction, which will be described below. The feature shape extracted from the data of the upper characteristic measurement / display device is preferably extracted only in a plane substantially parallel to the z direction and the y direction. In addition, when the three-dimensional upper characteristic measurement / display device is an OCT device, the OCT data has a refractive index expanded in the direction of the measurement light, so that a biomaterial (e.g. enamel) below the occlusal surface in the substantially z direction in the pattern matching process. It is very preferable to correct the refractive index of In this case, it is preferable to apply 1.4 to 1.6 as the refractive index of human enamel.
With respect to claim 3, by using two or more data obtained by imaging the same part from different directions, the image of the OCT apparatus is corrected to the actual size, and the refractive index distribution of each part of the oral tissue is estimated. Is.

(Embodiment for Claim 3) This specific embodiment will be described with reference to FIGS. 2a to 2c, FIG. 2a is a schematic diagram of a general tooth cross section, FIG. 2b is a schematic diagram of an OCT tomographic measurement image using measurement light from above, and FIG. 2c is an OCT tomography measurement image using measurement light from the side. FIG. The illustrated points A and B are feature points obtained from the image, and the points A in FIGS. 2a and 2b and the points B in FIGS. 2a and 2b are regarded as the same points. This is, for example, a point that is particularly bent in a cross-sectional curve where the luminance changes. For example, the measurement direction z direction is bent from the x direction by utilizing the fact that the refractive index expansion occurs but the x direction does not occur. This is a point that is regarded as the same point by using the property of counting the points and corresponding order. Once these are considered identical,

In the figure, z1 = x2 × λ1
z2 = x1 × λ2
It becomes. Here, λ1 is the refractive index in the measurement light direction in FIG. 2b, and λ2 is the refractive index in the measurement light direction in FIG. 2c. To obtain the refractive index of each part, λ1 = z1 / x2
λ2 = z2 / x1
Should be done. For isotropic materials, the finer the feature points, the more likely it will be λA = λB. Furthermore, to obtain a real image from FIG. 2b, z1 ′ = z1 / λ1
To obtain a real image from FIG. 2c, z2 ′ = z2 / λ2.
Should be done.

In the above-described method, as shown in FIGS. 2b and 2c, the two measurement images obtained the refractive index information and the actual image by the measurement light orthogonal to each other, but the two measurement directions do not need to be orthogonal. Needless to say, if the angle between the two measurement directions is known, the refractive index information and the actual image can be obtained by the same principle.
With respect to claim 4, it is possible to obtain the actual shape of the occlusal surfaces of the upper and lower teeth in the occlusal state using the method described in claim 4. In other words, in measurement of a tooth in an occlusal state or an occlusal movement state, the actual shape data of the occlusal surface is extracted and output using two or more data obtained by imaging the same part from different directions, or in an occlusal state It is possible to correct the still image or the moving image representing the occlusal movement to the actual size. Although not stated in the claims, it is also possible to obtain the actual shape of the facing surfaces or contact surfaces of two adjacent teeth in the same manner.

The present invention can provide a new function that has not been obtained in the past when the three-dimensional characteristic measurement / display device is applied to dentistry. This new function is to measure the surface shape and occlusal surface shape, and in particular, to measure the contact state of the upper and lower jaws and the occlusal teeth occlusal surface in the occlusal state and the occlusal movement state. Further, when the three-dimensional characteristic measurement / display device is an OCT device, the image of the OCT device that is deformed by the refractive index is corrected to the actual size, and the refractive index distribution of each part of the oral tissue is estimated. Is.

Basic configuration of OCT system Principle of refractive index correction

Explanation of symbols

1 Light source 2a Fiber coupler (light splitting / interference part)
3 Reference mirror 4 Photodetector (photodetector)
5 Computer (calculation unit)
6-1-4 Optical fibers 7-1-5, 7-7 Lens 7-6 (Objective) lens 8-1-2 Galvano mirror U2 Probe unit U3 PC unit (PC Unit)
U1 OCT unit

Claims (4)

  Three-dimensional characteristic measurement / display for measuring and displaying the surface shape, occlusal surface shape, and occlusal state of oral tissues, using a tissue in a living tissue or an artificial composition of the jaw-and-mouth region as a measurement object and having a data calculation unit Tooth including shape data of tooth surface not in occlusal state, shape data of upper and lower occlusal surfaces in occlusion state including occlusal movement state, and occlusal surface of upper and lower occlusal teeth in occlusion state including occlusal movement state Either at least one of the data, the contact point or contact line of the upper and lower occlusal surface or the data of the contact surface is calculated and displayed by the calculation unit, or further, separately from the calculation by the three-dimensional characteristic measurement / display device A three-dimensional characteristic measurement / display device that simultaneously displays the shape data of a tooth surface that is not in an occlusal state. A dental optical coherence tomography apparatus using a tissue in an oral cavity region of a living body or an artificial composition of an oral cavity region as a measurement object, a light source, and a reference light for irradiating a reference mirror with the light source light emitted from the light source A light splitting unit that divides the measurement light to irradiate the measurement object, an interference unit that causes the measurement light reflected by the measurement object and the reference light reflected by the reference mirror to interfere with each other, and interference light; A light detection unit that measures light, and in a system in which the light source simultaneously generates light of a certain wavelength band, a diffraction grating that spectrally separates interference light according to the wavelength between the interference light and the light detection unit and a one-dimensional or In a system in which a light detection unit is formed by a two-dimensional imaging device and the light source scans light of a certain wavelength band in time, a light detection unit is formed by one or two light detection elements, and the light Dryness measured by the detector By performing Fourier transform or inverse Fourier transform on the intensity at each stage of the wavelength of light, the reflection property data representing the position and reflection intensity of the measurement light reflected by the measurement object is generated, and the image of the measurement object is generated. The three-dimensional characteristic measurement / display device according to claim 1, wherein the device is a dental optical coherence tomography device including a calculation unit. A dental optical coherence tomography apparatus using a tissue in an oral cavity region of a living body or an artificial composition of an oral cavity region as a measurement object, a light source, and a reference light for irradiating a reference mirror with the light source light emitted from the light source A light splitting unit that divides the measurement light to irradiate the measurement object, an interference unit that causes the measurement light reflected by the measurement object and the reference light reflected by the reference mirror to interfere with each other, and interference light; A light detection unit that measures light, and in a system in which the light source simultaneously generates light of a certain wavelength band, a diffraction grating that spectrally separates interference light according to the wavelength between the interference light and the light detection unit and a one-dimensional or In a system in which a light detection unit is formed by a two-dimensional imaging device and the light source scans light of a certain wavelength band in time, a light detection unit is formed by one or two light detection elements, and the light Dryness measured by the detector By performing Fourier transform or inverse Fourier transform on the intensity at each stage of the wavelength of light, the reflection property data representing the position and reflection intensity of the measurement light reflected by the measurement object is generated, and the image of the measurement object is generated. A dental optical coherence tomography device including a calculating unit that estimates a refractive index distribution from two or more data obtained by photographing the same part from different directions, or further calculates and generates an actual size image 3D characteristic measurement / display device. In measuring occlusal or occlusal movement, occlusal surface shape data is extracted and output, and two or more data of the same part taken from different directions are used to measure the actual dimensions of the image. The three-dimensional characteristic measurement / display device according to claim 1, wherein the surface shape and the occlusal surface shape are measured and displayed by correcting to the above.