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EP-4385456-B1 - FACIAL SHAPE CLASSIFICATION METHOD AND DENTURE DESIGN DEVICE THEREFOR

EP4385456B1EP 4385456 B1EP4385456 B1EP 4385456B1EP-4385456-B1

Inventors

  • KIM, YOUNG SEOK
  • CHO, IN HO
  • CHOI, KYOO OK

Dates

Publication Date
20260506
Application Date
20220712

Claims (8)

  1. A facial shape classification method, which is performed using a denture design device (1), comprising: in the denture design device (1), acquiring facial data of a patient; extracting a plurality of landmarks (311, 312, 321, 322, 331, 332) from the acquired facial data; classifying a facial shape of the patient using distances (341, 342, 343) between the plurality of extracted landmarks (311, 312, 321, 322, 331, 332); and classifying and providing an artificial tooth shape of the patient according to the classified facial shape; characterized in that the extracting of the plurality of landmarks (311, 312, 321, 322, 331, 332) comprises extracting, as the plurality of landmarks, (i) endpoints (311, 312) on both sides of the one-third portion of a forehead area, and (ii) tragus points (321, 322) on both sides of the face, and (iii) gonion points (331, 332) on both sides of the face ; and the classifying of the facial shape of a patient comprises: calculating a first distance (341) of a first line segment connecting endpoints (311, 312) on both sides of the one-third portion of the forehead area in the facial data, a second distance (342) of a second line segment connecting the tragus points (321, 322) on both sides, and a third distance (343) of a third line segment connecting the gonion points (331, 332) on both sides; and classifying the facial shape of the patient based on a comparison of the calculated first, second, and third distances (341, 342, 343).
  2. The facial shape classification method of claim 1, wherein in the classifying and providing of the artificial tooth shape of a patient, the artificial tooth shape is classified as at least one of square, tapering, or ovoid, or a combination of at least two thereof according to the facial shape.
  3. The facial shape classification method of claim 1, wherein in the classifying and providing of the artificial tooth shape of a patient, when the facial shape is such that - first distance (341) equals the second distance (342) and the second distance (342) equals the third distance (343) , or - the first distance (341) is smaller than the second distance (342) and the second distance (342) equals the third distance (343), or - the first distance (341) is greater than the second distance (342) and the second distance (342) equals the third distance (343), or - the first distance (341) equals the second distance (342) and the second distance (342) is smaller than the third distance (343), the artificial tooth shape is classified as square; when the facial shape is such that - the first distance (341) is greater than the second distance (342) and the second distance (342) is greater than the third distance (343), or - the first distance (341) is smaller than the second distance (342) and the second distance (342) is smaller than the third distance (343), or the first distance (341) is greater than the second distance (342) and the second distance (342) is smaller than the third distance (343), the artificial tooth shape is classified as tapering; and when the facial form is such that the first distance (341) is smaller than the second distance (342) and the second distance (342) is greater than the third distance (343), the artificial tooth shape is classified as ovoid, wherein the first distance (341) is the distance of the first line segment connecting the endpoints (311, 312) on both sides of the one-third portion of the forehead area in the facial data, the second distance (342) is the distance of the second line segment connecting the tragus points (321, 322) on both sides, and the third distance (343) is the distance of the third line segment connecting the gonion points (331, 332) on both sides.
  4. The facial shape classification method of claim 1, further comprising, when there are multiple classified artificial tooth shapes, providing the multiple artificial tooth shapes, receiving a specific artificial tooth shape selected from among the multiple provided artificial tooth shapes through a user action, and providing the selected artificial tooth shape.
  5. The facial shape classification method of claim 1, further comprising receiving a manipulation signal based on a user action for the provided artificial tooth shape, and modifying and providing the artificial tooth shape.
  6. The facial shape classification method of claim 5, wherein the modifying and providing of the artificial tooth shape comprises, when providing a first artificial tooth shape (500), vertically dividing the first artificial tooth shape (500) into right and left halves (530, 520) while displaying a dividing line (510), and in response to selecting either the left half (520) or the right half (530) through a manipulation signal based on a user action, providing a modified artificial tooth shape (540, 550) in which, when the right half (530) is selected, the right half (530) is modified to a second artificial tooth shape (540), or, when the left half (520) is selected, the left half (520) is modified to a third artificial tooth shape (550).
  7. The facial shape classification method of claim 5, wherein the modifying and providing of the artificial tooth shape comprises, in response to selecting a specific artificial tooth shape (500) through a user manipulation, displaying an artificial tooth replacement list (600) on a screen and in response to selecting a specific artificial tooth shape from the artificial tooth replacement list (600) through a user manipulation, modifying the artificial tooth shape to the selected artificial tooth shape and providing the modified artificial tooth shape.
  8. A denture design device (1) comprising: a data acquisition unit (10) configured to acquire facial data of a patient; a control unit (14) configured to extract a plurality of landmarks (311, 312, 321, 322, 331, 332) from the acquired facial data, to classify a facial shape of the patient using distances (341, 342, 343) between the plurality of extracted landmarks (311, 312, 321, 322, 331, 332), and to classify an artificial tooth shape of the patient according to the classified facial shape; and an output unit (18) configured to provide the classified artificial tooth shape, characterized in that the control unit (14) is configured to extract, as the plurality of landmarks, (i) endpoints (311, 312) on both sides of a one-third portion of a forehead area in the facial data, (ii) tragus points (321, 322) on both sides of the face, and (iii) gonion points (331, 332) on both sides of the face, and the control unit (14) is configured to classify the facial shape of the patient by: calculating a first distance (341) of a first line segment connecting the endpoints (311, 312) on both sides of the one-third portion of the forehead area, a second distance (342) of a second line segment connecting the tragus points (321, 322) on both sides, and a third distance (343) of a third line segment connecting the gonion points (331, 332) on both sides; and classifying the facial shape of the patient based on a comparison of the calculated first, second, and third distances (341, 432, 433).

Description

[Technical Field] The present invention relates to dental image processing technology, and more specifically, to technology for designing a denture using dental images. [Background Art] Restoration using complete dentures in edentulous patients is a treatment concept entirely different from restorative treatment of natural teeth. A user must set everything, including the positions of artificial teeth, and all teeth move as one unit, with a constant risk of dislodgment. When making such complete dentures, if the optimal artificial teeth are selected and placed, it may become easier to make occlusal adjustments for complete denture patients. Currently, one method to choose appropriate artificial teeth is for the user to visually inspect the patient's facial photos or model data and make a selection. In this case, the method relies on the user's experience rather than precise data. The conventional method that relies on user experience is cumbersome, as it requires the user to choose the shape of artificial teeth each time, and the results may vary depending on the user's proficiency. KR 10-1067942 B1 relates to a dental image processing system and method in which patient image data are acquired and processed by a computing device to support dental treatment and prosthesis-related operations. The document describes extracting feature information from image data and performing calculations based on such extracted features in order to derive information relevant for dental applications. In particular, KR 10-1067942 B1 is concerned with computer-assisted processing of patient-related image data and the use of calculated parameters derived from image features to assist dental procedures and decision-making in a digital dental environment. WO 2018/230873 A1 discloses a tooth shape classifying and dental prosthesis shape guiding method in which images of a patient's teeth are acquired, prosthetic tooth sample images are classified according to shape-related characteristics, and a prosthetic tooth image is selected and applied to generate an expected prosthetically treated tooth image. The document focuses on classification and selection of artificial tooth shapes based on visual characteristics of tooth images and provides a user-guided workflow for selecting and applying prosthetic tooth shapes within a digital dental treatment context. [Disclosure] [Technical problem] It is an object of the present invention to provide a facial shape classification method and device which can select the optimal artificial tooth when designing a complete denture, minimize user's manipulation, and increase the patient's aesthetic satisfaction, and a denture design device therefor. [Technical Solution] The object is achieved by the features of independent claim 1 regarding the method and of independent claim 8 regarding the device. Further embodiments are defined in the dependent claims. [Advantageous Effects] According to a facial shape classification method in accordance with the invention and a denture design device therefor, it is possible to minimize user's manipulation by automatically classifying and providing the shape of an artificial tooth in a complete denture production. In addition, by considering the individual facial shape of a patient to determine and provide the shape of artificial teeth, accuracy and patient aesthetic satisfaction may be enhanced. Moreover, allowing a user to modify the provided patient's facial shape increases user convenience. [Description of Drawings] FIG. 1 is a diagram illustrating a configuration of a denture design device.FIG. 2 is a flowchart illustrating a facial shape classification method.FIG. 3 illustrates facial shapes classified.FIG. 4 is a table showing facial shape-specific artificial tooth shapes classified.FIG. 5 is a diagram illustrating an example of user modification to the shape of an artificial tooth provided.FIG. 6 is a diagram illustrating an example of user modification to the shape of an artificial tooth provided. [Mode of the Invention] The advantages and features of the present invention and the manner of achieving the advantages and features will become apparent with reference to detailed description below together with the accompanying drawings. However, the present invention may be implemented in many different forms and should not be construed as being limited to the description set forth herein. Throughout the entire specification, the same or like reference numerals designate the same or like elements. In describing examples , a detailed description of related known configurations or functions incorporated herein will be omitted when it is determined that the detailed description thereof may unnecessarily obscure the subject matter of the present invention. The terms which will be described below are terms defined in consideration of the functions in the present invention, and may be different according to users, intentions of the users, or customs. Therefore, the