A periodontal guide for 3D printing assisted membrane gingival widening surgery and a preparation method thereof

Abstract

The application discloses a preparation method of a periodontal guide plate for 3D printing assisted aesthetic membrane gingival widening surgery, and the method comprises the following steps: obtaining patient data including oral scanning data, facial scanning data and electronic face arch data; importing the obtained data into dental CAD design software and integrating the data to reconstruct a virtual patient and generate a first model of a tooth arrangement; determining the crown length of upper anterior teeth and the position of the upper anterior gum edge according to the first model of the tooth arrangement, generating a digital aesthetic virtual restoration; longitudinally measuring the gingival edge downward height of the aesthetic virtual restoration; combining the aesthetic virtual restoration with the oral scanning data to generate a second model; importing the second model into the dental CAD design software to determine the drawing range of the periodontal guide plate and generate model data of the periodontal guide plate; and performing 3D printing based on the model data of the periodontal guide plate to obtain the periodontal guide plate. The application also discloses the periodontal guide plate prepared by the above method, which has wide application value.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a 3D-printed periodontal guide plate for assisted gingival widening surgery and its preparation method. Background Technology

[0002] With economic development, people have increasingly higher aesthetic demands for teeth, and problems such as alveolar bone resorption and gingival recession caused by periodontal disease are receiving more and more attention. Anterior aesthetic restorations can largely meet patients' expectations for appearance, enhancing their self-confidence and social skills. Good anterior aesthetic restorations can reduce the psychological stress and feelings of inferiority caused by dental problems. Gingival recession and black triangles are among the main problems leading to patients' perception of unattractive teeth. In addition, conditions such as cervical abrasion, insufficient keratinized gingiva, and frenulum attachment close to the gingival margin all require gingival membrane surgery. Therefore, aesthetic gingival membrane surgery has become an important treatment method for treating anterior gingival recession and excessively long clinical crowns. Furthermore, problems such as cervical defects, insufficient keratinized gingiva, and frenulum attachment close to the gingival margin all require treatment through aesthetic gingival membrane surgery.

[0003] Aesthetic mucogingival surgery refers to a surgical method that repairs receding gingival tissue and shortens the clinical crown by creating a connective tissue flap in the hard palate, dividing it, and filling the area of ​​aesthetic defects. Traditional anterior mucogingival surgery generally relies on the dentist's experience to adjust the gingival position. This method, depending solely on the dentist's visual perception and experience, often introduces errors, resulting in unsatisfactory aesthetic outcomes. Determining the target gingival margin in aesthetic mucogingival surgery requires extremely high precision and aesthetics. Given the individualized needs of different patients and the varying clinical experience and methods of different dentists, traditional methods for determining the target gingival margin are complex, lack precision, and require dentists to adopt personalized treatment approaches based on the specific circumstances.

[0004] like Figure 2 As shown, this is the condition of the patient's teeth and gums before the gingival widening surgery.

[0005] Due to age, illness, and other reasons, patients experience upward receding of the gingival margin, resulting in excessive exposure of the upper front teeth when smiling. Uneven gingival recession can significantly impact aesthetics (even a difference of only 1mm to 2mm in the anterior-posterior gingival margin can have a substantial visual impact). In the early to mid-stages of gingival recession, a membrane-gingival surgery is performed. This involves using a connective tissue flap taken from the palate to fill the receding gingival area, causing the gingival margin to move downwards and cover more of the tooth root. This is currently the most common treatment method both domestically and internationally.

[0006] During a face-to-face consultation, such as Figure 4As shown, uneven wear of the incisal edges of the upper anterior teeth on both sides can occur due to acid erosion, occlusion, etc., resulting in inconsistent tooth exposure on both sides when smiling, and mismatch between the line connecting the incisal edges of the upper anterior teeth and the upper edge of the lower lip, which can also greatly affect aesthetics. In the process of developing an aesthetic restoration plan, it is necessary to design the shape of the patient's aesthetic virtual restoration, and reposition the new incisal edge position and gingival margin position of the anterior teeth. Then, the problem of the mismatch between the gingival margin and the smile line is solved through gingival surgery. At this time, a periodontal guide plate needs to be designed to guide the surgeon to accurately anchor the palatal connective tissue flap to the set gingival margin position.

[0007] However, during the treatment of patients, due to the certain degree of defects in the patient's teeth, the designed virtual restoration is based on the patient's initial teeth with the addition of some virtual tooth tissue. If the periodontal guide is directly 3D printed on the virtual restoration model, there will be a certain gap between the guide and the patient's initial teeth. The guide is difficult to fit completely onto the surface of the initial defective teeth, resulting in instability and movement of the guide during the operation, which affects the precise positioning of the newly added gingiva in the gingival surgery.

[0008] Currently, there are several methods for preparing periodontal surgical guides using digital technology. For example, Chinese invention patent application CN111616824A discloses a periodontal surgical guide and its preparation method. This guide includes a fixed-length, fixed-width guide that wraps around and attaches to the maxilla. A depth-fixing guide is fixedly installed at the corresponding maxillary cementoenamel junction position of the fixed-length, fixed-width guide via a snap-fit ​​structure to abut against the edge of a scalpel handle to limit its cutting depth. An incision is provided inside the depth-fixing guide along the transverse gingival margin of the maxillary cementoenamel junction to provide space for the scalpel blade's movement. This prior art mainly guides and limits the blade's direction and cutting depth. The purpose of this guide is for operations involving the harvesting of connective tissue from the palate, a method to confirm the depth during surgery to reduce damage to blood vessels, and to avoid damage to important tissues during mesogingival surgery. However, it does not precisely determine the operation and related functions of the gingival flap transplantation area.

[0009] Furthermore, Chinese invention patent CN115531014B provides a method for manufacturing a guide plate for crown lengthening surgery, which uses restoration as a guide to precisely position the height and thickness of alveolar bone removal for teeth requiring crown lengthening. However, this patent mainly addresses cases where clinical crowns are too short, using this guide plate to cover the tooth and bone surfaces of the anterior region to guide the removal of gingiva and bone, thereby increasing the crown height.

[0010] However, in cases where the clinical crown height is too large, the incisal edges of the teeth on both sides are asymmetrical, and the position of the incisal edge needs to be adjusted, and the height of the gingiva on both sides needs to be reduced, there is an urgent need for a surgical aid device and manufacturing method that can accurately locate the target gingival margin, is easy to operate, and has a wide range of applications. Summary of the Invention

[0011] To address the shortcomings of existing technologies, the present invention aims to provide a customized periodontal guide for 3D-printed assisted aesthetic gingival augmentation surgery and its preparation method. The periodontal guide of this invention is fabricated using 3D printing technology. The guide body can be fitted and fixed to the tooth position in the surgical area, facilitating the determination of the gingival height and morphology of the area to be transplanted after harvesting a connective tissue flap from the palate, without addressing the gingival flap preparation issues of existing technologies. The method of this invention combines intraoral and facial scan data, CBCT, and electronic facebow design to precisely locate the target gingival margin, guiding the smooth progress of aesthetic gingival augmentation surgery. It effectively avoids the problems of complex operation, inaccurate gingival margin positioning, and the need for personalized design of the target gingival margin position in existing technologies. The periodontal surgical guide prepared by this invention has a simple structure, achieving the goal of guiding precise surgical implementation, not only reducing the difficulty of surgical operation but also ensuring the aesthetic effect of the surgery, and can be widely promoted in clinical practice.

[0012] Therefore, the present invention provides the following technical solution:

[0013] On one hand, the present invention provides a method for preparing a customized periodontal guide plate for 3D printing-assisted aesthetic gingival widening surgery, the method comprising the following steps:

[0014] Step 1: Acquire patient data including oral scan data, facial scan data, and electronic face bow data;

[0015] Step 2: Import the data obtained in Step 1 into dental CAD design software and integrate it to reconstruct the 3D virtual patient image and generate the first model of the dental arch.

[0016] Step 3: Based on the first dental arch model, determine the crown length and gingival margin position of the upper anterior teeth, and generate a digital aesthetic virtual restoration; the upper anterior teeth include the maxillary central incisors, maxillary lateral incisors, and maxillary canines;

[0017] Step 4: Measure the gingival margin displacement height of the aesthetic virtual restoration longitudinally;

[0018] Step 5: Merge the aesthetic virtual restoration with the intraoral scan data to generate a second model;

[0019] Step 6: Import the second model into the dental CAD design software, determine the area for drawing the periodontal guide plate, and generate the model data of the periodontal guide plate;

[0020] Step 7: 3D print the periodontal guide plate based on its model data to obtain the periodontal guide plate.

[0021] In step one, when the patient has special facial problems such as facial asymmetry or deviation of the incisal edge line in the anterior teeth area, CBCT data is collected in addition to the CBCT data.

[0022] And / or,

[0023] The oral scan data is a three-dimensional digital model of the upper and lower dentition and occlusion obtained by intraoral scanning using an intraoral scanner; and / or,

[0024] The facial scan data is facial morphology data in a smiling state obtained through facial scanning using a 3D facial scanner; and / or...

[0025] The electronic facebow data refers to data collected and recorded by an electronic facebow device, including information on maxillary position and mandibular movement; and / or,

[0026] The CBCT data refers to the morphological features of the upper and lower jaw teeth and jawbones obtained by scanning the maxillofacial region.

[0027] In step two, by importing and integrating the oral scan data, facial scan data, electronic facebow data, and / or CBCT data, a 3D virtual patient image is reconstructed to generate a first model of the dental arch.

[0028] Specifically, the steps include the following:

[0029] Step 2.1. Import oral scan data, facial scan data, and electronic face bow data;

[0030] Alternatively, import oral scan data, facial scan data, electronic facial bow data, and CBCT data;

[0031] Step 2.2. Match the imported oral scan data with the electronic facebow data to align the static dentition 3D model and the mandibular movement trajectory in the 3D coordinate system, ensuring the spatial consistency between the model and the actual occlusal movement;

[0032] Step 2.3. Match the imported facial scan data with the oral scan data to align the patient's smiling tooth-showing morphology and the static dentition 3D model in the 3D coordinate system, ensuring the consistency between the teeth and the model when the face is smiling;

[0033] Step 2.4. Generate a virtual patient model that includes intraoral scan data, dynamic trajectory of the electronic face bow, and facial scan data;

[0034] When patients have specific facial issues, CBCT can be used to create a more accurate model.

[0035] Specifically, including:

[0036] By adjusting the CBCT threshold, data with relatively clear skeleton and complete dentition are obtained. Point-to-point registration is then performed in the advanced pattern matching grid to further match the CBCT data and intraoral scan data.

[0037] And / or,

[0038] The CBCT threshold values ​​are restored to the facial morphology, and the facial scan data is registered point-to-point with the CBCT data through facial structure.

[0039] In step three, the aesthetic virtual restoration designs the crown length and width of the upper anterior teeth according to the internationally recognized optimal aesthetic proportions of the upper anterior teeth; the digital aesthetic virtual restoration designs the gingival margin position of the upper anterior teeth when smiling according to the mid-smile line principle; the upper anterior teeth include the maxillary central incisors, maxillary lateral incisors, and maxillary canines;

[0040] And / or,

[0041] The design requirements for the aesthetic virtual restoration include: the direction and angle of the long axis of the maxillary anterior teeth in the aesthetic virtual restoration are consistent with the long axis of the original teeth; the gingival margin of the maxillary central incisor is level with the upper lip margin when smiling; the apex of the gingival margin of the maxillary lateral incisor is 0-1mm lower than the apex of the gingival margin of the maxillary central incisor; the apex of the gingival margin of the maxillary canine is level with the apex of the gingival margin of the maxillary central incisor; and the labial cervical surface of the maxillary anterior teeth is consistent with the labial cervical surface of the original teeth.

[0042] Finally, the target gingival margin and incisal margin positions of the upper anterior teeth were determined.

[0043] In step four, the height of the gingival margin reduction is the difference between the original gingival margin height and the designed gingival margin height on the sagittal plane;

[0044] Specifically, it includes:

[0045] Step 4.1. Design the incisal edge of the upper anterior teeth according to the lower lip edge when smiling, so that the line connecting the incisal edges of the upper anterior teeth is 0-2mm above the lower lip edge; the upper anterior teeth include the maxillary central incisors, maxillary lateral incisors and maxillary canines;

[0046] Step 4.2. Based on the width-to-length ratio of the maxillary central incisor, which is 75-85%, design the gingival margin position of the maxillary central incisor. The gingival margin is scalloped, and the top of the gingival margin is flush with the upper lip margin.

[0047] And / or,

[0048] The gingival position of the bilateral maxillary lateral incisors is designed based on the gingival position of the maxillary central incisor, wherein the gingival position of the maxillary lateral incisor is 0-1 mm lower than the apex of the gingival position of the maxillary central incisor;

[0049] And / or,

[0050] The gingival position of the bilateral maxillary canines is designed based on the gingival position of the maxillary central incisor, so that it is level with the apex of the gingival margin of the maxillary central incisor.

[0051] In one specific embodiment, preferably, the crown of the maxillary central incisor is determined to have a width-to-length ratio of 75% to 85%, that is, the width of the crown of the maxillary central incisor is 75% to 85% of its length; the crown width of the maxillary lateral incisor is determined to be 65% to 80% of the width of the maxillary central incisor; and the crown width of the maxillary canine is determined to be 40% to 60% of the width of the maxillary central incisor.

[0052] In step six, the periodontal guide plate covers the tooth body from the anterior region to the bilateral molar region. The palatal edge of the guide plate is drawn according to the palatal gingival margin line of the dentition. The labial edge position of the guide plate at the target tooth position is drawn according to the anterior tooth gingival position designed in the second model. The labial edge lines of the remaining teeth in the guide plate are drawn according to their gingival margin lines.

[0053] It is important to note that the labial area of ​​the guide plate should be closely attached to the gingival margin of the designed virtual restoration, and the location of the gingival papilla should be clearly exposed;

[0054] Specifically, it includes:

[0055] The labial portion of the periodontal guide should be closely fitted to the gingival margin of the designed virtual restoration, clearly exposing the location of the gingival papilla to create a customized periodontal guide; and / or,

[0056] The target gingival margin position of the periodontal guide is recorded based on the gingival margin position of the virtual restoration in the second model.

[0057] When a patient's teeth are incomplete and require modification of the incisal edge position of the anterior teeth, the following steps need to be added between steps six and seven:

[0058] Delete all virtual restorations in the second model, redefine the internal morphology of the periodontal guide using the first dental arch model, and regenerate the model data of the periodontal guide.

[0059] In one specific implementation, the deletion tool of dental CAD design software is used to select and delete all virtual restoration parts in the second model; the internal shape of the guide is redefined according to the tooth morphology in the first model, a new guide data is generated and saved in STL format; this step is to make the guide fit the patient's original tooth morphology better, so that the guide remains stable during the gingival surgery; if the patient's teeth are intact and there is no need to change the incisal edge position of the patient's anterior teeth, this step can be omitted.

[0060] The present invention also provides a periodontal guide plate prepared by the above preparation method, wherein the periodontal guide plate covers and wraps the tooth body of the upper anterior teeth and / or bilateral molar areas, the internal morphology of the periodontal guide plate matches the virtual restoration or the first model of the dental arch, and the labial edge is flush with the target gingival margin;

[0061] And / or,

[0062] The periodontal guide plate is provided with a palatal retention plate on the lingual side, which allows the periodontal guide plate to be more firmly attached and fixed to the teeth.

[0063] Advantages and positive effects of this invention: The periodontal surgical guide of this invention is simpler to manufacture, can be prepared and widely used in most medical institutions, has greater applicability, and the manufacturing of the guide greatly reduces the difficulty of clinical operation for doctors, while saving clinical operation time. The periodontal surgical guide of this invention, combined with digital technology, can accurately locate the target gingival margin, has good matching with the dentition, and is stably installed, thereby achieving the purpose of precise surgical guidance. The periodontal surgical guide can be customized according to the different needs and actual conditions of patients without increasing the clinical operation time, greatly reducing the design difficulty of gingival margin positioning in aesthetic gingival widening surgery. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0065] Figure 1 This is a flowchart illustrating an embodiment of the method for preparing a periodontal guide plate for 3D printing-assisted gingival widening surgery according to the present invention.

[0066] Figure 2 The patient's original tooth and gum morphology before treatment.

[0067] Figure 3 A photograph of the patient's lips when smiling before the implementation of the 3D-printed assisted gingival widening surgery of this invention using a periodontal guide plate.

[0068] Figure 4 This is a frontal view of the initial maxillary dentition via oral scanning.

[0069] Figure 5 Before using the periodontal guide plate for 3D printing to assist in gingival widening according to the present invention, the patient's oral scan data, facial scan data, CBCT data and mandibular movement trajectory data are integrated and a virtual patient scenario is constructed.

[0070] Figure 6 A photo of the lips of a virtual patient when they smile.

[0071] Figure 7 A digital aesthetic virtual prosthesis designed in dental CAD design software based on the patient's smiling state in facial scan data.

[0072] Figure 8A frontal view of the maxillary dentition including an aesthetic virtual restoration.

[0073] Figure 9 This is a schematic diagram of the periodontal guide plate in the preparation method of the periodontal guide plate for 3D printing assisted gingival widening surgery according to the present invention; wherein, (A) is a front view schematic diagram of the periodontal guide plate; (B) is a side view schematic diagram of the periodontal guide plate.

[0074] Figure 10 This is a bottom view of the periodontal guide plate covering the dentition in an embodiment of the method for preparing a periodontal guide plate for 3D printing-assisted gingival widening surgery according to the present invention.

[0075] Figure 11 In the method for preparing a periodontal guide plate for 3D printing-assisted gingival widening surgery according to the present invention, Figure 10 The sagittal sectional view obtained by longitudinally sectioning along line A-A' in the periodontal surgical guide shown.

[0076] Among them, 1-maxillary central incisor; 2-maxillary lateral incisor; 3-maxillary canine; 4-target gingival margin of maxillary central incisor; 5-target gingival margin of maxillary lateral incisor; 6-target gingival margin of maxillary canine; 7-incisal margin of maxillary central incisor; 8-incisal margin of maxillary lateral incisor; 9-cusp of maxillary canine; 10-gingiva anterior to treatment; 11-guide plate body; 12-palatal retention plate. Detailed Implementation

[0077] The present invention will be further described in detail below with reference to the specific embodiments and accompanying drawings. Except for the contents specifically mentioned below, the processes, conditions, and experimental methods for implementing the present invention are all common knowledge and general knowledge in the art, and the present invention does not have any particular limitations.

[0078] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0079] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0080] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this disclosure. The drawings only show the components related to this disclosure and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0081] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0082] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0083] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0084] This invention provides a customized periodontal guide for 3D-printed assisted aesthetic gingival augmentation surgery and its preparation method. The customized periodontal guide for 3D-printed assisted aesthetic gingival augmentation surgery can be fitted and retained in the surgical area. By combining intraoral and facial scan data, cone-beam computed tomography (CBCT), and electronic facebow design, the periodontal guide can accurately locate the target gingival margin, guiding the smooth progress of the aesthetic gingival augmentation surgery. This invention effectively avoids the problems of complex operation, inaccurate gingival margin positioning, and the need for personalized design of the target gingival margin position for different patients in existing technologies. The surgical guide prepared by this invention has a simple structure, achieving the goal of guiding precise surgical implementation. It not only reduces the difficulty of surgical operation but also increases the accuracy of surgical operation, making the surgical results more aesthetically pleasing, and can be widely promoted in clinical practice.

[0085] The customized periodontal guide for 3D-printed assisted aesthetic gingival hyperplasia surgery disclosed in this invention is made using 3D printing technology. The guide body can fit and be fixed in place at the tooth position in the surgical area. The periodontal surgical guide is designed by combining intraoral and facial scan data, CBCT and electronic face bow to accurately locate the target gingival margin and guide the smooth performance of aesthetic gingival hyperplasia surgery.

[0086] like Figure 1 The diagram illustrates a flowchart of a method for fabricating a custom periodontal guide for 3D-printed assisted aesthetic gingival augmentation surgery, as described in an embodiment of the present invention. This method for fabricating the custom periodontal guide for 3D-printed assisted aesthetic gingival augmentation surgery includes the following steps:

[0087] Step 1: Obtain the patient's oral scan data, facial scan data, and electronic face bow data.

[0088] Specifically, including:

[0089] An intraoral scanner is used to scan the inside of the patient's mouth to obtain intraoral scan data.

[0090] Intraoral scanning uses an intraoral scanner to obtain three-dimensional images of the shape and features of teeth from the patient's mouth. It employs ultrafast optical sectioning and confocal microscopy techniques, capturing over 3000 two-dimensional images per second. By combining hundreds of three-dimensional digital images, it creates three-dimensional digital information in real time. The intraoral scan data is a three-dimensional digital model of the upper and lower dentition and occlusion output by the intraoral scanner. Suitable intraoral scanners include brands such as 3Shape, iTero, and Shining.

[0091] Figure 2 The patient's original tooth and gum morphology before treatment. Figure 4 This is a frontal view of the initial oral scan data of the patient's dentition.

[0092] A 3D facial scanner was used to scan the patient's face to obtain facial scan data.

[0093] Facial scanning uses a 3D facial scanner and multiple cameras to quickly capture 3D data of the patient's face using stereoscopic imaging technology, generating a highly realistic color 3D face model.

[0094] In this invention, the facial scan data mainly refers to the facial shape of the patient when smiling. Suitable facial 3D scanners include 3dMD and Shining 3D.

[0095] The patient's maxillary position and mandibular movement information were recorded using an electronic facebow device.

[0096] Electronic facebow devices utilize ultrasonic pulse measurement technology to record all commonly used data on mandibular movement and describe electromyographic changes in the condylar joint and muscles. Examples of suitable electronic facebow devices include Zebris, KAVO, and Modjaw™.

[0097] Specifically, patients need to wear an electronic face bow device. After the device locates the position of the patient's maxilla, the patient performs prescribed movements such as moving to the left or right, protruding forward, and opening the mouth. The system will accurately and completely record the patient's mandibular movement trajectory.

[0098] The electronic facebow is used to transfer the position of the patient's maxilla and record the movement information of the mandible.

[0099] Preferably, when the patient also has special facial problems such as facial asymmetry or deviation of the incisal edge line in the anterior teeth region, step one may also include:

[0100] The patient's maxillofacial region was scanned using a CBCT scanner to obtain morphological data of the upper and lower teeth and jawbone.

[0101] CBCT, or Cone Beam CT, is a type of CBCT scanner. Available CBCT devices include the KaVo Cone Beam Multi-Purpose Dental CT scanner.

[0102] Cone-beam computed tomography (CBCT) imaging equipment works by using an X-ray generator to perform circular DR (digital radiography) imaging around the subject with a low dose of radiation (typically around 10 mA tube current). This is then repeated multiple times, usually 180-360 times, depending on the product. The data obtained from the intersection of these digital imaging sessions is then reconstructed in a computer to obtain a three-dimensional image.

[0103] Step 2: Import the collected intraoral and facial scan data into professional dental CAD design software and integrate them. Import the acquired electronic facebow dynamic trajectory, reconstruct the virtual patient, and generate the first model of the dental arch.

[0104] The design is performed by importing data digitally into professional dental CAD design software, in conjunction with intraoral scan data. Compared to previous static occlusal adjustments, this invention enables more accurate dynamic occlusal adjustments. Suitable professional dental CAD design software includes Exocad, Amann Girrbach Ceramill Mind, etc.

[0105] Exocad software (complete denture module) is a professional dental CAD design software with powerful functions and flexible operation, which can provide great convenience for denture designers.

[0106] Preferably, when the patient also has special facial problems such as facial asymmetry or deviation of the incisal edge line in the anterior teeth region, in addition to oral scan data, facial scan data, and electronic facebow data, it is also necessary to integrate CBCT data.

[0107] Figure 5 In one specific embodiment of the present invention, when preparing the periodontal guide plate for 3D printing to assist in gingival widening, the following scenario is described: after collecting oral scan data, facial scan data, CBCT data, and electronic facebow device data, a virtual patient is constructed.

[0108] Specifically, step two further includes:

[0109] Step 2.1: In the dental CAD design software, import the patient's oral scan data, facial scan data, and electronic facebow data according to the patient's condition requirements. If necessary, CBCT data can also be imported.

[0110] Step 2.2: By importing the scanning data of the maxillary occlusal fork from the electronic facebow, three-dimensional matching is performed by point selection in the occlusal record matching function of the dental CAD design software. The mandibular motion trajectory file is imported to achieve the registration of the electronic facebow data, so that the static dentition three-dimensional model and the mandibular motion trajectory are aligned in the three-dimensional coordinate system, ensuring the spatial consistency between the model and the actual occlusal motion.

[0111] Step 2.3: Match the imported facial scan data with the oral scan data to align the patient's smiling tooth-showing morphology and the static dentition 3D model in the 3D coordinate system, ensuring the consistency between the teeth and the model when the face is smiling;

[0112] Step 2.4. Generate a virtual patient model that includes intraoral scan data, dynamic trajectory of the electronic face bow, and facial scan data.

[0113] When patients have specific facial issues, CBCT can be used to create more precise models. The relevant steps include:

[0114] In the medical digital imaging software interface, the CBCT threshold is adjusted to obtain data with relatively clear bones and complete dentition. Point-to-point registration is then performed in the advanced mode matching grid to further match the CBCT data and the intraoral scan data.

[0115] The medical digital imaging software, such as the DICOM interface, can be used to view and analyze CBCT data;

[0116] And / or,

[0117] The CBCT threshold values ​​are restored to the facial morphology, and the facial scan data is registered point-to-point with the CBCT data through facial structure.

[0118] Step 3: Based on the first model generated in Step 2, determine the crown length and gingival margin position of the upper anterior teeth, and generate a digital aesthetic virtual restoration. The long axis of the upper anterior teeth in the digital aesthetic virtual restoration is consistent with the direction and angle of the long axis of the original teeth.

[0119] Preferably, the digital aesthetic virtual restoration is generated by combining the median smile line principle.

[0120] The digital aesthetic virtual restoration is based on the internationally recognized optimal length-to-width ratio of the maxillary anterior teeth. Specifically, the width-to-length ratio of the crown of the maxillary central incisor 1 is 75% to 85%; the width of the crown of the maxillary lateral incisor 2 is determined to be 65% to 80% of the width of the maxillary central incisor 1; and the width of the crown of the maxillary canine 3 is determined to be 40% to 60% of the width of the maxillary central incisor 1.

[0121] The aesthetic virtual restoration is designed based on the internationally recognized optimal aesthetic length-width ratio of the upper anterior teeth, and the crown length of the upper anterior teeth is designed based on the principle of the mid-smile line, and the position of the gingival margin of the upper anterior teeth is designed based on the principle of the mid-smile line.

[0122] The upper anterior teeth include the maxillary central incisor 1, the maxillary lateral incisor 2, and the maxillary canine 3;

[0123] Specifically, when designing a digital aesthetic virtual restoration, the gingival margin of the maxillary central incisor 1 is aligned with the upper lip margin when smiling; the apex of the gingival margin of the maxillary lateral incisor 2 is 0-1 mm lower than the gingival margin of the maxillary central incisor 1; and the apex of the gingival margin of the maxillary canine 3 is aligned with the apex of the gingival margin of the maxillary central incisor 1. The long axis of the maxillary anterior teeth in the digital aesthetic virtual restoration is consistent with the long axis of the original teeth. The labial cervical region of the maxillary anterior teeth in the digital aesthetic virtual restoration is consistent with the labial cervical region of the original teeth. The target gingival margin position, incisal margin position, and gingival margin position of the maxillary anterior teeth are determined.

[0124] Figure 7 A digital aesthetic virtual prosthesis designed in dental CAD design software based on the patient's smiling state in facial scan data.

[0125] Figure 8 This is a frontal view of the oral cavity containing an aesthetic virtual prosthesis.

[0126] Step 4: Use the measurement tool in the dental CAD design software to longitudinally measure the gingival margin displacement height of the digital aesthetic virtual restoration generated in Step 3.

[0127] The gingival margin displacement height is the difference between the original gingival margin height and the designed gingival margin height on the sagittal plane.

[0128] Specifically, step four includes:

[0129] Step 4.1: In dental CAD design software, design the incisal edge of the upper anterior teeth according to the lower lip edge when the patient smiles, so that the line connecting the incisal edges of the upper anterior teeth is 0-2mm above the lower lip edge;

[0130] The upper anterior teeth include the maxillary central incisor 1, the maxillary lateral incisor 2, and the maxillary canine 3;

[0131] Step 4.2: Based on the width-to-length ratio of the maxillary central incisor 1, which is 75-85%, design the position of the gingival margin of the maxillary central incisor 1. The gingival margin is scalloped and the top of the gingival margin is level with the upper lip margin.

[0132] And / or,

[0133] The gingival positions of the bilateral maxillary lateral incisors 2 are designed based on the gingival position of the maxillary central incisor 1, so that the gingival position of the maxillary lateral incisor 2 is 0-1 mm lower than the apex of the gingival position of the maxillary central incisor 1;

[0134] And / or,

[0135] The gingival position of the bilateral maxillary canines 3 is designed based on the gingival position of the maxillary central incisor 1, so that it is level with the apex of the gingival margin of the maxillary central incisor 3.

[0136] Preferably, the length of the crown of the maxillary central incisor 1 is determined according to the width-to-length ratio of the crown of the maxillary central incisor 1 being 75% to 85%; the width of the crown of the maxillary lateral incisor 2 is determined according to the width of the maxillary lateral incisor 2 being 65% to 80% of the width of the maxillary central incisor 1; and the width of the crown of the maxillary canine 3 is determined according to the width of the maxillary canine 3 being 40% to 60% of the width of the maxillary central incisor 1.

[0137] In practice, the gingival margin position and periodontal guide can be designed in a personalized manner according to the different needs and actual conditions of the patients, without increasing the clinical operation time. This greatly reduces the design difficulty of gingival margin position in aesthetic gingival surgery.

[0138] Combination Figure 3 and Figure 4In dental CAD design software, the incisal edge 7 of the maxillary central incisor, the incisal edge 8 of the maxillary lateral incisor, and the cusp 9 of the maxillary canine are designed according to the lower lip edge when the patient smiles, so that the incisal edge 7 of the maxillary central incisor, the incisal edge 8 of the maxillary lateral incisor, and the cusp 9 of the maxillary canine are located 0-2mm above the lower lip edge.

[0139] Furthermore, based on the width-to-length ratio of the maxillary central incisor 1 within the range of 75-85%, the position of the target gingival margin 4 of the maxillary central incisor is designed, with the gingival margin being scallop-shaped and the top of the gingival margin being flush with the upper lip margin.

[0140] Furthermore, the target gingival margin 5 of the maxillary lateral incisor is designed based on the target gingival margin 4 of the maxillary central incisor, so that the target gingival margin 5 of the maxillary lateral incisor is 0-1 mm lower than the target gingival margin 4 of the maxillary central incisor.

[0141] Furthermore, the target gingival margin 6 of the maxillary canine is designed based on the target gingival margin 4 of the maxillary central incisor, so that it is flush with the top of the target gingival margin 4 of the maxillary central incisor.

[0142] Preferably, the crown length of the maxillary central incisor 1 is determined according to a crown width-to-length ratio of 75% to 85%; the crown width of the maxillary lateral incisor 2 is determined according to a crown width of 65% to 80% of the width of the maxillary central incisor 1; and the crown width of the maxillary canine 3 is determined according to a crown width of 40% to 60% of the width of the maxillary central incisor 1.

[0143] Step 5: Merge the aesthetic virtual restoration with the intraoral scan data to generate an STL file, which will serve as the second model.

[0144] In the merging of the aesthetic virtual prosthesis and intraoral scan data, a seamlessly integrated digital model is generated to ensure that the final edge of the prosthesis completely matches the anatomical morphology of the pre-designed virtual prosthesis and soft tissue.

[0145] The merged digital model can be exported as an STL file, a common file format widely used in 3D printing CAD / CAM processing. STL files store 3D data in the form of triangular meshes, accurately describing the model's surface geometry. This STL file is then re-imported into dental CAD design software and used as a secondary model. This secondary model plays a crucial role in restorative design, allowing for further analysis, adjustments, and optimizations, such as refining edge line designs.

[0146] This digital workflow integrates virtual prosthesis aesthetic design with oral scan data, improving both the accuracy and efficiency of prosthesis design and providing a reliable data foundation for subsequent guide fabrication (such as cutting or 3D printing). This technology fully demonstrates the advantages of digital dentistry, significantly enhancing the predictability of restorative treatment.

[0147] Step 6: Use the occlusal plate function of dental CAD design software to create a periodontal guide plate. Import the second model and start drawing the guide plate area.

[0148] The periodontal guide plate covers the teeth from the anterior region to the bilateral molar regions. The palatal edge of the guide plate is drawn according to the palatal gingival margin of the dentition. The labial edge of the guide plate at the target tooth position is drawn according to the gingival position of the anterior teeth designed in the second model. The labial edge lines of the remaining teeth in the guide plate are drawn according to their gingival margins. It should be noted that the labial range of the guide plate must be close to the gingival margin of the designed virtual restoration and the position of the exposed gingival papilla must be clearly defined.

[0149] And / or,

[0150] The labial portion of the periodontal guide plate must be closely attached to the gingival margin of the designed virtual restoration, and the location of the gingival papilla must be clearly exposed to generate a customized periodontal guide plate;

[0151] And / or,

[0152] The target gingival margin position of the periodontal guide is recorded based on the gingival margin position of the virtual restoration in the second model.

[0153] Adjust the model's perspective using the software's "view tools" to ensure the gingival margin area of ​​the restoration is clearly visible. By adjusting the cross-sectional position, the shape and position of the gingival margin can be accurately displayed.

[0154] Record the location of the target gingival margin

[0155] In dental CAD design software, select the "Edge Line Design Tool," which allows users to draw the edge lines of the restoration on the 3D model. Using a mouse or digital pen, trace point by point along the gingival margin of the virtual restoration to generate a continuous edge line. During the tracing process, the software automatically captures the geometric features of the model, ensuring the smoothness and accuracy of the edge line. Users can adjust the position of the edge line as needed to ensure it perfectly matches the target gingival margin.

[0156] When a patient's teeth are incomplete and the position of the incisal edge of the anterior teeth needs to be modified, the following steps should also be added: Use the deletion tool of dental CAD design software to select and delete all virtual restoration parts in the second model; enter the guide plate internal design and redefine the guide plate internal shape according to the tooth morphology in the first model, generate a new guide plate data and save it as an STL format.

[0157] Specifically, the aesthetic virtual restoration is deleted by selecting it individually using the mesh editing function in the advanced mode of dental CAD design software. After deleting the aesthetic virtual restoration, the original data is obtained, and the internal morphology of the periodontal guide is defined.

[0158] In cases where patients have incomplete teeth (e.g., missing teeth) requiring restorations, gingival surgery is necessary before restoration surgery because the gums are soft tissue. Since the periodontal guide is made based on a second model that incorporates data for the aesthetic restoration, the guide cannot perfectly conform to the patient's tooth shape during gingival surgery, leading to movement and inaccuracies. Therefore, to ensure a proper fit between the guide and the patient's existing tooth shape, the aesthetic restoration data needs to be removed.

[0159] The process of redefining the internal morphology of the guide plate includes selecting and deleting the digital aesthetic virtual restoration separately using the mesh editing function in the advanced mode of dental CAD design software. After deleting the digital aesthetic virtual restoration, the original data is obtained, and the internal morphology of the periodontal guide plate is defined to make the guide plate fit the patient's original tooth shape better and to keep the guide plate stable during gingival surgery.

[0160] Figure 9 This is a schematic diagram of the periodontal guide plate in the preparation method of the periodontal guide plate for 3D printing assisted gingival widening surgery according to the present invention; wherein, (A) is a front view schematic diagram of the periodontal guide plate; (B) is a side view schematic diagram of the periodontal guide plate.

[0161] like Figure 9 and Figure 11 As shown, the guide plate body 11 is retained by the palatal retention plate 12, so that the guide plate body 11 can closely and extensively fit on the clinical crown of the maxillary bilateral posterior teeth and clearly expose the position of the gingival papilla, which helps to make the surgical operation more precise and the surgical result more aesthetic.

[0162] Figure 10 This is a bottom view of a patient wearing a customized periodontal guide plate in an embodiment of the method for preparing a periodontal guide plate for 3D printing assisted gingival widening surgery according to the present invention. Figure 11 In the method for preparing a periodontal guide plate for 3D printing-assisted gingival widening surgery according to the present invention, Figure 10 The sagittal view obtained by longitudinally slicing the periodontal surgical guide shown.

[0163] Step 7: Import the STL data obtained after designing the guide plate using dental CAD design software into a 3D printing device for 3D printing to obtain the guide plate for lengthening the gingiva in auxiliary gingival surgery.

[0164] like Figure 9The diagram shows a front view and a side view of the structure of a periodontal guide plate for 3D-printed assisted aesthetic gingival augmentation surgery prepared using the above-described method. According to the specific structure of the customized periodontal guide plate 11 for 3D-printed assisted aesthetic gingival augmentation surgery of the present invention, the customized periodontal guide plate 11 can be fastened to the patient's maxillary teeth, and the gap between it and the patient's pre-treatment gingiva 10 is the gingival margin to be augmented in the gingival augmentation surgery.

[0165] The guide plate body 11 includes a palatal retention plate 12 that can be attached and fixed to the area from the maxillary central incisor 1, maxillary lateral incisor 2 and maxillary canine 3 to the bilateral molar region, the target gingival margin of the maxillary central incisor 4, the target gingival margin of the maxillary lateral incisor 5, the target gingival margin of the maxillary canine 6, the incisal margin of the maxillary central incisor 7, the incisal margin of the maxillary lateral incisor 8 and the incisal margin of the maxillary canine 9.

[0166] The periodontal guide plate fabrication method for the assisted aesthetic gingival surgery described in the above embodiments is simpler, can be prepared and widely used by most medical institutions, has greater applicability, and the fabrication of the guide plate greatly reduces the operational difficulty for clinicians, while saving clinical operation time.

[0167] The periodontal surgical guide in this invention, combined with digital technology, can precisely locate the target gingival margin, thereby achieving the goal of accurately guiding the surgery. Compared to a periodontal surgical guide and its preparation method disclosed in Chinese invention patent application CN111616824A, which includes a fixed-length, fixed-width guide wrapped around and attached to the maxilla, and a fixed-depth guide fixedly installed at the corresponding maxillary cementoenamel junction position of the fixed-length, fixed-width guide via a snap-fit ​​structure to abut against the edge of the scalpel handle to limit its cutting depth, and an incision provided at the transverse gingival margin along the maxillary cementoenamel junction to provide space for the scalpel blade's movement, this technology mainly guides and limits the direction and cutting depth of the scalpel blade during gingival flap preparation, avoiding damage to important tissues during mesogingival surgery. However, this technology only describes the method of gingival flap preparation and does not describe the operation and related functions of precisely determining the gingival margin position of the subsequent gingival flap transplantation area. The effect of the periodontal surgical guide disclosed in this prior art differs from that of this invention, especially in that it does not precisely locate the gingival margin.

[0168] Compared to the manufacturing method of a dental crown lengthening guide provided by Chinese invention patent CN115531014B, which uses restoration as a guide to precisely locate the height and thickness of alveolar bone removal for teeth requiring crown lengthening, this patent primarily addresses cases where clinical crowns are too short. It uses the guide to cover the tooth and bone surfaces of the anterior region to guide the removal of gingiva and bone, thereby increasing crown height. In this technique, the crown lengthening surgery only requires lengthening and utilizes intraoral and CBCT data, without incorporating facial scan and electronic facebow data. Furthermore, it does not restore any tooth defects, nor does it set the target gingival position using facial scan and electronic facebow data. Based on the combination of intraoral scanning, facial scanning, electronic facebow, and CBCT data, this invention first performs aesthetic design on the defective tooth portion in the anterior region. The incisal edge and gingival margin positions of the expected restoration are determined according to the relationship between the upper and lower lips when the patient smiles. The gingival margin position of the periodontal guide is designed according to these positions to guide the periodontist in accurately placing the gingival flap in the gingival flap transplantation area. This greatly avoids problems such as the inability to accurately position the gingival margin due to the patient's limited upper and lower lip movement after anesthesia during periodontal surgery, or the blurring of artificial markings on the tooth due to the presence of saliva in the mouth.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

[0170] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0171] The basic principles of this disclosure have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details for implementation.

[0172] It should also be noted that in the systems and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions to this disclosure.

[0173] Various changes, substitutions, and modifications can be made to the technology described herein without departing from the teachings defined by the appended claims. Furthermore, the scope of the claims of this disclosure is not limited to the specific aspects of the processes, machines, manufactures, events, means, methods, and actions described above. Currently existing or later-developed processes, machines, manufactures, events, means, methods, or actions that perform substantially the same function or achieve substantially the same result as the corresponding aspects described herein can be utilized. Therefore, the appended claims include such processes, machines, manufactures, events, means, methods, or actions within their scope.

[0174] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0175] The scope of protection of this invention is not limited to the above embodiments. Any variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of this invention are included in this invention and are protected by the appended claims.

Claims

1. A method for preparing a periodontal guide plate for 3D-printed assisted aesthetic gingival widening surgery, characterized in that, The method includes: Step 1: Acquire patient data including oral scan data, facial scan data, and electronic face bow data; Step 2: Import the data obtained in Step 1 into dental CAD design software and integrate it to reconstruct the virtual patient and generate the first model of the dental arch. Step 3: Based on the first dental arch model, determine the crown length and gingival margin position of the upper anterior teeth, and generate a digital aesthetic virtual restoration; Step 4: Measure the gingival margin displacement height of the aesthetic virtual restoration longitudinally; Step 5: Merge the aesthetic virtual restoration with the intraoral scan data to generate a second model; Step 6: Import the second model into the dental CAD design software, determine the area for drawing the periodontal guide plate, and generate the model data of the periodontal guide plate; Step 7: 3D print the periodontal guide plate based on its model data to obtain the periodontal guide plate.

2. The preparation method according to claim 1, characterized in that, In step one, when the patient has facial problems such as facial asymmetry and deviation of the incisal edge line in the anterior teeth area, CBCT data is collected in addition to the facial data. And / or, The oral scan data is a three-dimensional digital model of the upper and lower dentition and occlusion obtained by intraoral scanning using an intraoral scanner; and / or, The facial scan data is facial morphology data in a smiling state obtained through facial scanning using a 3D facial scanner; and / or... The electronic facebow data refers to data collected and recorded by an electronic facebow device, including information on maxillary position and mandibular movement; and / or, The CBCT data refers to the morphological features of the upper and lower jaw teeth and jawbones obtained by scanning the maxillofacial region.

3. The preparation method according to claim 1, characterized in that, Step two specifically includes: Step 2.

1. Import oral scan data, facial scan data, and electronic face bow data; Alternatively, import oral scan data, facial scan data, electronic facial bow data, and CBCT data; Step 2.

2. Match the imported oral scan data with the electronic facebow data to align the static dentition 3D model and the mandibular movement trajectory in the 3D coordinate system, ensuring the spatial consistency between the model and the actual occlusal movement; Step 2.

3. Match the imported facial scan data with the oral scan data to align the patient's smiling tooth-showing morphology and the static dentition 3D model in the 3D coordinate system, ensuring the consistency between the teeth and the model when the face is smiling; Step 2.

4. Generate a virtual patient model that includes intraoral scan data, dynamic trajectory of the electronic face bow, and facial scan data; And / or, It also includes: introducing CBCT data, adjusting the CBCT threshold to obtain data with clear bones and complete dentition, and performing point-to-point registration in the advanced pattern matching grid to further match the CBCT data and intraoral scan data; And / or, The CBCT threshold values ​​are restored to the facial morphology, and the facial scan data is registered point-to-point with the CBCT data through facial structure.

4. The preparation method according to claim 1, characterized in that, In step three, the aesthetic virtual restoration designs the crown length and width of the upper anterior teeth according to the optimal aesthetic length-width ratio of the upper anterior teeth; the digital aesthetic virtual restoration designs the gingival margin position of the upper anterior teeth when smiling according to the principle of the median smile line; the upper anterior teeth include the maxillary central incisor (1), the maxillary lateral incisor (2) and the maxillary canine (3); And / or, The design requirements for the aesthetic virtual restoration include: the direction and angle of the long axis of the anterior teeth of the aesthetic virtual restoration are consistent with the long axis of the original teeth; the gingival margin of the maxillary central incisor (1) is level with the upper lip margin when smiling; the apex of the gingival margin of the maxillary lateral incisor (2) is 0-1 mm lower than the apex of the gingival margin of the maxillary central incisor (1); the apex of the gingival margin of the maxillary canine (3) is level with the apex of the gingival margin of the maxillary central incisor (1); the labial cervical surface of the anterior teeth is consistent with the labial cervical surface of the original teeth. Finally, the target gingival margin and incisal margin positions of the upper anterior teeth were determined.

5. The preparation method according to claim 1, characterized in that, In step four, the height of the gingival margin reduction is the difference between the original gingival margin height and the designed gingival margin height on the sagittal plane; And / or, Step four specifically includes: Step 4.

1. Design the incisal edge of the upper anterior teeth according to the lower lip edge when smiling, so that the line connecting the incisal edges of the upper anterior teeth is 0-2mm above the lower lip edge; the upper anterior teeth include the maxillary central incisor (1), maxillary lateral incisor (2) and maxillary canine (3); Step 4.

2. Based on the width-to-length ratio of the maxillary central incisor (1) within the range of 75-85%, design the gingival margin position of the maxillary central incisor (1). The gingival margin is scalloped and the top of the gingival margin is flush with the upper lip margin. And / or, The gingival position of the bilateral maxillary lateral incisors (2) is designed according to the gingival position of the maxillary central incisor (1), wherein the gingival position of the maxillary lateral incisor (2) is 0-1 mm lower than the gingival apex of the maxillary central incisor (1); And / or, The gingival position of the bilateral maxillary canines (3) is designed according to the gingival position of the maxillary central incisor (1), so that the gingival margin of the maxillary canines (3) is flush with the apex of the gingival margin of the maxillary central incisor (1).

6. The preparation method according to claim 5, characterized in that, The crown width of the maxillary central incisor (1) is determined to be 75% to 85% of its length; the crown width of the maxillary lateral incisor (2) is determined to be 65% to 80% of the width of the maxillary central incisor (1); the crown width of the maxillary canine (3) is determined to be 40% to 60% of the width of the maxillary central incisor (1).

7. The preparation method according to claim 1, characterized in that, In step six, the periodontal guide plate covers the tooth body from the anterior region to the bilateral molar region. The palatal edge of the guide plate is drawn according to the palatal gingival margin line of the dentition. The labial edge position of the guide plate at the target tooth position is drawn according to the anterior tooth gingival position designed in the second model. The labial edge lines of the remaining teeth in the guide plate are drawn according to their gingival margin lines. And / or, The labial portion of the periodontal guide plate should be closely attached to the gingival margin of the designed virtual restoration, and the location of the gingival papilla should be clearly exposed; And / or, The target gingival margin position of the periodontal guide is recorded based on the gingival margin position of the virtual restoration in the second model.

8. The preparation method according to claim 1, characterized in that, When a patient's teeth are incomplete and require modification of the incisal edge position of the anterior teeth, the following steps need to be added between steps six and seven: Delete all virtual restorations in the second model, redefine the internal morphology of the periodontal guide using the first dental arch model, and regenerate the model data of the periodontal guide.

9. A periodontal guide plate prepared by the preparation method according to any one of claims 1-8, characterized in that, The periodontal guide plate covers and wraps the tooth body of the upper anterior teeth and / or bilateral molar areas. The internal morphology of the periodontal guide plate matches the virtual restoration or the first model of the dental arch, and the labial edge is flush with the target gingival margin. And / or, The periodontal guide plate is provided with a palatal retention plate (12) on the lingual side.

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