A PEEK long nail pre-drilling guide system for mandibular block fixation and a design and preparation method thereof

Abstract

The application relates to a PEEK long nail pre-drilling guide system for mandibular block fixation and a design and preparation method thereof, and relates to the technical field of oral and maxillofacial surgery. The system comprises a mandibular block fixation guide plate, an osteotomy guide structure arranged on the mandibular block fixation guide plate, at least four preset holes arranged on the mandibular block fixation guide plate, a guide sleeve arranged in the preset hole and a PEEK long nail matched with the guide sleeve; the mandibular block fixation guide plate is used for being attached to an exposed bone surface of a patient's mandible; the osteotomy guide structure is used for guiding or prompting a mandibular osteotomy position; the guide sleeve is inserted into the preset hole; and the PEEK long nail is used for realizing block fixation along the guide sleeve after the mandibular block is moved. The application can improve the consistency of preoperative planning to intraoperative transfer, and reduce the risk of damage to adjacent tooth roots, mental foramen, inferior alveolar nerve canal, weak areas of bone cortex or other important anatomical structures caused by deviation from the planned hole.

Description

Technical Field

[0001] This invention relates to the field of oral and maxillofacial surgery, specifically to a PEEK long screw pre-drilling guide system for fixing mandibular bone blocks and its design and fabrication method. Background Technology

[0002] Mandibular osteotomy followed by fixation surgery typically involves osteotomy, relocation, and fixation of localized mandibular bone fragments to improve mandibular contour, lower facial proportions, local asymmetry, and related soft tissue support. Genioplasty is a typical application of mandibular bone fragment relocation and fixation. With the development of digital surgical techniques, 3D reconstruction based on patient CT imaging data, virtual mandibular bone fragment relocation design, and personalized guide fabrication are increasingly being applied to mandibular osteotomy, bone fragment relocation, and fixation in related maxillofacial surgeries.

[0003] Currently, titanium plates and titanium screws are commonly used for mandibular bone fixation. Titanium internal fixation materials have good mechanical properties and a mature clinical application base; however, concerns related to metal implants may still exist in some cases, such as the risk of metal allergy, imaging artifacts, impact on postoperative imaging evaluation, and high consumable costs. Polyetheretherketone (PEEK) materials have been widely used in the medical field due to their excellent mechanical properties and biocompatibility. The elastic modulus of PEEK material is relatively close to that of human bone tissue, which helps reduce stress shielding and does not produce significant metal artifacts in imaging examinations. If PEEK screws are used for mandibular bone fixation, the screw entry point, axis, length, and channel spatial path must be clearly defined during the preoperative design phase, and this channel must be stably reproduced during the operation.

[0004] However, unlike traditional short screws or titanium plates and screws, PEEK long screws have a longer fixation path, requiring greater accuracy in entry point location, axial direction, channel depth, and spatial trajectory. If freehand or experience-based drilling is relied upon during surgery, the drilling entry point, direction, and depth are easily affected by factors such as the surgeon's feel, surgical field of vision, soft tissue traction, instrument operating space, and local mandibular bone morphology, making it difficult to stably and accurately replicate the preoperative virtual plan. Especially with a long screw path, even small proximal angular deviations can be significantly amplified distally, increasing the risk of channel deviation, lateral drilling errors, inconsistent fixation paths, and damage to adjacent important anatomical structures.

[0005] Existing mandibular osteotomy guides or bone block positioning guides are mostly used for auxiliary positioning of the osteotomy line, osteotomy plane, or bone block movement position. They usually fail to adequately define the three-dimensional orientation, expected entry depth, and spatial trajectory of the PEEK screw channels. Especially after the mandibular bone block has been osteotomized and moved to the target position, the original bony reference relationship changes. If the fixation channels are determined on the fly at this time, it may lead to inconsistencies between the fixation path and the preoperative plan, and increase the risk of skewed drilling, lateral drilling errors, and damage to adjacent structures.

[0006] Therefore, how to provide a personalized guidance system that can coordinate the design of osteotomy guidance, PEEK long screw channel guidance and post-osteotomy fixation path, and its design and preparation method, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a PEEK long screw pre-drilling guide system for mandibular bone fixation and its design and preparation method. This system can improve the consistency of preoperative planning and intraoperative transfer, and reduce the risk of damage to adjacent tooth roots, mental foramina, inferior alveolar nerve canal, weak areas of cortical bone, or other important anatomical structures due to deviation from the planned channel.

[0008] To achieve the above objectives, the present invention provides a PEEK long screw pre-drilling guide system for fixing mandibular bone fragments, comprising: a mandibular bone fragment fixing guide plate, an osteotomy guide structure disposed on the mandibular bone fragment fixing guide plate, at least four pre-drilled channels disposed on the mandibular bone fragment fixing guide plate, a guide sleeve disposed in the pre-drilled channels, and a PEEK long screw cooperating with the guide sleeve. The mandibular bone fixation guide plate is used to conform to the exposed bone surface of the patient's mandible; the osteotomy guide structure is used to guide or indicate the position of mandibular osteotomy; the guide sleeve is inserted into a preset channel; and the PEEK long nail is used to fix the bone block along the guide sleeve after the mandibular bone block is moved.

[0009] Furthermore, it also includes a depth-limiting structure, which is fitted onto the drill bit to limit the depth to which the drill bit enters the bone.

[0010] A method for designing and fabricating a PEEK long screw pre-drilling guide system for mandibular bone block fixation includes the following steps: Step S1: Obtain CT image data of the patient's maxillofacial region and reconstruct a three-dimensional model including the area of ​​the mandible to be osteotomized and adjacent anatomical structures. Step S2: Based on the patient's local mandibular morphology, facial improvement goals, and clinical plan, a virtual mandibular bone block fixation design is performed, determining the osteotomy plane, osteotomy line, bone block movement direction, movement distance, and target position. Step S3: Plan the PEEK screw fixation path based on the target position after the bone block is moved; Step S4: When planning the fixation path, avoid tooth roots, mental foramina, inferior alveolar nerve canal, areas of weak bone cortex, and the edge of osteotomy line, so that the long screw can connect the moving bone block and the fixed bone segment after the bone block is moved; Step S7: Generate the bone surface fitting and positioning surface of the personalized mandibular bone block fixation guide plate, and form an osteotomy guide structure on the mandibular bone block fixation guide plate to guide the bone saw cutting. Step S8: Generate a guide sleeve on the mandibular bone block fixation guide plate based on the PEEK long nail, so that the inlet position, outlet position and axial direction of the guide sleeve correspond to the planned channel; determine the PEEK long nail parameters based on the amount of movement of the chin bone block, and complete the design of the axial direction, inner diameter of the sleeve, axial length and outer diameter; Step S9: The digital model of the mandibular bone fixation guide plate is made into a mandibular bone fixation guide plate through 3D printing, cutting, or other medical processing methods, and then post-processed, cleaned, disinfected and sterilized, and preoperative adaptation examination is performed.

[0011] Furthermore, in step S3, the PEEK spike fixing path includes the number of spikes, entry point, axial direction, length, expected entry depth, and channel space trajectory.

[0012] Furthermore, it also includes step S10, setting a depth limiting structure and fitting it onto the drill bit; the depth limiting structure can move along the drill bit axis and be fixed at a preset position. When the drill bit is advanced along the guide sleeve to the preset depth, the depth limiting structure abuts against the proximal end face of the guide sleeve, thereby limiting the drill bit from continuing to penetrate into the bone tissue.

[0013] Furthermore, the length of a single PEEK spike Based on the preoperative virtual surgical plan, the details are as follows: Obtain the proximal entry point of the PEEK spike. Distal fixation points before chin segment repositioning and the three-dimensional movement vector of the chin segment. After the chin segment is moved, the planned location of the distal fixation point is as follows: The design length of a single PEEK spike is based on the formula. Calculation, where For safety margin, the clinical setting is 2mm.

[0014] Furthermore, the design length of the PEEK spikes must also meet safety constraints: ,in This is the distance along the path of the spike from the point of entry to the nearest dangerous anatomical structure. Maintain safe distance.

[0015] Furthermore, the effective guiding length of the guide sleeve The determination is based on the fit clearance between the drill bit and the sleeve, the effective intraosseous path length of the PEEK screw, and the allowable distal lateral deviation, as follows: The effective guiding length of the guide sleeve is calculated according to the formula. Calculate, where, The diameter gap between the sleeve and the drill bit. The effective intraosseous path length of the PEEK screw from the entry point to the distal fixation point. For the allowable distal lateral deviation, Tolerances for sleeve machining and operation.

[0016] Furthermore, the inner and outer diameters of the guide sleeve are determined based on the outer diameter of the pre-drilled drill bit, the fitting clearance, and the sleeve wall thickness, as follows: inner diameter of guide sleeve Determine according to the following formula: in, The inner diameter of the guide sleeve, The outer diameter of the pre-drilling drill bit. This refers to the one-sided clearance between the outer wall of the drill bit and the inner wall of the guide sleeve. outer diameter of guide sleeve Determine according to the following formula: in, The outer diameter of the guide sleeve, The thickness of one side of the guide sleeve.

[0017] Furthermore, for pre-drilling holes in the fixed lateral bone segment, the distance from the depth-limiting structure to the drill bit tip... According to the formula It is confirmed that, among them, The effective guide length of the fixed side guide sleeve, To plan the effective length of the orifice within the fixed lateral bone segment, Allowance for drilling depth to fix the lateral bone segment; For pre-drilling of free segment of the chin bone, the distance from the depth-limiting structure to the drill bit tip is... According to the formula It is confirmed that, among them, The effective guiding length of the free section guide sleeve, To plan the effective channel length within the free segment of the chin bone, This is the allowance for drilling depth of the free segment of the chin bone.

[0018] The beneficial effects of this invention are as follows: 1. This invention integrates the osteotomy guidance structure for mandibular bone block fixation with the PEEK long screw channel guide sleeve into the same guidance system, which helps to simultaneously transfer the osteotomy position and long screw fixation path in the preoperative virtual design to the intraoperative period.

[0019] 2. The guide sleeve with axial length can define the drilling entry point and drilling direction, so that the pre-prepared channel before osteotomy matches the final fixation path of the PEEK screw, which helps to reduce the number of times the drilling direction is adjusted manually.

[0020] 3. Since the pre-set channels are prepared based on a stable bone surface reference before osteotomy, the present invention helps to reduce channel positioning errors caused by changes in the position of bone blocks after osteotomy.

[0021] 4. By preoperatively planning the orifice to avoid tooth roots, mental foramen, inferior alveolar nerve canal, areas of weak cortical bone, and the edge of osteotomy line, this invention helps reduce the risk of deviating from the planned orifice and approaching adjacent important structures.

[0022] 5. Under the premise of meeting fixed requirements, the use of PEEK long nails can reduce the reliance on titanium plate and titanium nail combination, which helps to reduce the use of metal consumables and reduce some fixed consumable costs.

[0023] 6. Optional depth limiting structure can help control the drilling depth, improve the consistency of hole preparation, and reduce excessive drilling and unnecessary bone tissue damage. Attached Figure Description

[0024] Figure 1 The layout of the mandibular bone fixation guide plate of the present invention Figure 1 ; Figure 2 The layout of the mandibular bone fixation guide plate of the present invention Figure 2 ; Figure 3 This is a schematic diagram of the installation structure of the mandibular block fixing guide plate and guide sleeve of the present invention; Figure 4 This is a schematic diagram of the installation structure of the mandibular block fixing guide plate, guide sleeve and PEEK long screw of the present invention; Figure 5 This is a schematic diagram of the installation structure of the guide sleeve and PEEK spike of the present invention; Figure 6 This is a schematic diagram of the installation structure of the depth-limiting structure and the drill bit of the present invention; Figure 7 This is a schematic diagram of virtual genioplasty surgical design and bone block target location planning; Figure 8 This is a schematic diagram of the fixed path planning for PEEK spikes; Figure 9 This is a diagram illustrating the preoperative planning and avoidance of important anatomical structures for PEEK fixation. Figure 1 ; Figure 10 This is a diagram illustrating the preoperative planning and avoidance of important anatomical structures for PEEK fixation. Figure 2 .

[0025] In the figure: 1-Mandibular block fixation guide plate; 2-Osteotomy guidance structure; 3-Pre-set channel; 4-Guide sleeve; 5-PEEK long screw; 6-Depth limiting structure; 7-Drill bit. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application 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 for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover 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.

[0028] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0029] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0030] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0031] The purpose of this invention is to provide a PEEK long screw pre-drilling guide system for mandibular bone fixation and its design and fabrication method. Through patient-personally personalized digital design, the mandibular osteotomy guide structure, the pre-drilled channels of the PEEK long screw, and the guide sleeve with axial guiding function are integrated into the same guide plate scheme. This allows the guide plate to conform to the exposed bone surface of the mandible for positioning during surgery, and the drilling entry point, drilling direction, and drilling depth are defined before osteotomy, thereby creating pre-drilled channels consistent with the preoperative plan.

[0032] To achieve the above objectives, refer to Figures 1 to 6 The present invention provides a PEEK long screw pre-drilling guide system for fixing mandibular bone fragments, comprising: a mandibular bone fragment fixing guide plate 1, an osteotomy guide structure 2 disposed on the mandibular bone fragment fixing guide plate 1, at least four pre-set channels 3 disposed on the mandibular bone fragment fixing guide plate 1, a guide sleeve 4 disposed in the pre-set channels 3, and a PEEK long screw 5 cooperating with the guide sleeve 4. The device comprises a mandibular bone fixation guide plate 1, which conforms to the exposed bone surface of the patient's mandible; an osteotomy guide structure 2, which guides or indicates the location of the mandibular osteotomy; a guide sleeve 4, which is inserted into a pre-set channel; and a PEEK long screw 5, which fixes the mandibular bone along the guide sleeve after the mandibular bone has moved. This device integrates the mandibular bone fixation guide plate, the osteotomy guide structure, the guide sleeve, and the PEEK long screw matching the pre-set channel to achieve integrated guidance for mandibular bone osteotomy, drilling, and fixation.

[0033] The number of guide sleeves 4 can be at least four, or six, eight or more depending on the fixing requirements; three PEEK long pins are a preferred embodiment, but not a necessary limitation. The guide sleeves and the guide plate body can be integrally formed, or they can be achieved through detachable connection, embedded metal bushing, snap-fit ​​or threaded connection. The PEEK long pins can be self-tapping or non-self-tapping, and can have different thread sections, head limiting structures and screw-in mating parts, without limiting the specific thread profile.

[0034] The present invention also includes a depth-limiting structure 6, which is fitted onto the drill bit 7 to limit the depth of the drill bit entering the bone. The shape of the depth-limiting structure is not limited to a circular ring, and can be designed as a circular ring, a thin ring, a cylindrical ring, a frustum shape, a stepped shape, an ellipse, a polygon, a notched ring, an elastic snap-on ring, or other structures that can cooperate with the drill bit and achieve axial depth-limiting function, depending on the outer diameter of the drill bit, the shape of the guide sleeve end face, and the requirements of intraoperative operation.

[0035] To further optimize the technical solution, the mandibular bone block fixation guide plate 1 is made of medical resin, photosensitive resin, titanium alloy or other sterilizable medical materials; the manufacturing method may include 3D printing, cutting and processing, molding or other medical manufacturing methods.

[0036] This invention also provides a method for designing and fabricating a PEEK long screw pre-drilling guide system for mandibular bone block fixation, comprising the following steps: Step S1: Obtain CT image data of the patient's maxillofacial region and reconstruct a three-dimensional model including the area of ​​the mandible to be osteotomized and adjacent anatomical structures. Step S2: Based on the patient's local mandibular morphology, facial contour improvement goals, and clinical plan, a virtual mandibular bone block fixation design is performed, determining the osteotomy plane, osteotomy line, bone block movement direction, movement distance, and target position (see [link to relevant documentation]). Figure 7 ); Step S3: Plan the PEEK screw fixation path based on the target position after the bone fragment is moved (see...). Figure 8 The PEEK spike fixing path includes the number of spikes, entry point, axial direction, length, expected entry depth, and spatial trajectory of the hole.

[0037] Step S4 involves avoiding tooth roots, mental foramina, inferior alveolar nerve canal, areas of weak cortical bone, osteotomy line margins, and other important anatomical structures when planning the fixation path. This facilitates the connection between the moving bone segment and the fixed bone segment after the bone segment has moved (see [link to documentation]). Figure 9 and Figure 10 ); Step S7: Generate the bone surface fitting and positioning surface of the personalized mandibular bone block fixation guide plate, and form an osteotomy guide structure on the mandibular bone block fixation guide plate to guide the bone saw cutting. Step S8: Generate a guide sleeve on the mandibular bone block fixation guide plate based on the PEEK long nail, so that the inlet position, outlet position and axial direction of the guide sleeve correspond to the planned channel; determine the PEEK long nail parameters based on the amount of movement of the chin bone block, and complete the design of the axial direction, inner diameter of the sleeve, axial length and outer diameter; Step S9: The digital model of the mandibular bone fixation guide plate is made into a mandibular bone fixation guide plate through 3D printing, cutting or other medical processing methods, and then post-processing, cleaning, disinfection and sterilization and preoperative adaptation examination are performed. Step S10: Set a depth limiting structure and fit it onto the drill bit. The depth limiting structure can move along the drill bit axis and be fixed in a preset position. When the drill bit is advanced to the preset depth along the guide sleeve, the depth limiting structure abuts against the proximal end face of the guide sleeve, thereby limiting the drill bit from continuing to penetrate into the bone tissue.

[0038] Length of a single PEEK spike Based on the preoperative virtual surgical plan, the details are as follows: Obtain the proximal entry point of the PEEK spike. Distal fixation points before chin segment repositioning and the three-dimensional movement vector of the chin segment. After the chin segment is moved, the planned location of the distal fixation point is as follows: The design length of a single PEEK spike is based on the formula. Calculation, where For safety margin, the clinical setting is 2mm.

[0039] The design length of the PEEK spikes must also meet safety constraints: ,in This is the distance along the path of the spike from the point of entry to the nearest dangerous anatomical structure. For safe avoidance distance, when the calculated length of the spike exceeds the safety constraint, the spike insertion path, guide sleeve angle, or entry point position should be adjusted, rather than simply increasing the spike length.

[0040] Effective guide length of guide sleeve The determination is based on the fit clearance between the drill bit and the sleeve, the effective intraosseous path length of the PEEK screw, and the allowable distal lateral deviation, as follows: The effective guiding length of the guide sleeve is calculated according to the formula. Calculate, where, The diameter gap between the sleeve and the drill bit. The effective intraosseous path length of the PEEK screw from the entry point to the distal fixation point. The allowable distal lateral deviation is preferably set to 0.5 mm. To accommodate the machining and handling tolerances of the sleeve, a tolerance of 1 mm is preferred.

[0041] The inner and outer diameters of the guide sleeve are determined based on the outer diameter of the pre-drilled drill bit, the fitting clearance, and the sleeve wall thickness, as follows: inner diameter of guide sleeve Determine according to the following formula: in, The inner diameter of the guide sleeve, The outer diameter of the pre-drilling drill bit. The preferred clearance is the one-sided fit clearance between the outer wall of the drill bit and the inner wall of the guide sleeve. The value is 0.09 mm; outer diameter of guide sleeve Determine according to the following formula: in, The outer diameter of the guide sleeve, The wall thickness on one side of the guide sleeve varies depending on the material. For medical-grade resin or photosensitive 3D resin, 1.2 mm is recommended; for metal, 0.5 mm is recommended. This design allows the drill bit to pass smoothly through the guide sleeve while limiting its radial oscillation within the sleeve and ensuring sufficient structural strength.

[0042] For pre-drilling of the fixed lateral bone segment, the distance from the depth-limiting structure to the drill bit tip is... According to the formula It is confirmed that, among them, The effective guide length of the fixed side guide sleeve, To determine the effective length of the orifice within the fixed lateral bone segment, preoperative VSP planning and measurement are used. To ensure sufficient drilling depth margin for the fixed lateral bone segment, the preferred method is... It is 0.5mm; For pre-drilling of free segment of the chin bone, the distance from the depth-limiting structure to the drill bit tip is... According to the formula It is confirmed that, among them, The effective guiding length of the free section guide sleeve, To determine the effective length of the orifice within the free segment of the chin, preoperative VSP planning and measurement were performed. To allow for the drilling depth margin of the free segment of the chin bone, the optimal method is... It is 0.5mm.

[0043] This invention enables the preparation of planned channels using a guide sleeve before mandibular osteotomy, and the use of these channels for PEEK screw fixation after bone block movement. This improves the consistency of preoperative planning with intraoperative transfer, reducing the risk of damage to adjacent tooth roots, mental foramina, inferior alveolar nerve canal, weak cortical bone areas, or other important anatomical structures due to deviation from the planned channels. This system is suitable for chin bone block fixation during genioplasty and can also be extended to other scenarios involving mandibular bone block movement and fixation after osteotomy.

[0044] Example

[0045] This embodiment provides a method for designing and fabricating a PEEK long screw pre-drilling guide system for mandibular bone block fixation, including the following steps: 1. Collect the patient's preoperative CT imaging data and reconstruct a three-dimensional bone model including the chin region of the mandible.

[0046] 2. Determine the chin osteotomy plane and osteotomy line in digital design software, and simulate the forward, backward, upward, downward, rotational or combined movement of the chin bone block to form a virtual mandibular bone block fixation scheme.

[0047] 3. Plan the fixation path for three PEEK screws based on the target location of the moved chin bone block. One screw corresponds to the midline region of the chin, and the other two correspond to the left and right lateral regions respectively. The path of each PEEK screw avoids tooth roots, mental foramina, inferior alveolar nerve canal, areas of weak cortical bone, and the edge of the osteotomy line, while meeting the requirements for fixation length and bone volume.

[0048] 4. Design a personalized mandibular bone fixation guide plate according to the patient's chin bone surface morphology, so that the mandibular bone fixation guide plate has a bone surface fitting and positioning surface that matches the chin or anterior mandibular bone surface.

[0049] 5. Set an osteotomy guide structure on the mandibular bone block fixation guide plate so that it corresponds to the preoperatively planned chin osteotomy line.

[0050] 6. Three guide sleeves are provided on the mandibular bone fixation guide plate, and the axis of the guide channel of each guide sleeve is aligned with the axis of the pre-set channel of the corresponding PEEK screw. Preferably, the guide sleeves are integrally formed with the mandibular bone fixation guide plate.

[0051] 7. The mandibular bone block fixation guide plate model is 3D printed using medical resin or photosensitive resin, or processed using medical materials such as titanium alloy, and then post-processed, cleaned, disinfected and sterilized, and preoperative adaptation examination is performed.

[0052] 9. After exposing the chin bone surface during the operation, the mandibular bone fixation guide plate is attached to the bone surface and the position is confirmed to be stable. If necessary, the mandibular bone fixation guide plate is fixed through temporary fixation holes.

[0053] 10. Before osteotomy, the drill bit passes through the guide sleeve in sequence to form the pre-set channels for the centerline and the left and right PEEK long nails under the restriction of the depth limiting ring.

[0054] 11. After completing the preparation of the channel, perform chin osteotomy according to the osteotomy guide structure on the mandibular bone block fixation guide plate.

[0055] 12. Move the removed chin bone fragment to the pre-planned position so that the pre-prepared channels made before osteotomy correspond to the fixation path after the bone fragment is moved.

[0056] 13. Screw in three PEEK screws in sequence to connect and fix the moved chin bone fragment to the fixed mandibular bone segment. After fixation, check the position of the bone fragment and the stability of the fixation.

[0057] This invention provides a pre-drilled guide device for PEEK long screw fixation of the mandibular bone fragment and its design and fabrication method. The device is personalized based on the patient's preoperative imaging data and virtual surgical planning. By setting a guide sleeve on the mandibular bone fragment fixation guide plate that matches the pre-set PEEK long screw implantation path, precise control of the drilling direction, implantation position, and implantation depth of the PEEK long screw is achieved. This device has advantages such as good biocompatibility, excellent mechanical properties, and no imaging artifacts, reducing the impact of metal artifacts on postoperative imaging evaluation. It simplifies the surgical procedure, improves surgical safety and repeatability, and achieves significant clinical application value while reducing consumable costs.

[0058] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A PEEK long screw pre-drilling guide system for mandibular bone block fixation, characterized in that, include: The mandibular bone block fixation guide plate, the osteotomy guide structure set on the mandibular bone block fixation guide plate, at least four pre-set channels set on the mandibular bone block fixation guide plate, the guide sleeve set in the pre-set channels, and the PEEK long screw that cooperates with the guide sleeve. The mandibular bone fixation guide plate is used to conform to the exposed bone surface of the patient's mandible; the osteotomy guide structure is used to guide or indicate the position of mandibular osteotomy; the guide sleeve is inserted into a preset channel; and the PEEK long nail is used to fix the bone block along the guide sleeve after the mandibular bone block is moved.

2. The PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 1, characterized in that, It also includes a depth-limiting structure, which is fitted onto the drill bit to limit the depth to which the drill bit enters the bone.

3. A method for designing and fabricating a PEEK long screw pre-drilling guide system for mandibular bone fixation, characterized in that, Includes the following steps: Step S1: Obtain CT image data of the patient's maxillofacial region and reconstruct a three-dimensional model including the area of ​​the mandible to be osteotomized and adjacent anatomical structures. Step S2: Based on the patient's local mandibular morphology, facial improvement goals, and clinical plan, a virtual mandibular bone block fixation design is performed, determining the osteotomy plane, osteotomy line, bone block movement direction, movement distance, and target position. Step S3: Plan the PEEK screw fixation path based on the target position after the bone block is moved; Step S4: When planning the fixation path, avoid tooth roots, mental foramina, inferior alveolar nerve canal, areas of weak bone cortex, and the edge of osteotomy line, so that the long screw can connect the moving bone block and the fixed bone segment after the bone block is moved; Step S7: Generate the bone surface fitting and positioning surface of the personalized mandibular bone block fixation guide plate, and form an osteotomy guide structure on the mandibular bone block fixation guide plate to guide the bone saw cutting. Step S8: Generate a guide sleeve on the mandibular bone block fixation guide plate based on the PEEK long nail, so that the inlet position, outlet position and axial direction of the guide sleeve correspond to the planned channel; determine the PEEK long nail parameters based on the amount of movement of the chin bone block, and complete the design of the axial direction, inner diameter of the sleeve, axial length and outer diameter; Step S9: The digital model of the mandibular bone fixation guide plate is made into a mandibular bone fixation guide plate through 3D printing, cutting, or other medical processing methods, and then post-processed, cleaned, disinfected and sterilized, and preoperative adaptation examination is performed.

4. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 3, characterized in that, In step S3, the PEEK pin fixing path includes the number of pins, entry point, axial direction, length, expected entry depth, and channel space trajectory.

5. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 4, characterized in that, It also includes step S10, setting a depth limiting structure and fitting it onto the drill bit; the depth limiting structure can move along the drill bit axis and be fixed at a preset position. When the drill bit is advanced along the guide sleeve to the preset depth, the depth limiting structure abuts against the proximal end face of the guide sleeve, thereby limiting the drill bit from continuing to penetrate into the bone tissue.

6. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 5, characterized in that, Length of a single PEEK spike Based on the preoperative virtual surgical plan, the details are as follows: Obtain the proximal entry point of the PEEK spike. Distal fixation points before chin segment repositioning and the three-dimensional movement vector of the chin segment. After the chin segment is moved, the planned location of the distal fixation point is as follows: The design length of a single PEEK spike is based on the formula. Calculation, where For safety margin, the clinical setting is 2mm.

7. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 6, characterized in that, The design length of the PEEK spikes must also meet safety constraints: ,in This is the distance along the path of the spike from the point of entry to the nearest dangerous anatomical structure. Maintain safe distance.

8. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 7, characterized in that, Effective guide length of guide sleeve The determination is based on the fit clearance between the drill bit and the sleeve, the effective intraosseous path length of the PEEK screw, and the allowable distal lateral deviation, as follows: The effective guiding length of the guide sleeve is calculated according to the formula. Calculate, where, The diameter gap between the sleeve and the drill bit. The effective intraosseous path length of the PEEK screw from the entry point to the distal fixation point. For the allowable distal lateral deviation, Tolerances for sleeve machining and operation.

9. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 8, characterized in that, The inner and outer diameters of the guide sleeve are determined based on the outer diameter of the pre-drilled drill bit, the fitting clearance, and the sleeve wall thickness, as follows: inner diameter of guide sleeve Determine according to the following formula: in, The inner diameter of the guide sleeve, The outer diameter of the pre-drilling drill bit. This refers to the one-sided clearance between the outer wall of the drill bit and the inner wall of the guide sleeve. outer diameter of guide sleeve Determine according to the following formula: in, The outer diameter of the guide sleeve, The thickness of one side of the guide sleeve.

10. The design and fabrication method of a PEEK long screw pre-drilling guide system for mandibular bone block fixation as described in claim 9, characterized in that, For pre-drilling of the fixed lateral bone segment, the distance from the depth-limiting structure to the drill bit tip is... According to the formula It is confirmed that, among them, The effective guide length of the fixed side guide sleeve, To plan the effective length of the orifice within the fixed lateral bone segment, Allowance for drilling depth to fix the lateral bone segment; For pre-drilling of free segment of the chin bone, the distance from the depth-limiting structure to the drill bit tip is... According to the formula It is confirmed that, among them, The effective guiding length of the free section guide sleeve, To plan the effective channel length within the free segment of the chin bone, This is the allowance for drilling depth of the free segment of the chin bone.

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