Joint jaw position retainer and manufacturing method thereof

Abstract

The invention relates to the technical field of oral medical instruments, in particular to a joint jaw position retainer and a manufacturing method thereof, and the method comprises the following steps: acquiring a lower jaw movement discrete point set during jaw opening and closing movement; the lower jaw movement discrete point set is fitted to generate a guide curve, the guide curve is segmented according to the tooth point rotation angle, a preset number of sub-curves are obtained, the arc length of each sub-curve is monotonically decreased in the jaw opening direction, and the tooth point rotation angle is an included angle formed by the starting point and the ending point of the guide curve with the condylar process center as the circle center; the sub-curves are correspondingly manufactured into guide rails, the guide rails are sequentially connected in series and connected in a sleeved mode according to the connection sequence of the sub-curves in the guide curves to form the guide telescopic assembly capable of stretching and retracting in the axial direction, the mandibular movement is restrained within the normal jaw opening and closing movement track range, and the necessary movement freedom degree is guaranteed while the disc-condyle relation is stabilized.

Description

Technical Field

[0001] The present application relates to the technical field of oral medical instruments, and in particular to a jaw retainer and a manufacturing method thereof. Background Art

[0002] The temporomandibular joint (TMJ) is the only dynamic joint in the maxillofacial region, primarily supporting flexible and varied mandibular movement. The TMJ's main components are the condyle, articular disc, and articular tubercle. The condyle and articular disc work in concert to facilitate mandibular movement. When the condyle and articular disc become structurally disrupted, mandibular movement is impaired, resulting in TMJ disorder.

[0003] The treatment and maintenance of temporomandibular joint (TMJ) disorders are challenging issues in the field of dentistry. Clinical research suggests that occlusal reconstruction through orthodontic or restorative treatment, after repositioning the bite plate or surgically restoring the disc-condylar relationship, can cure TMJ disorders. However, studies have shown that even with the bite fixed in a protrusive position, disc displacement tends to recur. Therefore, wearing a jaw retainer after treatment is crucial to stabilize the disc-condylar relationship and promote its recovery.

[0004] A currently used maxillary and mandibular fixed retainer utilizes a self-curing resin to secure the maxillary and mandibular compression mold retainers to the opposing edges of the upper and lower incisors in occlusal contact. While this retainer effectively maintains the relative mandibular position and achieves the therapeutic goal of fixating the mandibular joint, it suffers from several drawbacks: First, it completely restricts the mandibular opening and closing function, preventing patients from engaging in normal physiological activities such as chewing, swallowing, and speech. Second, due to the limited mandibular movement, the temporomandibular joint remains in a passive fixed state for a long time, which can easily lead to muscle fatigue in the joint area and hinder the restoration and stabilization of the disc-condylar relationship in the joint area. Summary of the Invention

[0005] In response to the above problems, the present application provides a joint jaw retainer and a manufacturing method thereof, which can constrain the mandibular movement within the range of normal jaw opening and closing movement trajectory, stabilize the disc-condylar relationship while ensuring the necessary freedom of movement.

[0006] To achieve the purpose of this application, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a method for manufacturing a joint jaw retainer, the method comprising:

[0008] Obtaining the discrete point set of mandibular motion during jaw opening and closing movements;

[0009] Fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, wherein the arc length of the sub-curve decreases monotonically along the jaw opening direction, and the tooth point rotation angle is the angle formed by the starting point and end point of the guide curve with the condyle center as the center;

[0010] Each of the sub-curves is made into a guide rail, and each section of the guide rail is serially connected in sequence according to the connection order of the sub-curves in the guide curve to form an axially retractable guide telescopic assembly. The joint jaw retainer includes the guide telescopic assembly, wherein the axial curvature and axial arc length of the guide rail are the same as the curvature and arc length of the corresponding sub-curve, the radial curvature of each of the guide rails is the same, the radial arc length of each of the guide rails is different and changes monotonically along the jaw opening direction, and the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentition.

[0011] In a possible implementation, obtaining a discrete point set of mandibular movement during jaw opening and closing movement further includes:

[0012] The patient wears the electronic face bow device, and the mandibular fork connected to the jaw sensor is bonded inside the patient's mandibular oral cavity;

[0013] Taking the clinical crown centers of the second premolars on both sides of the maxilla as reference points and the clinical crown centers of the first molars on both sides of the mandible as observation points, the jaw sensor is used to collect the total motion trajectory of the patient's multiple jaw opening and closing movements, and the motion trajectory with the mouth opening degree within the preset range of mouth opening is selected from the total motion trajectory, wherein the jaw opening and closing movement is performed under the condition that the relationship between the articular disc and the condyle is normal, and the preset range of mouth opening degree is 0-25mm;

[0014] A mandibular movement discrete point set corresponding to the mandibular movement trajectory with a mouth opening degree within a preset mouth opening degree range is derived from a mandibular movement analysis system connected to the mandibular sensor and the electronic face bow.

[0015] In a possible implementation, fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, further comprising:

[0016] Performing filtering on the mandibular movement discrete point set to remove noise points and outliers;

[0017] Fitting the mandibular movement discrete point set to obtain a first guide curve, wherein the curvature of the first guide curve is consistent;

[0018] Obtaining a tooth point rotation angle and a radius of the first guide curve according to the first guide curve and setting a preset number, wherein the preset number is determined according to the total arc length of the first guide curve. When the total arc length is between 0 and 20 mm, the preset number is 2, 3, or 4; and when the total arc length is greater than 20 mm, the preset number is 5, 6, or 7.

[0019] Calculate the arc length of each sub-curve and the central angle of each sub-curve according to the tooth point rotation angle, radius, preset number and segment weight, where the preset number of segment weights decreases in value and the arc length range of the sub-curve is 5-10mm;

[0020] Calculate the coordinates of the end point of each sub-curve according to the starting point of the first guide curve, the arc length of the sub-curve, and the central angle corresponding to each sub-curve;

[0021] Segmenting the first guide curve according to the end point coordinates to obtain a preset number of sub-curves;

[0022] According to the arc length and curvature of each sub-curve, each guide rail is manufactured correspondingly through 3D printing technology.

[0023] In a possible implementation, fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, further comprising:

[0024] Performing filtering on the mandibular movement discrete point set to remove noise points and outliers;

[0025] The discrete point set of mandibular movement is fitted to obtain a second guiding curve with continuous curvature;

[0026] Determine the tooth point rotation angle and set a preset number according to the second guide curve, and divide the tooth point rotation angle into a preset number of first circle center angles;

[0027] The second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the condyle center, and each first circle center angle, to obtain each initial sub-curve corresponding to each circle center angle;

[0028] Calculate the mean curvature of each initial sub-curve. If the mean curvature of each initial sub-curve decreases along the jaw opening direction, sort them from large to small according to the mean curvature. Weight the first center angles of the initial sub-curves corresponding to the 45%-50% mean curvatures before sorting to obtain the second center angles. Deweight the first center angles of the initial sub-curves corresponding to the 50%-55% mean curvatures after sorting to obtain the second center angles. When weighting, the weighting coefficient decreases in descending order according to the mean curvature. When deweighting, the deweighting coefficient increases in descending order according to the mean curvature. The sum of the absolute values of all weighting coefficients is equal to the sum of the absolute values of all deweighting coefficients.

[0029] The second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the condyle center, and each second circle center angle to obtain each sub-curve corresponding to each second circle center angle.

[0030] In one possible implementation, the guide rail includes a curved pipe, an inner limit ring is provided on the inner circumference of one sleeve end of the curved pipe, and an outer limit ring is provided on the outer circumference of the other sleeve end of the curved pipe. The curved pipe is sequentially sleeved through the inner sleeve ring and the outer sleeve ring in the order of monotonically changing radial arc length.

[0031] In one possible implementation, the guide track includes curved panels, which are telescopically connected in sequence along a monotonically changing radial arc length, and the curved panel with a smaller radial arc length is sleeved inside the curved panel with a larger radial arc length;

[0032] Except for the curved plate with the smallest radial arc length, the inner walls of the other curved plates are all provided with arc-shaped grooves along their own axial directions. The arc length of the arc-shaped groove is equal to the length of the curved plate itself, and the axial curvature of the arc-shaped groove is equal to the axial curvature of the curved plate with the smallest radial arc length that is sleeved therewith.

[0033] Except for the curved panel with the largest radial arc length, the outer wall of one end of the remaining curved panels close to the curved panel with the largest radial arc length is provided with a sliding table that is slidably connected to the arc groove, wherein the axial curvature of the curved panel is equal to the curvature of the corresponding sub-curve and the axial arc length is equal to the arc length of the corresponding sub-curve.

[0034] In a possible implementation, the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentition, further comprising:

[0035] Grooves are provided on both ends of the guide telescopic assembly and on one side close to the teeth. The grooves are detachably connected to the protrusions of the upper and lower mandibular split retainers. The protrusions are respectively located at the clinical crown center of the second premolar of the maxillary split retainer and the clinical crown center of the first molar of the mandibular split retainer. Both ends of the guide telescopic assembly and on one side close to the face are provided with arc chamfers.

[0036] The maxillary split retainer and the mandibular split retainer are made using 3D digital printing technology based on digital models of the upper and lower jaw dentitions. The labial sides of the maxillary split retainer and the mandibular split retainer are both made of PETG material and the lingual sides are both made of double-row nickel-titanium wire.

[0037] In the second aspect, the present application provides a joint jaw retainer, including a guide telescopic assembly manufactured according to the above-mentioned method of manufacturing a joint jaw retainer, wherein the guide telescopic assembly can be telescoped along its own axis, and the guide telescopic assembly includes guide rails that are serially connected in sequence, and the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentitions respectively.

[0038] The joint jaw retainer of the present application is designed and manufactured according to the normal jaw opening and closing movement trajectory to achieve personalized biological simulation; at the same time, the guide telescopic component of the joint jaw retainer can be axially extended and retracted, specifically, when the upper and lower jaws are completely closed, the guide telescopic component is in a retracted state, and during the jaw opening movement, the guide telescopic component gradually extends and the limited trajectory path of the guide telescopic component is consistent with the normal jaw opening and closing movement path, so that the mandibular movement can be restricted within the normal jaw opening and closing movement path, thereby improving the stability of the disc-condylar relationship, and can also adapt to the mandibular movement needs within a certain range, solving the problem of passive fixation of the mandible caused by traditional fixed retainers; at the same time, the detachable connection method between the guide telescopic component of the joint jaw retainer and the upper and lower jaw dentition ensures the convenience of wearing and disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application.

[0040] Figure 1 A flowchart of a method for manufacturing a joint jaw retainer provided in an embodiment of the present application;

[0041] Figure 2 A schematic structural diagram of a guide telescopic assembly provided in an embodiment of the present application;

[0042] Figure 3 A schematic structural diagram of another curved panel provided in an embodiment of the present application;

[0043] Figure 4 A schematic structural diagram of another guide telescopic assembly provided in an embodiment of the present application;

[0044] Figure 5 A schematic diagram of the structure of the upper and lower mandibular separate retainers provided in an embodiment of the present application;

[0045] Figure 6 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when in an open jaw state;

[0046] Figure 7 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when in a jaw closed state;

[0047] Figure 8 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when worn in the oral cavity;

[0048] Figure 9 A schematic diagram of the total mandibular motion trajectory of different patients performing mandibular motion according to an embodiment of the present application;

[0049] Illustrations: 1. Guide telescopic assembly; 11. Bend; 12. Curved plate; 121. Arc groove; 122. Slide; 13. Groove; 2. Maxillary split retainer; 21. Bump; 3. Mandibular split retainer; 31. Double-row nickel-titanium wire. DETAILED DESCRIPTION

[0050] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present application.

[0052] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features indicated. Thus, features specified as "first" or "second" may explicitly or implicitly include one or more of such features; and in the description of this application, unless otherwise specified, "plurality" means two or more.

[0053] Figure 1 A flowchart of a method for manufacturing a joint jaw retainer provided in an embodiment of the present application; Figure 2A schematic structural diagram of a guide telescopic assembly provided in an embodiment of the present application; Figure 3 A schematic structural diagram of another curved panel provided in an embodiment of the present application; Figure 4 A schematic structural diagram of another guide telescopic assembly provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of the upper and lower mandibular separate retainer provided in an embodiment of the present application; Figure 6 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when in an open jaw state; Figure 7 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when in a jaw closed state; Figure 8 A schematic diagram of the structure of the jaw retainer provided in an embodiment of the present application when worn in the oral cavity; Figure 9 The following is a schematic diagram of the total mandibular motion trajectory of different patients performing mandibular motion according to the embodiment of the present application. Figures 1-9 The following content describes this application plan.

[0054] The joint jaw retainer and its manufacturing method of the present application are based on the theory of joint kinectics system (JK system) and clinical practice. The joint jaw retainer is used for patients with temporomandibular joint disorder after mandibular repositioning treatment, orthodontics or restorative occlusal reconstruction. It can prevent the recurrence of articular disc displacement and further stabilize the articular disc condyle relationship.

[0055] like Figure 1 As shown, a method for manufacturing a jaw retainer provided in an embodiment of the present application includes the following steps:

[0056] S100 obtains a discrete point set of mandibular movement during jaw opening and closing movement.

[0057] In some embodiments, S100 acquires a discrete point set of mandibular movement during jaw opening and closing movement, including the following steps:

[0058] First, after patients with temporomandibular joint disorder undergo mandibular repositioning treatment, orthodontics or restorative occlusal reconstruction, their mandibular movement discrete point sets are collected when their condyle and articular disc structures are normal. During the collection, the patients sit with their heads fixed to reduce interference. Then they wear an electronic face bow device, and the mandibular fork connected to the jaw sensor is bonded into the patient's mandibular oral cavity.

[0059] Then, using the clinical crown centers of the second premolars on both sides of the maxillary cavity as reference points and the clinical crown centers of the first molars on both sides of the mandible as observation points, the jaw sensor was used to collect the total motion trajectory of the patient's multiple jaw opening and closing movements (sampling frequency was 50-60 Hz), and the motion trajectory with the mouth opening degree within the preset range was selected from the total motion trajectory. Figure 9 FIG. 1 is a schematic diagram of the total mandibular motion trajectory of different patients performing mandibular motion according to an embodiment of the present application, wherein the positions of the reference point and the observation point can be adjusted according to the actual situation of the patient.

[0060] Finally, the mandibular motion analysis system, which is connected to the jaw sensor and the electronic face bow, derives a set of discrete mandibular motion points corresponding to the mandibular motion trajectory within a preset range of mouth opening. Specifically, this set of discrete mandibular motion points is the motion trajectory of the mandibular first molar.

[0061] It should be noted that the jaw opening and closing movement is performed when the relationship between the articular disc and the condyle is normal, and the preset range of mouth opening is 0-25mm. The mouth opening here refers to the distance between the incisal edges of the upper and lower central incisors. The forms of temporomandibular joint movement are divided into simple rotational movement, simple sliding movement or sliding and rotational movement. In the process from the closed position (recessed contact position) to the maximum mouth opening position, the joint movement first undergoes simple rotational movement and then changes to sliding and rotational movement. Among them, simple rotational movement is also called hinge movement or small opening movement. Small opening movement mainly occurs in the subarticular cavity. At this time, the condyle makes a simple rotation in the front-to-back direction under the articular disc while the articular disc basically does not move. It usually occurs in the symmetrical movement of the bilateral joints. The opening movement starting from the closed position (recessed contact position) is the movement of the condyle of this type of small opening movement (hinge movement). Generally speaking, the small opening movement can continue until the mouth opening at the upper and lower central incisors reaches 18-25mm. In this patent, the movement when the mouth opening is within the preset range of mouth opening (0-25mm) is the small opening movement. Of course, the preset range of mouth opening is determined based on the patient's actual situation. For some patients with less mandibular mobility, the range of small mouth opening movement is relatively large, so the preset range of mouth opening can be appropriately increased, such as 0-28mm or 0-30mm. For some patients with less mandibular mobility, the preset range of mouth opening can be appropriately reduced, such as 0-15mm, 0-18mm, or 0-20mm.

[0062] Based on this, limiting the movement of the temporomandibular joint to a purely rotational range can, to a certain extent, ensure that the condyle can hinge under the articular disc, i.e., the anatomical position of the condyle and the articular disc remains unchanged. Clinical practice has confirmed that small mouth opening movement (i.e., a preset mouth opening range of 0-25mm) has no negative impact on the patient's daily life. Therefore, this application is based on the mandibular movement trajectory data corresponding to the patient's small mouth opening movement to produce a joint jaw retainer.

[0063] It should also be noted that the mandibular motion analysis system includes an independent head-mounted electronic face bow, jaw sensors and analysis software. This analysis system has a wide range of uses and can accurately record the movement position of the condyle. It can also record the movement trajectory of the mandible in all degrees of freedom with high precision. It can be used to create and plan functional dental restoration plans, as well as record and detect oral and maxillofacial rehabilitation processes.

[0064] S200 fits the discrete point set of mandibular movement to generate a guide curve, and divides the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, wherein the arc length of the sub-curve decreases monotonically along the jaw opening direction.

[0065] The tooth point rotation angle is the angle formed by the starting point of the guide curve, the center of the condyle, and the end point of the guide curve. This mandibular rotation angle can be directly determined from the guide curve. The tooth point here is the observation point set in the mandibular dentition when the motion trajectory is acquired by the jaw sensor. The starting and end points of this observation point during jaw opening movement are approximately the starting and end points of the guide curve.

[0066] At the same time, the embodiment of the present application sets the dentition observation point for the mandibular sensor to collect data as the mandibular first molar. This is because the first molar is closer to the center of the condyle than the incisors and is located on the same side as the condyle. Therefore, compared with installing the guide telescopic assembly on the upper and lower incisors at the same mouth opening, installing it on the first molar can reduce the telescopic range of the assembly and make the curvature of the motion trajectory smoother, thereby improving the adaptability and stability of the guide telescopic assembly.

[0067] It should be noted that the arc length of the sub-curve strictly decreases along the jaw opening direction (i.e., L1>L2>L3, and the sub-curve corresponding to L1 connects the upper jaw), which can ensure the movement continuity and mechanical reliability of the guiding telescopic component. Specifically, when the second section (L2) extends from the first section (L1), its movement trajectory completely inherits the curvature characteristics of the first section, forming a seamless movement path. This design enables the entire guiding system to maintain a single, coherent curvature transmission, avoiding sudden changes in the direction of movement. At the same time, from a biomechanical point of view, this decreasing design can simulate the "acceleration-deceleration" characteristics of natural mandibular movement. Therefore, a larger range of motion is allowed in the early stage of small mouth movement (corresponding to the long arc segment), while fine control is provided in the late stage of small mouth movement (corresponding to the short arc segment), thereby maximizing the biological similarity between the telescopic trajectory of the guiding telescopic component and the natural mandibular movement.

[0068] In some embodiments, S200 fits the mandibular movement discrete point set to generate a guide curve, and segments the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, specifically including the following steps:

[0069] First, filter the discrete point set of mandibular motion to remove noise and outliers. This filtering process can be performed using Python or Matlab software.

[0070] Then, the mandibular movement discrete point set is fitted to obtain a first guide curve, and the tooth point rotation angle and the radius of the first guide curve are obtained according to the first guide curve, and a preset number is set.

[0071] The curvature of the first guide curve is consistent, that is, the first guide curve is a circular arc. The least squares method can be used to fit the first guide curve. The preset number is determined based on the total arc length of the first guide curve, which is the displacement experienced by the observation point (i.e., the mandibular first molar) during mandibular movement. When the total arc length is between 0 and 20 mm, the preset number is 2, 3, or 4. When the total arc length is greater than 20 mm, the preset number is 5, 6, or 7.

[0072] Next, the arc length and corresponding center angle of each sub-curve are calculated based on the tooth point rotation angle, radius, preset number, and segment weight. The center angle is calculated from the tooth point rotation angle and the segment weight. The number of segment weights is the same as the preset number and the values decrease in sequence. For example, the segment weight values can be uniformly reduced by a fixed difference to form an arithmetic progression, thus obtaining a preset number of center angles that decrease in the direction of jaw opening. The radius can be obtained from the first guide curve.

[0073] Then, based on the starting point of the first guide curve, the arc length of the sub-curve, and the central angle corresponding to each sub-curve, the coordinates of the end point of each sub-curve are calculated. The specific calculation process is: with the center of the condyle as the center of the circle, the starting point or the end point of the previous sub-curve is rotated by the central angle to obtain the new end point of the sub-curve.

[0074] The first guide curve is then segmented based on the endpoint coordinates to produce a predetermined number of sub-curves. The arc length of the sub-curves ranges from 5 to 10 mm. This arc length is equal to the axial arc length of the guide rail. When the axial arc length of the guide rail ranges from 5 to 10 mm, the maximum retraction distance of the guide telescopic assembly during jaw closing is guaranteed to be 10 mm, ensuring compatibility with the articulated jaw retainer even when the patient's jaw is closed.

[0075] It should be noted that small mouth opening movement can be approximately regarded as a near-circular motion with the connection between the condyle and the articular disc as the center and the distance from the condyle rotation center to the mandibular incisor as the radius. Therefore, fitting the discrete point set of mandibular movement into an arc line conforms to the simple biomechanical model.

[0076] In some embodiments, S200 fits the mandibular movement discrete point set to generate a guide curve, and segments the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, specifically including the following steps:

[0077] First, the mandibular motion discrete point set is fitted to obtain the second guiding curve, where the second guiding curve is second-order continuous and differentiable to ensure the curvature continuity of the second guiding curve. Here, the fitting is performed using the B-spline curve method.

[0078] Then, the tooth point rotation angle is determined and a preset number is set based on the second guide curve, and the tooth point rotation angle is evenly divided into a preset number of first center angles; the second guide curve is segmented based on the starting point of the second guide curve, the straight-line distance from the starting point to the center of the condyle, and each first center angle, to obtain each initial sub-curve corresponding to each center angle. The specific calculation method for determining the initial sub-curve includes: with the center of the condyle as the center of the circle, rotating the starting point or the end point of the previous initial sub-curve by the first center angle to obtain the end point, and the intersection of the line between the end point and the center of the circle and the second guide curve is the end point of the corresponding initial sub-curve.

[0079] Next, the mean curvature of each initial sub-curve is calculated. If the mean curvature of each initial sub-curve decreases along the jaw opening direction, the curvature mean is sorted from large to small, and the first center angles of the initial sub-curves corresponding to the curvature mean of 45%-50% before sorting are weighted to obtain the second center angles, and the first center angles of the initial sub-curves corresponding to the curvature mean of 50%-55% after sorting are weighted to obtain the second center angles. When weighting, the weighting coefficient decreases in descending order according to the curvature mean, and when weighting, the weighting coefficient increases in descending order according to the curvature mean, and the sum of the absolute values of all weighting coefficients is equal to the sum of the absolute values of all weighting coefficients. By weighting and weighting, the requirement of decreasing arc length of each sub-curve along the jaw opening direction is also met, which is in line with the biomechanical characteristics of mandibular movement.

[0080] Finally, the second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the condyle center, and each second circle center angle to obtain each sub-curve corresponding to each second circle center angle.

[0081] The analysis and demonstration of the mandibular movement trajectory led to the conclusion that: at the beginning of jaw opening, due to rapid muscle contraction, the movement amplitude is large and belongs to the high curvature segment; at the end of jaw opening, due to gradual muscle relaxation, the movement is slow and belongs to the low curvature segment. Therefore, in this application, further adjustments are made based on the initial sub-curve, that is, the weight of the initial sub-curve with high curvature is increased, thereby increasing the arc length of the initial sub-curve with high curvature, and the weight of the initial sub-curve with low curvature is reduced, thereby reducing the arc length of the initial sub-curve with high curvature. It should be noted that when allocating weights, it is also necessary to ensure that the arc length of each sub-curve decreases monotonically along the jaw opening direction, and at the same time, the arc length range of the sub-curve should be limited to 5-10mm.

[0082] In this way, by extending the arc length of the sub-curve with high curvature and compressing the arc length of the sub-curve with gentle curvature, the telescopic trajectory of the final guide telescopic assembly can conform to the dynamic characteristics of mandibular movement to a greater extent. In some embodiments, if the mean curvature of each initial sub-curve along the jaw opening direction does not meet the decreasing requirement, the tooth point rotation angle is determined according to the second guide curve and a preset number of segment weights with arithmetically decreasing values are set; then, the center angles of each circle are calculated according to the tooth point rotation angle and the weights of each segment, wherein the preset number is determined according to the total arc length of the second guide curve. When the total arc length is between 0 and 20 mm, the preset number is 2, 3, or 4; when the total arc length is greater than 20 mm, the preset number is 5, 6, or 7. Then, the second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the center of the condyle, and each center angle to obtain each sub-curve corresponding to each center angle. Finally, the arc length of each sub-curve is calculated. If the arc length of each sub-curve meets the decreasing requirement along the jaw opening direction, the sub-curve is retained; if the arc length of each sub-curve does not meet the decreasing requirement, the segment weight is reset until the arc length of each sub-curve decreases along the jaw opening direction.

[0083] In some embodiments, if the mean curvature of each initial sub-curve along the jaw opening direction does not meet the decreasing requirement, the discrete point set of mandibular movement can be fitted into a second guide curve with decreasing curvature along the jaw opening direction, and then the sub-curves are generated according to the method shown in the above embodiment of "determining the tooth point rotation angle according to the second guide curve and setting a preset number, and dividing the tooth point rotation angle into a preset number of first center circle angles".

[0084] S300 makes each sub-curve into a guide rail, and connects each section of the guide rail in series according to the connection order of each sub-curve in the guide curve to form an axially retractable guide telescopic assembly, wherein the axial curvature and axial arc length of the guide rail are the same as the curvature and arc length of the corresponding sub-curve, the radial curvature of each guide rail is the same, the radial arc length of each guide rail is different and changes monotonically along the jaw opening direction, and the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentition.

[0085] This step covers the process of converting the digital sub-curves into physical guide rails.

[0086] In some embodiments, preparing the guide rail based on the sub-curves divided from the first guide curve specifically includes: manufacturing each guide rail correspondingly through 3D printing technology according to the arc length and curvature of each sub-curve.

[0087] Among them, the axial curvature and axial arc length of the guide rail are the same as the curvature and arc length of the corresponding sub-curve, the radial curvature of each guide rail is the same, the radial arc length of each guide rail is different and changes monotonically along the jaw opening direction. Exemplarily, the guide telescopic assembly includes a first guide rail, a second guide rail and a third guide rail, wherein the axial arc length and axial curvature of the first guide rail, the second guide rail and the third guide rail are determined according to the corresponding sub-curve, the radial curvature of the first guide rail, the second guide rail and the third guide rail are the same, the radial arc length of the first guide rail is greater than the radial arc length of the second guide rail and the radial arc length of the third guide rail, or, the radial arc length of the first guide rail is less than the radial arc length of the second guide rail and the radial arc length of the third guide rail. The monotonous change of the radial arc length of the guide rail is to meet the sleeve and sliding connection between the guide rails, so that the contact stress is evenly distributed and friction mutations are reduced.

[0088] In some embodiments, as Figure 2 As shown, the guide track formed based on the first guide curve is a curved tube 11. The cross-section of the curved tube 11 is an asymmetric cross-section with a larger outer arc radius than the inner arc. The outer arc is the arc corresponding to the radial curvature. An inner stop ring is provided on the inner circumference of the sleeve end of the curved tube 11, and an outer stop ring is provided on the outer circumference of the other sleeve end of the curved tube 11. The curved tube 11 is sequentially sleeved with the inner sleeve ring and the outer sleeve ring in a sequence of monotonically changing radial arc lengths. For example, the radial arc length of the first curved tube 11 is smaller than that of the second curved tube 11. The first curved tube 11 is sleeved within the second curved tube 11, and the outer sleeve ring of the first curved tube 11 and the inner sleeve ring of the second curved tube 11 block each other to prevent the first curved tube 11 and the second curved tube 11 from separating due to excessive extension.

[0089] In some embodiments, as Figure 3-4 As shown, the guide track formed based on the sub-curve of the first guide curve or the second guide curve includes a curved plate 12, the axial curvature and arc length of the curved plate 12 being consistent with the sub-curve. A predetermined number of curved plates 12 are telescopically connected in a sequence with a monotonically varying radial arc length, and the curved plates 12 with smaller radial arc lengths are nested within the curved plates 12 with larger radial arc lengths. It should also be noted that:

[0090] Except for the curved panel 12 with the smallest radial arc length, the inner walls of the other curved panels 12 are all provided with arc-shaped grooves 121 along their own axial directions. The arc length of the arc-shaped groove 121 is equal to the length of the curved panel 12 itself, and the axial curvature of the arc-shaped groove 121 is equal to the axial curvature of the curved panel 12 with the smaller radial arc length that is sleeved therewith; except for the curved panel 12 with the largest radial arc length, the outer walls of one end of the other curved panels 12 close to the curved panel 12 with the larger radial arc length are provided with a slide 122 embedded in the arc-shaped groove 121 and slidably connected to the arc-shaped groove, wherein the axial curvature of the curved panel 12 is equal to the curvature of the corresponding sub-curve and the axial arc length is equal to the arc length of the corresponding sub-curve.

[0091] In some embodiments, the cooperation between the arc-shaped groove 121 and the sliding platform 122 can increase the smoothness of the two curved panels 12 in sliding connection when they extend and retract along the axial direction.

[0092] Relatively speaking, the first guide curve is an arc with consistent curvature. The use of a bent tube can achieve telescopic extension and retraction, which can ensure the reliability of the joint jaw retainer during mandibular movement. The second guide curve is a curve with continuous curvature. It is more appropriate to choose a curved plate with strong multi-degree-of-freedom deformation ability, which can guide the smoothness of the telescopic extension and retraction of the telescopic component.

[0093] For example, the bent pipe, curved plate, and slide can be made of thermoplastic polyurethane material, which has a wide hardness range, good elasticity, wear resistance, and can absorb the tiny stress generated during expansion and contraction. Its excellent resilience ensures that the bent pipe can still return to its original shape after repeated expansion and contraction.

[0094] For example, the bent pipes, curved panels, and slides can be made of polyetheretherketone (PEEK), which has both rigidity and toughness. When the curved panels expand and contract along complex curved paths, the creep resistance of PEEK can inhibit plastic deformation. At the same time, its elastic modulus range of 0.3-1GPa can adaptively adjust local stiffness and balance motion accuracy and stress buffering requirements.

[0095] Exemplarily, the bend pipe, the curved plate and the slide can be made of medical grade pure titanium. Of course, the materials used to make the bend pipe, the curved plate and the slide can be the same or different, and can be selected from thermoplastic polyurethane, polyetheretherketone and medical grade pure titanium.

[0096] In some embodiments, as Figure 5-8 As shown, grooves 13 are provided at both ends of the guide telescopic component 1 and on the side close to the teeth. The grooves 13 are detachably connected to the protrusions 21 of the upper and lower mandibular split retainers. The protrusions 21 are respectively located at the clinical crown center of the second premolar of the maxillary split retainer 2 and the clinical crown center of the first molar of the mandibular split retainer 3. Both ends of the guide telescopic component 1 and on the side close to the face are set to arc chamfers, which can facilitate wearing and improve wearing comfort.

[0097] Moreover, the purpose of designing the connector in the middle of the dental arch in this embodiment is: compared with placing it at the front end of the dental arch, it does not affect the aesthetics; compared with placing it at the back end of the dental arch, it is less likely to cause nausea in the patient; and the position of the first molar is relatively constant.

[0098] The mandibular and maxillary retainers are made of PETG on the labial side and double-row nickel-titanium wire on the lingual side.

[0099] First, a 3shape oral scanner was used to obtain the digital models of the patient's maxillary and mandibular dentition after occlusal reconstruction.

[0100] Then, for each tooth model in the digital model of the upper and lower mandibular dentition, an upper auxiliary plane passing through the upper edge of the tooth model, a lower auxiliary plane passing through the lower edge of the tooth model, and a middle auxiliary plane passing through the middle of the tooth model were established; the intersection lines of each tooth model with the corresponding upper auxiliary plane, lower auxiliary plane, and middle auxiliary plane were extracted and recorded as the upper intersection line, lower intersection line, and middle intersection line, respectively.

[0101] Then, the upper intersection lines, lower intersection lines and middle intersection lines of all upper teeth are fused respectively to obtain the upper contour line, lower contour line and middle contour line of the upper dentition; the upper intersection lines, lower intersection lines and middle intersection lines of all lower teeth are fused respectively to obtain the upper contour line, lower contour line and middle contour line of the lower dentition.

[0102] Then, the upper contour line, lower contour line and middle contour line of the upper dentition are used as the track for scanning, and the lower contour line of the upper dentition is closed to generate the inner surface of the upper braces; the upper contour line, lower contour line and middle contour line of the lower dentition are used as the track for scanning, and the upper contour line of the lower dentition is closed to generate the inner surface of the lower braces.

[0103] Finally, the inner surfaces of the upper and lower braces were thickened outward to a predetermined thickness. Using Boolean operations, the lingual sides of the upper and lower braces were designed with a double row of nickel-titanium wires 31, resulting in a model of the upper and lower mandibular separate retainers. Using 3D printing technology, the upper and lower mandibular separate retainers were printed from the model, with the labial side made of a transparent polymer material (i.e., PETG) and the lingual side made of a memory nickel-titanium alloy.

[0104] Among them, the labial side uses transparent polymer material (i.e. PETG material) to ensure the beauty of the upper and mandibular split retainers, and the lingual side uses memory nickel-titanium alloy material with good shape memory effect, superelasticity, biocompatibility and corrosion resistance. When it is located on the lingual side of the upper and mandibular split retainers, it does not affect the beauty and can reduce the deformation rate of the upper and mandibular split retainers.

[0105] In some embodiments, a jaw retainer may be used to simulate the opening and closing movement of the mouth, and its movement trajectory may be detected to see whether it matches the mandibular movement trajectory.

[0106] like Figure 2-8As shown, the embodiment of the present application also provides a jaw joint retainer, including a guide telescopic assembly 1 manufactured according to the manufacturing method of the jaw joint retainer described above, the guide telescopic assembly 1 can be telescoped along its own axis, the guide telescopic assembly 1 includes guide rails that are serially sleeved in sequence, and the two ends of the guide telescopic assembly 1 are respectively detachably connected to the upper and lower jaw dentitions. The jaw joint retainer also includes upper and lower jaw split retainers, the two ends of the guide telescopic assembly are respectively detachably connected to the clinical crown center of the second premolar of the upper jaw split retainer 2 and the clinical crown center of the first molar of the mandibular split retainer 3, and the upper and lower jaw split retainers are respectively detachably connected to the upper and lower jaw dentitions.

[0107] The joint jaw retainer of the present application is designed and manufactured according to the normal jaw opening and closing movement trajectory to achieve personalized biological simulation; at the same time, the guide telescopic component of the joint jaw retainer can be axially extended and retracted, specifically, when the upper and lower jaws are completely closed, the guide telescopic component is in a retracted state, and during the jaw opening movement, the guide telescopic component gradually extends and the limited trajectory path of the guide telescopic component is consistent with the normal jaw opening and closing movement path, so that the mandibular movement can be restricted within the normal jaw opening and closing movement path, thereby improving the stability of the disc-condylar relationship, and can also adapt to the mandibular movement needs within a certain range, solving the problem of passive fixation of the mandible caused by traditional fixed retainers; at the same time, the detachable connection method between the guide telescopic component of the joint jaw retainer and the upper and lower jaw dentition ensures the convenience of wearing and disassembly.

[0108] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. The present application is not limited to the precise structures described above and illustrated in the accompanying drawings, and it cannot be assumed that the specific implementation of the present application is limited to these descriptions. For those skilled in the art of the present application, any changes and modifications made without departing from the concept of the present application should be deemed to fall within the scope of protection of the present application.

Claims

1. A method for manufacturing a jaw retainer, characterized in that: The method comprises: Obtaining the discrete point set of mandibular motion during jaw opening and closing movements; Fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, wherein the arc length of the sub-curve decreases monotonically along the jaw opening direction, and the tooth point rotation angle is the angle formed by the starting point and end point of the guide curve with the condyle center as the center; Each of the sub-curves is made into a guide rail, and each section of the guide rail is serially connected in sequence according to the connection order of the sub-curves in the guide curve to form an axially retractable guide telescopic assembly. The joint jaw retainer includes the guide telescopic assembly, wherein the axial curvature and axial arc length of the guide rail are the same as the curvature and arc length of the corresponding sub-curve, the radial curvature of each of the guide rails is the same, the radial arc length of each of the guide rails is different and changes monotonically along the jaw opening direction, and the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentition.

2. The method for manufacturing the joint jaw retainer according to claim 1, characterized in that: The step of obtaining a discrete point set of mandibular movement during jaw opening and closing movement further includes: The patient wears the electronic face bow device, and the mandibular fork connected to the jaw sensor is bonded inside the patient's mandibular oral cavity; Taking the clinical crown centers of the second premolars on both sides of the maxilla as reference points and the clinical crown centers of the first molars on both sides of the mandible as observation points, the jaw sensor is used to collect the total motion trajectory of the patient's multiple jaw opening and closing movements, and the motion trajectory with the mouth opening degree within the preset range of mouth opening is selected from the total motion trajectory, wherein the jaw opening and closing movement is performed under the condition that the relationship between the articular disc and the condyle is normal, and the preset range of mouth opening degree is 0-25mm; A mandibular movement discrete point set corresponding to the mandibular movement trajectory with a mouth opening degree within a preset mouth opening degree range is derived from a mandibular movement analysis system connected to the mandibular sensor and the electronic face bow.

3. The method for manufacturing the joint jaw retainer according to claim 1, characterized in that: Fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, further comprising: Performing filtering on the mandibular movement discrete point set to remove noise points and outliers; Fitting the mandibular movement discrete point set to obtain a first guide curve, wherein the curvature of the first guide curve is consistent; Obtaining a tooth point rotation angle and a radius of the first guide curve according to the first guide curve and setting a preset number, wherein the preset number is determined according to the total arc length of the first guide curve. When the total arc length is between 0 and 20 mm, the preset number is 2, 3, or 4; and when the total arc length is greater than 20 mm, the preset number is 5, 6, or 7. Calculate the arc length of each sub-curve and the central angle of each sub-curve according to the tooth point rotation angle, radius, preset number and segment weight, where the preset number of segment weights decreases in value and the arc length range of the sub-curve is 5-10mm; Calculate the coordinates of the end point of each sub-curve according to the starting point of the first guide curve, the arc length of the sub-curve, and the central angle corresponding to each sub-curve; Segmenting the first guide curve according to the end point coordinates to obtain a preset number of sub-curves; According to the arc length and curvature of each sub-curve, each guide rail is manufactured correspondingly through 3D printing technology.

4. The method for manufacturing the joint jaw retainer according to claim 1, characterized in that: Fitting the mandibular movement discrete point set to generate a guide curve, segmenting the guide curve according to the tooth point rotation angle to obtain a preset number of sub-curves, further comprising: Performing filtering on the mandibular movement discrete point set to remove noise points and outliers; The discrete point set of mandibular movement is fitted to obtain a second guiding curve with continuous curvature; Determine the tooth point rotation angle and set a preset number according to the second guide curve, and divide the tooth point rotation angle into a preset number of first circle center angles; The second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the condyle center, and each first circle center angle, to obtain each initial sub-curve corresponding to each circle center angle; Calculate the mean curvature of each initial sub-curve. If the mean curvature of each initial sub-curve decreases along the jaw opening direction, sort them from large to small according to the mean curvature. Weight the first center angles of the initial sub-curves corresponding to the 45%-50% mean curvatures before sorting to obtain the second center angles. Deweight the first center angles of the initial sub-curves corresponding to the 50%-55% mean curvatures after sorting to obtain the second center angles. When weighting, the weighting coefficient decreases in descending order according to the mean curvature. When deweighting, the deweighting coefficient increases in descending order according to the mean curvature. The sum of the absolute values of all weighting coefficients is equal to the sum of the absolute values of all deweighting coefficients. The second guide curve is segmented according to the starting point of the second guide curve, the straight-line distance from the starting point to the condyle center, and each second circle center angle to obtain each sub-curve corresponding to each second circle center angle.

5. The method for manufacturing the joint jaw retainer according to claim 3, characterized in that: The guide track includes a curved pipe, an inner limit ring is provided on the inner wall circumference of one sleeve end of the curved pipe, and an outer limit ring is provided on the outer wall circumference of the other sleeve end of the curved pipe. The curved pipe is sleeved in sequence through the inner sleeve ring and the outer sleeve ring in the order of monotonically changing radial arc length.

6. The method for manufacturing the joint jaw retainer according to claim 3 or 4, characterized in that: The guide rail includes curved plates, which are telescopically connected in sequence along a monotonically changing radial arc length, and the curved plate with a smaller radial arc length is sleeved inside the curved plate with a larger radial arc length; Except for the curved plate with the smallest radial arc length, the inner walls of the other curved plates are all provided with arc-shaped grooves along their own axial directions. The arc length of the arc-shaped groove is equal to the length of the curved plate itself, and the axial curvature of the arc-shaped groove is equal to the axial curvature of the curved plate with the smallest radial arc length that is sleeved therewith. Except for the curved panel with the largest radial arc length, the outer wall of one end of the remaining curved panels close to the curved panel with the largest radial arc length is provided with a sliding table that is slidably connected to the arc groove, wherein the axial curvature of the curved panel is equal to the curvature of the corresponding sub-curve and the axial arc length is equal to the arc length of the corresponding sub-curve.

7. The method for manufacturing the joint jaw retainer according to claim 1, characterized in that: The two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentition, and further include: Grooves are provided on both ends of the guide telescopic assembly and on one side close to the teeth. The grooves are detachably connected to the protrusions of the upper and lower mandibular split retainers. The protrusions are respectively located at the clinical crown center of the second premolar of the maxillary split retainer and the clinical crown center of the first molar of the mandibular split retainer. Both ends of the guide telescopic assembly and on one side close to the face are provided with arc chamfers. The maxillary split retainer and the mandibular split retainer are made using 3D digital printing technology based on digital models of the upper and lower jaw dentitions. The labial sides of the maxillary split retainer and the mandibular split retainer are both made of PETG material and the lingual sides are both made of double-row nickel-titanium wire.

8. A jaw retainer, characterized in that: It comprises a guide telescopic assembly manufactured according to the manufacturing method of the joint jaw retainer as described in any one of claims 1 to 7, wherein the guide telescopic assembly can be telescoped along its own axis, and the guide telescopic assembly comprises guide rails that are serially sleeved in sequence, and the two ends of the guide telescopic assembly are detachably connected to the upper and lower jaw dentitions respectively.

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