Digital complete denture preparation method based on mandibular precise positioning

Abstract

The invention discloses a digital complete denture preparation method based on mandibular precise positioning, and belongs to the technical field of denture preparation. The preparation method comprises the following steps: S1, acquiring oral cavity data; s2, digital design is carried out through three-dimensional editing software, and the jaw position is adjusted; s3, designing a jaw position guide plate with a tray function by dissecting missing teeth, and performing tooth arrangement; s4, a fine impression is prepared, and an occlusion record is obtained; and S5, designing and preparing the complete denture according to the edentulous jaw data and the occlusion record. The method solves the problems that a patient with dentition deficiency is difficult to obtain an accurate occlusal relationship, the process is complicated and the technical sensitivity is high, and provides a clear and visual method for directly moving the condyle process and the mandible on the three-dimensional relationship of the glenoid fossa, the condyle process and the mandible to obtain the therapeutic jaw position. And the complete denture can be prepared by directly utilizing the adjusted mandibular position through digital design, and the prepared complete denture is accurate in data, simple and convenient to prepare and operate and low in technical sensitivity.

Description

Technical Field

[0001] The present invention relates to the technical field of denture preparation, and in particular to a method for preparing a digital full-mouth denture based on precise positioning of the mandible. Background Art

[0002] With the aging population, the number of patients with edentulous teeth increases. Because patients with edentulous teeth lose the locking effect of the cusp and fossa of the upper and lower teeth, the position of the mandible relative to the maxilla cannot be determined. In addition, edentulous patients will cause degenerative changes in the bone structure of the temporomandibular joint, the morphology of the condyle and mandibular fossa will change, and bone density will also be affected. Some studies have observed that the condyle of edentulous patients moves backward and upward, the mandible rotates forward and upward, and the articular disc moves forward accordingly.

[0003] Patients with edentulous teeth need to find a suitable mandibular position for full denture restoration. Traditional full denture restoration technology relies on doctors to determine the occlusal relationship between the upper and lower jaws based on experience, and requires repeated impression making. The process is complicated and the technology is highly sensitive. At the same time, improper impression making and improper occlusal relationship may lead to worsening of the condition. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the purpose of the present invention is to provide a digital full denture preparation method based on precise positioning of the mandible, so as to solve the problems that the position relationship of the mandible, condyle and fossa of existing edentulous patients is difficult to accurately determine, the occlusal relationship of the upper and lower jaws is difficult to obtain, and the accuracy is poor.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: A method for preparing a digital complete denture based on precise positioning of the mandible comprises the following steps: S1: Data acquisition: Perform CBCT and intraoral optical scanning on the patient to obtain the patient's craniomaxillofacial CBCT data and upper and lower mandibular edentulous data; S2: Digital design of jaw position: First, the craniomaxillofacial CBCT data obtained in S1 is imported into the 3D editing software for 3D reconstruction, and the maxillary bone data with the articular fossa and maxillary edentulous jaw and the mandibular bone data with the condyle and mandibular edentulous jaw are obtained by segmentation. Then, the upper and lower edentulous jaw data obtained in S1 are aligned, and finally the jaw position is adjusted to obtain the adjusted upper and lower edentulous jaw data. S3: Jaw guide plate production and tooth arrangement: First, the jaw guide plate is designed based on the adjusted upper and lower edentulous jaw data obtained in S2, wherein the maxillary dentition is designed from the right maxillary second molar to the left maxillary second molar, and the mandibular dentition is designed from the right mandibular canine to the left mandibular canine, or the mandibular dentition is designed from the right mandibular second molar to the left mandibular second molar, to obtain the anatomical missing tooth structure, and then the anatomical missing teeth in the edentulous area are connected as a whole through the gingival design module, and the gingival of the mandibular posterior tooth area is designed with fixing pins or the anatomical missing tooth structure of the mandibular posterior tooth area is lowered to form an occlusal and aesthetic confirmation device, and then the teeth are arranged according to the three-dimensional spatial position of the teeth, and finally the jaw guide plate is produced according to the data after tooth arrangement; S4: Preparation of fine impressions and confirmation of jaw position and aesthetic relationship: The jaw position guide obtained in S3 is used to prepare fine impressions of the upper and lower jaws, and the bite record data is obtained in the posterior tooth area after occlusion; S5: Preparation of full denture: The fine impression obtained in S4 is scanned to obtain the edentulous jaw data of the full denture, and the full denture data is obtained by fitting with the bite record data, and then prepared by 3D printing or cutting.

[0006] The beneficial effects of the present invention are as follows: in view of the problem that it is difficult for patients with edentulous teeth to obtain accurate occlusal relationship and the acquisition process is complicated and technically sensitive, the present invention provides a method for obtaining therapeutic jaw position by directly moving the condyle and mandible in the three-dimensional position of the fossa, condyle and mandible with clear visualization, and full dentures can be designed and produced directly according to the adjusted mandibular position using digital methods, which is easy to operate and has low technical sensitivity.

[0007] Furthermore, in S1, before performing CBCT and intraoral optical scanning, a fluid resin is adhered to the alveolar ridge mucosa of the patient to form a small cone shape.

[0008] Furthermore, in S1, the patient's craniomaxillofacial CBCT data are DICOM data, and the upper and lower edentulous jaw data are STL data.

[0009] Further, in S2, the jaw position adjustment is performed by the following steps: First, align the chin point of the mandible with the midline of the face. The mandibular angle points are on the same horizontal line when in the 40-50° supine position. The condyles on both sides are symmetrical and the mandible is centered. Then confirm that the condyles are located in the articular fossa. Then adjust the mandible to the side view. Using the orbital axis plane as the reference, adjust the mandible position to an angle of 20-30° between the mandibular plane angle and the orbital axis plane. Finally, adjust the vertical distance between the upper and lower jaws in the plane of the midline of the face to 12-18 mm.

[0010] The beneficial effect of adopting the above-mentioned further technical solution is as follows: the present invention obtains a suitable full-mouth denture restoration space and a preliminary clear visualization of the digitized three-dimensional position of the fossa, condyle and mandible by adjusting the mandibular angle point, condyle position, mandibular position and the relative distance between the upper and lower jaws.

[0011] Furthermore, in S3, an occlusal plane plate with an angle of 0-25° is used for tooth arrangement, and the three-dimensional spatial position of the teeth is designed according to the following formula: X=a+b+c; Where X is the inclination of the protrusive condyle, a is the angle of the occlusal plane, b is the inclination of the cusp, and d is the posterior tooth separation angle.

[0012] The beneficial effect of adopting the above-mentioned further technical scheme is as follows: the present invention adopts an angled occlusal plane plate to arrange teeth for the digitally designed jaw guide plate, and can ensure the accuracy and aesthetics of tooth arrangement according to the calculation formula of the three-dimensional spatial position of the teeth. There is no need to transfer the jaw relationship or use a physical articulator, and the operation is simple.

[0013] Furthermore, the preparation method of the S3 mid-jaw guide plate is CNC cutting or 3D printing.

[0014] Furthermore, the gingival design module in S3 is a built-in module in the three-dimensional editing software.

[0015] Furthermore, the bite record data in S4 is obtained by the following steps: First, the silicone rubber is fixed through the retention pins designed on the gums of the mandibular posterior teeth area of ​​the jaw guide, and then the upper and lower dentitions obtained after fine impressions are occluded, the midlines of the upper and lower dentitions are aligned, and the bite record data is obtained in the posterior teeth area.

[0016] Furthermore, after the bite record data of S4 is obtained, it is determined whether the patient's jaw position and aesthetic relationship are appropriate, and the mandible is adjusted.

[0017] Furthermore, the fine impression in S4 can also be prepared by directly scanning the data using an intraoral scanner after the patient wears the jaw guide.

[0018] The beneficial effect of adopting the above-mentioned further technical scheme is as follows: the present invention installs silicone rubber in the anatomical missing tooth area of ​​the missing tooth area through fine impression to perform bite record testing, and the data acquisition efficiency is high and the data is accurate. At the same time, the jaw position and aesthetic relationship of the patient's teeth can be adjusted in real time and quickly according to the acquired data.

[0019] A digital complete denture based on precise positioning of the mandible is prepared by the above-mentioned preparation method.

[0020] The present invention has the following beneficial effects: The present invention provides a digital preparation method for complete dentures based on precise positioning of the mandible. The preparation method does not require repeated preparation of physical impressions, does not require the transfer of jaw position relationships and the use of physical articulators. The operation is simple and the repeatability is strong. The design and production of complete dentures can directly replicate the occlusion and aesthetic relationship confirmed in the mouth. The operation is simple and the technical sensitivity is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the preparation of digital complete dentures based on accurate positioning of the mandible according to the present invention; Figure 2 Schematic diagram of tooth arrangement design using the angled occlusal plane plate in S3 of the present invention, wherein a is a jaw position guide plate without tooth arrangement, and b is a schematic diagram of teeth arrangement using the angled occlusal plane plate; Figure 3 A three-dimensional front view of the jaw guide plate with tray function made by S3 of the present invention; Figure 4 This is a schematic diagram of the process of obtaining bite record data and confirming bite aesthetics in S4 of the present invention; wherein, a is a schematic diagram of the tooth occlusion model before obtaining bite record data and confirming bite aesthetics, and b is a schematic diagram of the tooth occlusion model during the process of obtaining bite record data and confirming bite aesthetics. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific conditions are specified in the examples, the process is carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased from the market. Example: A method for preparing digital complete dentures based on precise positioning of the mandible (preparation flow chart as shown in Figure 1 ), including the following steps: S1: Acquisition of initial diagnosis data Fluid resin was bonded to the alveolar ridge mucosa of the patient to form a small vertebral shape for later positioning. The patient was then subjected to CBCT and intraoral optical scanning to obtain DICOM data of the patient's craniomaxillofacial region (including the temporomandibular joint and complete mandibular area) and STL data of the upper and lower edentulous jaws.

[0023] S2: Digital design of therapeutic jaw position First, the DICOM data of the CBCT obtained by S1 was imported into the 3D editing software (EXOCAD software) for 3D reconstruction, and the maxillary data of the edentulous maxilla with the fossa and the mandibular data of the edentulous mandible with the condyle were segmented. The same fluid resin cone data was used in the software to align the obtained maxillary and mandibular data with the STL data of the edentulous maxilla obtained by S1. Then adjust the jaw position. First adjust the horizontal position in three-dimensional space, align the mandibular chin point with the midline of the face, and keep the mandibular angle points on the same horizontal line when in a 45° supine position. Keep the condyles symmetrical when looking up from bottom to top. Adjust the mandible to the center without deviation. Then confirm that the condyles are in the articular fossa. Finally, adjust the mandible to the side view (the bilateral condyles and bilateral orbits are overlapped). With the orbital axis plane as the reference, adjust the mandible to the angle between the mandibular plane angle and the orbital axis plane of 25°. From the frontal view, measure the vertical distance between the upper and lower jaws in the plane where the midline of the face is located to ensure that the vertical distance between the upper and lower jaws is 15 mm. Obtain a suitable space for full denture restoration and complete the adjustment of the mandibular position. Finally, place the articulator base plate on the reference plane (different reference planes are selected according to different types of articulators), and export the adjusted upper and lower edentulous jaw data (maxillary with articulator base plate data) directly into STL format.

[0024] S3: jaw guide plate preparation and tooth alignment Directly use the upper and lower jaw data adjusted by S2 and adopt the fixed design module (fixed denture design mode in EXOCAD software) to design the jaw guide with tray function and arrange the teeth. First, design the anatomical missing teeth on the upper and lower edentulous jaw data, design the maxillary dentition from the right maxillary second molar to the left maxillary second molar, and only design the mandibular dentition from the right mandibular canine to the left mandibular canine; Then, through the gum design module (the gum design module included in EXOCAD software), the anatomical missing teeth of each edentulous area are connected into a whole, and retention pins are designed on the gums of the mandibular posterior teeth area to facilitate the occlusal recording of silicone rubber retention, forming an occlusal and aesthetic confirmation device. At the same time, the edge of the device is 2 mm shorter than the edge of the base, and the maxillary palatal side is 2 mm behind the palatal fossa for subsequent impression preparation; Then, the occlusal plane with an angle (5-25°) is used to guide the arrangement of teeth, and the three-dimensional spatial position of the teeth is designed according to the following formula (such as Figure 2 shown): X=a+b+c; Where X is the inclination of the protrusive condyle, a is the angle of the occlusal plane, b is the inclination of the cusp, and d is the posterior tooth separation angle.

[0025] Finally, the STL format data of the jaw guide after tooth arrangement is imported into a CNC cutting machine or a 3D printer for preparation to obtain a jaw guide with a tray function. The three-dimensional front view is as follows: Figure 3 shown.

[0026] S4: Detailed impression preparation and confirmation of jaw position and aesthetic relationship The jaw guide with tray function was made by S3 to make fine impressions of the upper and lower jaws. After making fine impressions, the upper and lower dentitions were directly occluded, the midlines of the upper and lower dentitions were aligned, and silicone rubber was installed on the posterior tooth fixation pins to obtain the bite record data to determine whether the patient's jaw position and aesthetic relationship were appropriate (the confirmation process of the bite record data and the bite aesthetic relationship is as follows Figure 4 and make proofreading adjustments.

[0027] S5: Scan the fine impression obtained in S4 and perform data fitting with the occlusal data record (or the occlusal record data after the jaw position and aesthetic relationship are corrected) to obtain the STL format data of the final full denture, and prepare the digital full denture based on the precise positioning of the mandible through 3D printing or cutting.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing digital complete dentures based on precise positioning of the mandible, characterized in that: The following steps are involved: S1: Data acquisition: Perform CBCT and intraoral optical scanning on the patient to obtain the patient's craniomaxillofacial CBCT data and upper and lower mandibular edentulous data; S2: Digital design of jaw position: First, the craniomaxillofacial CBCT data obtained in S1 is imported into the 3D editing software for 3D reconstruction, and the maxillary bone data with the articular fossa and maxillary edentulous jaw and the mandibular bone data with the condyle and mandibular edentulous jaw are obtained by segmentation. Then, the upper and lower edentulous jaw data obtained in S1 are aligned, and finally the jaw position is adjusted to obtain the adjusted upper and lower edentulous jaw data. S3: Jaw guide plate production and tooth arrangement: First, the jaw guide plate is designed based on the adjusted upper and lower edentulous jaw data obtained in S2, wherein the maxillary dentition is designed from the right maxillary second molar to the left maxillary second molar, and the mandibular dentition is designed from the right mandibular canine to the left mandibular canine, or the mandibular dentition is designed from the right mandibular second molar to the left mandibular second molar, to obtain the anatomical missing tooth structure, and then the anatomical missing teeth in the edentulous area are connected as a whole through the gingival design module, and the gingival of the mandibular posterior tooth area is designed with fixing pins or the anatomical missing tooth structure of the mandibular posterior tooth area is lowered to form an occlusal and aesthetic confirmation device, and then the teeth are arranged according to the three-dimensional spatial position of the teeth, and finally the jaw guide plate is produced according to the data after tooth arrangement; S4: Preparation of fine impressions and confirmation of jaw position and aesthetic relationship: The jaw position guide obtained in S3 is used to prepare fine impressions of the upper and lower jaws, and the bite record data is obtained in the posterior tooth area after occlusion; S5: Preparation of full denture: The fine impression obtained in S4 is scanned to obtain the edentulous jaw data of the full denture, and the full denture data is obtained by fitting with the bite record data, and then prepared by 3D printing or cutting.

2. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: In S1, before performing CBCT and intraoral optical scanning, a fluid resin is adhered to the alveolar ridge mucosa of the patient to form a small cone shape.

3. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: In S1, the patient's craniomaxillofacial CBCT data are DICOM data, and the upper and lower edentulous jaw data are STL data.

4. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: In S2, the jaw position adjustment is performed by the following steps: First, align the chin point of the mandible with the midline of the face. The mandibular angle points are on the same horizontal line when in the 40-50° supine position. The condyles on both sides are symmetrical and the mandible is centered. Then confirm that the condyles are located in the articular fossa. Then adjust the mandible to the side view. Using the orbital axis plane as the reference, adjust the mandible position to an angle of 20-30° between the mandibular plane angle and the orbital axis plane. Finally, adjust the vertical distance between the upper and lower jaws in the plane of the midline of the face to 12-18 mm.

5. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: In S3, an occlusal plane plate with an angle of 0-25° is used to arrange teeth, and the three-dimensional spatial position of the teeth is designed according to the following formula: X=a+b+c; Where X is the inclination of the protrusive condyle, a is the angle of the occlusal plane, b is the inclination of the cusp, and d is the posterior tooth separation angle.

6. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: The S3 mid-jaw guide plate is prepared by CNC cutting or 3D printing.

7. The method for preparing digital complete dentures based on accurate positioning of the mandible according to claim 1, characterized in that: The bite record data in S4 is obtained by the following steps: First, the silicone rubber is fixed through the retention pins designed on the gums of the mandibular posterior teeth area of ​​the jaw guide, and then the upper and lower dentitions obtained after fine impressions are occluded, the midlines of the upper and lower dentitions are aligned, and the bite record data is obtained in the posterior teeth area.

8. A digital complete denture based on precise positioning of the mandible, characterized in that: The method is prepared by the preparation method according to any one of claims 1 to 7.

Images