Method and apparatus for examining alveolar bone formation.

Abstract

This invention provides a method and apparatus for examining alveolar bone formation using an oral scanner with tomography capabilities. [Solution] A method for examining alveolar bone formation, comprising the steps of: filling the alveolar bone requiring bone grafting with bone graft material, suturing the gums to cover the bone graft material, obtaining a surface shape image of the portion where alveolar bone is to be formed using the surface shape acquiring optical meter; obtaining an internal cross-sectional image showing the state of the alveolar bone and bone graft material at a predetermined position in the obtained surface shape image using the internal cross-sectional acquiring optical meter; after a predetermined period of time has elapsed, moving the oral scanner to obtain the surface shape of the gums, and if the surface shape of the gums at a position where an internal cross-sectional image was previously obtained is detected, obtaining an internal cross-sectional image showing the state of the alveolar bone and bone graft material at that position using the internal cross-sectional acquiring optical meter of the oral scanner; and comparing the internal cross-sectional images obtained at predetermined intervals.

Description

Technical Field

[0004] , ,

[0001] The present invention relates to a method and apparatus for examining bone formation of alveolar bone, and more particularly, to a method and apparatus for examining bone formation of alveolar bone using an oral scanner having a tomographic imaging function.

Background Art

[0002] Recently, in order to restore the edentulous area, the number of cases where dental implants (artificial tooth roots) are implanted in the alveolar bone has been increasing. In order to implant a dental implant in the alveolar bone, an alveolar bone composed of bone of an appropriate amount and size is required. In order to establish an alveolar bone of an appropriate size, various bone regeneration techniques have been developed, and the most widely used alveolar bone formation technique is bone grafting (GBR: graft bone regeneration). Bone grafting (GBR) is also called bone transplantation (bone graft), and is a method of filling a bone graft material (bone filling material) into a bone defect site of the alveolar bone, inducing bone formation, and forming the alveolar bone into a form in which an implant can be implanted.

[0003] FIG. 1 is a diagram showing each step of a normal bone grafting. As shown in FIG. 1, in a normal bone grafting, the gingiva 6 surrounding the alveolar bone 2 where the bone grafting is to be performed is incised to open the alveolar bone 2 (A in FIG. 1). Next, the opened alveolar bone 2 is filled with a bone graft material 4 (also referred to as a "bone filling material") (B in FIG. 1), and the gingiva 6 is sutured so as to cover the bone graft material 4 (C in FIG. 1). If the filled bone graft material 4 is sufficiently ossified and the alveolar bone is formed into a form in which an implant can be implanted, an implant 8 is implanted in the formed alveolar bone. Thus, an implant can be implanted only after the bone defect site is filled with a bone graft material and bone, that is, alveolar bone, is formed to a level where the implant can be implanted.

[0004] On the other hand, in order to perform bone grafting and implant implants, it is necessary to confirm the degree to which the bone graft material 4 has ossified and formed bone, i.e., alveolar bone 2. To confirm the degree of alveolar bone formation, methods have been attempted to estimate bone density from dental cone-beam computed tomography (CBCT) images, but currently, a practical clinical method capable of analyzing the bone density at the target site where alveolar bone should be implanted and examining the degree of bone formation has not yet been developed.

[0005] Furthermore, methods such as measuring the Implant Stability Quotient (ISQ) by contacting the upper surface of the implanted dental implant after placement, measuring the reflex signal after striking the implant (PerioTest), and the Implant Stability Test (IST) are also known. However, these are not methods for measuring bone formation, but rather methods for measuring the fixation (stability) of the implant after placement.

[0006] Therefore, it has been difficult to determine the timing of implant placement because it is hard to know the degree of alveolar bone formation where the implant should be placed before the implant is implanted. For this reason, generally, the timing of implant placement is set to be several months after bone grafting, depending on the patient's age and the amount of bone graft required, allowing a long waiting period for the bone graft material to ossify sufficiently. In other words, conventionally, the timing of implant placement has been determined empirically based on the patient's age and the amount of bone graft required, and there is currently no suitable method for examining the degree of bone formation of the bone graft material. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Republic of Korea Registered Patent No. 10-2458985 Gazette [Non-patent literature]

[0008] [Non-Patent Document 1] Proc. of SPIE Vol. 8914, 2013, doi: 10.1117 / 12.2036345, Laura-Cristina Rusu ≪Time Domain Optical Coherence Tomography Investigation of Bone Matrix Interface in Rat Femurs” [Non-Patent Document 2] Proc. of SPIE Vol. 8925, 2014, doi: 10.1117 / 12.2045849, Laura-Cristina RUSU et al. “Different Matrix Evaluation for the Bone Regeneration of Rats Femours using Time Domain Optical Coherence Tomography” [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The object of the present invention is to provide a method and apparatus for examining alveolar bone formation, which allows for the examination of the alveolar bone formation state of bone graft material using an oral scanner with tomography capabilities.

[0010] Another object of the present invention is to provide a bone formation examination method and apparatus that helps determine the timing of implant placement by examining the bone density of the alveolar bone formation site at the target position where the implant should be placed, before implant placement.

[0011] Another object of the present invention is to provide a bone formation examination method and apparatus that can increase the success rate of implant placement and minimize patient inconvenience through early implant placement by examining the degree of bone formation of the alveolar bone and enabling implant placement at an appropriate time. [Means for solving the problem]

[0012] To achieve the above objective, the present invention provides a method for examining alveolar bone formation using an oral scanner with tomography capabilities, which includes surface shape acquiring optical meters 12 and 14 for obtaining surface shape images of an oral structure S and internal cross-sectional acquiring optical meters 22 and 24 for obtaining internal cross-sectional images of an oral structure S, comprising the steps of: filling the alveolar bone 2 where bone grafting is required with bone graft material 4, suturing the gums 6 so as to cover the bone graft material 4, and then using the surface shape acquiring optical meters 12 and 14 to obtain a surface shape image of the portion where alveolar bone is to be formed, and at a predetermined position 6a of the obtained surface shape image The present invention provides a method for examining alveolar bone formation, comprising the steps of: obtaining an internal cross-sectional image showing the state of the alveolar bone 2 and bone graft material 4 using the internal cross-sectional optical meters 22 and 24; after a predetermined period of time has elapsed, moving the oral scanner to obtain the surface shape of the gums, and if the surface shape of the gums at a position 6a where an internal cross-sectional image was previously obtained is detected, using the internal cross-sectional optical meters 22 and 24 of the oral scanner to obtain an internal cross-sectional image showing the state of the alveolar bone 2 and bone graft material 4 at that position; and comparing the internal cross-sectional images obtained at predetermined intervals.

[0013] Furthermore, the present invention provides an oral scanner body 50 that houses surface shape acquisition optical meters 12, 14 for obtaining surface shape images of an oral structure S and internal cross-sectional acquisition optical meters 22, 24 for obtaining internal cross-sectional images of an oral structure S, and has an opening 52 that allows shape measurement light irradiated onto the surface of the oral structure S, tomography measurement light irradiated into the interior of the oral structure S, and reflected light reflected from the oral structure S to pass through; and a pressing window 60 attached to the opening 52 of the oral scanner body 50 that allows the shape measurement light, tomography measurement light and signal light to pass through, and increases the transmission depth of the tomography measurement light by contacting the surface of the oral structure S and pressing the surface of the oral structure S. [Effects of the Invention]

[0014] According to the method and device for examining bone formation of the alveolar bone according to the present invention, by using an oral scanner having a tomographic imaging function to examine the formation state of the alveolar bone of the bone graft material, the implant can be implanted at an appropriate time, thereby increasing the success rate of implant implantation and minimizing the inconvenience to the patient through early implantation of the implant.

Brief Description of the Drawings

[0015] [Figure 1] (A) to (D) are diagrams showing each step of a normal bone grafting procedure. [Figure 2] A diagram showing the configuration of an oral scanner having a tomographic imaging function that can be used in the present invention. [Figure 3] A photograph showing the surface shape image of the part where the alveolar bone is to be formed. [Figure 4] (A) and (B) are internal cross-sectional images showing the state where the alveolar bone is formed at the lower part of the gingiva. [Figure 5] A diagram showing the bone formation inspection device according to an embodiment of the present invention. [Figure 6] A diagram showing the bone formation inspection device according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0016] Hereinafter, the present invention will be described in detail based on the accompanying drawings.

[0017] FIG. 2 is a diagram showing the configuration of an oral scanner having a tomographic imaging function that can be used in the present invention. As shown in FIG. 2, the oral scanner having a tomographic imaging function that can be used in the present invention includes surface shape acquisition optical meters 12 and 14 for obtaining surface shape images of oral structures S such as teeth, gums, and alveolar bones, and internal cross-section acquisition optical meters 22 and 24 for detecting reflected light (scattered light) reflected from each internal cross-section of the oral structure S to obtain an internal cross-sectional image of the oral structure S.

[0018] For example, an oral scanner having a tomographic imaging function according to the present invention may include a surface shape acquisition optical meter including a shape measurement light projector 12 and a shape measurement camera 14, an internal cross-section acquisition optical meter including an optical coherence tomography (OCT) measurement unit 22 (hereinafter referred to as an OCT measurement unit) and an OCT scan probe 24, and a beam splitter 30 (beam splitter).

[0019] The shape measurement light projector 12 irradiates shape measurement light for obtaining a shape image of an oral structure S such as a tooth, a gingiva, and an alveolar bone. As the shape measurement light, measurement light capable of obtaining a shape image of the oral structure S can be used without limitation, and preferably, visible light, for example, visible light having a wavelength of 400 to 700 nm can be used.

[0020] The shape measurement camera 14 is a device that detects reflected light formed by reflection of shape measurement light from the surface of the oral structure S to obtain a surface shape image of the oral structure S, and includes a normal image sensor.

[0021] In operation, shape measurement light is emitted from the shape measurement light projector 12, and the emitted shape measurement light is irradiated onto the oral structure S after passing through the beam splitter 30, and the reflected light reflected from the oral structure S is detected by the shape measurement camera 14 to obtain a surface shape image of the oral structure S. At this time, the two-dimensional image of the oral structure S acquired by the at this time, the two-dimensional image of the oral structure S acquired by the shape measurement camera 14 can be converted into a three-dimensional image using a triangulation method or the like.

[0022] The OCT measurement unit 22 transmits tomographic measurement light (e.g., near-infrared light) through the oral structure S, detects reflected light (scattered light) reflected from each tomography within the oral structure S, and obtains an internal cross-sectional image of the oral structure S. The OCT measurement unit 22 is a device that obtains tomographic information of the inside of an object using the coherence of the tomographic measurement light. For example, the tomographic measurement light is broadband low-coherence light with a short coherence distance, and preferably near-infrared light, specifically near-infrared light with a wavelength of 750 to 1500 nm.

[0023] The OCT scan probe 24 is a device that irradiates a desired position on the oral structure S with tomographic light emitted from the OCT measurement unit 22 and transmits the reflected light from the oral structure S to the OCT measurement unit 22. The OCT scan probe 24 may include a collimator 24a that focuses the tomographic light and its reflected light, a reflective mirror 24b that reflects the focused tomographic light to a desired imaging position on the oral structure S and transmits the reflected light from the oral structure S to the collimator 24a, and an objective lens 24c that focuses the measurement light reflected from the reflective mirror 24b to a desired imaging position on the oral structure S. Here, as the reflective mirror 24b, a MEMS mirror (micro electro mechanical system mirror) that can sequentially scan the imaging position of the oral structure S by adjusting the reflection angle of the tomographic light can be used. For example, the reflective mirror 24b rotates with respect to two axes (for example, the x-axis and y-axis which are orthogonal to each other) to sequentially scan the plane on which the oral structure S is located, and tomographic light is shone into the interior of the oral structure S in a direction perpendicular to the plane (in the z-axis direction, orthogonal to the x-axis and y-axis), thereby obtaining a three-dimensional tomographic image of the oral structure S.

[0024] The beam splitter 30 is a device that superimposes the path of shape measurement light emitted from the shape measurement light projector 12 and the path of tomography light emitted from the OCT scan probe 24, superimposing the surface shape acquisition optical meter formed by the shape measurement light projector 12 and the shape measurement camera 14 and the internal cross-section acquisition optical meter formed by the OCT measurement unit 22 and the OCT scan probe 24. For example, as shown in Figure 2, the beam splitter 30 may be a dichroic mirror 30 that transmits the shape measurement light emitted from the shape measurement light projector 12 and reflects the tomography light emitted from the OCT scan probe 24, irradiating the oral structure S with the shape measurement light and the tomography light, and separating and transmitting the reflected light to the shape acquisition optical meter (specifically, the shape measurement camera 14) and the tomography acquisition optical meter (specifically, the OCT measurement unit 22). As shown in Figure 2, by positioning a dichroic mirror 30 that allows the shape measurement light from the shape measurement light projector 12 to pass through, reflects the tomography light at a location not included in the field of view (FOV) of the shape measurement camera 14, and transmits the shape measurement light, an integrated optical instrument can be formed in which the measurement areas of the shape acquisition optical instrument and the tomography optical instrument, i.e., the regions of interest (ROI), overlap. Therefore, by irradiating the oral structure S with the superimposed shape measurement light and tomography light using the dichroic mirror 30, both an external surface shape image and an internal cross-sectional image of the oral structure S can be obtained.

[0025] Next, with reference to Figures 2 to 4, a method for examining alveolar bone formation according to one embodiment of the present invention will be described. Figure 3 is a photograph showing the surface shape of the gums in the area where alveolar bone should be formed, and Figure 4 is a photograph showing an internal cross-sectional image showing the state in which alveolar bone is formed in the lower part of the gums.

[0026] According to the present invention, in order to examine the formation of the alveolar bone, bone graft material 4 is filled into the alveolar bone 2 that requires bone grafting, and the gums 6 are sutured to cover the bone graft material 4. Then, as shown in Figure 2, surface shape images of the area where the alveolar bone is to be formed, specifically, surface shape images of the gums 6 (see Figure 3), are obtained using surface shape acquisition optics 12 and 14 of an oral scanner with tomography capabilities.

[0027] At predetermined positions 6a, 6b, 6c, 6d, and 6e of the surface shape image obtained in this manner, an internal cross-sectional image showing the state of the alveolar bone 2 and bone graft material 4 in the lower part of the gum 6 is obtained using internal cross-sectional acquisition optics 22 and 24 of an oral scanner with tomography capabilities, as shown in Figure 2 (see (A) in Figure 4).

[0028] Here, the surface shape image obtained using the shape-acquiring optical meter of the oral scanner (for example, Figure 3) serves as a guide image for determining the positions 6a, 6b, 6c, 6d, and 6e from which internal cross-sectional images can be obtained. To explain this in more detail, while moving the oral scanner to obtain the surface shape of the gums (i.e., progressive scanning), when a predetermined shape of the gum surface is obtained, the tomographic optical meter of the oral scanner is used to obtain an internal cross-sectional image (for example, (A) in Figure 4) showing the state of the alveolar bone 2 and bone graft material 4 at that position (for example, position 6a in Figure 3). At this time, if necessary, the oral scanner can be further moved to obtain the surface shape of the gums at other positions, and the internal cross-sectional optical meter 22, 24 of the oral scanner can be used to obtain further internal cross-sectional images showing the state of the alveolar bone 2 and bone graft material 4 at other positions (for example, position 6b in Figure 3).

[0029] After obtaining an internal cross-sectional image after filling with bone graft material 4 in this manner, and after a predetermined period (e.g., 3 months) has elapsed, the oral scanner is moved further to obtain the surface shape of the gums. If the surface shape of the gums at a position where an internal cross-sectional image was previously obtained (e.g., position 6a in Figure 3) is detected (e.g., Figure 3), an internal cross-sectional image showing the state of the alveolar bone 2 and bone graft material 4 at that position (e.g., (B) in Figure 4) is obtained using the internal cross-sectional acquisition optics 22 and 24 of the oral scanner.

[0030] It is recognized that the surface shape of the patient's gums is substantially the same during the bone formation process. Therefore, by obtaining a surface shape image of the area where alveolar bone is to be formed using an oral scanner surface shape acquisition optical meter, and obtaining internal cross-sectional images (for example, (A) and (B) in Figure 4) at the same location where the same surface image was obtained at predetermined intervals, it is possible to observe changes in the internal cross-sectional images (for example, (A) and (B) in Figure 4) at the same location.

[0031] Therefore, the surface shape images obtained using the surface shape acquisition optics 12 and 14 of the oral scanner serve as "guide images for determining (tracking) the acquisition position of internal cross-sectional images obtained using the internal cross-sectional acquisition optics 22 and 24 of the oral scanner," i.e., for tracking. Furthermore, the internal cross-sectional images obtained using the internal cross-sectional acquisition optics of the oral scanner at predetermined time intervals (for example, (A) and (B) in Figure 4) show the bone formation state of the bone graft material 4. By comparing the internal cross-sectional images obtained at predetermined time intervals (for example, (A) and (B) in Figure 4), the degree of bone formation of the alveolar bone can be examined. In other words, by comparing the internal cross-sectional images, it is possible to determine whether the degree of bone formation of the bone graft material 4 is suitable for implant placement.

[0032] For example, in the initial internal cross-sectional image shown in (A) of Figure 4, the image of the black alveolar bone 2 and the image of the bone graft material 4 are clearly distinguishable. However, after three months, in the internal cross-sectional image shown in (B) of Figure 4, it can be confirmed that the image of the bone graft material 4 has changed to almost the same color as the surrounding area, indicating that ossification is progressing. Here, in the initial stage, the bone graft material 4 is in the form of agglomerated powder, so reflection from the surface of each powder occurs, resulting in an image with a different color from the surrounding area. However, once the bone graft material 4 ossifies, the powder becomes agglomerated and the boundary disappears, resulting in an image with almost the same color as the surrounding area.

[0033] The method for examining alveolar bone formation according to the present invention is a method for obtaining information regarding the degree of bone formation of a bone graft material 4, and may be performed by a control unit (not shown) of an oral scanner having a tomography function. For example, the control unit of an oral scanner having a tomography function can control surface shape acquisition optical meters 12, 14 and internal cross-sectional acquisition optical meters 22, 24 to obtain the surface shape image and internal cross-sectional image, compare the similarities and differences between the surface shape images and internal cross-sectional images to set the position where the internal cross-sectional image should be obtained, sense changes in the internal cross-sectional image, and obtain information on alveolar bone formation.

[0034] The bone formation examination method according to the present invention may be performed using an oral scanner with a conventional tomography function, as shown in Figure 2. However, because the internal cross-sectional acquisition optical meter of a conventional oral scanner has a small tomography depth, it is not possible to obtain a sufficient cross-sectional image of the bone graft material 4 below the gums 6 (see (C) in Figure 1) when the gums 6 are thick. Therefore, the present invention provides a bone formation examination device particularly suitable for the bone formation examination method according to the present invention.

[0035] Figure 5 shows a bone formation inspection device according to an embodiment of the present invention. As shown in Figure 5, the bone formation inspection device according to an embodiment of the present invention comprises an oral scanner body 50 which houses surface shape acquisition optical meters 12, 14 for obtaining a surface shape image of an oral structure S and internal cross-sectional acquisition optical meters 22, 24 for detecting reflected light reflected from each tomography inside the oral structure S to obtain an internal cross-sectional image of the oral structure S, and which has an opening 52 that allows shape measurement light irradiated onto the surface of the oral structure S, tomography measurement light irradiated into the inside of the oral structure S, and reflected light reflected from the oral structure S to pass through; and a pressing window 60 which is attached to the opening 52 of the oral scanner body 50 and transmits the shape measurement light, tomography measurement light and signal light, and increases the transmission depth of the tomography measurement light by contacting the surface of the oral structure S and pressing the oral structure S, specifically the gums 6.

[0036] The pressing window 60 may be made of a material that transmits the shape measurement light, tomography measurement light, and signal light, and increases the transmission depth of the tomography measurement light by contacting and pressing the surface of the oral structure S against the surface of the oral structure S. For example, it may be made of glass, light-transmitting plastic, or the like.

[0037] When the surface of the oral structure S is pressed using the pressing window 60, the thickness of the surface of the oral structure S is reduced, making it easier to inspect the formation of alveolar bone inside the oral structure S.

[0038] Figure 6 shows a bone formation inspection device according to another embodiment of the present invention. The bone formation inspection device according to the embodiment shown in Figure 6 has the same configuration as the bone formation inspection device shown in Figure 5, except that an oral tip 40, to which a reflective mirror 42 for guiding the shape measurement light and tomography measurement light into the oral cavity is attached, is attached to the oral scanner body 50, and a pressing window 62 is attached to the shape measurement light, tomography measurement light, and signal light transmission area at the end of the oral tip 40. In the embodiment shown in Figure 6, the pressing window 62 has a rectangular parallelepiped shape according to the shape of the end of the oral tip 40.

[0039] In the bone formation inspection apparatus of the present invention, the shapes of the pressing windows 60 and 62 can be varied in many ways. As shown in Figures 5 and 6, the pressing window 60 may have not only a rectangular prism shape, but also a polygonal prism shape such as a triangular prism or a cylinder, and its width and thickness may be appropriately set according to the position of the oral structure S to be observed.

[0040] The present invention has been described above with reference to the attached drawings and exemplary embodiments, but the present invention is not limited in any way to the illustrated content and the embodiments described above. Reference numerals are used in the following claims to enhance understanding of the present invention, but the following claims are not limited in any way to the reference numerals and illustrated content, and should be interpreted as encompassing any variations of the exemplary embodiments, equivalent configurations and functions.

Claims

1. A method for examining alveolar bone formation using an oral scanner with tomography capabilities, comprising surface shape acquisition optical meters (12) (14) for obtaining surface shape images of oral structures (S) and internal cross-sectional acquisition optical meters (22) (24) for obtaining internal cross-sectional images of oral structures (S), The steps include filling the alveolar bone (2) where bone grafting is required with bone graft material (4), suturing the gums (6) to cover the bone graft material (4), and then using the surface shape acquiring optical instruments (12) (14) to obtain a surface shape image of the area where the alveolar bone is to be formed, The steps include obtaining an internal cross-sectional image showing the state of the alveolar bone (2) and bone graft material (4) at a predetermined position (6a) of the obtained surface shape image using the internal cross-sectional acquisition optical meter (22) (24), After a predetermined period of time has elapsed, the oral scanner is moved to obtain the surface shape of the gums, and if the surface shape of the gums at a position (6a) where an internal cross-sectional image was previously obtained is detected, the oral scanner's internal cross-sectional acquisition optical meter (22) (24) is used to obtain an internal cross-sectional image showing the state of the alveolar bone (2) and bone graft material (4) at that position. The steps include comparing the internal cross-sectional images obtained at predetermined intervals, A method for examining alveolar bone formation, including the following.

2. The method for examining alveolar bone formation according to claim 1, wherein the surface shape image of the portion where the alveolar bone is to be formed is a surface shape image of the gums (6).

3. The method for examining alveolar bone formation according to claim 1, further comprising the step of moving the oral scanner to obtain the surface shape of the gums at other positions, and using an internal cross-sectional acquisition optical meter (22) (24) of the oral scanner to obtain an internal cross-sectional image showing the state of the alveolar bone (2) and bone graft material (4) at another position (6b).

4. The method for examining alveolar bone formation according to claim 1, wherein the step of comparing the internal cross-sectional images is used to determine whether the degree of bone formation of the bone graft material (4) is suitable for implant placement.

5. The method for examining alveolar bone formation according to claim 1, wherein the method for examining alveolar bone formation is performed by a control unit of an oral scanner having a tomographic imaging function.

6. An oral scanner body (50) is provided, which houses surface shape acquisition optical meters (12) (14) for obtaining surface shape images of oral structures (S) and internal cross-sectional acquisition optical meters (22) (24) for obtaining internal cross-sectional images of oral structures (S), and has an opening (52) that allows shape measurement light irradiated onto the surface of the oral structure (S), tomography measurement light irradiated into the interior of the oral structure (S), and reflected light reflected from the oral structure (S) to pass through. A pressing window (60) is attached to the opening (52) of the oral scanner body (50) and transmits the shape measurement light, tomography measurement light, and signal light, and increases the transmission depth of the tomography measurement light by contacting the surface of the oral structure (S) and pressing the surface of the oral structure (S), A bone formation examination device equipped with the following features.

7. The bone formation examination device according to claim 6, wherein the surface of the oral structure (S) is the gums (6).

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