Impacted tooth crown cutting and traction integrated tool for inferior alveolar nerve injury risk

Abstract

The invention discloses a crown cutting and traction integrated tool for impacted teeth with inferior alveolar nerve injury risk, which utilizes a telescopic part made of a hydrogel material, has reversible performance of water absorption expansion and dehydration contraction, can realize micro-amplitude reciprocating deformation under the natural water environment change of an oral cavity or humidity control adjustment, and can be used for preventing and treating the impacted teeth with the inferior alveolar nerve injury risk. Therefore, slight stress stimulation in alternating directions is continuously applied to impacted teeth after traction is completed, periodontal ligament activity and an open state of a traction channel are maintained through reciprocating small force action, bridging hard connection between tooth roots and bone tissues is effectively prevented, initial resistance of second-time traction is remarkably reduced, and the secondary traction effect of the impacted teeth is improved. The operation risk of breaking through adhesion tissues again in clinic is reduced, the postoperative nerve traction complications and the tooth root absorption probability are further reduced, and the safety and efficiency of the whole treatment process are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oral medical devices, and particularly relates to a wisdom tooth crown-cutting and traction integrated tool for lower alveolar nerve injury risk. BACKGROUND

[0002] Lower third molar impaction is one of the most common dentition abnormalities in oral clinics, especially when the tooth root is close to or partially wraps around the inferior alveolar nerve canal. There is a high risk of nerve injury during extraction or traction, and the lower third molar impaction is often not suitable for one-time extraction because of its close distance to the inferior alveolar nerve canal. Clinically, the method of crown-cutting and traction is widely used, that is, the wisdom tooth is gradually moved away from the nerve canal by mechanical traction force on the basis of retaining the tooth root, and then the extraction operation is completed at a later date. Considering individual differences, postoperative reactions and nerve avoidance strategies, traction treatment is usually divided into two stages: the first traction slowly moves the tooth root to the target intermediate position, and then enters the traction interval to observe healing and nerve status, and then the second traction is started to complete the final positioning or extraction.

[0003] However, in the fractional traction scheme, the tissue around the tooth root will undergo bone healing and fibrous healing during the traction interval. The response of alveolar bone to traction force gradually disappears, and then direct connection between the tooth root and the bone tissue, i.e., bone healing or dense fibrous adhesion, may occur. This phenomenon makes the tooth root lose physiological micro-motion and enter a functional fixed state, resulting in the displacement effect of the subsequent traction force. At the same time, the bone bridge structure formed during the interval further "locks" the tooth root in the local bone cavity, significantly increasing the technical difficulty and failure risk of the second traction, and may induce complications such as nerve traction, bone fracture or tooth root absorption.

[0004] Therefore, it is necessary to design a wisdom tooth crown-cutting and traction integrated tool for lower alveolar nerve injury risk to solve the above problems. SUMMARY

[0005] The present application overcomes the shortcomings of the prior art and provides a wisdom tooth crown-cutting and traction integrated tool for lower alveolar nerve injury risk.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a wisdom tooth crown-cutting and traction integrated tool for lower alveolar nerve injury risk, comprising: a navigation base plate and a traction anchorage assembly;

[0007] The profile of the navigation base plate matches the anatomical morphology of the crown surface of the target wisdom tooth and its adjacent teeth, and is used for positioning and stabilizing on the dentition during surgery, and the traction anchorage assembly is installed on the jaw;

[0008] The traction anchorage assembly comprises a traction pin, a bracket mounted on one end of the traction pin, and a connecting piece mounted on the other end of the bracket, the traction pin is implanted in the jaw bone at a predetermined angle and depth, and the connecting piece is adhered to the distal crown surface of the impacted tooth.

[0009] In a preferred embodiment of the present application, the bracket is provided with a micro drive assembly at the end in contact with the connecting piece, the micro drive assembly comprises a moving sleeve, a spring connected to the end of the moving sleeve, and an expansion piece for driving the spring to deform.

[0010] The bracket is provided with a sliding groove at the end in contact with the moving sleeve, the moving sleeve is slidably connected to the bracket through the sliding groove, one end of the spring is fixedly connected to the moving sleeve, the other end is fixedly connected with a moving plate, the moving plate is slidably connected to the moving sleeve, and the expansion piece is mounted between the moving plate and the inner wall of the sliding groove.

[0011] In a preferred embodiment of the present application, the end of the moving sleeve in contact with the sliding groove is open, the moving plate is mounted in the inner cavity of the moving sleeve and slidably connected thereto.

[0012] In a preferred embodiment of the present application, the end of the moving sleeve away from the bracket is mounted on the connecting piece.

[0013] In a preferred embodiment of the present application, the inner wall of the sliding groove is provided with a limiting block, the moving sleeve is provided with a mounting groove in limiting cooperation with the limiting block, the moving sleeve is mounted on the inner wall of the sliding groove through the mounting groove, and the limiting block extends into the inner cavity of the moving sleeve.

[0014] The movement of the moving plate is limited by the limiting block.

[0015] In a preferred embodiment of the present application, a plurality of mounting holes are formed in the bracket, the mounting holes are equidistantly distributed, and the bracket is mounted and limited on the traction pin through the mounting holes and bolts.

[0016] In a preferred embodiment of the present application, the navigation base plate is a dental surgery guide plate customized based on the preoperative cone beam CT image data of the patient through 3D printing technology.

[0017] In a preferred embodiment of the present application, the distal crown position is etched, and the end of the moving sleeve is adhered to the distal crown position.

[0018] The present application solves the defects in the background art, and has the following advantages:

[0019] (1) The application provides a tool for integrated extraction of impacted teeth and crown cutting and traction, which utilizes a telescopic member made of hydrogel, has reversible water absorption and expansion and dehydration and shrinkage, and can realize micro reciprocating deformation under changes in the natural water environment of the oral cavity or under humidity control, so that the tool can continuously apply slight stress stimulation of alternating directions to the impacted teeth after traction is completed, maintains the activity of the periodontal membrane and the open state of the traction channel through the reciprocating small force, effectively prevents the formation of bridging hard connections between the tooth roots and the bone tissue, significantly reduces the initial traction resistance in the second traction, reduces the operation risk of breaking through the adhesive tissue again in the clinic, further reduces the risk of postoperative nerve traction complications and tooth root absorption, and improves the safety and efficiency of the overall treatment process.

[0020] (2) The application provides a tool for integrated extraction of impacted teeth and crown cutting and traction, which forms a mechanical buffer unit by arranging a sliding groove, a moving sleeve, a spring, a moving plate and a telescopic member in the bracket structure, utilizes the response characteristics of the telescopic member to changes in the humidity of the oral cavity, generates reversible volume deformation in the water absorption and expansion and dehydration and shrinkage processes, and then converts the expansion force into reciprocating traction displacement of the teeth through the spring and the moving plate, so that micro reciprocating traction is completed without causing tissue damage, the activity of the periodontal blood flow and bone remodeling is maintained through rhythmic microstimulation, the formation of bone bridges or fibrous adhesions between the tooth roots and the alveolar bone caused by inactivity is effectively inhibited, and thus the mechanical preparation and channel preactivation for the second traction are realized without interrupting the healing process, thereby improving the continuity and success rate of the overall treatment.

[0021] (4) The application provides a tool for integrated extraction of impacted teeth and crown cutting and traction, which allows the connection angle and the traction force action line to be adjusted according to the in-situ positioning accuracy requirements through the multi-hole installation structure between the bracket and the traction pin, so that the traction force vector is more in line with the preset dislocation direction and anatomical avoidance requirements, and the low-amplitude mechanical fluctuations generated by the micro drive structure not only enhance the directional stability of the traction force, but also reduce the transmission of the reaction force to the anchorage tooth while maintaining constant physiological stimulation, reduce the interference of the traction process on the adjacent teeth and the alveolar bone, and further reduce the risk of postoperative loosening of the adjacent teeth, bone resorption and disorder of the occlusal relationship. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, a brief introduction will be given below to the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments described in the application, and other drawings can be obtained by those skilled in the art without creative labor;

[0023] Figure 1 is a traction pin installation structure diagram of the preferred embodiment of the application, and a bracket cooperation structure diagram;

[0024] Figure 2 is a bracket structure schematic diagram of a preferred embodiment of the present application;

[0025] Figure 3 is a micro drive structure schematic diagram of a preferred embodiment of the present application;

[0026] Figure 4 is a micro drive structure exploded schematic diagram of a preferred embodiment of the present application.

[0027] In the figure: 1, traction nail; 2, bracket; 3, moving sleeve; 4, spring; 5, telescopic piece; 6, sliding groove; 7, moving plate; 8, limiting block; 9, mounting groove; 10, mounting hole; 11, breathable micropore. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0029] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced without the specific details, other than those described herein, and therefore the scope of the application is not limited to the details in the following description.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application. In addition, the terms "first", "second", and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] As shown in Figure 1 A lower alveolar nerve injury risk impacted tooth crown extraction and traction integrated tool, comprising: a navigation base plate and a traction anchorage assembly;

[0033] The profile of the navigation base plate matches the crown surface anatomical morphology of the target impacted tooth and its adjacent teeth, and is used to be positioned and stabilized on the dentition during surgery, and the traction anchorage assembly is installed on the jaw bone;

[0034] The three-dimensional profile consistent with the crown surface morphology of the impacted tooth and the adjacent teeth is adopted, so that it can be stably clamped on the patient's dentition in a geometric interlocking manner during surgery.

[0035] The unique concave-convex morphology of the crown surface has a highly individualized feature in three-dimensional space, so when the navigation base plate is placed in the mouth, its position is naturally limited by the crown geometry, and there is no redundant degree of freedom, thereby forming a stable spatial reference surface.

[0036] Through geometric positioning, the navigation base plate can be reset at almost the same position in each operation, so that the implant pin implantation point and the traction direction have spatial coordinate repeatability. The navigation base plate is equivalent to fixing the preoperative CBCT-based digital planning in the patient's mouth, and changes the doctor's traction force direction from experience judgment to strictly following three-dimensional guidance, realizing stable avoidance of the traction initial force line to the nerve tube.

[0037] In this way, when the patient experiences biological processes such as bone healing and tooth position change between the first traction and the second traction, the navigation base plate can still be seated on the original crown geometry of the second molar and the impacted tooth, so that the traction direction remains consistent with the first operation, solving the problem of difficult space reconstruction in multiple tractions.

[0038] The traction anchorage assembly comprises: a traction pin 1, a bracket 2 mounted on one end of the traction pin 1, and a connecting piece mounted on the other end of the bracket 2; the traction pin 1 is implanted into the jaw bone at a predetermined angle and depth, and the connecting piece is adhered to the distal crown surface of the impacted tooth.

[0039] The traction pin 1 is implanted into the jaw bone at a predetermined angle and depth, so that its implantation path matches the anatomical data of the patient's mandibular cortical bone thickness, cancellous bone density and nerve canal running, which not only ensures the biomechanical stability of the anchorage implant, but also maintains a safe distance from the nerve canal during implantation, thereby reducing the risk of structural damage.

[0040] The bracket 2, as an intermediate element connecting the traction pin 1 and the tooth, can convert the point support provided by the traction pin 1 into a stable multi-dimensional mechanical platform, so that the installation angle, height and direction of the corresponding connecting piece are not limited by the small morphology of the head of the traction pin 1, and can be adjusted according to the anatomical planning.

[0041] The connecting piece is finally bonded to the distal crown of the impacted tooth, so that the traction force directly acts on the target surface in the direction of dislocation, rather than bypassing other parts of the tooth crown, thereby reducing unnecessary rotation or compression caused by mechanical component forces, and forming a complete, continuous and controllable force link from the jaw bone to the tooth. The entire structure effectively prevents the traction force vector from deviating from the original planned direction due to instrument assembly deviations, significantly reducing the potential risk of the force pressing against the side of the nerve canal during traction.

[0042] Among them, the connecting piece bonded to the distal crown of the impacted tooth is the component that applies the traction force. Since the bracket 2 has optimized and stabilized the mechanical direction, the connecting piece can apply the direction to the target surface of the tooth without distortion, so that the traction force is stably transmitted in the distal direction to meet the requirement of the tooth root moving away from the nerve canal.

[0043] The stable bonding of the connecting piece not only ensures the accuracy of the mechanical path of the first traction, but also maintains the force application point unchanged when the periodical healing of the periodontal tissue or the slight changes of the tooth occur during the traction interval, so that the second traction can be started in the same direction, avoiding the need to break through the bone bridge again due to the change of the force application position, and reducing pain, damage and traction resistance.

[0044] As can be seen, the connecting piece is not only the terminal of the traction, but also the key to maintaining the continuity of the mechanical path, so that the two-stage traction is completely unified at the structural level.

[0045] Considering that in the clinical fraction traction scheme, after the first traction is completed, the tooth root has been pulled away from the original high-risk area, but a healing observation period is still needed before starting the second traction. During this traction interval, the bone channel opened by the traction gradually loses stress stimulation, the periodontal membrane tension is weakened, and the alveolar bone will start the repair program. The trabecular bone gradually crosses the traction gap to form a bone bridge or dense fibrous adhesion, so that the tooth root changes from a movable state to a functional fixation. Therefore, in the present application, the connecting piece is designed to be a Figure 2 , Figure 3 and Figure 4As shown, the end of the bracket 2 in contact with the connecting piece is provided with a micro drive assembly, which includes a moving sleeve 3, a spring 4 connected to the end of the moving sleeve 3, and an expansion piece 5 driving the deformation of the spring 4.

[0046] The end of the bracket 2 in contact with the moving sleeve 3 is provided with a sliding groove 6, the moving sleeve 3 is slidingly connected with the bracket 2 through the sliding groove 6, one end of the spring 4 is fixedly connected with the moving sleeve 3, the other end is fixedly connected with a moving plate 7, the moving plate 7 is slidingly connected with the moving sleeve 3, and the expansion piece 5 is installed between the moving plate 7 and the inner wall of the sliding groove 6.

[0047] The expansion piece 5 is a hydrogel material, preferably one of N-isopropyl acrylamide, polyvinyl alcohol network structure or acrylamide-based copolymer hydrogel; the design swelling rate is not less than 50% under the oral physiological humidity environment, and the expansion and contraction are carried out according to the water environment in the oral cavity, so as to reciprocally apply different direction forces to the impacted tooth.

[0048] The inner wall of the sliding groove 6 and the inner cavity of the moving sleeve 3 are both provided with a plurality of penetrating air-permeable micropores 11, allowing the water vapor in the oral environment to fully exchange with the hydrogel expansion piece 5, so as to control the response period of the expansion and contraction.

[0049] By setting the micro drive assembly at one end of the bracket 2, the traditional static bracket 2 is upgraded to a dynamic bracket 2 with an internal sliding mechanism, the end of the bracket 2 close to the connecting piece is provided with a sliding groove 6, the sliding groove 6 is equivalent to a linear motion cavity with guiding function, the moving sleeve 3 is slidingly connected along the sliding groove 6, which is equivalent to installing a small sliding block that can move forward and backward on the bracket 2, the end of the moving sleeve 3 is connected with a spring 4, the other end of the spring 4 is fixedly connected with a moving plate 7, the moving plate 7 continues to slidingly cooperate with the moving sleeve 3, and the expansion piece 5 is clamped between the moving plate 7 and the inner wall of the sliding groove 6.

[0050] By setting the moving sleeve 3 slidingly in the bracket 2 and controlling the reciprocating movement of the moving sleeve 3 through the expansion piece 5, a reciprocating bidirectional force is applied to the impacted tooth, avoiding the situation that the bone channel opened by traction gradually loses stress stimulation during the traction interval, the trabeculae gradually cross the traction gap, forming a bone bridge or dense fibrous adhesion, so that the tooth root changes from a movable state to a functional fixed state, and the initial resistance of the second traction is significantly reduced.

[0051] Specifically, the telescopic member 5 is between the sliding groove 6 and the moving plate 7, and by expanding and contracting, the telescopic member 5 pushes the moving plate 7 to produce a slight displacement, and then the energy storage and rebound of the spring 4 convert the displacement into mechanical movement with a back-and-forth feature, so that the telescopic member 5 drives the moving plate 7 to move, and because the two ends of the spring 4 are fixed to the moving plate 7 and the moving sleeve 3 respectively, the moving sleeve 3 is given a moving force by the spring 4 during the movement of the moving plate 7, but because the end of the moving sleeve 3 is adhered to the impacted tooth, the movement of the moving sleeve 3 is limited.

[0052] With the continuous movement of the moving plate 7, the force given to the moving sleeve 3 by the spring 4 will increase, and the force acting on the impacted tooth by the moving sleeve 3 will also increase, forming a bidirectional traction force acting on the impacted tooth, thereby activating the stress reaction zone in the alveolar bone and inhibiting the formation of bone bridge and slowing down the process of ankylosis.

[0053] In the present application, the end of the moving sleeve 3 in contact with the sliding groove 6 is provided with an open end, and the moving plate 7 is installed in the inner cavity of the moving sleeve 3 and is in sliding connection with the moving sleeve 3.

[0054] Considering the second traction phase of the mandibular impacted tooth, if a fixed value of traction force is immediately applied, it is easy to cause the tooth to be frustrated or the patient to have obvious pain due to the local bone healing residual and insufficient adhesion release.

[0055] And the compression degree of the spring 4 is positively correlated with the stroke of the moving plate 7, and the reaction force gradually increases with the displacement, which means that the initial output force is very gentle, and gradually increases with the accumulation of structural deformation over time, and this gradual loading method can effectively buffer the initial traction impact, giving the periodontal tissue enough stress adaptation period, greatly reducing the risk of root absorption, nerve traction or bone fracture caused by sudden traction.

[0056] Further, with the repeated expansion and contraction of the telescopic member 5, the moving plate 7 compresses the spring 4 every time it advances, but the compression degree does not immediately reach the limit, and in one or more physiological periods, the energy storage of the spring 4 gradually accumulates, and the reaction force rises exponentially, and the effect of the force accumulating over time not only forms a continuous and gradually increasing tension environment in the alveolar bone channel, but also helps to awaken the remodeling response of the surrounding bone cells and periodontal membrane, so that the tooth gradually separates from the adhesion area in a painless micro-motion.

[0057] Specifically, the force acting on the impacted tooth by the spring 4 given to the moving sleeve 3 by the telescopic member 5 is dynamically changing, and the telescopic member 5 produces linear displacement by water absorption and expansion and water loss and contraction, pushes the moving plate 7 to slide, and further compresses the spring 4.

[0058] And the spring 4 due to one end fixed to the moving plate 7, the other end is connected to the moving sleeve 3, so its compression process will actually gradually accumulate elastic potential energy inside the structure, and through the moving sleeve 3 to the body output traction.

[0059] Because this force transmission mode is closely related to the activity of the telescopic part 5, the traction force of the spring 4 acting on the tooth is not static fixed, but dynamically changes with the telescopic rhythm and the compression degree of the spring 4, the non-constant force output improves the comfort of the tooth traction.

[0060] At the same time, the use of telescopic part 5 reciprocating force avoids the fatigue damage of constant one-way traction force on the tooth, and the traditional orthodontic or surgical traction device often uses constant tension mode, which is easy to cause long-term compression of periodontal membrane, degeneration of root membrane fiber, and even cause root absorption. In the dynamic traction structure, the spring 4 is gradually compressed with the expansion of the telescopic part 5, and the traction force gradually increases from a few grams to dozens of grams. In this process, the tooth is always in the cycle of loading-adapting-relaxing-reloading, simulating physiological occlusion or mild functional stimulation, so that tissue repair and bone remodeling match the traction force synchronously, significantly reducing the incidence of adverse physiological reactions.

[0061] Secondly, the existence of spring 4 establishes a mechanical feedback buffer path in the structure. When the telescopic part 5 expands rapidly and the thrust is too large, the spring 4 is compressed first to buffer, avoiding the tooth directly bearing the instantaneous force impact; when the telescopic part 5 contracts and loses the thrust, the spring 4 can automatically release the deformation amount to realize reverse traction or unloading.

[0062] Therefore, no matter in the case of rapid water absorption and expansion of the telescopic part 5, environmental humidity fluctuation, or oral microenvironment changes caused by patient chewing activity, the spring 4 can dynamically adjust the traction force size and direction to ensure that the total force acting on the tooth always remains within the physiological safe range.

[0063] Furthermore, for the impacted tooth after the first traction, its root is often wrapped by bone bridge or fibrous tissue. At this time, forcibly starting the second traction can easily cause bone fracture or tooth collapse. Through the dynamic force transmission mechanism of the spring 4, the system outputs a light stress at the initial stage, which is only used to activate the bone-tooth interface; then with the further driving of the telescopic part 5, the spring 4 accumulates energy to form a stronger thrust, so as to gradually loosen the adhesion, break through the bone passage lock, and realize non-invasive secondary traction.

[0064] In summary, the stretchable member 5 made of hydrogel material has reversible properties of water absorption and expansion and dehydration and shrinkage, and can realize micro-reciprocal deformation under natural changes in oral environment or humidity control, thereby continuously applying slight stress stimulation in alternating directions to the impacted tooth after traction, maintaining periodontal membrane activity and traction channel opening state through reciprocal small force, effectively preventing the formation of bridging hard connections between the tooth root and bone tissue, significantly reducing the initial traction resistance of the second traction, reducing the risk of operation to break through the adhesive tissue again, further reducing the probability of postoperative nerve traction complications and tooth root absorption, and improving the safety and efficiency of the overall treatment process.

[0065] In a preferred embodiment of the present application, the end of the mobile sleeve 3 away from the bracket 2 is mounted on the connecting member.

[0066] In order to avoid the mobile plate 7 directly compressing the spring 4 to contact the mobile sleeve 3, causing the force of the stretchable member 5 to act directly on the impacted tooth, the present application provides a limiting block 8 on the inner wall of the sliding groove 6, and an installation groove 9 is provided on the mobile sleeve 3 to limit the limiting block 8, the mobile sleeve 3 is installed in the inner wall of the sliding groove 6 through the installation groove 9, and the limiting block 8 extends into the inner cavity of the mobile sleeve 3.

[0067] The movement of the mobile plate 7 is limited by the limiting block 8.

[0068] On the one hand, the limiting block 8 forms a guide rail, and the mobile sleeve 3 is inserted into the sliding groove 6, which can provide a clear direction for the movement of the mobile sleeve 3 in the sliding groove 6, prevent the mobile sleeve 3 from rotating, deflecting or tilting in the sliding groove 6, and ensure that the reciprocal micro-motion does not deviate from the original traction path, and does not cause horizontal interference to the surrounding soft and hard tissues.

[0069] On the other hand, when the mobile plate 7 moves distally under the action of the stretchable member 5 and the spring 4, its movement distance will be limited by the structure of the limiting block 8, and it cannot move forward indefinitely, thereby indirectly limiting the maximum compression amount of the spring 4 and the effective stroke that the stretchable member 5 can apply.

[0070] Specifically, through the cooperation between the limiting block 8 and the mobile plate 7, the maximum movement displacement of the mobile plate 7 is actively limited within a safe range, and since the distance that the mobile plate 7 can advance is limited, the pushing force that it can apply is also upper limited, which means that the spring 4 will not be completely compressed to the top dead center, and the mobile plate 7 will not continue to press the mobile sleeve 3 after completely flattening the spring 4.

[0071] The force generated by the telescopic part 5 during water absorption and expansion does not directly and without buffering act on the moving sleeve 3 and the connecting part and the impacted tooth, but is always dispersed and buffered in the elastic chain of the water gel-moving plate 7-spring 4-moving sleeve 3, effectively avoiding the sudden large volume change of the water gel in some environment with large fluctuations, which causes the moving plate 7 to push the spring 4 and the moving sleeve 3, and directly transmits the instantaneous excessive stress to the impacted tooth, causing the risk of severe discomfort of the tooth root and even damage to the tissue.

[0072] In the present application, a plurality of mounting holes 10 are formed in the bracket 2, the mounting holes 10 are equidistantly distributed, and the bracket 2 is installed and limited with the traction nail 1 through the mounting holes 10 penetrated by bolts.

[0073] Specifically, the plurality of mounting holes 10 on the bracket 2 are equidistantly distributed, and a circle of optional anchor points is preset in the circumferential or adjacent area of the traction nail 1.

[0074] In actual surgery, the doctor can select the most suitable group of mounting holes 10 according to the inclination direction of the impacted tooth, the shape of the tooth root, and the spatial running of the inferior alveolar nerve canal, and connect the head of the traction nail 1 through the hole by bolts, so that the bracket 2 produces a certain angular offset relative to the traction nail 1, to fine-tune the overall posture of the bracket 2.

[0075] In this way, even if the implantation angle of the traction nail 1 is determined in priority according to the bone quality and nerve avoidance, the bracket 2 can still obtain the final installation posture that meets the expected traction vector through the combination of different hole positions on this basis, so that the micro-drive assembly and the connecting part on the bracket 2 are more in line with the traction direction planned before the operation in the three-dimensional space. The equidistantly distributed hole positions ensure that this angle adjustment is controllable, predictable and easy to quantify, which is beneficial to the reproduction in the operation record and repositioning.

[0076] On the other hand, the bracket 2 is installed and limited with the traction nail 1 through the mounting holes 10 penetrated by bolts, which not only realizes the connection, but more importantly forms a mechanical anti-rotation and anti-slippage structure.

[0077] The bolt-penetration type fixation is equivalent to firmly locking the bracket 2 on the traction nail 1, so that it is still not easy to rotate or shift under the long-term action of the traction force and the interference of oral chewing. As long as the bracket 2 is bolted again with the traction nail 1 at the original hole position, the original traction direction and mechanical path can be restored.

[0078] In a preferred embodiment of the present application, the navigation base plate is a dental surgery guide plate personalized based on the preoperative cone beam CT image data of the patient through 3D printing technology.

[0079] In a preferred embodiment of the present invention, the distal coronal position is acid-etched, and the end of the movable sleeve 3 is adhered to the distal coronal position.

[0080] Essentially, it precisely and stably transmits the micro-amplitude reciprocating motion generated by the aforementioned micro-drive components to the optimal force application point of the impacted tooth itself: First, acid etching is performed on the distal crown position to remove dirt and mineralized dense layer from the enamel surface, exposing the microstructure of enamel or dentin with a certain degree of roughness, so that the subsequent adhesive can form a stronger micromechanical interlocking and chemical bond, thereby significantly improving the bonding strength between the end of the moving sleeve 3 and the tooth body, and preventing it from falling off or loosening under long-term reciprocating micro-motion and oral chewing force interference.

[0081] Secondly, the end of the movable sleeve 3 is directly bonded to the distal crown position after acid etching, so that the displacement vector output by the micro-drive device is naturally coaxial with the distal movement direction of the impacted tooth. This not only helps the traction force to act in a direction away from the inferior alveolar nerve canal, but also reduces unnecessary rotational or lateral stress, and reduces the risk of absorption or microcracks caused by uneven force on the tooth root.

[0082] Meanwhile, since the movable sleeve 3 itself is a key force transmission component in the entire sliding-spring 4-hydrogel drive link, its end is firmly integrated with the tooth body, which can ensure that the low-frequency, low-amplitude reciprocating micro-motion generated by the drive device during the traction interval is not dissipated midway, but is effectively transmitted to the tissues around the tooth root, maintaining the traction channel in a state of mild stress activity, thereby inhibiting bone bridge crossing and fibrous adhesion formation, and creating an ideal mechanical environment for the second traction with low initial displacement resistance and the channel not being completely closed.

[0083] When using this invention,

[0084] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A tool for integrated extraction of crown of impacted tooth and traction of lower alveolar nerve injury risk, characterized in that, The utility model relates to a navigation template and traction anchorage assembly for the surgical positioning and stabilization of impacted teeth, comprising: a navigation template matching the crown surface topography of the impacted tooth and its adjacent teeth for surgical positioning and stabilization on the dentition, and a traction anchorage assembly installed in the jawbone; the traction anchorage assembly comprises a traction screw, a bracket mounted on one end of the traction screw, and a connector mounted on the other end of the bracket; the traction screw is implanted in the jawbone at a predetermined angle and depth, and the connector is adhered to the distal crown surface of the impacted tooth. the end of the bracket in contact with the connector is provided with a micro-drive assembly, which comprises a moving sleeve, a spring connected to the end of the moving sleeve, and an expansion and contraction element for driving the deformation of the spring; 2. The tool according to claim 1, wherein the tool is characterized by: the end of the bracket in contact with the moving sleeve is provided with a sliding groove, and the moving sleeve and the bracket are connected through the sliding groove; one end of the spring is fixedly connected to the moving sleeve, and the other end is fixedly connected to a moving plate; the moving plate is connected to the moving sleeve through sliding; and the expansion and contraction element is installed between the moving plate and the inner wall of the sliding groove. the end of the moving sleeve in contact with the sliding groove is open; the moving plate is installed in the inner cavity of the moving sleeve and connected to it through sliding.

3. The tool according to claim 1, wherein the tool is characterized by: the end of the moving sleeve away from the bracket is installed on the connector.

4. The tool according to claim 1, wherein the tool is characterized by: the inner wall of the sliding groove is provided with a limiting block, and the moving sleeve is provided with an installation groove matched with the limiting block; the moving sleeve is installed on the inner wall of the sliding groove through the installation groove, and the limiting block extends into the inner cavity of the moving sleeve; 5. The tool according to claim 1, wherein: the movement of the moving plate is limited by the limiting block. a plurality of installation holes are formed in the bracket; the installation holes are equidistantly distributed; and the bracket is installed on the traction screw through the installation holes and bolts.

6. The tool according to claim 1, wherein: the navigation template is a dental surgical template customized based on the preoperative cone beam CT image data of the patient through 3D printing technology.

7. The tool according to claim 1, wherein the tool is characterized by: the distal crown position is etched, and the end of the moving sleeve is adhered to the distal crown position.

8. The tool according to claim 1, wherein the tool is characterized by: the expansion and contraction element is a hydrogel material that expands and contracts according to the water environment in the oral cavity, and reciprocally applies different directional forces to the impacted tooth.

9. The tool according to claim 1, wherein the tool is characterized by: a plurality of penetrating gas-permeable micropores are formed in the inner wall of the sliding groove and the inner cavity of the moving sleeve, allowing the water vapor in the oral environment to fully exchange with the hydrogel expansion and contraction element to regulate the response period of its expansion and contraction.

10. The tool according to claim 1, wherein the tool is characterized by: ​

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