CN110811897B

CN110811897B - Method for generating virtual gingiva based on tooth model feature points

Info

Publication number: CN110811897B
Application number: CN201810953377.7A
Authority: CN
Inventors: 叶轩
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-08-13
Filing date: 2018-08-13
Publication date: 2021-09-14
Anticipated expiration: 2038-08-13
Also published as: CN110811897A

Abstract

The invention discloses a method for generating a virtual gum based on a tooth model characteristic point, which belongs to the technical field of computer digital three-dimensional graphic image processing, sequentially generates a gum line, a gum bottom extension point and a gum bottom edge line according to an input full-jaw single tooth characteristic point and the gum height, then generates a gum surface at the lip and tongue side of a tooth, and generates a far and middle tangent plane of the tooth according to the single tooth characteristic point and the gum bottom extension point if the tooth is the first or last tooth of the full jaw. If there is a tooth on the left of the single tooth that generates the gum, then according to the characteristic point and the extension point of the left tooth, the characteristic point and the extension point of the single tooth generate the faying face between the labial lingual side teeth between two teeth and the near-far faying face, this method can show the generation speed that improves virtual gum, can be applicable to the condition of missing the tooth, and can set up the gum according to the parameter and generate highly adapt to pleasing to the eye and print the demand, have apparent technical practicality and effect.

Description

Method for generating virtual gingiva based on tooth model feature points

Technical Field

The invention belongs to the technical field of computer digital three-dimensional graphic image processing, and relates to a method for generating virtual gingiva based on tooth model feature points.

Background

With the continuous development of the digital oral technology, the oral cavity auxiliary diagnosis and treatment system based on the three-dimensional digital technology depends on the establishment of three-dimensional digital models of teeth and gums of a patient.

The plaster model is copied by occluding silicon rubber of a traditional patient, the plaster model is scanned, or a three-dimensional digital tooth model and a gum model of the patient are directly obtained by using a digital intraoral scanner, the obtained tooth model data has higher precision, but the gum model data has the problems of bubbles, folds, incomplete deletion and the like.

The invention provides a method for quickly generating virtual gingiva based on tooth model feature points, which does not depend on problematic scanned gingiva data.

Disclosure of Invention

The invention provides a virtual gum generation method based on tooth model feature points, which is simple, convenient and quick, can adapt to gum generation of missing teeth, can be used for an oral auxiliary diagnosis and treatment system, and can also be used for an input data printing model of a 3D printer.

The invention adopts the following technical scheme:

(1) the input parameters are the sequential characteristic points distributed on the gum line of the lingual side of the labial side of each single tooth and the gum height required to be generated.

(2) And generating a gum line on the labial side of the single tooth according to the characteristic points on the labial side of the single tooth.

(3) And generating a gum bottom extension point of the labial side of the single tooth along the tooth root direction according to the characteristic point of the labial side of the single tooth.

(4) And generating a single tooth labial gingival bottom extension line according to the single tooth labial gingival bottom extension point.

(5) According to the gum line on the labial side of the single tooth, the extension line at the bottom of the gum on the labial side of the single tooth generates the gum surface on the labial side of the single tooth

(6) And repeating the operations 2-5 to generate the lingual gum surface of the single tooth by using the lingual characteristic points.

(7) And (3) using the ordered full-jaw teeth, and repeating the operations 2-6 to generate the labial-lingual gingival surfaces of the full-jaw teeth.

(8) In the process of generating the labial-lingual gingival surfaces of the full-jaw teeth, if a single tooth is the first or last tooth of the full jaw, a far-middle section of the tooth is generated according to the characteristic point of the single tooth and the extension point of the gingival bottom.

(9) In the process of generating the gum surface of the labial lingual side of the full jaw teeth, if a tooth is arranged on the left side of a single tooth, the labial lingual side inter-tooth faying surface is generated according to the characteristic points of two adjacent teeth and the extension point of the gum bottom.

(10) In the process of generating the gum surface of the labial lingual side of the full jaw teeth, if a tooth is arranged on the left side of a single tooth, a near-far inter-tooth faying surface is generated according to the characteristic points of two adjacent teeth and the extension point of the gum bottom.

The generation method of the invention is to generate a gum curve, a gum bottom extension point and a gum bottom extension line according to the characteristic points of a single tooth model, generate a gum curved surface by using the gum curve and the gum bottom extension line, generate a far middle tangent plane, a labial-lingual side inter-tooth faying surface and a near-far middle inter-tooth faying surface by using the characteristic points and the extension points, and combine a plurality of curved surfaces of a plurality of teeth to generate the virtual gum. The method has the advantages that the virtual gingiva is not influenced by the number of teeth, the method is suitable for the tooth missing condition, meanwhile, the truth degree of generated gingiva can be improved or reduced according to the number of input characteristic points, or the speed of generating the gingiva is improved by reducing the characteristic points, meanwhile, curve and curved surface interpolation can be controlled in the generation process to control smoothness according to requirements, the requirements of different oral cavity auxiliary diagnosis and treatment systems on the appearance effect and the speed of the generated gingiva can be met, meanwhile, the input parameter gingival height can be controlled, and materials are saved for 3D printing of a tooth model or the printing effect is emphasized.

Drawings

FIG. 1 is a diagram of a maxillary tooth model for example import;

FIG. 2 is a schematic diagram of 5 characteristic points in labial sequence for implementing an example of single tooth input;

FIG. 3 is a schematic view of the base and extension points of the labial-lingual gingiva for implementing an exemplary single tooth generation;

FIG. 4 is a schematic view of labial and lingual gingival surfaces implementing an exemplary single tooth generation;

FIG. 5 is a schematic diagram of a fully jawed virtual gum generated by an exemplary embodiment;

FIG. 6 is a schematic diagram of a full jaw virtual gum with missing teeth generated by an example implementation;

Detailed Description

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some embodiments of the invention are shown and described, but the invention is not limited thereto.

The method comprises the following specific steps:

the ordered teeth model of the whole jaw is introduced, the teeth are numbered 17-11 and 21-27 in sequence, and are also from the right side to the left side of the patient, the maxillofacial vertical direction is the Z-axis direction of the world coordinate system, and the maxillofacial sagittal direction is the Y-axis direction of the world coordinate system, as shown in figure 1.

The single tooth is input into 5 feature points distributed on the lingual gingival line of the labial side, and the height of the generated gingiva is 15 mm as shown in fig. 1.

(1) The gum line on the labial side of the tooth is fitted by using the characteristic points on the labial side of the single tooth, straight line fitting is used in the embodiment, and other fitting methods can be used according to the requirement.

(2) And (3) using the first labial characteristic point of the single tooth to extend along the Z-axis direction of a world coordinate system, wherein the extension height is the parameter gum height, namely the X and Y coordinate values of the extension point are equal to the X and Y coordinate values of the characteristic point, and the Z coordinate value is equal to the Z coordinate value of the characteristic point plus the gum height parameter, and determining the labial gum bottom extension point (also called as the base point) of the first characteristic point.

(3) Determining the fifth labial feature point according to the labial gingival bottom base point, wherein the extending point has X and Y coordinate values equal to those of the feature point, and the Z coordinate value is equal to that of the labial gingival bottom base point, as shown in fig. 3.

(4) And connecting the labial gingival bottom base point and the fifth Z-axis extension point to generate a gingival bottom edge line.

(5) The labial gingival surface of the tooth is generated from the labial gingival line and the labial gingival bottom edge line, as shown in fig. 4.

(6) The above method is repeated to generate the tooth lingual gingival surface, and the Z-axis coordinate value of the bottom base point of the lingual gingival surface is the Z-coordinate value of the labial gingival bottom base point, as shown in fig. 4.

(7) Repeating the steps 1-6 to generate the labial-lingual gingival surfaces of the full jaw teeth.

(8) If a single tooth is the first tooth of the full jaw face, a tooth far and middle tangent plane is generated according to the first characteristic point of the labial side, the first characteristic point of the lingual side, the base point of the gingival bottom of the labial side and the base point of the gingival bottom of the lingual side.

(9) If a single tooth is the last tooth of the full jaw face, the far and middle tangent plane of the tooth is generated according to the last characteristic point of the labial side, the last extension point of the labial side and the gingival bottom and the last extension point of the lingual side and the gingival bottom, as shown in fig. 5.

(10) Repeating the above steps 1-9 to generate the labial and lingual gingival surfaces of all teeth and the distal and medial sections of the first and last teeth of the full jaw in turn, as shown in fig. 5.

(11) If there is a tooth on the left side of a single tooth generating the gum, a labial interdental bonding surface between the two teeth is generated according to the bottom extension point of the fifth labial characteristic point and the fifth labial characteristic point of the left tooth and the bottom extension point of the gum of the first labial characteristic point and the first labial characteristic point of the single tooth.

(12) Using the lingual feature points and the gingival base extension points, the lingual interproximal junction between two teeth is created in step 11, as shown in FIG. 5.

(13) If there is a tooth on the left side of the tooth currently generating the gum, a near-far junction between two teeth is generated according to the fifth labial feature point and the fifth lingual feature point of the left tooth and the first labial feature point and the first lingual feature point of the current tooth, as shown in fig. 6.

The virtual gum is successfully generated, and the method generates the full-jaw virtual gum within 600 milliseconds through repeated implementation, and has remarkable technical practicability and effect.

Claims

1. The method for generating the virtual gingiva based on the feature points of the tooth model is characterized by comprising the following steps:

(1) the input parameters are sequence characteristic points distributed on the gum line of the lingual side of the labial side of a single tooth and the height of the gum to be generated;

(2) generating a gum line on the labial side of the single tooth according to the characteristic points on the labial side of the single tooth;

(3) generating a gum bottom extension point on the labial side of the single tooth along the tooth root direction according to the characteristic point on the labial side of the single tooth and the height of the gum;

(4) generating a gum bottom extension line on the labial side of the single tooth according to the gum bottom extension point on the labial side of the single tooth;

(5) according to the gum line on the labial side of the single tooth, the extension line at the bottom of the gum on the labial side of the single tooth generates the gum surface on the labial side of the single tooth;

(6) repeating the operations (2) to (5) by using the characteristic points of the single tooth lingual side to generate a gum surface of the single tooth lingual side;

(7) repeating the operations (2) to (6) to generate the labial-lingual gingival surfaces of the full jaw teeth by using the ordered full jaw teeth;

(8) in the process of generating the gingival surfaces of the labial and lingual sides of the full jaw teeth, if a single tooth is the first tooth of the full jaw surfaces, a tooth far and middle tangent plane is generated according to the first characteristic point of the labial side, the first characteristic point of the lingual side, the first extension point of the gingival bottom of the labial side and the first extension point of the gingival bottom of the gingival of the lingual side;

(9) in the process of generating the gingival surfaces of the labial and lingual sides of the full teeth, if a tooth is arranged on the left side of a single tooth, generating a labial interdental bonding surface between the two teeth according to the last characteristic point of the labial side of the left tooth, the last extension point of the gingival bottom of the labial side, the first characteristic point of the labial side of the current single tooth and the first extension point of the gingival bottom of the labial side of the gingival;

(10) using the lingual characteristic points and the gingival bottom extension points to generate lingual interdental bonding surfaces between the two teeth by the same operation as the operation (9);

(11) in the process of generating the labial-lingual gingival surfaces of the full teeth, if a tooth exists on the left side of a single tooth, a near-far junction surface between the two teeth is generated according to the last labial characteristic point and the last lingual characteristic point of the left tooth and the first labial characteristic point and the first lingual characteristic point of the current single tooth;

(12) the generated gingival surfaces on the labial and lingual sides of the teeth, the far and middle tangent planes of the teeth, the faying surfaces between the labial and lingual sides of the two teeth and the near and far faying surfaces between the two teeth are used for obtaining the virtual gingiva.