A maxillary Le Fort I type block osteotomy interdental osteotomy guide plate and manufacturing method

Abstract

The application discloses an interdental osteotomy guide plate for maxillary Le Fort I type block osteotomy, which comprises a bite positioning plate, an osteotomy line positioning guide plate, a buffer area and a lip baffle, wherein the upper surface of the bite positioning plate is provided with an initial tooth impression; the osteotomy line positioning guide plate is provided with a screw hole, a hollow window area and an osteotomy line position direction indicating area; the buffer area is connected between the bite positioning plate and the osteotomy line positioning guide plate and is used for avoiding orthodontic devices on the tooth surface and stripping soft tissue on the bone surface; the lip baffle is arranged above the osteotomy line positioning guide plate and is used for blocking the upper lip tissue to expose the operation area; and the gum baffle is arranged below and on the inner side of the osteotomy line position direction indicating area and is used for blocking the gum tissue to expose the osteotomy operation area. The bite positioning, the positioning of the position and direction of the osteotomy line and the soft tissue isolation function are integrated in one guide plate, so that the surgical procedure is simplified and the dependence on many assistants is reduced.

Description

Technical Field

[0001] This application relates to the field of oral and maxillofacial surgical instruments and technology, and in particular to an interdental osteotomy guide plate for Le Fort I type segmental osteotomy of the maxilla. Background Technology

[0002] Le Fort I segmental osteotomy of the maxilla is a commonly used surgical procedure for correcting skeletal maxillary protrusion and other dentofacial deformities. This surgery often requires extraction of the maxillary first premolar and osteotomy between the roots of the maxillary canine and second premolar to remove bone interference and align the maxillary bone segment to the predetermined position. However, due to the limited surgical field and complex local anatomy, intraoperative interdental osteotomy is highly susceptible to damage to surrounding gingiva, mucosa, and the roots and periodontal tissues of adjacent teeth, leading to complications such as palatal fistula, root injury, root-bone separation, and pulp necrosis, and even medical disputes.

[0003] Currently, interdental osteotomy in maxillary Le Fort I segmental osteotomy still relies heavily on the surgeon's experience and free-hand operation, leading to inconsistencies between preoperative digital design and intraoperative placement, increasing surgical uncertainty and risk. While surgical navigation systems can assist in positioning, they suffer from time-consuming registration and limited accuracy (approximately 1.46±0.24mm), making it difficult to meet the stringent precision requirements of interdental osteotomy. Although surgical guides have demonstrated high precision advantages in other fields (such as dental implants and orthopedics), a dedicated guide specifically for the interdental osteotomy step in maxillary Le Fort I segmental osteotomy, along with a systematic fabrication method integrating biomechanical safety design and functional optimization, is currently lacking in the field. Summary of the Invention

[0004] This invention relates to a guide plate for interdental osteotomy in maxillary Le Fort I segmental osteotomy and its manufacturing method, in order to solve the problem that in the prior art, the interdental osteotomy operation in maxillary Le Fort I segmental osteotomy still mainly relies on the surgeon's experience to perform free hand operation, resulting in inconsistency between preoperative digital design and intraoperative implementation position, which increases the uncertainty and risk of the operation.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, embodiments of this application provide a guide plate for interdental osteotomy in maxillary Le Fort I segmental osteotomy, comprising: Occlusal positioning plate, with initial tooth impressions on its upper surface; The osteotomy line positioning guide plate is equipped with screw holes, a perforated window area, and an osteotomy line position and direction indicator area. A buffer zone connects the occlusal positioning plate and the osteotomy line positioning guide plate, used to avoid the orthodontic device on the tooth surface and the soft tissue stripping from the bone surface. A lip baffle, positioned above the osteotomy line positioning guide, is used to block upper lip tissue to expose the surgical area; A gingival baffle, located below and inside the area indicating the direction of the osteotomy line, is used to block gingival tissue to expose the osteotomy area.

[0006] Furthermore, the osteotomy line position direction indication area is an osteotomy groove, and the sidewall of the osteotomy groove has a wave-shaped or reinforcing structure.

[0007] Furthermore, a funnel-shaped guide slope is formed at the entrance of the osteotomy groove.

[0008] Furthermore, the lip baffle and gingival baffle are configured to replace surgical retractors to expose the surgical area and protect the buccal soft tissue and gingival tissue from damage by the power system during osteotomy.

[0009] Secondly, embodiments of this application provide a method for fabricating an interdental osteotomy guide plate, comprising the following steps: S1: Multimodal data acquisition and 3D reconstruction: Acquire the patient's maxillofacial CT data and intraoral scan data, and reconstruct them into a 3D skeletal model of the maxilla and a 3D dentition model, respectively; S2: Data fusion and virtual model preparation: The three-dimensional skeletal model of the maxilla is registered and fused with the three-dimensional dental arch model to obtain the fused three-dimensional maxillary model; S3: Osteotomy line positioning: On the three-dimensional maxillary model, osteotomy planes are planned between the maxillary canine and the first premolar and between the maxillary first premolar and the second premolar, and the maxillary bone blocks are simulated to be moved to their final positions. S4: Guide plate design: S4.1: Design the osteotomy line positioning guide plate on the maxillary bone wall surface corresponding to the maxillary canine, first premolar and second premolar; S4.2: Design the buffer area to connect the osteotomy line positioning guide plate and the occlusal positioning plate into a whole; S4.3: Design the occlusal positioning plate that surrounds the maxillary canine and the second premolar, and form the initial tooth impression on its upper surface through Boolean operation; S4.4: Design the gingival baffle according to the planned osteotomy line position, and design the labial baffle according to the overall morphology of the maxilla; S5: 3D printing and post-processing of the guide plate: The three-dimensional model designed in step S4 is used to prepare a solid guide plate using 3D printing technology, and then post-processed and sterilized.

[0010] Furthermore, step S4 also includes a dynamic structure optimization step: reinforcing the sidewall of the osteotomy line position direction indicator area to suppress vibration deviations generated during osteotomy instrument operation.

[0011] Furthermore, the dynamic structure optimization step includes: using finite element analysis to simulate the vibration modes of the osteotomy instrument, and accordingly designing a wave-shaped or ribbed reinforcement for the sidewall.

[0012] Furthermore, the dynamic structure optimization step also includes: designing a funnel-shaped guide ramp at the entrance of the osteotomy line position direction indication area.

[0013] Furthermore, step S3 specifically includes: S3.1: Establish the osteotomy plane for cutting bone blocks between the maxillary teeth: The osteotomy plane is located between the tooth roots and closer to the root surface of the first premolar to avoid damaging the roots of the canine and the second premolar; S3.2: Virtual cutting of the maxilla: Divide the maxilla into anterior and posterior segments according to the osteotomy plane; S3.3: Moving the anterior maxillary bone block: Simulate moving the anterior maxillary bone block backward and / or rotating it clockwise to improve maxillary protrusion, reduce the labial inclination of the anterior teeth, and establish a normal occlusal relationship, ultimately determining the final position of the maxillary bone block.

[0014] The above-mentioned technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: Integrated design: The positioning of occlusion, the location and direction of osteotomy line, and soft tissue isolation function are integrated into a single guide plate, simplifying the surgical procedure and reducing reliance on multiple assistants. Precise positioning and protection: Dual positioning is achieved through "initial impression" and bone surface attachment, resulting in high precision. Dedicated gingival and labial baffles effectively protect soft tissue and provide a clear and stable surgical field. Dynamic stability: The reinforced structure and guiding ramp optimized through finite element analysis effectively resist vibrations of osteotomy instruments, ensuring the accuracy of the osteotomy path, which is not available in conventional guide plates. Personalization and safety: Designed based on patient-specific anatomical data, it fully considers individualized factors such as orthodontic appliances and tooth root positions, minimizing the risk of damage to nerves, blood vessels, and tooth roots. Improved surgical efficiency: The use of the guide plate reduces the time spent on repeated measurements and trial osteotomies during surgery, making complex segmented osteotomy surgery more controllable and efficient. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a three-dimensional structural diagram of the osteotomy guide plate provided in the embodiments of this specification.

[0016] Figure 2This is a three-dimensional structural diagram of the osteotomy guide plate provided in the embodiments of this specification from another direction.

[0017] Figure 3 This is a schematic diagram illustrating the usage state provided in the embodiments of this specification.

[0018] Figure 4 This is a schematic diagram of the preoperative virtual design of the interdental osteotomy line in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0021] This specification provides an example of an interdental osteotomy guide plate for maxillary Le Fort I segmental osteotomy. Please refer to [link to relevant documentation]. Figure 1 , Figure 2 and Figure 3 As shown, the procedure includes: an occlusal positioning plate 1 with an initial tooth impression 9 on its upper surface; an osteotomy line positioning guide plate 3 with screw holes 8, a perforated window area 4, and an osteotomy line position direction indicator area 5; a buffer area 2 connecting the occlusal positioning plate and the osteotomy line positioning guide plate 3, used to avoid orthodontic devices on the tooth surface and soft tissue stripping on the bone surface; a lip baffle 6, positioned above the osteotomy line positioning guide plate 3, used to block upper lip tissue to expose the surgical area; and a gingival baffle 7, positioned below and inside the osteotomy line position direction indicator area 5, used to block gingival tissue to expose the osteotomy surgical area. Specifically, the osteotomy line position direction indicator area is an osteotomy groove, the sidewall of which has a wavy or reinforced structure. A funnel-shaped guide slope is formed at the entrance of the osteotomy groove. The lip baffle 6 and the gingival baffle 7 are configured to replace surgical retractors to expose the surgical area and protect the buccal soft tissue and gingival tissue, preventing damage from the power system during osteotomy.

[0022] In one possible specific implementation, the present invention and its technical effects will be described in detail below with reference to the accompanying drawings and several specific embodiments.

[0023] Example: Standard case of maxillary protrusion 1. Case and data: The patient was a 22-year-old female diagnosed with Angle Class II malocclusion and maxillary protrusion.

[0024] 2. Virtual surgical design and guide plate structure implementation: Plan the osteotomy line of the canine area on the 3D model.

[0025] Guide plate structure implementation: Based on the plan, we designed a guide plate with the structural features of this invention: Occlusal positioning plate and initial impression 9: An occlusal positioning plate was designed to surround the maxillary canine and second premolar, and an initial impression 9, which is a perfect mirror image of the patient's tooth crown morphology, was formed on its upper surface through Boolean operations. This structure ensures zero initial positioning error of the guide plate in both the vertical and horizontal directions.

[0026] Osteotomy line positioning guide 3 and osteotomy groove: An osteotomy line positioning guide 3 is designed on the corresponding bone surface, the core of which is the osteotomy line position and direction indication area (i.e., osteotomy groove). The width of the groove matches the diameter of the selected ultrasonic bone scalpel tip (1.0 mm), providing precise path constraints for osteotomy.

[0027] Buffer Zone 2: Since the patient is wearing orthodontic brackets, we designed a buffer zone 2 between the occlusal positioning plate and the osteotomy line positioning guide plate 3 to lift and avoid the brackets and soft tissue stripped from the bone surface, ensuring that the guide plate can still be perfectly positioned when orthodontic devices are present and during actual operation.

[0028] Lip baffle 6 and gingival baffle 7: Based on the exposure requirements of the surgical area, we extend the lip baffle 6 upwards to block the upper lip; and extend the gingival baffle 7 downwards to protect and push back the gingiva. These two baffles completely replace the assistant's retractor during the operation, achieving stable exposure of the surgical field.

[0029] 3. Intraoperative Application: After the guide plate is positioned through the initial impression 9 and fixed through the screw holes 8, the surgical field is clear. The surgeon performs osteotomy along the osteotomy groove, and the process is smooth. After the osteotomy is completed, the osteotomy line on the bone surface is completely aligned with the projection of the osteotomy groove designed on the guide plate, and the soft tissue protected by the gingival baffle 7 remains intact.

[0030] Example 2: High-risk cases adjacent to tooth roots 1. Case risk: The roots of the first premolar 4 and the second premolar 5 in the right maxilla are abnormally close together, with the narrowest distance between the roots being only 0.8 mm.

[0031] 2. Implementation of guide plate structure optimization: After planning a safe osteotomy path, we optimized the dynamic structure of the core osteotomy groove.

[0032] Reinforcement Structure Implementation: Finite element analysis revealed a vibration risk in the standard groove wall. Based on this, we designed a "wave-shaped" reinforcement structure for the sidewalls of the osteotomy groove. These wave-shaped grooves act like "ribs" added to the groove wall, significantly improving its rigidity.

[0033] Guided ramp implementation: Simultaneously, at the entrance of the osteotomy groove, we designed a funnel-shaped guide ramp. This ramp has an angle of 20°, facilitating the shock-free insertion of instruments.

[0034] In one possible implementation, please refer to Figure 4 As shown, this description further provides method embodiments. An adult patient diagnosed with maxillary protrusion with labial inclination of the anterior teeth 1. Data Acquisition and Model Preparation: Obtain the patient's maxillofacial CBCT data (0.25mm slice thickness) and intraoral scan data. After reconstructing the models separately, registration and fusion were performed in reverse engineering software (such as GeomagicWrap) to obtain an accurate digital maxillary model containing tooth roots and bones.

[0035] 2. Virtual Surgical Design: The surgeon analyzes the surgical plan using software such as CCMFPlan. Example Details: Based on the preoperative design, the anterior maxillary bone segment is retracted by 4mm. Accordingly, osteotomy lines are designed on the virtual model between the 3rd and 4th quarter teeth and between the 4th and 5th teeth, avoiding contact between the osteotomy lines and the roots of the canines and second premolars on all CT sections. The anterior maxillary bone segment is moved 4mm posteriorly and rotated clockwise according to the axis of the maxillary anterior teeth. The software simulation shows smooth bone segment movement without skeletal interference, and establishes good anterior tooth guidance and posterior tooth occlusal contact.

[0036] 3. Guide plate design: Osteotomy line positioning guides are generated on the bone surface corresponding to the 3rd, 4th, and 5th teeth.

[0037] Example Details: Standard MBT metal brackets were bonded to the patient's teeth. When designing the buffer zone, care was taken to avoid orthodontic appliances on the teeth and mucosal tissue detached from the bone surface during the procedure, ensuring the guide plate could be fully positioned without resistance.

[0038] Generate an occlusal positioning plate that surrounds the crowns of teeth 3 and 5, and generate initial dental impressions.

[0039] Following the osteotomy line, a gingival baffle, approximately 4mm long, extends downwards close to the alveolar ridge crest, effectively retracting the gingiva. A labial baffle, approximately 10mm long, extends upwards, stably retracting the upper lip during the procedure.

[0040] Dynamics optimization example: Finite element analysis was performed on the designed osteotomy groove. Simulation revealed that when a certain type of ultrasonic bone scalpel was used within the groove, slight deformation occurred in the middle section of the groove wall. To address this, three annular wavy reinforcing ribs were designed in this area. Additionally, a 20° angled flared guide ramp was designed at the inlet. The optimized simulation results showed that the vibration-induced path deviation decreased from 0.3 mm to 0.08 mm.

[0041] 4. Guide Plate Fabrication and Use: 3D printing was performed using medical-grade biocompatible resin. During the procedure, the guide plate was first inserted into the maxillary dentition based on the initial dental impression. After confirming complete positioning, a retention screw was inserted into each of the screw holes on both sides to fix the guide plate to the bone surface. At this point, the labial and gingival baffles automatically pushed aside the soft tissue, ensuring sufficient exposure of the surgical area. The surgeon then guided the osteotomy instrument (ultrasonic osteotome) along the beveled edge of the flared end into the osteotomy groove, performing the osteotomy stably along the reinforced groove wall. The entire osteotomy process was precise, with excellent soft tissue protection, and no instrument slippage or vibration displacement occurred.

[0042] In a preferred embodiment, a micro-irrigation channel is integrated inside the guide plate. This micro-irrigation channel has an outlet leading to the vicinity of the osteotomy groove and an irrigation channel interface for connecting a water pipe. The outlet is located on the inner walls of both sides of the osteotomy groove, allowing water to flow towards the working surface. The interface is designed in an area that does not interfere with the operation, such as the outer side of the labial baffle. The individualized interdental osteotomy guide plate is then inserted, providing excellent stability. The irrigation pipe is connected to the irrigation channel interface of the guide plate. The irrigation fluid is turned on, and a micro-oscillating saw is easily inserted into the osteotomy groove along the guide ramp. Osteotomy is completed under continuous cooling, resulting in a clear surgical field and smooth, stable operation.

[0043] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0044] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A guide plate for interdental osteotomy in maxillary Le Fort I segmental osteotomy, characterized in that, include: Occlusal positioning plate, with initial tooth impressions on its upper surface; The osteotomy line positioning guide plate is equipped with screw holes, a perforated window area, and an osteotomy line position and direction indicator area. A buffer zone connects the occlusal positioning plate and the osteotomy line positioning guide plate, used to avoid the orthodontic device on the tooth surface and the soft tissue stripping from the bone surface. A lip baffle, positioned above the osteotomy line positioning guide, is used to block upper lip tissue to expose the surgical area; A gingival baffle is positioned below and inside the area indicating the direction of the osteotomy line to block gingival tissue from exposing the osteotomy area. The osteotomy line position and direction indication area is an osteotomy groove. The sidewall of the osteotomy groove has a wave-shaped or reinforcing structure, and the entrance of the osteotomy groove has a funnel-shaped guide slope.

2. The interdental osteotomy guide plate according to claim 1, characterized in that, The lip and gingival baffles are configured to replace surgical retractors to expose the surgical area and protect the buccal soft tissue and gingival tissue from damage by the power system during osteotomy.

3. A method for fabricating an interdental osteotomy guide plate as described in claim 1 or 2, characterized in that, Includes the following steps: The patient's maxillofacial CT data and intraoral scan data were collected and reconstructed into a three-dimensional skeletal model of the maxilla and a three-dimensional model of the dental arch, respectively. The three-dimensional skeletal model of the maxilla is registered and fused with the three-dimensional dental arch model to obtain the fused three-dimensional maxillary model; On the three-dimensional maxillary model, osteotomy planes are planned between the maxillary canine and the first premolar and between the maxillary first premolar and the second premolar, and the movement of the maxillary bone block to the final position is simulated. The osteotomy line positioning guide plate is designed on the maxillary bone wall surface corresponding to the maxillary canine, first premolar and second premolar; The occlusal positioning plate is designed to surround the maxillary canine and the second premolar, and an initial tooth impression is formed on its upper surface through Boolean operations; The gingival baffle is designed according to the planned osteotomy line position, and the lip baffle is designed according to the overall morphology of the maxilla. Post-processing and sterilization are performed after 3D printing.

4. The manufacturing method according to claim 3, characterized in that, The steps described above, specifically including planning osteotomy planes on the three-dimensional maxillary model between the maxillary canine and the first premolar, and between the maxillary first premolar and the second premolar, and simulating the movement of the maxillary bone blocks to their final positions, include: Establish the osteotomy plane for cutting bone blocks between the maxillary teeth: The osteotomy plane is located between the tooth roots and closer to the root surface of the first premolar to avoid damaging the roots of the canine and the second premolar; Virtual cutting of the maxilla: The maxilla is divided into anterior and posterior segments according to the osteotomy plane; Moving the anterior maxillary bone block: Simulating the posterior movement and / or clockwise rotation of the anterior maxillary bone block to improve maxillary protrusion, reduce anterior labial inclination, and establish a normal occlusal relationship, ultimately determining the final position of the maxillary bone block.

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