Method for designing and manufacturing an orthognathic surgery bite guide based on an invisible orthodontic device

Abstract

The application is based on the design and manufacturing method of orthognathic surgery occlusion guide plate of invisible orthodontic device, three-dimensional data of craniofacial and teeth of a patient is collected through CT scanning, the three-dimensional virtual tooth data of the patient is prepared by the preparation of hard plaster tooth model, the data of the patient is imported into craniofacial surgery planning software to establish the virtual craniofacial model of the patient, the prepared hard plaster tooth model is three-dimensionally scanned to obtain the data of the dentition, the simulation surgery is carried out on the virtual craniofacial model, then the target position of the mandibular tooth bone segment is determined based on the final occlusion relationship, the data of the dentition of the patient is imported into three-dimensional virtual design software to carry out Boolean operation, and the orthognathic surgery occlusion guide plate is manufactured by using three-dimensional printing technology, the application is not fully covered in the anterior tooth area, the resistance and difficulty during dislocation and positioning are reduced, the operation time is saved, the observation window is set to avoid the out-of-position condition of the dentition, and the operation precision is ensured.

Description

[0001] This application is a divisional application of the invention patent application filed on May 14, 2024, with application number 2024105936312 and invention title "Occlusal guide plate for orthognathic surgery based on invisible orthodontic device and its design and manufacturing method". Technical Field

[0002] This invention provides a method for designing and manufacturing an orthognathic surgery occlusal guide based on an invisible orthodontic device. Background Technology

[0003] Severe dentofacial deformities often lead to malocclusion, malocclusion, masticatory dysfunction, and unattractive facial appearance. These deformities are difficult to treat effectively with orthodontics alone and often require combined orthodontic and orthognathic surgery. Preoperative orthodontic treatment removes dental compensations, orthognathic surgery moves jawbone blocks to correct jawbone deformities, and postoperative orthodontic treatment continues to finely adjust the occlusal relationship. Traditional fixed braces are increasingly failing to meet patients' needs due to their lack of aesthetics, poor comfort, and difficulty in maintaining oral hygiene.

[0004] Clear aligner orthodontics, also known as invisible aligner technology, is a method of correcting tooth alignment using transparent, removable plastic aligners. Compared to traditional metal or ceramic brackets, clear aligners offer advantages such as aesthetics, comfort, ease of oral hygiene maintenance, and predictable treatment results. Furthermore, clear aligners are custom-made based on the patient's 3D oral scan data, gradually guiding teeth to the desired position. Throughout the digital treatment process, orthodontists have a more comprehensive understanding of tooth movement, while patients can gain a better understanding of the entire treatment process through simulation animations. Therefore, an increasing number of patients undergoing combined orthodontic and orthognathic surgery are requesting clear aligners, and correspondingly, their application in combined orthodontic and orthognathic surgery is becoming increasingly widespread.

[0005] While clear aligner technology has revolutionized preoperative orthodontic treatment, this change has also presented some clinical challenges for maxillofacial surgeons. For patients using traditional fixed orthodontic appliances, the conventional method involves intermaxillary fixation using stainless steel wires between the maxillary and mandibular archwires, utilizing traditional non-overlapping intermediate and terminal occlusal guides to fix the maxillary and mandibular dentition segments in their target positions. However, patients undergoing clear aligner orthodontic treatment lack intraoral archwires. How then can intermaxillary fixation be performed to secure the maxillary and mandibular dentition segments during surgery? Currently, the most commonly used methods are arch splints and intermaxillary traction screws, but both methods have certain drawbacks.

[0006] Dental arch splints: These splints are ligated to the dentition using stainless steel wires. During the procedure, stainless steel wire loops are used to ligate between the traction hooks of the splint to achieve intermaxillary fixation. Then, with the help of traditional occlusal guides, the positions of the maxillary and mandibular bone segments are fixed. The disadvantages are that stainless steel ligation wires need to be used on every tooth in the entire dentition to fix the splint, which causes greater damage to periodontal tissues, takes a long time during the procedure, and poses a risk of needlestick injury to the surgeon. It is also not conducive to patients maintaining oral hygiene after the procedure and can easily lead to adverse consequences such as gingival swelling and necrosis.

[0007] Intermaxillary traction screws: This method involves implanting a total of 8-10 titanium self-tapping intermaxillary traction screws into the upper and lower jawbones. The implantation sites are typically between the lateral incisors and canines, between the first premolars, or between the second premolars and first molars in each region. Stainless steel wire loops are used to ligate the screws between the upper and lower jaws to achieve intermaxillary fixation. Then, using a traditional occlusal guide, the positions of the maxillary and mandibular bone segments are fixed. Compared to arch splints, this method can effectively improve oral hygiene and shorten the operation time. However, this method carries the risk of root damage, and the traction screws may loosen or break. Postoperative pain may also occur due to the screws and loops being encased in soft tissue. Summary of the Invention

[0008] This invention provides a method for designing and manufacturing an occlusal guide for orthognathic surgery based on an invisible orthodontic device. This invention is compatible with invisible orthodontic devices, eliminating the need for preoperative grinding of invisible orthodontic attachments, reducing operational steps and patient discomfort. During surgery, the occlusal guide of this invention allows the upper and lower dentition to be embedded within it, providing stable intermaxillary fixation without the need for arch splints, intermaxillary traction screws, or other devices, thus fixing the positions of the maxillary and mandibular bone segments. The occlusal guide of this invention does not fully cover the anterior teeth region, reducing resistance and difficulty during dislocation and placement, saving surgical time. The included observation window prevents misalignment of the dentition due to interference points during fabrication, ensuring surgical precision.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An orthognathic surgery occlusal guide based on an invisible orthodontic device, characterized in that it includes an intermediate occlusal guide and a terminal occlusal guide. The intermediate occlusal guide is designed based on the intermediate occlusal relationship formed by the maxillary bone segment and the initial position of the mandibular bone segment, and is used to determine the target position of the maxillary bone segment during orthognathic surgery. The terminal occlusal guide is designed based on the final occlusal relationship formed by the maxillary bone segment and the mandibular bone segment, and is used to determine the target position of the mandibular bone segment during orthognathic surgery. The intermediate occlusal guide plate is integrally formed from a first upper contact surface, a first lower contact surface, and a connecting part. The connecting part is located between the first upper contact surface and the first lower contact surface. A first upper tooth occlusal position is provided on the first upper contact surface for the upper teeth to be inserted into the position. Three first upper observation windows are provided on the first upper contact surface. A first lower tooth occlusal position is provided on the first lower contact surface for the lower teeth to be inserted into the position. Three first lower observation windows are provided on the first lower contact surface. The terminal occlusion guide plate is integrally formed by combining a second upper contact surface and a second lower contact surface. A second upper tooth occlusion position is provided on the second upper contact surface for the upper teeth to be inserted and positioned. A second lower tooth occlusion position is provided on the second lower contact surface for the lower teeth to be inserted and positioned. Three second observation windows are provided between the second upper contact surface and the second lower contact surface, which can simultaneously observe the positioning of the upper and lower teeth. The three first upper observation windows are located in the anterior tooth area and bilateral posterior tooth area of ​​the first upper contact surface, respectively. The position of the maxillary teeth can be confirmed through the first upper observation windows. The three first lower observation windows are located in the anterior tooth area and bilateral posterior tooth area of ​​the first lower contact surface, respectively. The position of the mandibular teeth can be confirmed through the first lower observation windows. The anterior tooth region of the first upper contact surface covers 1 / 2 of the crown of the maxillary incisor, and the anterior tooth region of the first lower contact surface covers 1 / 2 of the crown of the mandibular incisor; The edge of the first upper contact surface is 1-2 mm away from the maxillary gingiva, and the edge of the first lower contact surface is 1-2 mm away from the mandibular gingiva; The three second upper observation windows are located in the anterior tooth area and bilateral posterior tooth area between the second upper contact surface and the second lower contact surface, respectively. The positioning of the maxillary and mandibular teeth can be confirmed simultaneously through the second upper observation window. The anterior tooth area of ​​the second upper contact surface covers 1 / 2 of the crown of the maxillary incisor, and the anterior tooth area of ​​the second lower contact surface covers 1 / 2 of the crown of the mandibular incisor. The edge of the second upper contact surface is 1-2 mm away from the maxillary gingiva, and the edge of the second lower contact surface is 1-2 mm away from the mandibular gingiva; The intermediate occlusal guide plate and the terminal occlusal guide plate are made of nylon material; The method for designing and manufacturing the orthognathic surgery occlusal guide based on the invisible orthodontic device includes the following steps: Step 1: Before the operation, the patient undergoes a spiral CT scan of the maxillofacial region and a hard plaster tooth model is made. Step 2: Use a 3D laser scanning device to scan the hard plaster tooth model, save the acquired virtual dentition data in STL format, and replace the dentition data in the CT data to obtain higher dentition data accuracy; Step 3: Import the patient's CT data into the craniofacial surgery planning software in DICOM format to create a virtual three-dimensional craniofacial model; Step 4: Simulate the Le Fort I osteotomy of the maxilla and the sagittal split of the mandibular ramus on the established virtual three-dimensional craniomaxillary model. Move the maxillary bone segment to the target position according to the surgical plan, and then determine the target position of the mandibular bone segment based on the final occlusal relationship. Step 5: Import the dental arch data into the 3D design software in STL format. Based on the intermediate occlusal relationship between the maxillary tooth bone segment at the target position and the mandibular tooth bone segment at the initial position, design an intermediate occlusal guide using the 3D design software. The intermediate occlusal guide is integrally formed by a first upper contact surface, a first lower contact surface, and a connecting part. The connecting part is set between the first upper contact surface and the first lower contact surface. The first upper tooth occlusal position is set on the first upper contact surface. Three first upper observation windows are set on the first upper contact surface, and three first lower observation windows are set on the first lower contact surface. The intermediate occlusal guide covers 1 / 2 of the crowns of the maxillary and mandibular incisors, and covers the crowns of the maxillary and mandibular canines, premolars, and first and / or second molars. The edge of the guide is 1-2 mm away from the gingival margin. A total of three observation windows are set in the anterior tooth area and the bilateral posterior tooth areas. Step 6: The terminal occlusal guide is designed based on the final occlusal relationship determined by the maxillary and mandibular bone segments at the target location. The guide edge and observation window are set in the same way as the intermediate occlusal guide. The terminal occlusal guide is integrally formed by combining a second upper contact surface and a second lower contact surface. A second maxillary occlusal position is set on the second upper contact surface, and a second mandibular occlusal position is set on the second lower contact surface. A second observation window is set between the second upper contact surface and the second lower contact surface. The intermediate occlusal guide and the terminal occlusal guide are manufactured using 3D printing technology according to the data designed by 3D design software.

[0010] The beneficial effects of this invention are: 1. Compatible with invisible orthodontic appliances, no need to grind down the invisible orthodontic attachments before orthognathic surgery, and can use the invisible orthodontic attachments for retention. There is no need to remove the attachments used for invisible orthodontics that are bonded to the tooth surface before surgery. The positioning is achieved by the interlocking force between the guide plate and the tooth, and between the guide plate and the invisible orthodontic attachments. No additional auxiliary methods are required, avoiding the possibility of damage to the gums and tooth roots.

[0011] 2. The intermediate and terminal occlusal guides are not fully covering in the anterior region, but are designed to cover the entire dentition in the posterior region, reducing resistance during dislocation and placement. The difficulty was reduced, but the operation time was saved.

[0012] 3. The designed observation window avoids misalignment of the teeth due to interference points during processing. When properly positioned, stable intermaxillary fixation can be provided during orthognathic surgery without the need for other auxiliary means, ensuring surgical precision.

[0013] 4. Nylon 3D printing material is used. This material has excellent elasticity and toughness, and is not prone to producing debris. It facilitates intraoperative procedures while ensuring the strength of intermaxillary fixation, guaranteeing stable placement and easy insertion and removal.

[0014] 5. It can provide stable intermaxillary fixation during surgery without the need for traditional fixed orthodontic devices, arch splints, or intermaxillary traction screws, with almost no risk of skin punctures or transmission of bloodborne viruses or pathogens, thus improving the safety of the application. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the intermediate interlocking guide plate.

[0016] Figure 2 This is a front view of the intermediate interlocking guide plate.

[0017] Figure 3 This is a side view of the intermediate interlocking guide plate.

[0018] Figure 4 This is a structural diagram of the terminal engagement guide plate.

[0019] Figure 5 This is a front view of the terminal engagement guide plate.

[0020] Figure 6 This is a side view of the terminal occlusion guide plate.

[0021] Explanation of reference numerals in the attached drawings: 1-Intermediate occlusal guide; 11-First upper contact surface; 12-First lower contact surface; 13-Connecting part; 14-First upper tooth occlusal position; 15-First upper observation window; 16-First lower tooth occlusal position; 17-First lower observation window; 2-Terminal occlusal guide; 21-Second upper contact surface; 22-Second lower contact surface; 23-Second upper tooth occlusal position; 24-Second lower tooth occlusal position; 25-Second upper observation window. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0023] like Figures 1 to 6As shown, an orthognathic surgery occlusal guide based on an invisible orthodontic device is characterized by comprising an intermediate occlusal guide 1 and a terminal occlusal guide 2. The intermediate occlusal guide 1 is designed based on the intermediate occlusal relationship formed by the maxillary bone segment and the initial position of the mandibular bone segment, and is used to determine the target position of the maxillary bone segment during orthognathic surgery. The terminal occlusal guide 2 is designed based on the final occlusal relationship formed by the maxillary and mandibular bone segments, and is used to determine the target position of the mandibular bone segment during orthognathic surgery. The intermediate occlusal guide 1 and the terminal occlusal guide 2 are made of nylon material.

[0024] Figures 1 to 3 As shown, the intermediate engagement guide plate 1 is integrally formed from a first upper contact surface 11, a first lower contact surface 12 and a connecting part 13, wherein the connecting part 13 is located between the first upper contact surface 11 and the first lower contact surface 12.

[0025] The first upper contact surface 11 is provided with a first upper tooth occlusal position 14 for the upper teeth to be inserted and positioned. The first upper contact surface 11 is provided with three first upper observation windows 15, which are located in the anterior tooth area and bilateral posterior tooth areas of the first upper contact surface 11, respectively. The positioning of the upper teeth can be confirmed through the first upper observation windows 15. The anterior tooth area of ​​the first upper contact surface 11 covers 1 / 2 of the crown of the maxillary incisor. The edge of the first upper contact surface 11 is 1-2 mm away from the maxillary gingiva.

[0026] The first lower contact surface 12 is provided with a first lower tooth occlusal position 16 for the lower teeth to be inserted and positioned. The first lower contact surface 12 is provided with three first lower observation windows 17. The three first upper observation windows 15 are respectively located in the anterior tooth area and the bilateral posterior tooth area of ​​the first upper contact surface 11. The positioning of the maxillary teeth can be confirmed through the first upper observation windows 15. The three first lower observation windows 17 are respectively located in the anterior tooth area and the bilateral posterior tooth area of ​​the first lower contact surface 12. The positioning of the lower teeth can be confirmed through the first lower observation windows 17. The anterior tooth area of ​​the first lower contact surface 12 covers 1 / 2 of the crown of the mandibular incisor. The edge of the first lower contact surface 12 is 1-2 mm away from the mandibular gingiva.

[0027] Figures 4 to 6As shown, the terminal occlusion guide 2 is integrally formed by combining a second upper contact surface 21 and a second lower contact surface 22. A second upper tooth occlusion position 23 is provided on the second upper contact surface 21 for the upper teeth to be inserted into and positioned. A second lower tooth occlusion position 24 is provided on the second lower contact surface 22 for the lower teeth to be inserted into and positioned. Three second observation windows 25 are provided between the second upper contact surface 21 and the second lower contact surface 22. The anterior tooth region and bilateral posterior tooth regions located between the second upper contact surface 21 and the second lower contact surface 22, respectively, allow simultaneous confirmation of the positioning of the maxillary and mandibular teeth through the second upper observation window 25. The anterior tooth region of the second upper contact surface 21 covers 1 / 2 of the crown of the maxillary incisor, and the edge of the second upper contact surface 21 is 1-2 mm away from the maxillary gingiva. The anterior tooth region of the second lower contact surface 22 covers 1 / 2 of the crown of the mandibular incisor, and the edge of the second lower contact surface 22 is 1-2 mm away from the mandibular gingiva.

[0028] A method for designing and manufacturing an orthognathic surgery occlusal guide based on an invisible orthodontic device, characterized by comprising the following steps: Step 1: Before the operation, the patient undergoes a spiral CT scan of the maxillofacial region and a hard plaster tooth model is made. Step 2: Use a 3D laser scanning device to scan the hard plaster tooth model, save the acquired virtual dentition data in STL format, and replace the dentition data in the CT data to obtain higher dentition data accuracy; Step 3: Import the patient's CT data into the craniofacial surgery planning software in DICOM format to create a virtual three-dimensional craniofacial model; Step 4: Simulate the Le Fort I osteotomy of the maxilla and the sagittal split of the mandibular ramus on the established virtual three-dimensional craniomaxillary model. Move the maxillary bone segment to the target position according to the surgical plan, and then determine the target position of the mandibular bone segment based on the final occlusal relationship. Step 5: Import the dental arch data into the 3D design software in STL format. Based on the intermediate occlusal relationship between the maxillary tooth bone segment at the target position and the mandibular tooth bone segment at the initial position, design the intermediate occlusal guide 1 using the 3D design software. The intermediate occlusal guide 1 is integrally formed from a first upper contact surface 11, a first lower contact surface 12, and a connecting part 13. The connecting part 13 is provided between the first upper contact surface 11 and the first lower contact surface 12. The first upper tooth occlusal position 14 is provided on the first upper contact surface 11. Three first upper observation windows 15 are provided on the first upper contact surface 11, and three first lower observation windows 17 are provided on the first lower contact surface 12. The intermediate occlusal guide 1 covers 1 / 2 of the crowns of the maxillary and mandibular incisors, and covers the crowns of the maxillary and mandibular canines, premolars, and first and / or second molars. The edge of the guide is 1-2 mm away from the gingival margin. A total of three observation windows are provided in the anterior tooth area and the bilateral posterior tooth areas. Step 6: The terminal occlusal guide 2 is designed based on the terminal occlusal relationship determined by the maxillary and mandibular bone segments at the target position. The edge and observation window of the guide are the same as those of the intermediate occlusal guide 1. The terminal occlusal guide 2 is integrally formed by combining a second upper contact surface 21 and a second lower contact surface 22. A second upper tooth occlusal position 23 is provided on the second upper contact surface 21, and a second lower tooth occlusal position 24 is provided on the second lower contact surface 22. A second observation window 25 is provided between the second upper contact surface 21 and the second lower contact surface 22. The intermediate occlusal guide 1 and the terminal occlusal guide 2 are manufactured using 3D printing technology based on the data designed by the 3D design software.

[0029] In this embodiment, after performing a Lefort I osteotomy on the maxilla, the upper and lower dentitions are positioned in the intermediate occlusal plate 1. The tooth positioning is observed through the first upper observation window 15 and the first lower observation window 17. The intermediate occlusal plate 1 provides a firm intermaxillary fixation while the upper and lower dentitions are embedded in the plate. The patient's maxillary bone segment is moved to the target position designed in the surgical plan. Miniature titanium plates are fixed to the edges of the piriform foramen and the zygomatic alveolar ridge on both sides. After the maxillary bone segment is fixed, the intermediate occlusal plate 1 is removed. The patient undergoes a bilateral sagittal split of the mandibular ramus. The upper and lower dentitions are embedded in the terminal occlusal plate 2. The target position of the mandibular bone segment is determined with the fixed maxilla as a reference. The tooth positioning is observed through the second upper observation window 25. Small titanium plates or titanium screws are fixed to the bilateral external oblique lines.

[0030] 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 of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for designing and fabricating an orthognathic surgical occlusal guide based on an invisible orthodontic device, characterized in that, Includes the following steps: Step 1: Before the operation, the patient undergoes a spiral CT scan of the maxillofacial region. The CT scan is performed on the patient and three-dimensional data of the craniofacial region and teeth are collected. The creation of a hard plaster tooth model is used to prepare for obtaining the patient's three-dimensional virtual tooth data. Step 2: Use a 3D laser scanning device to scan the hard plaster tooth model, save the acquired virtual dentition data in STL format, and replace the dentition data in the CT data to obtain higher dentition data accuracy; Step 3: Import the patient's CT data into the craniofacial surgery planning software in DICOM format to create a virtual three-dimensional craniofacial model; Step 4: Simulate the Le Fort I osteotomy of the maxilla and the sagittal split of the mandibular ramus on the established virtual three-dimensional craniomaxillary model. Move the maxillary bone segment to the target position according to the surgical plan, and then determine the target position of the mandibular bone segment based on the final occlusal relationship. Step 5: Import the dental arch data into the 3D design software in STL format. Based on the intermediate occlusal relationship between the maxillary bone segment at the target position and the mandibular bone segment at the initial position, design an intermediate occlusal guide (1) using the 3D design software. The intermediate occlusal guide (1) is integrally formed from a first upper contact surface (11), a first lower contact surface (12), and a connecting part (13). The connecting part (13) is provided between the first upper contact surface (11) and the first lower contact surface (12). The first upper tooth occlusal position (14) is set on the first upper contact surface (11). Three first upper observation windows (15) are provided on the first upper contact surface (11), and three first lower observation windows (17) are provided on the first lower contact surface (12). The intermediate occlusal guide (1) covers 1 / 2 of the crowns of the maxillary and mandibular incisors. The guide plate covers the crowns of the maxillary and mandibular canines, premolars, and first and / or second molars, with the edge of the guide plate 1-2 mm from the gingival margin. A total of three observation windows are set in the anterior tooth area and the bilateral posterior tooth areas. Step 6: The terminal occlusal guide (2) is designed based on the terminal occlusal relationship determined by the maxillary and mandibular bone segments at the target position. The edge and observation window of the guide are the same as those of the intermediate occlusal guide (1). The terminal occlusal guide (2) is integrally formed by combining a second upper contact surface (21) and a second lower contact surface (22). A second upper tooth occlusal position (23) is set on the second upper contact surface (21), and a second lower tooth occlusal position (24) is set on the second lower contact surface (22). A second observation window (25) is set between the second upper contact surface (21) and the second lower contact surface (22). The intermediate occlusal guide (1) and the terminal occlusal guide (2) are manufactured using 3D printing technology based on the data designed by the 3D design software.

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