Method for observing gingival capillaries and method for assessing the risk of periodontitis in diabetic patients

Abstract

To suitably observe gingival capillaries.SOLUTION: Provided is a method for observing gingival capillaries using an imaging device 10 having an objective lens, in which the following steps are performed in the order of description: a liquid immersion step of performing liquid immersed between the gingiva 11 to be observed and the objective lens; and an imaging step of imaging the capillaries of the gingiva using the imaging device. In the liquid immersion step, a gel with a viscosity of 30000 mPa s or more and 60000 mPa s or less is used for liquid immersion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for observing gingival capillaries and a method for assessing the risk of periodontitis in diabetic patients. [Background technology]

[0002] It is generally known that diabetic patients are more likely than non-diabetic patients to develop and progress to periodontitis, and are at higher risk of tooth loss due to the progression of periodontitis. However, conventional clinical diagnostic items for healthy periodontal tissues have not shown significant differences between diabetic and non-diabetic patients, making it difficult to determine the risk of periodontitis in diabetic patients.

[0003] One of the complications of diabetes is microvascular disease. Diabetic patients may also have impaired blood flow in the gums, which may make them more susceptible to developing periodontitis. Therefore, clinically, observing the gingival capillaries of diabetic patients may enable us to assess their risk of periodontitis.

[0004] Patent Document 1 describes a method for observing capillaries in the nail fold of a human finger. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-054483 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method described in Patent Document 1 requires that an attachment be attached to the tip of a finger for observation, and therefore cannot be applied to observation of gingival capillaries. A method that can suitably observe gingival capillaries is desired. [Means for solving the problem]

[0007] A method for observing gingival capillaries to solve the above problem is a method for observing gingival capillaries using an imaging device equipped with an objective lens, and includes, in this order, an immersion step of immersing the space between the gingiva to be observed and the objective lens in liquid, and an imaging step of imaging the gingival capillaries using the imaging device, wherein the immersion step uses a gel having a viscosity of 30,000 mPa·s or more and 60,000 mPa·s or less.

[0008] The above-mentioned method for observing gingival capillaries preferably includes a marking step of marking the periphery of the gingiva before the immersion step. A method for assessing the risk of periodontitis in a diabetic patient for solving the above-mentioned problems is a method for assessing the risk of periodontitis in a diabetic patient using an imaging device equipped with an objective lens, and comprises, in this order: an immersion step of immersing the space between the gingiva of the diabetic patient to be observed and the objective lens in liquid; an imaging step of imaging the capillaries of the gingiva using the imaging device; and a determination step of assessing the risk of periodontitis in the diabetic patient using the image obtained in the imaging step, wherein the immersion step is performed using a gel having a viscosity of 30,000 mPa·s or more and 60,000 mPa·s or less.

[0009] The method for assessing the risk of periodontitis in a diabetic patient preferably includes a marking step of marking the area around the gums prior to the immersion step. [Effects of the Invention]

[0010] According to the method for observing gingival capillaries of the present invention, gingival capillaries can be preferably observed. Furthermore, according to the method for assessing the risk of periodontitis in a diabetic patient of the present invention, the risk of periodontitis in a diabetic patient can be preferably assessed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing the positional relationship between a subject and an imaging device in a method for observing gingival capillaries according to an embodiment of the present invention. FIG. [Figure 2]10A and 10B are schematic diagrams showing a marking step in the method for observing gingival capillaries of the present embodiment. [Figure 3] 10 shows images comparing the presence and absence of the immersion step in the method for observing gingival capillaries of this embodiment. [Figure 4] This is an image comparing gingival capillaries with normal morphology and gingival capillaries with abnormal morphology. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the method for observing gingival capillaries of the present invention will be described. 1, the method for observing gingival capillaries uses an imaging device 10 equipped with an objective lens. The method for observing gingival capillaries includes, in this order, an immersion step of immersing the space between the gingiva 11 to be observed and the objective lens in liquid, and an imaging step of imaging the capillaries in the gingiva 11 using the imaging device 10. The method also includes a marking step of marking the periphery of the gingiva 11 to be observed before the immersion step.

[0013] The gingiva 11 to be observed is not particularly limited, and any gingiva in the oral cavity can be selected. Among them, the buccal marginal gingiva of the maxillary central incisors and mandibular central incisors is preferred because it is located on the front side and is easy to image. Furthermore, the buccal marginal gingiva 11a of the maxillary central incisors is preferred because it is easier to image in a more stable state.

[0014] Each step will be described below. <About the printing process> The marking step is a step of marking the periphery of the gingiva 11 to be observed. By marking the periphery of the gingiva 11 to be observed, in the subsequent imaging step, the marking can be imaged together with the capillaries of the gingiva 11 to be observed. Therefore, it is easy to know from the captured image which part of the gingiva 11 in the oral cavity the imaged capillaries belong to.

[0015] The area around the gums 11 to be observed is not particularly limited, and can be selected appropriately from an area within the range of the image captured in the imaging step. 2, the periphery of the gums 11 on which the marking step is performed may be, for example, the surface S of the buccal marginal gums 11a of the maxillary central incisors that is off from the imaging center P in the captured image 40. Alternatively, it may be the surface T of the tooth 13 that is close to the buccal marginal gums 11a of the maxillary central incisors in the image 40. Among these, the surface T of the tooth 13 is preferred because it is easy to perform the marking step.

[0016] The method for the marking step is not particularly limited, and any known marking method can be appropriately selected. Known marking methods include, for example, marking using a surgical skin pencil.

[0017] The items to be marked in the marking step are not particularly limited, and for example, it is possible to mark letters, symbols, figures, etc. for identifying the position of the gingiva 11 to be observed. In other words, the marking step is not limited to the mode of marking letters, but also includes the mode of marking symbols and figures.

[0018] <About the immersion process> The immersion step is a step of immersing the space between the gums 11 to be observed and the objective lens in liquid. By performing immersion, the resolution of the imaging device can be increased.

[0019] The liquid used in the liquid immersion step is not particularly limited, and any known liquid can be used, such as water, alcohol, or oil. The alcohol may be, for example, ethanol. The oil may be, for example, an aliphatic hydrocarbon, an alicyclic hydrocarbon, etc. Immersion using oil is referred to as oil immersion.

[0020] The liquid used in the immersion step is preferably a transparent gel. Here, "gel" refers to a liquid substance having a predetermined viscosity. An example of the predetermined viscosity is a viscosity of 30,000 mPa·s or more and 60,000 mPa·s or less. When the viscosity of the gel is within the above range, it is easily held between the gums 11 and the objective lens. In other words, immersion can be performed while the gel is appropriately held on the uneven surface of the gums 11.

[0021] As shown in Figure 3, when the immersion step is not performed, the image resolution is low, making it difficult to observe the gingival capillaries 12 in the gingiva 11. In contrast, when the immersion step is performed, it becomes easier to observe the gingival capillaries 12.

[0022] <About the imaging process> The imaging step is a step of imaging the capillaries in the gums 11 using an imaging device. The imaging device 10 used in the imaging step is not particularly limited, and a known imaging device 10 equipped with an objective lens can be used. Examples of known imaging devices 10 equipped with an objective lens include a film camera and a camera with a built-in photoelectric conversion image receiving element (hereinafter also referred to as a CCD camera). The CCD camera is preferably a CCD camera for observing blood flow.

[0023] The imaging step can be performed with the worker 30 holding the imaging device 10. Alternatively, imaging may be performed with the imaging device 10 fixed in a predetermined position using a known fixing tool such as a clamp holder.

[0024] By performing the above steps, an image of the gingival capillaries 12 can be acquired. The procedure for observing the gingival capillaries 12 will be described.

[0025] As shown in Figure 1, a subject 20 lies on his / her back. An operator 30 marks an observation area using a surgical dermatologist on the surface of a tooth 13 adjacent to the buccal marginal gingiva 11a of the maxillary central incisor, which is the gingiva 11 to be observed.

[0026] Next, the operator 30 grasps the CCD camera for observing blood flow as the imaging device 10 and brings the objective lens (not shown) of the CCD camera close to the buccal marginal gingiva 11a of the maxillary central incisor so that the objective lens is in a substantially horizontal position. Liquid is immersed between the objective lens of the CCD camera and the buccal marginal gingiva 11a of the maxillary central incisor.

[0027] Next, a CCD camera for observing blood flow is used to capture an image of the buccal marginal gingiva 11a of the maxillary central incisor so that the above-mentioned marked area is included. By performing the above procedure, it is possible to observe the gingival capillaries 12. In the imaging step, by imaging the buccal marginal gingiva 11a of the maxillary central incisors with the subject 20 lying on his back, it becomes possible to image the buccal marginal gingiva 11a of the maxillary central incisors while suitably suppressing misalignment.

[0028] A method for assessing the risk of periodontitis in diabetic patients will be described. The method for assessing the risk of periodontitis in diabetic patients includes a determination step of assessing the risk of periodontitis in diabetic patients using images of the gingival capillaries 12 obtained in the imaging step after performing each step in the above-mentioned method for observing gingival capillaries 12.

[0029] The above-mentioned determination step is carried out by detecting differences in the morphology of the gingival capillaries 12 of the diabetic patient (hereinafter also referred to as "morphological abnormalities") using gingival capillaries 12 having a normal morphology as a reference.

[0030] Morphological abnormalities of the gingival capillaries 12 can be detected, for example, from the following viewpoints: The viewpoints of morphological abnormalities include the length, arrangement, loop size, number of branches, whether or not there is tortuosity, whether or not there is a detour, etc. of the capillaries.

[0031] The following describes the viewpoint of morphological abnormalities. <Capillary length> As shown in Figure 4, gingival capillaries 12a without morphological abnormalities have a generally uniform length. Normally, the length of gingival capillaries 12 is 200 μm to 500 μm. In contrast, gingival capillaries 12b with morphological abnormalities have a non-uniform length, with some being shorter than the above numerical range and some being longer.

[0032] <array> As shown in Figure 4, in gingival capillaries 12a without morphological abnormalities, multiple capillaries extend in approximately the same direction and are aligned in a uniform arrangement. In contrast, in gingival capillaries 12b with morphological abnormalities, multiple capillaries extend in different directions and are not aligned in a uniform arrangement.

[0033] <Loop size> As shown in Figure 4, in gingival capillaries 12a without morphological abnormalities, the loops (see arrows in Figure 4), which are the curved parts of the blood vessels, are of approximately the same size. In contrast, in gingival capillaries 12b with morphological abnormalities, some loops are large and some are small, and the sizes are not uniform.

[0034] <Number of branches> As shown in Figure 4, gingival capillaries 12a without morphological abnormalities have at most one branching point, whereas gingival capillaries 12b with morphological abnormalities have multiple branching points.

[0035] <Presence or absence of torsion> As shown in Figure 4, gingival capillaries 12a without morphological abnormalities do not have any twisted portions where the capillaries are twisted. In contrast, gingival capillaries 12b with morphological abnormalities have twisted portions. Note that the degree of twisting that normally exists in gingival capillaries 12a without morphological abnormalities is not included in the twisted portions.

[0036] <Whether or not there is a detour> As shown in Figure 4, gingival capillaries 12a without morphological abnormalities do not have any tortuous or twisted portions where the capillaries are in a wavy or twisted state. In contrast, gingival capillaries 12b with morphological abnormalities have tortuous portions. Note that the degree of undulation that is normally present in gingival capillaries 12a without morphological abnormalities is not included in the twisted portions.

[0037] Morphological abnormalities can be detected by targeting each of the above-mentioned aspects. It is not necessary to consider the presence or absence of morphological abnormalities by targeting all of the above-mentioned aspects, and it is also possible to consider the presence or absence of morphological abnormalities by targeting at least one of the above-mentioned aspects.

[0038] The operation and effects of this embodiment will be described. (1) The method for observing gingival capillaries 12 includes, in this order, an immersion step of immersing the space between the gingiva 11 to be observed and the objective lens in liquid, and an imaging step of imaging the capillaries of the gingiva 11 using the imaging device 10. In the immersion step, immersion is performed using a gel having a viscosity of 30,000 mPa·s or more and 60,000 mPa·s or less. By performing the immersion step, the gingival capillaries 12 can be observed favorably. Furthermore, since the viscosity of the gel is 30,000 mPa·s or more and 60,000 mPa·s or less, the gel is more easily retained between the gingiva and the objective lens, making it easier to observe the gingival capillaries 12 more favorably.

[0039] (2) Before the immersion step, a marking step is performed in which a mark is made around the gingiva 11 to be observed. In the subsequent imaging step, the marking can be imaged together with the capillaries of the gingiva 11 to be observed. Therefore, it is easy to determine from the image which part of the gingiva 11 in the oral cavity the imaged gingival capillaries 12 belong to.

[0040] (3) The method for assessing the risk of periodontitis in a diabetic patient includes a step of assessing the risk of periodontitis in a diabetic patient using an image of the gingival capillaries 12 obtained in the imaging step after performing each step in the method for observing the gingival capillaries 12. Therefore, the risk of periodontitis in a diabetic patient can be appropriately assessed.

[0041] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The marking step may be omitted. For example, the observed region may be directly displayed on the image 40 captured in the imaging step.

[0042] The gingiva 11 to be observed is not limited to the buccal marginal gingiva 11a of the maxillary central incisors. It may also be the buccal marginal gingiva of the lateral incisors, canines, first premolars, second premolars, first molars, second molars, or third molars, or the palatal marginal gingiva. It may also be free gingiva. For example, by using a small CCD camera that can be inserted into the oral cavity, it becomes possible to observe gingiva other than the buccal marginal gingiva 11a of the maxillary central incisors.

[0043] The method for observing gingival capillaries 12 of this embodiment has been applied to a method for assessing the risk of periodontitis in diabetic patients, but is not limited to this. It can also be applied to a method for assessing the risk of periodontitis in non-diabetic patients. [Example]

[0044] The present embodiment will be described in more detail below with reference to test examples, but the present invention is not limited to these. The subjects were divided into a non-diabetic group and a diabetic group, as shown in Table 1. The non-diabetic group consisted of 11 subjects and the diabetic group consisted of 12. The subjects' general condition was investigated, and the results are shown in Table 1.

[0045] [Table 1] In Table 1, "SD" means standard deviation and "N" means percentage. "HbA1c" means the percentage of glycated hemoglobin. "Systolic blood pressure" and "diastolic blood pressure" mean the blood pressure measured during gingival capillary observation. "o-PCR" is the plaque control record; the higher the value (%), the more plaque adhered to the teeth.

[0046] The number of smokers, presence or absence of hypertension, and presence or absence of cardiovascular disease were investigated by interview. In addition, for the diabetic group, the most recent HbA1c, duration of diabetes, and presence or absence of diabetic complications were investigated by interview. The values ​​for HbA1c, systolic blood pressure, diastolic blood pressure, o-PCR, and duration of diabetes in Table 1 are average values.

[0047] As shown in Table 1, no significant differences were observed in the overall condition between the non-diabetic group and the diabetic group, except for the presence of diabetes. The significance level was set at 0.05 using Student's t-test, Mann-Whitney U test, and Fisher's exact test to evaluate the significance probability (p-value).

[0048] Next, the state of periodontitis was clinically diagnosed for the subjects shown in Table 1. Furthermore, the gingival capillaries 12 were observed using the observation method of the gingival capillaries 12 of this embodiment, and the rate of morphological abnormalities was measured. The clinical diagnostic items and results, as well as the measurement results of the rate of morphological abnormalities, are shown in Table 2.

[0049] [Table 2] In Table 2, "mean PPD" means the mean periodontal pocket depth.

[0050] "Width of keratinized gingiva" means the length from the alveolar crest to the gingival-alveolar mucosal junction. "Mobility" refers to the degree of tooth movement and was evaluated based on Miller's classification. The "plaque index" was calculated using the following formula.

[0051] Plaque index = ((total number of tooth surfaces with plaque) / (number of tooth surfaces tested)) x 100 The "gingivitis index" was evaluated as follows: normal gums were 0, mild inflammation with no bleeding was 1, moderate inflammation was 2, and severe inflammation was 3. The average score was calculated from 24 sites.

[0052] "Gingival capillary density" is 1mm 2 This means the number of capillaries per capillary. The values ​​for the above diagnostic items in Table 2 are the average values ​​for the non-diabetic group and the diabetic group.

[0053] The "percentage of morphological abnormalities" in Table 2 was measured by the following method. Example 1 First, a capillary blood flow scope (BSCAN-Z manufactured by GOKO Visual Equipment Co., Ltd.) was used as the imaging device. The subject was lying supine, and the observation area was marked on the tooth 13 adjacent to the buccal marginal gingiva 11a of the maxillary central incisor using a surgical skin pencil.

[0054] Next, the objective lens of the capillary blood flow scope was brought close to the buccal marginal gingiva 11a of the maxillary central incisor so that it was in an approximately horizontal position, and oil immersion was performed between the buccal marginal gingiva 11a of the maxillary central incisor and the objective lens using an oily transparent gel with a viscosity of 45,000 mPa·s.

[0055] In this state, the gingival capillaries 12 were imaged using a capillary blood flow scope. In the image 40, gingival capillaries 12b having morphological abnormalities were detected from the above viewpoint. 2 The number of capillaries per 1000 mm diameter and the number of capillaries with morphological abnormalities were counted, and the percentage of morphological abnormalities was calculated.

[0056] In addition, the unit area (1.8 mm 2 The number of capillaries per 100 mm diameter and the number of capillaries with morphological abnormalities were counted by three blinded individuals other than the person who performed the imaging, and the average values ​​were used. The results are shown in Table 2.

[0057] (Comparative Example 1) The gingival capillaries 12 were observed in the same manner as in Example 1, except that oil immersion was performed using an oily transparent gel with a viscosity of 2500 mPa·s. In Comparative Example 1, the viscosity of the gel was low, so the gel dripped during the imaging process. As a result, it was not possible to image the gingival capillaries 12.

[0058] As shown in Table 2, no significant difference was observed between the non-diabetic group and the diabetic group in the conventional periodontitis diagnostic items. In contrast, a significant difference was observed between the non-diabetic group and the diabetic group in the rate of morphological abnormalities measured using the gingival capillary 12 observation method of the present embodiment.

[0059] The method for observing gingival capillaries 12 of the present invention allows for suitable observation of gingival capillaries 12. As a result, it was discovered that the frequency of morphological abnormalities in the gingival capillaries 12 of diabetic patients is high. It is believed that a high frequency of morphological abnormalities makes blood flow disorders more likely to occur, increasing the risk of developing periodontitis. Therefore, it is possible to determine the risk of developing periodontitis in diabetic patients, which was difficult to predict using conventional periodontitis diagnostic criteria. [Explanation of symbols]

[0060] 10...imaging device, 11...gingiva, 11a...maxillary central incisor buccal marginal gingiva, 12...gingival capillaries, 12a...gingival capillaries without morphological abnormalities, 12b...gingival capillaries with morphological abnormalities, 13...tooth, 20...subject, 30...operator, 40...image, P...imaging center, S...surface, T...surface.

Claims

1. A method for observing gingival capillaries using an imaging device equipped with an objective lens, comprising: an immersion step of immersing the space between the gums to be observed and the objective lens in liquid; an imaging step of imaging the capillaries of the gingiva using the imaging device, in this order; A method for observing gingival capillaries, wherein the immersion step is performed using a gel having a viscosity of 30,000 mPa·s or more and 60,000 mPa·s or less.

2. The method for observing gingival capillaries according to claim 1 , further comprising a marking step of marking the periphery of the gingiva before the immersion step.

Images