A stent for repairing oral and maxillofacial bone defects

Abstract

The present invention belongs to the field of biomedical tissue engineering technology. In order to solve the technical problem that the existing stents for repairing oral and maxillofacial bone defects do not have corresponding fixing components, the stability of the stent is insufficient in the early stage of bone recovery, and the stent may be offset and dislocated due to the patient's movement during the recovery process, thereby affecting the subsequent recovery quality, the present invention provides a stent for repairing oral and maxillofacial bone defects, including a stent body, which is arranged at the defect site of the oral and maxillofacial bone, and the stent body and the defect site cooperate with each other; the stent body and the defect site of the oral and maxillofacial bone are fixed by a fixing mechanism. The present invention can achieve fixation of a filling unit to the oral and maxillofacial bone through the design of the fixing mechanism, thereby improving the stability of the filling unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedical tissue engineering, and in particular relates to a scaffold for repairing oral and maxillofacial bone defects. Background Art

[0002] The restoration of oral and maxillofacial bone defects caused by cleft lip and palate, congenital malformations, tooth extraction, tumor resection, or trauma is often affected by local and systemic pathological conditions. For example, periodontitis is a chronic inflammatory disease that can lead to inflammatory bone resorption, altering alveolar bone structure and damaging tooth-supporting tissues, resulting in severe periodontal infection and delayed bone healing at extraction sites. The healing pattern of the alveolar ridge is more complex and unpredictable than that of healthy teeth. Diabetes mellitus, characterized by chronic hyperglycemia caused by insufficient insulin secretion or utilization, can lead to delayed healing of extraction sockets and impaired osseointegration of implants. These pathological conditions often result in the failure of oral and maxillofacial bone defects to heal, causing chewing difficulties, aesthetic issues, and speech impairments. Therefore, effectively restoring oral and maxillofacial bone defects with intact function and aesthetics is crucial for maintaining the patient's physical and mental health and remains a challenge for oral surgeons. Traditional bone restoration typically utilizes autologous bone grafts. However, limited donor tissue availability, unavoidable additional surgery, and variable bone graft survival limit their practical application in clinical practice.

[0003] The rise of tissue engineering technology in recent decades has provided a promising alternative approach for repairing oral and maxillofacial bone defects. Tissue-engineered bone constructed using tissue engineering techniques involves seed cells, scaffold materials, and osteoinductive factors. Despite significant progress, this field still faces numerous challenges, including selecting appropriate seed cells, growth factors, scaffolds, and retention of the engineered bone, ensuring high engraftment rates, and ensuring long-term durability of the engineered tissue. The cell division capacity and undisputed potential for differentiation of seed cells play a crucial role in this tissue engineering process. Insulin is a hormone that primarily influences glucose homeostasis and is crucial for numerous biological functions, such as normal energy storage, cell growth, proliferation, and differentiation, through direct signaling through the insulin pathway. Accumulating evidence indicates that insulin acts as a growth regulator both in vitro and in vivo, stimulating the growth and proliferation of a range of cell types, including somatic cells, osteoblasts, osteoblast lineage cells, and stem cells. Furthermore, insulin is increasingly recognized as an osteoinductive agent. In vivo, insulin treatment improves skeletal abnormalities in rodents with type 1 diabetes and promotes fracture healing and tooth extraction socket healing in diabetic rabbits. In vitro, insulin enhances alkaline phosphatase (ALP) activity, type I collagen (COL-1) secretion, osteocalcin (OCN) gene expression, and mineralized nodule formation in MG-63 cells. It also promotes the osteogenic differentiation of MC3T3-E1 cells under high glucose conditions. Oral and maxillofacial bone marrow-derived mesenchymal stem cells (MSCs) play an important role in oral and maxillofacial bone healing and regeneration. Previous studies have demonstrated that insulin can promote the proliferation and osteogenic differentiation of alveolar bone marrow-derived mesenchymal stem cells (ABM-MSCs) cultured in vitro, as well as promote osteogenesis and angiogenesis of ABM-MSCs in vivo. Insulin-induced osteogenic differentiation of ABM-MSCs is dependent on insulin / mTOR signaling, suggesting that insulin has a direct anabolic effect on MSCs, potentially facilitating the repair of oral and maxillofacial bone defects.

[0004] The function of tissues and organs depends on the behavior of cells. Scaffolds play a vital role in maintaining high cell density and supporting cell proliferation and differentiation to simulate physiological conditions. They also play a crucial role in providing the nutritional factors necessary to repair bone defects. Scaffold materials determine the shape of the regenerated tissue, which is of great significance for the repair of maxillofacial bone defects, which require high aesthetic and functional requirements. Autologous bone grafts cannot be tailored to the patient's condition and are difficult to process into a shape that fits the bone defect, which is also a significant issue in the maxillofacial region.

[0005] Currently, commonly used tissue engineering bone scaffold materials are mainly divided into two categories: biodegradable natural materials and biodegradable synthetic materials. Biodegradable natural polymers (such as collagen and chitosan) have poor strength and processing properties, and their degradation rate cannot be adjusted. Biodegradable natural inorganic materials (such as coral) are hard, lack flexibility, and are difficult to shape. Degradable synthetic polymers (such as polylactic acid and polyglycolic acid) produce degradation products that can easily cause local aseptic inflammation. Biodegradable synthetic inorganic materials (such as calcium carbonate cement, tricalcium phosphate (TCP), hydroxyapatite (HA), and bioactive ceramics) are relatively fragile and lack biomechanical strength. Biodegradable synthetic composites (such as TCP / HA, HA / coral, and nanohydroxyapatite / collagen) are often considered ideal bone repair materials because their absorption and bone formation rates are more closely aligned, their biomechanical properties are closer to bone tissue, and their osteogenesis-enhancing effects are significantly improved compared to single materials. Nano-hydroxyapatite / collagen (nHAC) is a ceramic / polymer composite designed to mimic the nano- to micro-scale hierarchical structure of natural cancellous bone. Due to its low inflammatory response, good cytocompatibility, biodegradability, and ability to regulate cell growth and differentiation, nHAC is considered an ideal bone scaffold for tissue engineering. It can be personalized using digital reconstruction and rapid prototyping techniques based on the size of the bone defect. Studies have shown that personalized nHAC was used to repair skull defects in 13 children, with good results during postoperative follow-up. Previous studies have also demonstrated that dental stem cells can effectively adhere, proliferate, and differentiate on nHAC scaffolds, promoting the repair of mandibular defects in rabbits.

[0006] The scaffold material is transplanted into the bone defect site. The stability of the scaffold is particularly important in the early stage of bone recovery. If the scaffold is not firmly fixed and easily shifted and dislocated, it will not only affect the quality of bone regeneration, but also the function and appearance of the bone after formation.

[0007] The utility model patent with publication number CN206342720U discloses a degradable stent for repairing oral and maxillofacial bone defects. Although this patent sets the material of the stent body to a magnesium alloy stent material, which enables the magnesium alloy stent material to release magnesium ions during the degradation process, and magnesium ions can promote the proliferation and differentiation of osteoblasts after entering the human body, which is beneficial to the formation and mineralization of new bone and promotes the healing of maxillofacial bone defects, the degradable stent for repairing oral and maxillofacial bone defects still has defects during use. The stent is not provided with a corresponding fixing component. In the early stage of bone recovery, the stability of the stent is insufficient. During the recovery process, the stent may be offset and dislocated due to the patient's movement, thereby affecting the subsequent recovery quality. Over time, it may also have a negative impact on the temporomandibular joint, causing pain, bite problems or other temporomandibular joint disorders.

[0008] The invention patent with publication number CN118078501A discloses a degradable scaffold for repairing oral and maxillofacial bone defects, comprising: oral and maxillofacial bones, the oral and maxillofacial bones including a defect site, a vertical positioning shallow hole being opened at the bottom of the defect site, and a horizontal positioning shallow hole being opened on the side of the defect site; a filling structure, the filling structure being located inside the defect site, and the filling structure and the defect site being used in conjunction with each other; a stabilizing structure, the stabilizing structure being fixedly mounted on the oral and maxillofacial bones, and the stabilizing structure limiting the filling structure, although the above technical solution can fill the defect site by setting the filling structure, and limit the filling structure by the stabilizing structure, thereby improving the stability of the filling structure. However, the vertical outer bonding plate and the vertical inner bonding plate in the above technical solution can only limit the middle part of the filling structure, so that the two sides of the filling structure may not be able to fit better with the defective part, and screws need to be passed horizontally through the oral and maxillofacial bones to fix the vertical outer bonding plate and the vertical inner bonding plate in the middle, which increases the patient's pain; at the same time, the above technical solution needs to make the end of the horizontal positioning shallow column away from the limiting baffle pass through the connecting through hole and be inserted into the inside of the corresponding horizontal positioning shallow hole, and then the extrusion block needs to be inserted into the inside of the accommodating cavity to achieve the fixation of the filling structure and the oral and maxillofacial bones. Not only is the operation cumbersome, but also the difficulty of the operation is increased because people need to manually perform the above operations. Summary of the Invention

[0009] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a stent for repairing oral and maxillofacial bone defects.

[0010] To achieve the above object, the technical solution adopted by the present invention is:

[0011] A stent for repairing oral and maxillofacial bone defects comprises a stent body, which is arranged at the defect site of the oral and maxillofacial bone and is used in conjunction with the defect site.

[0012] The bracket body is fixed to the defective part of the oral and maxillofacial bones through a fixing mechanism.

[0013] Preferably, the bracket body includes a filling unit adapted to the defective part, a first mounting groove is opened in the middle of the top of the filling unit, a mounting film is provided on the top of the first mounting groove, two second mounting grooves are symmetrically opened on both sides of the filling unit, the bottom of the first mounting groove is connected with the two second mounting grooves, a fixing column is provided in the middle of the bottom of the filling unit, the fixing column is plugged into the third mounting groove opened on the bottom of the defective part, movable rods are respectively placed in the two second mounting grooves, two fourth mounting grooves are symmetrically opened on the two side walls of the defective part, and each movable rod is respectively plugged into the fourth mounting groove on the same side.

[0014] Preferably, the fixing mechanism includes an arc-shaped fitting plate and two limiting units. The arc-shaped fitting plate is arranged on the top of the filling unit. A first through hole is opened in the middle of the arc-shaped fitting plate. An extrusion rod is arranged in the first through hole. The bottom of the extrusion rod passes through the mounting film and is connected to the first mounting groove. The two limiting units are symmetrically arranged on the left and rear sides of the arc-shaped fitting plate, and each limiting unit is respectively in contact with the oral and maxillofacial bones and the filling unit.

[0015] Preferably, each limiting unit includes a vertical outer bonding plate and a vertical inner bonding plate, which are vertically symmetrically arranged on the front and rear sides of the arc-shaped bonding plate, respectively, and the vertical outer bonding plate is located on the outside of the oral and maxillofacial bones and the filling unit, the vertical inner bonding plate is located on the inside of the oral and maxillofacial bones and the filling unit, and the bottom of the arc-shaped bonding plate is connected to the top of the oral and maxillofacial bones and the filling unit.

[0016] Preferably, two second through holes are symmetrically provided on both sides of the top of the arc-shaped bonding plate, and two boss through holes are symmetrically provided on both sides of the bottom of the arc-shaped bonding plate, each boss through hole is connected to the corresponding second through hole above, and two fifth mounting grooves are provided on the top of the oral and maxillofacial bone, and the two fifth mounting grooves are respectively located on both sides of the defective part, and the arc-shaped bonding plate is fixed to the fifth mounting groove on the oral and maxillofacial bone by screws passing through the second through holes and the boss through holes in sequence.

[0017] Preferably, a first limiting fitting mechanism and a second limiting fitting mechanism are respectively provided between the two vertical outer fitting plates and between the two vertical inner fitting plates. The first limiting fitting mechanism and the second limiting fitting mechanism have the same structure, and the first limiting fitting mechanism is connected to the two vertical outer fitting plates, and the second limiting fitting mechanism is connected to the two vertical inner fitting plates.

[0018] Preferably, the first limiting fitting mechanism includes an arc-shaped limiting fixing plate, two sliding grooves, two sliding plates, two third through holes, two fixing screws and two threaded holes. The two sliding grooves are symmetrically opened on the adjacent side surfaces of the two vertical outer fitting plates, and the two sliding plates are symmetrically arranged on the two ends of the arc-shaped limiting fixing plate. The two sliding plates are slidably connected to the corresponding sliding grooves, and the two third through holes are symmetrically opened on both sides of the top of the arc-shaped fitting plate. Two threaded holes are respectively opened on the two sliding plates, and each threaded hole is located directly below the third through hole on the same side. Each fixing screw passes through the corresponding third through hole and threaded hole to fix the arc-shaped limiting fixing plate and the arc-shaped fitting plate.

[0019] The present invention also provides a method for installing the above-mentioned bracket for repairing oral and maxillofacial bone defects, comprising the following steps:

[0020] S1. Place the filling unit at the defect site of the oral and maxillofacial bone, so that the fixing column is plugged into the third mounting slot provided on the bottom of the defect site. The two movable rods are completely located within the corresponding second mounting slots, and the filling unit is in contact with both side surfaces and the lower surface of the defect site, and the filling unit is flush with the top plane of the oral and maxillofacial bone.

[0021] S2. Move the two vertical outer laminating plates and the two vertical inner laminating plates downward along the outer and inner sides of the filling unit and the oral and maxillofacial bones, respectively, until the bottom of the curved laminating plates abuts against the oral and maxillofacial bones and the top of the filling unit. The curved laminating plates, the vertical outer laminating plates, and the vertical inner laminating plates are used to position the filling unit, thereby achieving preliminary fixation of the filling unit and the oral and maxillofacial bones.

[0022] S3. Push the extrusion rod downward. The extrusion rod passes through the first through-hole and the mounting film and enters the interior of the first mounting groove. As the extrusion rod continues to move downward, the two movable rods are respectively pushed out of the second mounting groove by the downward pressure in the first mounting groove and inserted into the corresponding fourth mounting groove. When the extrusion rod is completely inserted into the first through-hole, the end of the movable rod contacts the bottom of the fourth mounting groove, thereby limiting the filling unit and the oral and maxillofacial bones.

[0023] S4. Twist the screw downward, and the screw gradually penetrates the fifth mounting slot along the boss through-hole and the fifth mounting slot into the oral and maxillofacial bone. Then, the lower end of the screw penetrates the movable rod to secure the movable rod, thereby securing the filling unit to the oral and maxillofacial bone.

[0024] S5. Simultaneously rotate the two fixing screws on the first limiting fitting mechanism. As the fixing screws rotate, the arc-shaped limiting fixing plate moves downward along the sliding groove through the sliding plate. When the arc-shaped limiting fixing plate moves to the outer side of the oral and maxillofacial bone at the lower half, stop rotating the fixing screws, and use the arc-shaped limiting fixing plate to limit and fix the bottom of the outer side of the filling unit and the outer side of the oral and maxillofacial bone; then simultaneously rotate the two fixing screws on the second limiting fitting mechanism. As the fixing screws rotate, the arc-shaped limiting fixing plate moves downward along the sliding groove through the sliding plate. When the arc-shaped limiting fixing plate moves to the inner side of the oral and maxillofacial bone at the lower half, stop rotating the fixing screws, and use the arc-shaped limiting fixing plate to limit and fix the bottom of the inner side of the filling unit and the inner side of the oral and maxillofacial bone.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention can fill the defect by providing a stent body made of a degradable material, and the filling unit is not easy to fall off after filling, thereby greatly improving the quality of filling;

[0027] (2) The present invention can limit the filling unit in all directions by placing the arc-shaped bonding plate, the vertical outer bonding plate and the vertical inner bonding plate on the top, the outer side and the inner side of the oral and maxillofacial bones respectively;

[0028] (3) The present invention can fix the two sides of the filling unit to the oral and maxillofacial bones respectively through the design of two limiting units, and better limit the filling unit, so that the filling unit can achieve a better fit with the defect part, which is beneficial to the later defect repair, and solves the technical problem that the existing bracket only limits the middle part of the filling unit, so that the two sides of the filling unit 4 cannot achieve a better fit with the defect part; and the present invention can directly clamp the filling unit and the oral and maxillofacial bones at the same time by arranging the limiting units on both sides, so that there is no need to use screws to pass through the oral and maxillofacial bones horizontally and then limit the limiting unit in the middle, which reduces the pain of the patient;

[0029] (4) The present invention can achieve fixation of the filling unit to the oral and maxillofacial bones through the design of the extrusion rod, connecting rod, fixing column and screw, thereby improving the stability of the filling unit;

[0030] (5) The present invention, through the combined design of the extrusion rod, the mounting film, and the second mounting groove and the fourth mounting groove, can achieve the fixation of both sides of the filling unit to the oral and maxillofacial bones by only one step of pushing the extrusion rod downward and utilizing the air pressure of the downward push. The operation is simple and convenient, and simplifies the operation of the existing bracket, which requires the horizontal positioning shallow column away from the limit baffle to pass through the connecting through hole and be inserted into the corresponding horizontal positioning shallow hole, and then the extrusion block needs to be inserted into the interior of the accommodating cavity, thereby avoiding cumbersome operation. Moreover, the present invention only needs to push the extrusion rod, and does not need to manually move the horizontal positioning shallow column into the horizontal positioning shallow hole, and then manually insert the extrusion block into the interior of the accommodating cavity, thereby reducing the difficulty of operation and facilitating clinical operation and use.

[0031] (6) The present invention can limit and fix the bottom of the outer side surface and the bottom of the inner side surface of the filling unit respectively through the design of the first limiting fitting mechanism and the second limiting fitting mechanism, thereby improving the fixing stability of the filling unit. In addition, the present invention can use the arc-shaped limiting fixing plate to move downward on the filling unit simply by rotating the fixing screw, so that the filling unit can be better fitted with the defective part, thereby improving the repair effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of a stent for repairing oral and maxillofacial bone defects provided in Example 1 of the present invention;

[0033] Figure 2This is an exploded view of the stent for repairing oral and maxillofacial bone defects provided in Example 1 of the present invention;

[0034] Figure 3 This is a schematic structural diagram of the stent for repairing oral and maxillofacial bone defects provided in Example 1 of the present invention with the screws removed;

[0035] Figure 4 This is a schematic structural diagram of the stent for repairing oral and maxillofacial bone defects provided in Example 1 of the present invention, with the fixing mechanism removed;

[0036] Figure 5 Schematic diagram of the structure of the oral and maxillofacial bones and defect site in Example 1 of the present invention;

[0037] Figure 6 Schematic diagram of the structure of the filling unit in Example 1 of the present invention;

[0038] Figure 7 Schematic diagram of the structure of the fixing mechanism in Example 1 of the present invention;

[0039] Figure 8 This is a schematic diagram of the connection structure between the fixing mechanism and the filling unit in Example 1 of the present invention;

[0040] Figure 9 Schematic diagram of the connection structure between the fixing mechanism and the movable rod in Example 1 of the present invention;

[0041] Figure 10 A schematic structural diagram of a stent for repairing oral and maxillofacial bone defects provided in Example 2 of the present invention;

[0042] Figure 11 Schematic diagram of the connection structure of the fixing mechanism, the first position-limiting and fitting mechanism, the second position-limiting and fitting mechanism, and the movable rod in Example 2 of the present invention;

[0043] Figure 12 Schematic diagram of the structure of the first position-limiting and laminating mechanism in Example 2 of the present invention;

[0044] In the figure: 1. oral and maxillofacial bone; 2. defect site; 3. fixing mechanism; 4. filling unit; 5. first mounting slot; 6. mounting membrane; 7. second mounting slot; 8. fixing column; 9. third mounting slot; 10. movable rod; 11. fourth mounting slot; 12. arc-shaped laminating plate; 13. limiting unit; 14. first through hole; 15. extrusion rod; 16. vertical outer laminating plate; 17. vertical inner laminating plate; 18. second through hole; 19. boss through hole; 20. fifth mounting slot; 21. screw; 22. arc-shaped limiting fixing plate; 23. sliding slot; 24. sliding plate; 25. third through hole; 26. fixing screw; 27. threaded hole. DETAILED DESCRIPTION

[0045] The following is a diagram of the embodiment of the present invention. Figures 1 to 12 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. Example 1

[0046] like Figures 1 to 9 As shown, an embodiment of the present invention provides a stent for repairing oral and maxillofacial bone defects. The stent body is disposed at a defect site 2 of an oral and maxillofacial bone 1, and the stent body and the defect site 2 cooperate with each other. The stent body and the defect site 2 are fixed by a fixing mechanism 3. In this embodiment of the present invention, all components of the fixing mechanism 3 are made of magnesium alloy, and the fixing column 8 and the movable rod 10 in the filling unit 4 are also made of magnesium alloy. Magnesium alloy has a certain strength and stability. This material setting not only provides a certain degree of fixation and protection for the filling unit 4 during the initial recovery process, ensuring the quality of bone recovery, but also, during the bone recovery process, as the fixing mechanism, fixing column 8, and movable rod 10 degrade, the magnesium ions decomposed therefrom can be absorbed by bone cells, promoting bone growth. At the same time, bone expands under the interaction of the stent body and its loaded osteoinductive factors with the bone defect microenvironment, thereby gradually replacing the stent body, ultimately completing bone recovery. The degradation rate of the stent body can be adjusted according to the patient's needs and the progress of bone healing, thereby ensuring a match between degradation and recovery. The degradable stent body and the fixing mechanism 3 made of magnesium alloy do not require a second operation to remove, which reduces the pain of the patient and effectively prevents the occurrence of secondary injuries caused by the operation.

[0047] In the embodiment of the present invention, the bracket body includes a filling unit 4 adapted to the defective part 2, a first mounting groove 5 is provided in the middle of the top of the filling unit 4, a mounting film 6 is provided on the top of the first mounting groove 5, and the mounting film 6 is used to close the first mounting groove 5. Two second mounting grooves 7 are symmetrically provided on both sides of the filling unit 4, and the bottom of the first mounting groove 5 is connected to the two second mounting grooves 7. The design of the connection between the first mounting groove 5 and the two second mounting grooves 7 facilitates the extrusion rod 15 to move downward in the first mounting groove 5, and facilitates the air pressure in the first mounting groove 5 to the two second mounting grooves 7. The filling unit 4 flows in the direction of the mounting groove 7; thereby facilitating the pushing out of the two movable rods 10 from their respective second mounting grooves 7; a fixing column 8 is provided in the middle of the bottom of the filling unit 4, and the fixing column 8 is plugged into the third mounting groove 9 opened on the bottom of the defective part 2. Through the design of the fixing column 8 and the third mounting groove 9, the filling unit 4 can be limited to achieve preliminary positioning with the defective part 2; movable rods 10 are respectively placed in the two second mounting grooves 7, and two fourth mounting grooves 11 are symmetrically opened on the two side walls of the defective part 2, and each movable rod 10 is respectively plugged into the fourth mounting groove 11 on the same side. In the specific design, a certain volume of inert gas can be filled into the first mounting groove 5. After the filling is completed, the notch of the first mounting groove 5 is immediately sealed by the mounting membrane 6, so that there is a certain air pressure between the first mounting groove 5 and the two second mounting grooves 7. As a result, when the extrusion rod 15 passes through the mounting membrane 6 and enters the first mounting groove 5 downward, the two movable rods 10 are pushed out of the second mounting groove 7 respectively by the air pressure in the first mounting groove 5 and inserted into the corresponding fourth mounting groove 11 on the same side, thereby further fixing the two sides of the filling unit 4 to the oral and maxillofacial bone 1. When the extrusion rod 15 completely enters the first through hole 14 (that is, the upper surface of the extrusion rod 15 is flush with the upper surface of the arc-shaped bonding plate 12), the end of the movable rod 10 contacts the bottom of the fourth mounting groove 11. That is, the present invention can fix the two sides of the filling unit 4 to the oral and maxillofacial bone 1 by simply pushing the extrusion rod 15 downward and utilizing the downward pushing air pressure, which is easy to operate.

[0048] In an embodiment of the present invention, the fixing mechanism 3 includes an arc-shaped bonding plate 12 and two limiting units 13. The arc-shaped bonding plate 12 is arranged on the top of the filling unit 4. A first through hole 14 is opened in the middle of the arc-shaped bonding plate 12. An extrusion rod 15 is arranged in the first through hole 14. The extrusion rod 15 is connected to the first through hole 14 by friction. The bottom of the extrusion rod 14 can pass through the mounting film 6 and be connected to the first mounting groove 5. The two limiting units 13 are symmetrically arranged on the left and rear sides of the arc-shaped bonding plate 12, and each limiting unit 13 is respectively in contact with the oral and maxillofacial bone 1 and the filling unit 4.

[0049] In the embodiment of the present invention, each limiting unit 13 includes a vertical outer bonding plate 16 and a vertical inner bonding plate 17. The vertical outer bonding plate 16 and the vertical inner bonding plate 17 are respectively arranged vertically symmetrically on the front side and the back side of the arc-shaped bonding plate 12, and the vertical outer bonding plate 16 is located on the outside of the oral and maxillofacial bone 1 and the filling unit 4, and the vertical inner bonding plate 17 is located on the inside of the oral and maxillofacial bone 1 and the filling unit 4, and the bottom of the arc-shaped bonding plate 12 is connected to the top of the oral and maxillofacial bone 1 and the filling unit 4. In the embodiment of the present invention, the vertical outer bonding plate 16 and the vertical inner bonding plate are both strip-shaped plates with a certain curvature that can fit the oral and maxillofacial bone 1 and the filling unit 4. Through the joint design of the vertical outer bonding plate 16 and the vertical inner bonding plate 17, the vertical outer bonding plate 16 and the vertical inner bonding plate 17 can be used to perform lateral two-way limiting on the filling unit 4, thereby improving the stability of the fixing of the filling unit 4. Moreover, the present invention uses two limiting units 13 to simultaneously clamp and limit the two sides of the filling unit 4 and the oral and maxillofacial bone 1, which not only can achieve the initial limiting fixation of the filling unit 4 and the oral and maxillofacial bone 1, but also can maintain a good fit with the defective part, thereby facilitating the smooth implementation of subsequent fixation.

[0050] In an embodiment of the present invention, two second through holes 18 are symmetrically provided on both sides of the top of the arc-shaped bonding plate 12, and two boss through holes 19 are symmetrically provided on both sides of the bottom of the arc-shaped bonding plate 12. Each boss through hole 19 is respectively connected to the corresponding second through hole 18 above, and each boss through hole 19 can be inserted into the corresponding fifth mounting groove 20. Through the design of the boss through hole 19 and the fifth mounting groove 20, the screw 21 can be guided so that when the screw 21 is screwed downward, the screw 21 can gradually penetrate the fifth mounting groove 20 along the boss through hole 19 and the fifth mounting groove 20 and enter the oral and maxillofacial bone 1, and the lower end of the screw 21 can penetrate the movable rod 10, thereby fixing the movable rod 10, and then achieving firm fixation of the filling unit 4 and the oral and maxillofacial bone 1. Two fifth mounting grooves 20 are provided on the top of the oral and maxillofacial bone 1, and the two fifth mounting grooves 20 are respectively located on both sides of the defective part 2. The arc-shaped fitting plate 12 is fixed to the movable rod 10 and the oral and maxillofacial bone 1 by screws 21 passing through the second through hole 18, the boss through hole 19, the fifth mounting groove 20 in sequence. Example 2

[0051] like Figures 10 to 12As shown, the structure of the stent for repairing oral and maxillofacial bone defects provided in the embodiment of the present invention is the same as that of the stent for repairing oral and maxillofacial bone defects provided in the embodiment, with the only difference being that a first limiting and second limiting fitting mechanism is provided between the two vertical outer bonding plates 16 and between the two vertical inner bonding plates 17 in the embodiment of the present invention, respectively. The first limiting and second limiting fitting mechanisms have the same structure, and the first limiting and second limiting fitting mechanisms are connected to the two vertical outer bonding plates 16, and the second limiting and second limiting fitting mechanisms are connected to the two vertical inner bonding plates 17. In order to ensure that the filling unit 4 can achieve better fit with the defect area 2, the present invention further designs a first limiting and second limiting fitting mechanism to limit and fix the filling unit 4, so that the filling unit 4 can be fully limited. At the same time, the tops of the two vertical outer bonding plates 16 and the two vertical inner bonding plates 17 are connected to form a whole by connecting plates, and the design of the connecting plates realizes the limit fixation of the tops of the outer and inner sides of the filling unit 4.

[0052] In this embodiment of the present invention, the first position-limiting and fitting mechanism comprises an arc-shaped position-limiting and fitting plate 22, two sliding grooves 23, two sliding plates 24, two third through-holes 25, two fixing screws 26, and two threaded holes 27. The two sliding grooves 23 are symmetrically provided on adjacent side surfaces of the two vertical outer fitting plates 16, and the two sliding plates 24 are symmetrically provided at both ends of the arc-shaped position-limiting and fitting plate 22. The two sliding plates 24 are slidably connected to the corresponding sliding grooves 23. The two third through-holes 25 are symmetrically provided on either side of the top of the arc-shaped fitting plate 12, and two threaded holes 27 are provided on the two sliding plates 24, with each threaded hole 27 located directly below the third through-hole 25 on the same side. Each fixing screw 26 passes through the corresponding third through-hole 25 and threaded hole 27 to secure the arc-shaped position-limiting and fitting plate 22 to the arc-shaped fitting plate 12. The two sliding grooves 23 of the second position-limiting and fitting mechanism are symmetrically provided on adjacent side surfaces of the two vertical inner fitting plates 17.

[0053] In the specific design, in the initial state, after each fixing screw passes through the corresponding third through hole 25, it is threadedly connected to the threaded hole below, and the top of the arc-shaped limiting fixing plate 22 contacts the bottom of the connecting plate. When the filling unit 4 is limited and fixed by the arc-shaped bonding plate 12, the vertical outer bonding plate 16 and the vertical inner bonding plate 17, the two arc-shaped limiting fixing plates 22 are respectively located on the outside and inside of the oral and maxillofacial bone 1, and then the two fixing screws 26 on the first limiting bonding mechanism are rotated at the same time. As the fixing screws 26 rotate, the arc-shaped limiting fixing plate 22 moves downward along the sliding groove 23 through the sliding plate 24. When the arc-shaped limiting fixing plate 22 moves to the lower half on the outer side of the oral and maxillofacial bone 1, stop rotating the fixing screws 26, and use the arc-shaped limiting fixing plate 22 to align the bottom of the outer side of the filling unit 4 with the outer side of the oral and maxillofacial bone 1. Perform limiting fixation; then simultaneously rotate the two fixing screws 26 on the second limiting fitting mechanism. As the fixing screws 26 rotate, the arc-shaped limiting fixing plate 22 moves downward along the sliding groove 23 through the sliding plate 24. When the arc-shaped limiting fixing plate 22 moves to the lower half on the inner side of the oral and maxillofacial bone 1, stop rotating the fixing screws 26, and use the arc-shaped limiting fixing plate 22 to limit and fix the bottom of the inner side of the filling unit 4 and the inner side of the oral and maxillofacial bone 1. During the rotation process, keep the rotation speed of each fixing screw 26 the same to ensure that the arc-shaped limiting fixing plate 22 can move from top to bottom along the filling unit 4 until the outer side and the bottom of the inner side of the filling unit 4 are fixed, thereby achieving full-surrounding limiting of the filling unit 4, so that the filling unit 4 can better fit the defective part 2, thereby improving the repair effect.

[0054] The filling unit in the scaffold for repairing oral and maxillofacial bone defects provided by the embodiment of the present invention is designed by the following method:

[0055] When it is necessary to repair the defective part 2 on the oral and maxillofacial bone 1, the doctor first performs a CT scan of the defective part of the oral and maxillofacial bone with more than 16 spiral CT scans, imports the obtained oral and maxillofacial bone image data into the medical reverse software, sets the upper and lower thresholds to select the oral and maxillofacial bones and exclude the surrounding soft tissues, and excludes the bone tissue not connected to the main oral and maxillofacial bones through the region growth operation to obtain a three-dimensional model of the oral and maxillofacial bones; then the three-dimensional model of the oral and maxillofacial bones is imported into the reverse engineering software to create a surface model of the internal repair surface and the external repair surface that match the oral and maxillofacial bone defect; furthermore, the obtained surface model is imported into the digital model carving software for detail processing; thereafter, the surface model after detail processing is imported into the reverse engineering software, the internal repair surface and the external repair surface are sutured into a closed entity to form a restoration model, and the restoration model is subjected to Boolean operation with the three-dimensional model of the oral and maxillofacial bones to make the edge of the restoration model coincide with the defective bone edge; finally, the restoration model is subjected to a mold turning operation to obtain the upper mold and lower mold processing for tool path programming The data is then processed into a 3D solid mold using a five-axis CNC machining center. A nano-hydroxyapatite collagen nHAC solution containing 10-20 mg / ml of insulin is prepared according to the size of the defect and injected into the processed 3D printed mold. The mold and the mixed suspension injected therein are placed in an environment of -20°C for pre-freezing. After the mixed suspension is frozen into a solid, the upper mold is removed and then placed in a freeze dryer for freeze drying until the weight no longer changes. The mold is removed to obtain a filling unit 4. After the filling unit 4 is manufactured, a first mounting groove 5 is opened in the middle of the top of the filling unit 4. A certain volume of inert gas is filled into the first mounting groove 5. After the filling is completed, a mounting film 6 is immediately placed on the top of the first mounting groove 5 to seal the notch of the first mounting groove 5. Two second mounting grooves 7 are symmetrically opened on both sides of the filling unit 4, and the bottom of the first mounting groove 5 is connected to the two second mounting grooves 7. Then, a fixing column 8 is set in the middle of the bottom of the filling unit 4, and a movable rod 10 is placed in each of the two second mounting grooves 7, completing the final preparation of the filling unit 4.

[0056] The working method of the scaffold for repairing oral and maxillofacial bone defects provided by the embodiment of the present invention is as follows:

[0057] Place the prepared filling unit 4 at the defective part 2, so that the fixing column 8 is plugged into the third mounting groove 9 opened on the bottom of the defective part 2. At this time, the two movable rods 10 are completely located inside the corresponding second mounting groove 7, and the filling unit 4 is fitted with the two side surfaces and the lower surface of the defective part 2, and the filling unit 4 is flush with the top plane of the oral and maxillofacial bone 1. Then, the two vertical outer laminating plates 16 and the two vertical inner laminating plates 17 are moved downward along the outer side and the inner side of the filling unit 4 and the oral and maxillofacial bone 1 respectively, until the bottom of the arc-shaped laminating plate 12 abuts against the oral and maxillofacial bone 1 and the top of the filling unit 4, and the arc-shaped laminating plate 17 is fixed to the top of the filling unit 4. The plywood 12, the vertical outer plywood 16 and the vertical inner plywood 17 limit the filling unit 4 to achieve preliminary fixation of the filling unit 4 and the oral and maxillofacial bone 1; then the extrusion rod 14 is pushed downward, the extrusion rod 15 passes through the first through hole 14, and penetrates the mounting film 6, and enters the interior of the first mounting groove 5. As the extrusion rod 15 continues to move downward, the two movable rods 10 are pushed out of the second mounting groove 7 respectively by the downward air pressure in the first mounting groove 5, and inserted into the corresponding fourth mounting groove 11. When the extrusion rod 15 completely enters the first through hole 14, the end of the movable rod 10 conflicts with the bottom of the fourth mounting groove 11. The filling unit 4 and the oral and maxillofacial bone 1 are limited, and then the screw 21 is screwed downward. The screw 21 gradually penetrates the fifth mounting groove 20 along the boss through hole 19 and the fifth mounting groove 20 and enters the oral and maxillofacial bone 1. Then the lower end of the screw 21 penetrates the movable rod 10 to fix the movable rod 10, thereby achieving a firm fixation of the filling unit 4 and the oral and maxillofacial bone 1; then the two fixing screws 26 on the first limiting fitting mechanism are rotated at the same time. As the fixing screws 26 rotate, the arc-shaped limiting fixing plate 22 moves downward along the sliding groove 23 through the sliding plate 24. Wait until the arc-shaped limiting fixing plate 22 moves to the lower half in the oral and maxillofacial position. When the arc-shaped limiting fixing plate 22 is on the outer side of the facial bone 1, stop rotating the fixing screw 26, and use the arc-shaped limiting fixing plate 22 to limit and fix the bottom of the outer side of the filling unit 4 and the outer side of the oral and maxillofacial bone 1; then simultaneously rotate the two fixing screws 26 on the second limiting fitting mechanism. As the fixing screws 26 rotate, the arc-shaped limiting fixing plate 22 moves downward along the sliding groove 23 through the sliding plate 24. When the arc-shaped limiting fixing plate 22 moves to the lower half of the inner side of the oral and maxillofacial bone 1, stop rotating the fixing screw 26, and use the arc-shaped limiting fixing plate 22 to limit and fix the bottom of the inner side of the filling unit 4 and the inner side of the oral and maxillofacial bone 1.

[0058] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A stent for repairing oral and maxillofacial bone defects, characterized in that: The bracket body is arranged at the defective part (2) of the oral and maxillofacial bone (1), and the bracket body and the defective part (2) are used in conjunction with each other; The stent body and the defect part (2) are fixed by a fixing mechanism (3); The bracket body includes a filling unit (4) adapted to the defective part (2), a first mounting groove (5) is provided in the middle of the top of the filling unit (4), a mounting film (6) is provided on the top of the first mounting groove (5), two second mounting grooves (7) are symmetrically provided on both sides of the filling unit (4), the bottom of the first mounting groove (5) is connected to the two second mounting grooves (7), a fixing column (8) is provided in the middle of the bottom of the filling unit (4), the fixing column (8) is plugged into the third mounting groove (9) provided on the bottom of the defective part (2), movable rods (10) are respectively placed in the two second mounting grooves (7), two fourth mounting grooves (11) are symmetrically provided on the two side walls of the defective part (2), and each movable rod (10) is plugged into the fourth mounting groove (11) on the same side; The fixing mechanism (3) comprises an arc-shaped laminating plate (12) and two limiting units (13), wherein the arc-shaped laminating plate (12) is arranged on the top of the filling unit (4), a first through hole (14) is provided in the middle of the arc-shaped laminating plate (12), an extrusion rod (15) is provided in the first through hole (14), the bottom of the extrusion rod (15) passes through the mounting film (6) and is connected to the first mounting groove (5), the two limiting units (13) are symmetrically arranged on the left and rear sides of the arc-shaped laminating plate (12), and each limiting unit (13) abuts against the oral and maxillofacial bone (1) and the filling unit (4), respectively; When the extrusion rod (15) is pushed downward, the extrusion rod (15) passes through the first through hole (14) and the mounting film (6) and enters the interior of the first mounting groove (5). As the extrusion rod (15) continues to move downward, the two movable rods (10) are pushed out of the second mounting groove (7) and inserted into the corresponding fourth mounting groove (11) by the air pressure pushing downward in the first mounting groove (5). When the extrusion rod (15) completely enters the first through hole (14), the end of the movable rod (10) contacts the bottom of the fourth mounting groove (11), thereby achieving the limiting of the filling unit (4) and the oral and maxillofacial bone (1).

2. The stent for repairing oral and maxillofacial bone defects according to claim 1, wherein: Each limiting unit (13) comprises a vertical outer bonding plate (16) and a vertical inner bonding plate (17), the vertical outer bonding plate (16) and the vertical inner bonding plate (17) being vertically symmetrically arranged on the front side and the rear side of the arc-shaped bonding plate (12), respectively, and the vertical outer bonding plate (16) is located on the outside of the oral and maxillofacial bone (1) and the filling unit (4), the vertical inner bonding plate (17) is located on the inside of the oral and maxillofacial bone (1) and the filling unit (4), and the bottom of the arc-shaped bonding plate (12) is connected to the top of the oral and maxillofacial bone (1) and the filling unit (4).

3. The stent for repairing oral and maxillofacial bone defects according to claim 1, wherein: Two second through holes (18) are symmetrically provided on both sides of the top of the arc-shaped bonding plate (12), and two boss through holes (19) are symmetrically provided on both sides of the bottom of the arc-shaped bonding plate (12), and each boss through hole (19) is connected to the corresponding second through hole (18) above. Two fifth mounting grooves (20) are provided on the top of the oral and maxillofacial bone (1), and the two fifth mounting grooves (20) are respectively located on both sides of the defective part (2). The arc-shaped bonding plate (12) is fixed to the fifth mounting groove (20) on the oral and maxillofacial bone (1) by screws (21) passing through the second through hole (18) and the boss through hole (19) in sequence.

4. The stent for repairing oral and maxillofacial bone defects according to claim 2, wherein: A first position-limiting fitting mechanism and a second position-limiting fitting mechanism are respectively provided between the two vertical outer fitting plates (16) and between the two vertical inner fitting plates (17). The first position-limiting fitting mechanism and the second position-limiting fitting mechanism have the same structure, and the first position-limiting fitting mechanism is connected to the two vertical outer fitting plates (16), and the second position-limiting fitting mechanism is connected to the two vertical inner fitting plates (17).

5. The stent for repairing oral and maxillofacial bone defects according to claim 4, characterized in that: The first position limiting and fitting mechanism comprises an arc-shaped position limiting fixing plate (22), two sliding grooves (23), two sliding plates (24), two third through holes (25), two fixing screws (26) and two threaded holes (27). The two sliding grooves (23) are symmetrically arranged on adjacent side surfaces of the two vertical outer fitting plates (16). The two sliding plates (24) are symmetrically arranged on both ends of the arc-shaped position limiting fixing plate (22). The two sliding plates (24) are slidably connected to the corresponding sliding grooves (23). The two third through holes (25) are symmetrically arranged on both sides of the top of the arc-shaped fitting plate (12). The two threaded holes (27) are respectively arranged on the two sliding plates (24), and each threaded hole (27) is located directly below the third through hole (25) on the same side. Each fixing screw (26) passes through the corresponding third through hole (25) and the threaded hole (27) to fix the arc-shaped position limiting fixing plate (22) and the arc-shaped fitting plate (12).

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