Oral cavity state analysis system, oral cavity state analysis program, storage medium for storing oral cavity state analysis program, and oral cavity state analysis method

Abstract

[Problem] To provide an oral cavity state analysis system and an oral cavity state analysis program for analyzing the oral cavity state, the system and program making it possible to easily acquire an oral cavity image suitable for analyzing the oral cavity state. [Solution] The present invention comprises: a video reception unit 251 that continuously receives, as input from an imaging unit 21 of a user terminal 2, a facial image V of a user U captured by the imaging unit 21; an image detection unit 252 that detects a mouth image F from the facial image V; a teeth detection unit 253 that detects a teeth area TA in the mouth image F; a gum detection unit 254 that detects a gum area GA in the mouth image F; a determination unit 256 that determines whether at least one of the teeth area TA and the gum area GA included in the mouth image F satisfies a prescribed condition; an image acquisition unit 257 that acquires a single or a plurality of mouth images F determined by the determination unit 256 to satisfy the condition; and an analysis unit 258 that analyzes the oral cavity state on the basis of the mouth image F acquired by the image acquisition unit 257.

Description

Oral cavity condition analysis system, oral cavity condition analysis program, storage medium for storing oral cavity condition analysis program, and oral cavity condition analysis method

[0001] The present invention relates to an oral cavity condition analysis system for analyzing an oral cavity condition, an oral cavity condition analysis program, a storage medium for storing the oral cavity condition analysis program, and an oral cavity condition analysis method.

[0002] In recent years, with the advancement of technology, analysis systems have been proposed that analyze the condition of the oral cavity based on images of the oral cavity captured by a camera on a mobile device such as a smartphone (see, for example, Patent Document 1).

[0003] International Publication No. 2015 / 016377

[0004] In such an analysis system, a user performs an operation of capturing a facial image as shown in FIG. 10( a) and an operation of acquiring an oral cavity image for analysis from the facial image as shown in FIG. 10( b). FIG. 10 is a schematic diagram showing a user's operation in a conventional analysis system. However, since both the facial image and the oral cavity image are selected by the user, they do not necessarily include regions or areas suitable for analyzing the oral cavity condition. Furthermore, the user must repeat the operation of capturing a facial image and the operation of acquiring an oral cavity image from the facial image until an oral cavity image that the user considers suitable for analyzing the oral cavity condition is acquired, which is inconvenient.

[0005] An object of the present invention is to provide an oral cavity condition analysis system and an oral cavity condition analysis program that are capable of automatically acquiring oral cavity images suitable for analyzing the oral cavity condition.

[0006] That is, the present invention encompasses the following inventions: (1) An oral cavity condition analysis system including: a video reception unit that continuously receives, as input from an imaging unit of a user terminal, facial images of a user captured by the imaging unit, an image detection unit that detects an image including a mouth area from the facial images received by the video reception unit, a teeth detection unit that detects a dental area from the image including the mouth area, a gum detection unit that detects a gum area from the image including the mouth area, a determination unit that determines whether at least one of the dental area and the gum area included in the image including the mouth area satisfies a predetermined condition necessary for analyzing the oral cavity condition, an image acquisition unit that acquires one or more images including the mouth area that are determined by the determination unit to satisfy the condition, and an analysis unit that analyzes the oral cavity condition based on the image including the mouth area acquired by the image acquisition unit.

[0007] With this configuration, oral images suitable for analyzing the oral condition can be automatically acquired without the user having to perform repeated operations, thereby providing a convenient oral condition analysis system.

[0008] (2) The oral cavity condition analysis system described in (1) is provided with an exclusion target detection unit that detects exclusion targets other than the tooth region and the gum region from an image including the mouth region.

[0009] With this configuration, areas other than the tooth area and gum area are detected as areas to be excluded when analyzing the oral condition, making the tooth area and gum area clearer and improving the accuracy of analyzing the oral condition.

[0010] (3) The oral condition analysis system described in (1) in which the judgment unit records at least one of the tooth area and the gum area, which changes for each image including the mouth area, as time-series data, and judges, based on the time-series data, whether the image including the mouth area satisfies specified conditions necessary for analyzing the oral condition.

[0011] According to this configuration, by recording at least one of the tooth area and gum area detected by the tooth detection unit and the gum detection unit as time-series data, the judgment unit can accurately judge whether or not the predetermined conditions necessary for analyzing the oral condition are met.

[0012] (4) An oral condition analysis system as described in (3), which is provided with a guidance display unit that displays a guidance means for guiding the mouth area to a predetermined position on the display screen of the user terminal on which the facial image is displayed.

[0013] According to this configuration, the user is guided by the guidance means displayed by the guidance display unit to a position on the display screen of the user terminal where an image including a mouth area that meets the predetermined conditions necessary for analyzing the oral condition can be easily acquired, thereby enabling images including the mouth area to be acquired efficiently.

[0014] (5) The oral condition analysis system described in (3), wherein the tooth detection unit extracts the tooth area from an image including the mouth area by color space conversion and a predetermined threshold, and the gum detection unit applies a differential filter to the image including the mouth area and detects the gum area by a flattening filter and a predetermined threshold.

[0015] (6) An oral cavity condition analysis program that causes a computer to function as: a video reception unit that continuously receives, as input from an imaging unit of a user terminal, facial images of a user captured by the imaging unit; an image detection unit that detects images including a mouth area from the facial images received by the video reception unit; a tooth detection unit that detects a dental area from the images including the mouth area; a gum detection unit that detects a gum area from the images including the mouth area; a determination unit that determines whether at least one of the dental area and the gum area included in the image including the mouth area satisfies predetermined conditions necessary for analyzing the oral cavity condition; an image acquisition unit that acquires one or more images including the mouth area that are determined by the determination unit to satisfy the conditions; and an analysis unit that analyzes the oral cavity condition based on the images including the mouth area acquired by the image acquisition unit.

[0016] (7) A computer-readable recording medium having recorded thereon an oral cavity condition analysis program for causing a computer to function as: a video reception unit that continuously receives, as input from an imaging unit of a user terminal, facial images of a user captured by the imaging unit; an image detection unit that detects images including a mouth area from the facial images received by the video reception unit; a tooth detection unit that detects a dental area from the images including the mouth area; a gum detection unit that detects a gum area from the images including the mouth area; a determination unit that determines whether at least one of the dental area and the gum area included in the images including the mouth area satisfies predetermined conditions necessary for analyzing the oral cavity condition; an image acquisition unit that acquires one or more images including the mouth area that are determined by the determination unit to satisfy the conditions; and an analysis unit that analyzes the oral cavity condition based on the images including the mouth area acquired by the image acquisition unit.

[0017] (8) A method for analyzing an oral condition, comprising: continuously receiving, as input from an imaging unit of a user terminal, facial images of a user captured by the imaging unit; detecting images including a mouth area from the facial images; detecting a tooth area and a gum area from the images including the mouth area; determining whether at least one of the tooth area and the gum area included in the images including the mouth area satisfies predetermined conditions required for analyzing the oral condition; acquiring one or more images including the mouth area that are determined to satisfy the conditions; and analyzing the oral condition based on the acquired images including the mouth area.

[0018] According to this method, oral images suitable for analyzing the oral condition can be automatically obtained without requiring repeated user operations, thereby providing a convenient method for analyzing the oral condition.

[0019] (9) The oral cavity condition analysis method according to (8), further comprising detecting exclusion targets other than the tooth region and the gum region from the image including the mouth region.

[0020] According to this method, areas other than tooth and gum regions are detected as areas to be excluded when analyzing the condition of the oral cavity, making the tooth and gum regions clearer and improving the accuracy of analyzing the condition of the oral cavity.

[0021] (10) An oral cavity condition analysis method as described in (8), which records at least one of the tooth area and the gum area, which changes for each image including the mouth area, as time-series data, and further determines whether the image including the mouth area satisfies specified conditions necessary for analyzing the oral cavity condition based on the time-series data.

[0022] According to this method, at least one of the tooth area and gum area detected by the tooth detection unit and the gum detection unit is recorded as time-series data, so that the judgment unit can accurately judge whether or not the predetermined conditions necessary for analyzing the oral condition are met.

[0023] The present invention can provide a convenient oral condition analysis system, an oral condition analysis program, a storage medium for storing the oral condition analysis program, and an oral condition analysis method that can automatically acquire oral images suitable for analyzing oral conditions.

[0024] 7 is a block diagram showing an oral cavity condition analysis system according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing a face image captured by an imaging unit. FIG. 2 is a schematic diagram showing a mouth image detected from the face image shown in FIG. 3. FIG. 3 is a schematic diagram showing a tooth region detected by a tooth detection unit in the mouth image shown in FIG. 3. FIG. 4 is a schematic diagram showing a gum region detected by a gum detection unit in the mouth image shown in FIG. 3. FIG. 4 is a schematic diagram showing other regions detected by an exclusion target detection unit in the mouth image shown in FIG. 3. A graph showing an example of time-series data in which a determination unit records tooth region values ​​and gum region values ​​at predetermined intervals. A graph showing an example of the amount of change in tooth region TA values ​​and gum region GA values ​​in the time-series data shown in FIG. 7. A flowchart showing the flow of the oral cavity condition analysis system shown in FIG. 1. A schematic diagram showing user operations in a conventional analysis system.

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An oral cavity condition analyzing system 1 is implemented in a user terminal 2 used by a user, as shown in FIG.

[0026] The user terminal 2 includes at least an imaging unit 21, a display unit 23, an information processing unit 25, and an information storage unit 27. The user terminal 2 may be a personal computer or a tablet terminal as long as it is a terminal that receives operations for analyzing the oral condition, but a smartphone is preferable in terms of portability. In the following description, the user terminal 2 will be described as a smartphone.

[0027] The imaging unit 21 is a camera that captures an image of the user's face. The display unit 23 is a display screen, such as a touch panel, that accepts user operations and displays the facial image V continuously captured by the imaging unit 21. The imaging unit 21 is preferably provided on the display unit 23 side that faces the user's face when the user operates the user terminal 2. The information processing unit 25 is a computing device such as a CPU (Central Processing Unit). The information processing unit 25 performs operations and processes of the oral condition analysis system 1 in the user terminal 2. The information storage unit 27 is a storage device composed of storage memories such as RAM and ROM, a hard disk, etc. The information storage unit 27 stores various processes and information executed by the information processing unit 25 in the user terminal 2, as well as an oral condition analysis program that functions the oral condition analysis system 1 according to the present invention. The information storage unit 27 also stores at least one type of information for analyzing the oral condition, such as the color and shape of teeth and gums, lips and skin around the lips other than teeth and gums, and shading during imaging.

[0028] Next, a description will be given of the information processing unit 25. When the information processing unit 25 executes the oral cavity condition analysis program stored in the information storage unit 27, it functions as at least a video receiving unit 251, an image detecting unit 252, a tooth detecting unit 253, a gum detecting unit 254, an exclusion target detecting unit 255, a determining unit 256, an image acquiring unit 257, and an analyzing unit 258.

[0029] First, when the user terminal 2 receives a predetermined action from the user U in an application, for example, the imaging unit 21 starts capturing images, and a facial video V consisting of multiple facial images of the user U is captured. The video receiving unit 251 receives the facial video V as input from the imaging unit. At this time, the facial video V received by the video receiving unit 251 may be temporarily stored in the information storage unit 27 for processing such as display on the display unit 23, but is not stored as an image for analyzing the oral cavity condition. The image detection unit 252 detects a mouth image F including a mouth region as shown in FIG. 3 from the facial video V consisting of multiple facial images as shown in FIG. 2. The image detection unit 252 can detect a mouth image F including the user's mouth and the mouth area around the mouth from the face image included in the face video V, for example, using an object detection algorithm such as SSD (Single Shot Multibox Detector) or semantic segmentation.

[0030] 4, the tooth detection unit 253 detects a tooth area TA indicating the location of teeth in the mouth image F. More specifically, the tooth detection unit 253 first converts the RGB color space of the pixels included in the mouth image F into an XYZ color space, and then converts from the XYZ color space to a Lab color space. The tooth detection unit 253 extracts only a-dimensional pixels from the pixels included in the mouth image F converted into the Lab color space. The tooth detection unit 253 binarizes the a-dimensional pixels based on a predetermined threshold, and detects pixels with label 1 as the tooth area TA.

[0031] As shown in FIG. 5 , the gum detection unit 254 detects a gum area GA indicating the gum region in the mouth image F. More specifically, the gum detection unit 254 first applies a differential filter, such as a Sobel filter or a Prewitt filter, to each pixel constituting the mouth image F. This emphasizes edge and contour information. The gum detection unit 254 binarizes the mouth image F resulting from application of the differential filter based on a predetermined threshold, and smooths the pixels by applying a smoothing filter. The gum detection unit 254 forms a polygon surrounded by pixels labeled 0 on the outside and pixels labeled 1 on the inside, and detects this as the gum area GA.

[0032] As shown in FIG. 6 , the exclusion target detection unit 255 detects other areas OA in the mouth image F that indicate areas other than the teeth and gums in the oral cavity. Specifically, the exclusion target detection unit 255 detects areas that may be misidentified, such as the inner walls of the oral cavity or shadows in the oral cavity that are captured when the facial video V is captured, to be excluded in the determination of the mouth image F performed by the determination unit 256 or the analysis of the oral cavity state performed by the analysis unit 258, which will be described later. The exclusion target detection unit 255 first converts the RGB color space of the pixels included in the mouth image F into the HSV color space. The exclusion target detection unit 255 binarizes the pixels included in the mouth image F based on a predetermined threshold, and detects pixels with label 1 as other areas OA. The exclusion target detection unit 255 may also detect the lips and the skin around the lips included in the mouth image F as areas to be excluded as other areas OA that indicate areas other than the teeth and gums in the oral cavity.

[0033] The judgment unit 256 judges whether the mouth image F detected by the image detection unit 252 satisfies the analysis conditions necessary to analyze the oral cavity state, based on the tooth area TA, gum area GA, and other area OA detected by the tooth detection unit 253, gum detection unit 254, and exclusion target detection unit 255.

[0034] The image acquisition unit 257 acquires one or more mouth images F that the determination unit 256 has determined to satisfy the analysis conditions, and stores the mouth images F as accumulated data in the information storage unit 27. The analysis unit 258 may use, for example, simple image analysis or a statistical method as a method for analyzing the oral cavity state, and preferably analyzes the oral cavity state using a machine learning model that has been machine-learned on the accumulated data stored in the information storage unit 27.

[0035] If the amount of accumulated data to be machine-learned by the machine learning model is large, the accumulated data may be stored in an external storage device as a database rather than stored in the information storage unit 27 of the user terminal 2. Furthermore, the analysis of the oral condition performed by the analysis unit 258 may be performed by an external arithmetic processing device. As another embodiment, the oral condition analysis system 1 may be configured such that the user terminal 2 is electrically connected to a server via a network such as the Internet.

[0036] In other embodiments, the oral condition analysis system 1 executes an oral condition analysis program on the server, and performs processing corresponding to the video reception unit 251, image detection unit 252, tooth detection unit 253, gum detection unit 254, exclusion target detection unit 255, judgment unit 256, image acquisition unit 257, and analysis unit 258 on the server.

[0037] Next, the determination unit 256 will be described. The determination unit 256 excludes other areas OA from the mouth image F as a determination target, and determines whether or not the tooth area TA and gum area GA in the mouth image F satisfy the analysis conditions. That is, the determination unit 256 determines whether or not the analysis conditions are satisfied based on the transitions and amounts of change in the tooth area TA value and gum area GA value, as shown in FIGS. 7 and 8 , which show the values ​​indicating the proportion of the tooth area TA in the mouth image F (hereinafter referred to as tooth area TA value) and the values ​​indicating the proportion of the gum area GA in the mouth image F (hereinafter referred to as gum area GA value) detected by the tooth detection unit 253 and the gum detection unit 254, recorded as time-series data.

[0038] There are various analysis conditions required for analyzing the oral cavity state, and one or more conditions may be included, and at least one of the tooth area TA and the gum area GA in the mouth image F must satisfy the analysis conditions, and it is preferable that both the tooth area TA and the gum area GA satisfy the analysis conditions. Examples of the analysis conditions include whether the tooth area TA in the mouth image F includes at least a predetermined number of teeth (crowns), whether the area of ​​the gum area GA in the mouth image F reaches the area required to analyze the oral cavity state, etc., and required numerical values ​​and targets can be set depending on the analysis method.

[0039] Specific examples of the determination by the determination unit 256 and the acquisition of images by the image acquisition unit 257 are as follows. The determination unit 256 sets the following analysis conditions to satisfy all of the following: (1) both the TA value of the tooth area and the GA value of the gum area reach a predetermined threshold value (e.g., 0.15) or more, (2) the state where the TA value of the tooth area and the GA value of the gum area reach a predetermined threshold value or more is maintained for a predetermined period (e.g., 30 frames) or more, and (3) the amount of change in the TA value of the tooth area and the GA value of the gum area is within a predetermined range (e.g., ±0.5). Furthermore, the determination unit 256 is set with a predetermined determination period (e.g., 10 seconds, 300 frames). The mouth image F used for the determination by the determination unit 256 is a mouth image F detected from a face video V captured at, for example, 30 fps.

[0040] The determination unit 256 constantly repeats the determination of whether the mouth image F satisfies the analysis conditions within a predetermined determination period. The determinations made by the determination unit 256 at time points (a) to (d) within the predetermined determination period will be described below.

[0041] 7 and 8 satisfies the above analysis conditions. Although the mouth image F at time point (a) satisfies analysis condition (3), the mouth image F at time point (a) does not satisfy analysis conditions (1) and (2). Therefore, the mouth image F at time point (a) is not acquired by the image acquisition unit 257.

[0042] 7 and 8 satisfies the above analysis conditions. Like the mouth image F at time point (a), the mouth image F at time point (b) satisfies the analysis condition (3), but does not satisfy the analysis conditions (1) and (2). Therefore, the mouth image F at time point (b) is not acquired by the image acquisition unit 257.

[0043] The determination unit 256 determines whether the mouth image F at time point (c) shown in Figures 7 and 8 satisfies the above analysis conditions. The mouth image F at time point (c) satisfies analysis condition (3), just like the mouth images F at time points (a) and (b). Furthermore, the tooth area TA value of the mouth image F at time point (c) reaches or exceeds the threshold value in analysis condition (1). However, the gum area GA value of the mouth image F at time point (c) does not reach the threshold value in analysis condition (1), and does not satisfy analysis condition (2). Therefore, the mouth image F at time point (c) is not acquired by the image acquisition unit 257.

[0044] 7 and 8 satisfies the above analysis conditions. The mouth image F at time point (d) satisfies all of the analysis conditions (1) to (3). Therefore, the mouth image F at time point (d) is acquired by the image acquisition unit 257.

[0045] Note that there may be more than one mouth image F that satisfies the analysis conditions (1) to (3) as determined by the determination unit 256. The encircled line P shown in Figures 7 and 8 indicates a period during which there are multiple mouth images F that satisfy the analysis conditions (1) to (3). Therefore, during the period enclosed by the encircled line P, which includes the time point (d), the image acquisition unit 257 acquires one or more mouth images F.

[0046] If the judgment period has elapsed and the judgment unit 256 determines that there is no mouth image F that satisfies the analysis conditions (1) to (3), the judgment unit 256 will temporarily end the judgment of whether the mouth image F satisfies the analysis conditions.

[0047] The flow of the oral condition analyzing system 1 according to the embodiment of the present invention will be described with reference to Fig. 9. First, the imaging unit 21 is activated to start imaging (step S1). For example, when a user operates an application on the user terminal 2, the application activates the imaging unit 21 included in the user terminal 2 to start imaging. When imaging by the imaging unit 21 starts, a face video V consisting of multiple facial images of the user U is captured.

[0048] At this time, it is preferable that a guidance display unit (not shown) displays guidance means on the display unit 23 to guide the user to an open mouth posture suitable for analyzing the oral cavity condition, i.e., a posture in which the teeth and gums are exposed. The guidance means is displayed as a rectangular frame that is elongated in the horizontal direction, the same as the mouth, but may be a frame of another shape, or may be a frame shaped to resemble teeth or gums. The guidance means may also be a frame that resembles the contours of a face.

[0049] The video receiving unit 251 receives the facial video V (step S2). The facial video V received by the video receiving unit 251 may be temporarily stored in the information storage unit 27 for processing to display the video on the display unit 23, but is not stored as an image for analyzing the state of the oral cavity.

[0050] The image detection unit 252 detects the mouth image F (step S3). The image detection unit 252 detects the mouth image F using a portion of the facial video V as a detection range. When the detection range detected by the image detection unit 252 is shown in the facial video V displayed on the display unit 23, the lower portion of the facial image V divided into upper and lower halves, particularly the mouth area such as the user's mouth and its surroundings, is used as the detection range for the mouth image F, and the mouth image F is detected from the facial video V.

[0051] In the mouth image F detected by the image detection unit 252, the tooth detection unit 253 detects a tooth area TA (step S4), the gum detection unit 254 detects a gum area GA (step S5), and the exclusion target detection unit 255 detects another area OA (step S6). Note that, although steps S4, S5, and S6 are performed simultaneously in the flowchart shown in Fig. 9, they may be performed in this order, or steps S4, S5, and S6 may be performed in any order.

[0052] The determination unit 256 determines whether the mouth image F satisfies the analysis conditions (step S7). If the mouth image F satisfies the analysis conditions (step S7: Yes), the determination unit 256 proceeds to step S8, and if the mouth image F does not satisfy the analysis conditions (step S7: No), the determination unit 256 proceeds to step S9.

[0053] The image acquisition unit 257 acquires a mouth image F that satisfies the analysis conditions (step S8). If the determination unit 256 determines that the mouth image F satisfies the analysis conditions (Yes in step S7), the image acquisition unit 257 acquires one or more mouth images F that the determination unit 256 has determined to satisfy the analysis conditions. The mouth images F acquired by the image acquisition unit 257 are temporarily stored in the information storage unit 27. At this time, it is preferable that a communication means be used to inform the user U that the capture of the mouth image F suitable for analyzing the oral cavity state has been completed, such as by temporarily lighting up the display unit 23 with a flash effect.

[0054] It is determined whether the imaging time has elapsed a predetermined determination period (step S9). If the determination unit 256 determines that the mouth image F does not satisfy the analysis conditions (step S7: No), the determination unit 256 further determines whether a predetermined determination period for determining whether the mouth image F satisfies the analysis conditions has elapsed. If the predetermined determination period has not elapsed (step S9: No), the process returns to step S2 and starts again from receiving the facial image V. If the predetermined determination period has elapsed (step S9: Yes), the oral cavity condition analysis system 1 according to the present invention is terminated.

[0055] The analysis unit 258 analyzes the oral cavity condition (step S10). The analysis unit 258 retrieves the mouth image F acquired by the image acquisition unit 257 from the information storage unit 27 and analyzes the oral cavity condition using, for example, a machine learning model that has undergone machine learning of data stored in the information storage unit 27. The analysis results obtained by the analysis unit 258 are displayed on the display unit 23 of the user terminal 2, and the oral cavity condition analysis system 1 according to the present invention is terminated. The analysis results obtained by the analysis unit 258 are preferably stored in the information storage unit 27 as new learning data. The analysis unit 258 may also use other methods for analyzing the oral cavity condition, such as simple image analysis, such as binarization processing for binarizing the mouth image F, or statistical methods, such as histogram analysis.

[0056] Therefore, the present invention can provide an oral condition analysis system and oral condition analysis program that are convenient and can automatically acquire oral images suitable for analyzing oral conditions.

[0057] Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

[0058] REFERENCE SIGNS LIST 1 Oral cavity condition analysis system 2 User terminal 21 Imaging unit 23 Display unit 25 Information processing unit 27 Information storage unit 251 Video reception unit 252 Image detection unit 253 Tooth detection unit 254 Gum detection unit 255 Exclusion target detection unit 256 Determination unit 257 Image acquisition unit 258 Analysis unit F Mouth image GA Gum region OA Other region P Encircling line TA Tooth region U User V Facial image

Claims

1. An oral condition analysis system comprising: a video receiving unit that continuously receives facial images of a user captured by an imaging unit of a user terminal as input from the imaging unit; an image detection unit that detects images including a mouth area from the facial images received by the video receiving unit; a teeth detection unit that detects a dental area from the images including the mouth area; a gum detection unit that detects a gum area from the images including the mouth area; a determination unit that determines whether at least one of the dental area and the gum area included in the images including the mouth area satisfy predetermined conditions necessary for analyzing an oral condition; an image acquisition unit that acquires one or more images including the mouth area that have been determined by the determination unit to satisfy the conditions; and an analysis unit that analyzes the oral condition based on the images including the mouth area acquired by the image acquisition unit.

2. The oral cavity condition analysis system according to claim 1, further comprising an excluded object detection unit that detects excluded objects other than the tooth area and the gum area from within an image including the mouth area.

3. The oral cavity condition analysis system of claim 1, wherein the judgment unit records at least one of the tooth area and the gum area, which changes for each image including the mouth area, as time-series data, and judges whether or not the image including the mouth area satisfies specified conditions necessary for analyzing the oral cavity condition based on the time-series data.

4. The oral cavity condition analysis system according to claim 3, further comprising a guidance display unit that displays a guidance means for guiding the mouth area to a predetermined position on the display screen of the user terminal on which the facial image is displayed.

5. The oral cavity condition analysis system of claim 3, wherein the tooth detection unit extracts the tooth area from the image including the mouth area by color space conversion and a predetermined threshold, and the gum detection unit applies a differential filter to the image including the mouth area and detects the gum area by a flattening filter and a predetermined threshold.

6. An oral cavity condition analysis program that causes a computer to function as an image receiving unit that continuously receives facial images of a user captured by an imaging unit of a user terminal as input from the imaging unit, an image detection unit that detects an image including a mouth area from the facial images received by the image receiving unit, a teeth detection unit that detects a teeth area from among the images including the mouth area, a gum detection unit that detects a gum area from among the images including the mouth area, a determination unit that determines whether or not at least one of the teeth area and the gum area included in the image including the mouth area satisfies predetermined conditions necessary for analyzing the oral cavity condition, an image acquisition unit that acquires one or more images including the mouth area that have been determined by the determination unit to satisfy the conditions, and an analysis unit that analyzes the oral cavity condition based on the images including the mouth area acquired by the image acquisition unit.

7. A computer-readable recording medium having recorded thereon an oral cavity condition analysis program for causing a computer to function as: a video receiving unit which continuously receives as input from an imaging unit of a user terminal facial images of a user captured by the imaging unit; an image detection unit which detects an image including a mouth area from the facial images received by the video receiving unit; a teeth detection unit which detects a tooth area from among the images including the mouth area; a gum detection unit which detects a gum area from among the images including the mouth area; a determination unit which determines whether or not at least one of the tooth area and the gum area included in the image including the mouth area satisfies predetermined conditions necessary for analyzing the oral cavity condition; an image acquisition unit which acquires one or more images including the mouth area which have been determined by the determination unit to satisfy the conditions; and an analysis unit which analyzes the oral cavity condition based on the images including the mouth area acquired by the image acquisition unit.

8. A method for analyzing an oral condition, comprising: continuously accepting as input from an imaging unit of a user terminal facial images of a user captured by the imaging unit; detecting images including a mouth area from the facial images; detecting teeth and gum areas from the images including the mouth area; determining whether at least one of the teeth and gum areas included in the images including the mouth area satisfies predetermined conditions required for analyzing the oral condition; acquiring one or more images including the mouth area that are determined to satisfy the conditions; and analyzing the oral condition based on the acquired images including the mouth areas.

9. The method for analyzing an oral cavity condition according to claim 8, further comprising the step of detecting an object to be excluded other than the tooth area and the gum area from the image including the mouth area.

10. A method for analyzing oral conditions as described in claim 8, further comprising recording as time-series data at least one of the tooth area and the gum area, which changes for each image including the mouth area, and further determining whether or not the image including the mouth area satisfies predetermined conditions necessary for analyzing the oral condition based on the time-series data.

Images