Auxiliary device for forward traction and correction system

Abstract

The invention provides an auxiliary device for forward traction and a correction system, and relates to the technical field of orthodontics, the auxiliary device for forward traction comprises an anchorage column and a connecting rod, the anchorage column is connected with teeth, one end of the connecting rod is connected with the anchorage column, the other end of the connecting rod is connected with a front traction surface frame, and the anchorage column is provided with a blind hole or a through hole; the correction system comprises a front traction surface frame and the auxiliary device. The anchorage foundation is transferred to the lower jaw dental arch from the traditional chin pocket, so that the stress discomfort of the chin is avoided; meanwhile, the blind hole or the through hole facilitates accurate positioning and stable assembly of the connecting rod, the overall structural stability and the force conduction efficiency are improved, and therefore the technical problems that a traditional front traction device is uncontrollable in anchorage, the chin pocket is pressed and uncomfortable, and molar distalization is difficult to support synchronously are solved, and the comfortable, stable and multifunctional integrated correction effect is achieved.

Description

Technical Field

[0001] This invention belongs to the field of oral medical technology and relates to an auxiliary treatment device for distalization and anterior traction of molars in the lower dental arch, specifically for the treatment of Class III facial profile and distalization of molars in children. Background Technology

[0002] Class III skeletal malocclusion is a common dentofacial deformity, clinically manifested primarily as midfacial hypoplasia, mandibular protrusion, and a concave profile. This deformity involves the soft and hard tissues of the entire craniofacial region, representing a complex multi-organ disorder. This malocclusion not only affects facial aesthetics but also impairs physiological functions such as chewing and speech, causing serious negative impacts on the patient's physical and mental health. For patients with mild to moderate Class III skeletal malocclusion, different types of orthodontic appliances, such as metal brackets, invisible orthodontics, ceramic brackets, and lingual braces, can be used to move the maxillary anterior teeth forward and retract the mandibular incisors to a certain extent, gradually adjusting the tooth position and achieving acceptable facial aesthetics and occlusion through dental compensation. However, the range of tooth movement is limited, thus the applicable cases are relatively restricted. Patients with severe skeletal Class III malocclusion, especially adults who have completed growth and development and have severely misaligned jaws, can undergo orthognathic surgery or a combination of orthodontics and orthognathic surgery to correct their facial shape. However, these surgeries are highly invasive, time-consuming, and expensive. For patients in their growth and development stage, functional orthodontic treatment can promote maxillary bone growth and improve facial profile. Treatment of skeletal Class III malocclusion requires a comprehensive consideration of the patient's specific situation, selection of appropriate treatment methods, and timely intervention during the mixed dentition period to achieve the best therapeutic outcome.

[0003] Some patients with skeletal Class III malocclusion may experience maxillary protrusion and mandibular inclination due to compensatory reasons. This requires improvement of the occlusal relationship and removal of the compensatory mechanism. If the patient is in the peak growth and development period, anterior traction can be performed to improve the maxilla. However, if the mandibular space is insufficient due to the structure of the orthodontic appliance and facial frame, and molar distalization is required to provide space, anterior traction must be performed before improving the mandibular molars. In this case, the optimal treatment period may be missed after anterior traction.

[0004] During peak growth and development, growth modification therapy is the preferred method for treating skeletal malocclusion, suitable for children and adolescents in the mixed dentition stage. This treatment aims to adjust the relationship between the upper and lower jaws by correcting skeletal deformities, rather than simply resolving tooth misalignment. For most skeletal malocclusions, satisfactory orthodontic results can be achieved with timely and correct growth modification therapy. Anterior traction is commonly used clinically to treat skeletal Class III malocclusions during the growth and development period, for patients with maxillary hypoplasia, relatively normal mandibular development, and who are still in the growth and development stage. This appliance helps to move the maxilla forward, improve midface flatness and the sagittal positional relationship between the upper and lower jaws, and has a good therapeutic effect on improving facial profile. Maxillary anterior traction typically consists of extraoral components (frontal pad, chin cup, and connecting face bow), intraoral components (intraoral device with traction hooks), and force application components (elastic rubber bands). The intraoral device can be a cast or ringed fixed maxillary appliance, an adhesive base appliance, or a full-arch removable base appliance, depending on the patient's specific situation. A stable and secure intraoral device is crucial for effective maxillary anterior traction. Among the extraoral components, the frontal pad and chin cup provide support for the anterior traction force and bear the reaction force. The chin cup has a much smaller contact area with the face than the frontal pad, thus bearing greater pressure. In clinical use, excessive pressure at the chin cup often leads to chin redness, swelling, pressure sores, and even scarring. Therefore, this invention addresses these issues by removing the chin cup and adding an intraoral mandibular device. Simultaneously, the newly added intraoral mandibular device assists in distalizing the mandibular dentition, working in conjunction with anterior traction to improve retrograde dentition.

[0005] Because traditional anterior traction appliances can cause discomfort, sensitivity, or allergies in the chin area due to the force applied to the chin pocket, this invention improves the intraoral device for anterior traction to improve the force application point of the chin pocket. At the same time, it can provide anchorage assistance to patients who need distalization of molars due to mesial movement of mandibular molars or who need anchorage from the mandibular dental arch, and can be used in conjunction with anterior traction. Summary of the Invention

[0006] This invention provides an auxiliary device and orthodontic system for anterior traction, which relies on its own dental arch for anchorage, has a stable structure, is simple to manufacture, improves the problem of uncontrollable changes in mandibular direction during anterior traction, and can also perform molar distalization.

[0007] The first aspect of this application provides an auxiliary device for front traction, including a support column and a connecting rod, wherein the support column is connected to a tooth; one end of the connecting rod is connected to the support column and the other end is connected to the front traction faceplate; and blind holes or through holes are provided on the support column.

[0008] Furthermore, the anchorage column is located on the outside of the personalized mandibular connecting pad, and the anchorage column and the personalized mandibular connecting pad are integrally formed or bonded together.

[0009] Furthermore, the anchor post is set on a fixing strip, and the anchor post and the fixing strip are integrally formed, with the fixing strip bonded to the outer side of the tooth row.

[0010] Furthermore, at least two anchorage posts are provided on one side of the mandible, with through holes in the anchorage posts in front of the dentition and blind holes in the anchorage posts behind the dentition.

[0011] Furthermore, the connecting rod is designed with a blocking protrusion, which serves as a support part to assist in the distal movement of the molar.

[0012] Furthermore, the end of the connecting rod is a straight rod or has a bent structure, which mutually limits the movement of the support column.

[0013] Furthermore, a cross-shaped connector is provided at the connection between the connecting rod and the front traction frame to enable the connecting rod to move left, right, up, and down at one end.

[0014] Furthermore, the connecting rod is connected to the front traction frame using a snap-fit ​​connection.

[0015] Furthermore, the personalized mandibular connecting pad was modeled using oral scan data and fabricated using 3D printing.

[0016] The second aspect of this application provides an orthodontic system for treating Class III facial profile and molar distalization in children, including anterior traction frame and an auxiliary device for anterior traction as described in any of the preceding claims.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: This application provides a method for setting anchorage posts that are directly connected to the teeth and connected to the anterior traction frame by connecting rods. The anchorage posts have blind holes or through holes, which transfers the anchorage basis from the traditional chin support to the mandibular dental arch itself, avoiding discomfort caused by force on the chin. At the same time, the blind holes or through holes facilitate the precise positioning and stable assembly of the connecting rods, improving the overall structural stability and force transmission efficiency. This solves the technical problems of uncontrollable anchorage, discomfort caused by chin support compression, and difficulty in simultaneously supporting molar distalization in traditional anterior traction devices, achieving a comfortable, stable, and multifunctional integrated orthodontic effect. Attached Figure Description

[0018] Figure 1 This is a top view of the connecting frame of the device structure described in this invention; Figure 2 This is a schematic diagram of a faceplate structure according to the present invention.

[0019] Figure 3 This is a top-view schematic diagram of a portion of the internal structure of the auxiliary device for forward traction. Figure 4 for Figure 3 A side view of the structure shown; Figure 5 Schematic diagram of a structure where support columns are installed on fixing strips; Figure 6 A partial schematic diagram showing a blocking protrusion on the cheek side for the connecting rod; Figure 7 A partial schematic diagram showing two blocking protrusions on the cheek side for the connecting rod; Figure 8 This is a schematic diagram of a usable cross-shaped connector structure according to this application, where a is a front view and b is a top view of a.

[0020] Figure 9 This is a schematic diagram of a structure with one straight rod on each side of this application.

[0021] In the attached diagram, 1-support column, 2-connecting rod, 3-fixing strip, 4-blocking protrusion, 5-front traction frame, 6-frame connecting rod Detailed Implementation The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: Class III skeletal malocclusion manifests as midfacial retrusion, mandibular protrusion, and concave profile during childhood growth and development. It not only affects facial aesthetics but is also often accompanied by decreased chewing efficiency, unclear pronunciation, and abnormal temporomandibular joint loading. Traditional anterior traction therapy relies on the chin support to apply posterior reaction force to drive maxillary anterior movement. However, long-term pressure from the chin support on the mandibular soft tissue can easily cause skin redness, indentation, allergic reactions, and poor patient compliance. Simultaneously, intraoral retention devices often use removable appliances with traction hooks or fixed bracket systems, whose anchorage is unstable. Especially when simultaneous mandibular molar distalization is required, the lack of a rigid, precisely positioned, and highly arch-fitting mandibular anchorage structure leads to deviation in the traction force transmission path, reduced efficiency, and may induce unfavorable compensatory mechanisms such as labial tipping of the mandibular anterior teeth or clockwise rotation of the mandible. Furthermore, existing devices cannot effectively achieve the dual goals of maxillary anterior traction and mandibular molar distalization within the same treatment cycle, typically requiring phased implementation, significantly prolonging the treatment course and missing the critical intervention window during the peak growth potential period. This embodiment provides an anterior traction auxiliary structure that does not rely on chin soft tissue force, has a reliable mandibular dental anchorage basis, a simple structure, and a clearly defined mechanical path, providing a scalable device for functional integration.

[0023] This embodiment provides an auxiliary device for anterior traction, constructing a rigid force transmission link with the mandible as the direct anchorage source: the anchorage post 1 achieves stable retention with the mandibular dentition, and the external traction force applied by the anterior traction frame 5 is accurately introduced into the intraoral anchorage system with the help of the connecting rod 2, avoiding chin cup compression and improving treatment stability and patient comfort; the blind holes or through holes provided on the anchorage post 1 are used for the assembly and positioning of the connecting rod 2, angle fine adjustment, addition of blocking structure, and replacement of connecting rods 2 of different specifications, enhancing the individual adaptability of the device and the flexibility of clinical operation.

[0024] The anchorage post 1 is a rigid columnar structure used to establish a mechanical connection between the mandibular dentition and the connecting rod 2. Its material can be biocompatible medical-grade titanium alloy, cobalt-chromium alloy, or high-strength light-cured resin. The cross-section is circular, elliptical, or polygonal with anti-rotation grooves, with a height of 3-8 mm and a diameter of 1.2-2.5 mm. The anchorage post 1 can be directly bonded to the buccal enamel surface of the mandibular crown with adhesive, or it can be embedded in the mandibular personalized connecting pad base through an integrated molding method. The traction force transmitted by the connecting rod 2 is evenly distributed to the connected single or multiple teeth to form a local strong anchorage unit, avoiding the anchorage loss caused by insufficient retention in traditional removable orthodontic appliances.

[0025] refer to Figure 1 , Figure 2 Connecting rod 2 can be connected to the two straight rods at the lip position using an arc-shaped steel wire. In the figure, to avoid facial features, artificial intelligence-assisted processing is used to eliminate facial features, retaining only the characteristic structure of the faceplate worn on the head.

[0026] refer to Figure 2 The present invention provides a schematic diagram of an implementable noodle frame connection. A bent noodle frame connecting rod 6 is provided on the noodle frame 5. The connecting rod of this application is connected to the noodle frame connecting rod 6, and the noodle frame 5 and the lip will maintain a certain space.

[0027] refer to Figure 2 and Figure 9 Alternatively, a straight rod can be used on each side, which can extend the connecting rod 2 to directly connect to the faceplate 5.

[0028] The connecting rod 2 is a linear force transmission component. Its main body is a cylindrical or rectangular cross-section rod, or the connection with the anchor post 1 is rectangular and the rest is cylindrical. The material can be stainless steel wire or nickel-titanium alloy wire. One end of the connecting rod 2 is rigidly connected to the anchor post 1 through mechanical fitting or bonding, and the other end is connected to the anterior traction frame 5 through a detachable interface. This ensures that the traction force direction is controllable, the magnitude is adjustable, and the path is minimized, reducing energy dissipation and unexpected displacement. The anchor post 1 achieves stable connection with the mandibular dentition through physical retention. This can be either a direct bonding interface to the hard tissue of the crown or an indirect overall retention achieved by relying on the personalized mandibular connecting pad. The connection meets the clinical requirements for short-term immediate retention strength and long-term stability, and can be removed without damage after treatment without damaging the tooth structure.

[0029] Blind holes or through holes are made on the anchorage column 1. The depth of the blind hole is 1 / 3–2 / 3 of the total length of the anchorage column 1. The through hole is a through channel that runs through both ends of the anchorage column 1 and has a diameter of 0.5–1.8 mm. Both can be used as guide references for the insertion and positioning of the connecting rod 2. The end of the connecting rod 2 can be designed as a frustum or with a radial flange. After being inserted into the blind hole, it is fixed by interference fit or glue application, which facilitates rapid clinical assembly and adjustment.

[0030] The anchorage post 1 is firmly connected to the tooth to establish the anchorage point; the connecting rod 2 transmits torque, and its two ends are connected to the anchorage post 1 and the anterior traction frame 5 respectively; the blind hole or through hole on the anchorage post 1 is the key structural interface for the installation, positioning and functional expansion of the connecting rod 2. It can bear and transmit the load required for anterior traction through only the hard tissue of the tooth, avoiding stimulation of the soft tissue; the anchorage post 1 is directly connected to the tooth, which avoids continuous pressure of the chin sac on the soft tissue of the chin, and solves the problems of patient discomfort, poor compliance and soft tissue damage mentioned in the background art.

[0031] Based on the above embodiments, the anchorage column 1 is located on the outside of the personalized mandibular connecting pad, and the anchorage column 1 and the personalized mandibular connecting pad are integrally formed or bonded to the personalized mandibular connecting pad.

[0032] By deeply integrating the anchorage post 1 with the personalized mandibular connecting pad in terms of spatial position and connection method, the mechanical synergy and morphological adaptation of the anchorage unit and the bearing base are achieved, improving the overall rigidity, retention stability and long-term wearing reliability of the intraoral anchorage system. The anchorage post 1 is located on the outside of the personalized mandibular connecting pad, meaning that the main structure of the anchorage post 1 is located outside the surface of the pad facing the buccal or labial side of the mouth, and can be partially embedded inside the pad body; its axis can be perpendicular to the surface of the pad, or can be extended at a preset angle to match the entry angle of the connecting rod 2 and optimize the lever arm distribution.

[0033] The anchorage column 1 and the personalized mandibular connection pad are integrally molded. When using 3D printing technology, the anchorage column 1 and the mandibular pad substrate share the same digital model and are integrally formed in a single printing operation without the need for subsequent assembly. As an optional embodiment, the anchorage column 1 can also be made by insert injection molding: first, the pre-formed titanium alloy anchorage column 1 is placed into the positioning tooling of the mold cavity, and then liquid medical acrylic resin is injected. After cooling and curing, a molecular-level interface bond is formed.

[0034] After the anchorage column 1 and the personalized mandibular pad are prepared separately, they can be reliably connected through a bio-adhesion system. The bonding interface is the bottom plane of the anchorage column 1, or between the annular boss and the pre-reserved support groove or support plane on the outside of the mandibular pad. In clinical practice, the compressive strength and shear bond strength of the bond meet the clinical requirements, and it has good resistance to saliva dissolution and long-term water aging stability.

[0035] The personalized mandibular connecting pad serves as the basic load-bearing platform, determining the spatial positioning benchmark of anchorage column 1. The arrangement of anchorage column 1 on the outside ensures unobstructed docking with connecting rod 2 and accessibility for clinical operation. The combined structure has reliable torque transmission, avoiding force attenuation and directional deviation caused by micro-motion friction in traditional separate structures.

[0036] Through the above technical embodiments, in the treatment of skeletal Class III malocclusion in children, when a combined intervention strategy of anterior traction and mandibular molar distalization is adopted, the anchorage column 1 can achieve good retention by relying on the personalized occlusal pad. Its lateral arrangement facilitates the quick attachment and angle adjustment of the connecting rod 2, while the integrated molding or high-strength bonding eliminates the tendency of relative displacement between the anchorage unit and the bearing base. The anchorage column 1 and the occlusal pad have a high-rigidity, zero-slip connection, which enables the anterior traction force to be efficiently and stably converted into an anterior traction effect on the maxilla, while providing reliable counter-resistance for mandibular molar distalization. This solves the problem of insufficient mandibular anchorage limiting the traction effect and molar distalization efficiency, thereby improving treatment synchronicity, shortening the treatment course, and enhancing the orthodontic effect.

[0037] Example 3: In this embodiment, the anchor post 1 is set on a fixing strip 3. The anchor post 1 and the fixing strip 3 are integrally formed, and the fixing strip 3 is bonded to the outer side of the tooth row.

[0038] By integrating the anchorage post 1 onto the universal fixation strip 3 and bonding it together, stable retention on the lateral side of the mandibular dentition is achieved, taking into account both the convenience of clinical operation and mechanical reliability. The fixation strip 3, as a supporting component for the anchorage post 1, extends along the buccal side of the mandibular dentition, and its length is adapted to at least 2–4 consecutive posterior teeth; the fixation strip 3 is generally in the shape of an arc-shaped thin sheet. The anchor post 1 is set on a fixing strip 3, which means that the anchor post 1 is spatially positioned and mechanically transmitted with the fixing strip 3 as the base. The fixing strip 3 does not participate in occlusal contact, but only plays a structural anchoring role. Its position can be selected to be symmetrically arranged on both sides of the buccal side of the mandibular dentition. The anchor post 1 and the fixing strip 3 are integrally formed, which means that there is no assembly interface during the manufacturing process. The material is continuous and the structure is integrated. It can be realized by metal laser selective melting (SLM) technology and dental photosensitive resin DLP 3D printing. The integrated structure eliminates the risk of the anchor post 1 moving slightly, loosening or plastic deformation relative to the fixing strip 3 under repeated loading. The outer side of the dentition refers to the buccal or lingual enamel area of ​​the mandibular crown, excluding the occlusal surface and proximal surface. The bonding interface is the three-phase interface of enamel, adhesive and fixing strip 3.

[0039] As a further optimization, at least two anchorage posts 1 are provided on one side of the mandible, with through holes in the anchorage post 1 in front of the dentition and blind holes in the anchorage post 1 behind the dentition.

[0040] By coordinating spatial positioning and aperture structure, a dual anchorage system with mechanical division of labor is constructed within a limited intraoral space: the anterior anchorage post 1 undertakes the main connection and force transmission functions, while the posterior anchorage post 1 provides auxiliary positioning and anti-rotation support. Together, they enhance the structural stability and motion control precision of the device under complex orthodontic force systems. This system is suitable for combined orthodontic scenarios requiring simultaneous maxillary anterior traction and mandibular molar distalization, and can alleviate problems such as deflection of the connecting rod 2, loosening of the anchorage post 1, or displacement of the occlusal pad caused by single anchorage and ambiguous positioning. At least two independent anchorage units are arranged in the lateral region of the dental arch on one side; each anchorage post 1 is arranged anteriorly and posteriorly along the long axis of the dentition, and the spacing between them is determined according to the individual mandibular morphology and the target molar distalization segment. The anchorage post 1 at the front of the dentition has a through hole, meaning that the anchorage post 1 located at the position corresponding to the segment from the mandibular canine to the first premolar has a circular or elliptical through hole axially through it. The hole wall is smooth and perpendicular to the central axis of the anchorage post 1. This through hole is used to pass the intraoral end of the connecting rod 2, so that the length of the connecting rod 2 can be adjusted by sliding along the axis, and it supports the subsequent installation of a locking nut or elastic snap ring to achieve axial limitation. The through hole can also be compatible with quick replacement of connecting rods 2 of different diameters. The through hole can be replaced with a cross-shaped through hole, a keyway through hole, or a through hole with internal threads to adapt to the interface of the connecting rod 2 with the corresponding structure and achieve anti-rotation fit. The anchorage post 1 at the rear of the dentition has a blind hole, meaning that the anchorage post 1 located at the position corresponding to the segment from the mandibular first molar to the second molar has a cylindrical blind hole with a planar or spherical bottom. The blind hole is used to insert a positioning pin, a limiting pin, or an elastic set screw to suppress the torsion or lateral sway of the connecting rod 2 around its own axis.

[0041] Based on the above embodiments, this embodiment further designs a blocking protrusion 4 in the connecting rod 2 as a support part to assist in the distal movement of the molar. (See reference) Figure 6 and Figure 7 ,in Figure 6 As shown, only one blocking protrusion 4 is provided, and the rear end of the connecting rod 2 is inserted into the blind hole of the support column 1. Figure 7 The diagram shows two blocking protrusions 4, and a through hole is also provided in the rear anchorage post 1. Specifically, by adding blocking protrusions 4 to the connecting rod 2, the connecting rod 2 can transmit anterior traction force and actively participate in and support the distalization of mandibular molars. This achieves synergistic intervention for two orthodontic goals with the same device, without increasing the feeling of a foreign body in the mouth or affecting occlusal contact and speech function. It solves the problems of insufficient mandibular anchorage limiting the traction effect and molar distalization efficiency, as well as the need for phased implementation of conventional treatment and the risk of missing the peak growth period. The blocking protrusions 4 can be cylindrical or triangular in cross-section. A rigid structure protrudes from the connecting rod 2, the shape of which is not limited, as long as it can be used to prevent the connecting rod 2 from moving backward.

[0042] Based on the above embodiments, the end of the connecting rod 2 is either a straight rod or has a bent structure, with the bent structure mutually limiting the movement of the support column 1. Specifically, by configuring an optional straight rod end or a bent end with a mechanical limiting fit between the connecting rod 2 and the support column 1, the problems of insufficient rigidity in the connection between the connecting rod 2 and the support column 1, easy axial slippage or radial sway, and high risk of loosening after long-term wear are solved in the front traction auxiliary device.

[0043] The connecting rod 2 extends into the oral cavity and is a terminal structure for direct connection with the anchorage column 1. The end is a rigid rod in the shape of a straight cylinder, prism, or truncated cone, and its cross-section can be circular, elliptical, rectangular, or polygonal. After being inserted into the blind hole or through hole of the anchorage column 1, it is positioned by the interference fit between the hole wall and the rod. The straight rod is suitable for situations where the diameter tolerance of the anchorage column 1 is well controlled and the vertical distance of the patient's bite is sufficient.

[0044] When the inner end of the connecting rod 2 adopts a straight rod structure, a stable basic connection is provided by the precision hole-shaft fit, which meets the requirements of conventional anterior traction. When a bent structure is adopted, the bent section is embedded in the hole of the anchor post 1 to form a multi-directional mechanical limit, which inhibits the axial dislodgement tendency and radial swing amplitude of the connecting rod 2 under the action of traction force. Since the straight rod and the bent structure are mutually exclusive options, the clinicians can flexibly switch according to the installation conditions of the anchor post 1, patient compliance and treatment stage goals, without having to replace the entire connecting rod 2 or jaw pad. The connection stability between the connecting rod 2 and the anchor post 1 is comprehensively improved, reducing the probability of accidental loosening caused by speaking, swallowing or chewing during daily wear, ensuring the continuous, accurate and repeatable application of anterior traction force, and alleviating the problems of decreased traction efficiency, increased anchorage consumption and prolonged treatment cycle caused by connection instability.

[0045] As a further optimization: a cross-shaped connector is provided at the connection between the connecting rod 2 and the front traction face frame 5. Specifically, the cross-shaped connector has three through holes on a solid body, with the axes of the three through holes perpendicular to each other. Two of these holes are used to connect to the face frame, and the third is used to install the connecting rod 2, allowing the connecting rod 2 to move left, right, up, and down at its outer end to adjust the specific force point. The connection between the connecting rod 2 and the front traction face frame 5 refers to the point where the connecting rod 2 extends from inside the mouth out of the cheek, passes through the face arch support or forehead pad fixing band area, and its interface with the main body of the front traction face frame 5 is not limited to a single fixed point. The face frame structure has optional installation sections, ensuring that the assembly and disassembly process requires no tools and allows for repeated positioning. Markings can also be set on the face frame to refer to gradually changing orthodontic wearing methods.

[0046] The cross-shaped connector orthogonal axis structure transforms the non-ideal displacement of the faceplate caused by head rotation, jaw opening and closing, or facial expression traction into a fine-tuning response of the outer end of the connecting rod 2 in three-dimensional space. This response does not change the overall vector direction of the traction force, effectively eliminating local stress concentration and soft tissue stimulation caused by the accumulation of small misalignments under rigid connection.

[0047] The snap-fit ​​connection, as a reusable mechanical connection method, is used in this embodiment to achieve quick, reliable, tool-free assembly between the outer end of the connecting rod 2 and the anterior traction frame 5. This connection method does not rely on permanent or semi-permanent fixation methods such as threaded fastening, welding, or bonding. When the snap-fit ​​is in the locked state, the traction force applied by the anterior traction frame 5 is efficiently and smoothly transmitted to the connecting rod 2 through the snap-fit ​​interface, and further transmitted to the maxilla or alveolar bone through the anchorage column 1 to achieve the maxillary anterior traction effect. At the same time, the snap-fit ​​structure itself does not participate in the molar distalization anchorage function. Its design is independent of the position and shape of the blocking protrusion 4, and only needs to ensure the connection stiffness and decoupling degree of freedom, but does not cause macroscopic rotation or axial movement.

[0048] The personalized mandibular connecting chin pad is modeled using intraoral scanning data and fabricated using 3D printing. The intraoral scanning data provides millimeter-level realistic anatomical input, laying a geometrically accurate foundation for model construction. The CAD modeling process embeds structural constraints such as the spatial positioning, orientation, and transition curvature of the anchorage column 1 with the chin pad body into the digital model, realizing design-to-manufacturing. 3D printing more realistically reproduces this digital definition, completing the integrated forming of the chin pad body, the anchorage column 1 body, and the zero-gap transition surface between the two in one go. This solves the problems of unstable fixation, anchorage displacement, and wearing discomfort caused by traditional chin pad manufacturing methods mentioned in the background technology.

[0049] A treatment system for Class III facial profile and molar distalization in children includes anterior traction frame 5 and the aforementioned anterior traction auxiliary device.

[0050] In this orthodontic system, the anterior traction frame 5 serves as the extraoral force source, providing stable, controllable, and directionally adjustable forward traction. The aforementioned anterior traction auxiliary device acts as a crucial hub for intraoral force transmission and anchorage distribution, achieving both rigid anchorage and morphological adaptation of the mandibular dentition. Furthermore, its built-in structured anchorage points convert some of the traction reaction force into an effective driving force for mandibular molar distalization. The entire system does not rely on additional anchorage implantation or the stacking of independent appliances, avoiding temporal conflicts and mechanical interference between treatment modules, allowing both types of orthodontic goals to be simultaneously and efficiently advanced during the peak of physiological growth.

[0051] The front traction face frame 5 refers to an extraoral device used to apply external traction force. Its typical structure includes a forehead pad, a chin pocket, and a face bow connecting the two. The two ends of the face bow are rigidly connected to the forehead pad and the chin pocket, respectively, and a traction hook or traction ring is provided in the chin pocket area for attaching elastic elements. In this embodiment, the front traction face frame 5 is not limited to a specific model.

[0052] In the early intervention of skeletal Class III malocclusion in children, an anterior traction frame 5 is used as the external power source, and the aforementioned anterior traction auxiliary device is used as the intraoral functional hub to construct a composite orthodontic system that can simultaneously perform maxillary anterior movement and mandibular molar distalization.

[0053] The following is an example of a patient undergoing orthodontic treatment.

[0054] Class III skeletal malocclusion is characterized by maxillary retrusion, mandibular protrusion, or both. Patients with this type of malocclusion often exhibit three-dimensional misalignments in their jawbone, teeth, and soft tissues, making treatment challenging. This case involves a child with early mixed dentition and skeletal Class III malocclusion who showed significant growth potential. Initial orthodontic treatment using traditional anterior traction resulted in excessive pressure on the chin support, leading to chin swelling, pressure sores, and scarring. Therefore, this case was later addressed by removing the chin support and adding an intraoral mandibular appliance. After replacing the traction appliance, the patient's chin swelling subsided, the reverse overbite was corrected, and the facial profile significantly improved.

[0055] Basic Information: Male, 11 years old, chief complaint: underbite, requesting orthodontic treatment. Present Illness: The patient has noticed a gradual worsening of midfacial concavity since his permanent teeth erupted. He has no history of orthodontic treatment. His father has a similar facial profile. The patient is in good general condition. Oral and Maxillofacial Examination: The child's mid-facial third is concave, while the lower third is longer, resulting in a severely concave profile. The upper lip is positioned behind the lower lip. Anterior crossbite is -2mm. The upper anterior teeth are labially inclined, and the lower anterior teeth are lingually inclined. Both molars are in mesial relationship. Temporomandibular joint examination was normal. X-ray examination, including lateral cephalometric radiographs, revealed: maxillary hypoplasia, mandibular hyperplasia, significant labial inclination of the upper anterior teeth, compensatory lingual inclination of the lower anterior teeth, and high-angle anterior crossbite. Diagnosis: Skeletal Class III high-angle anterior crossbite; Angle Class III; anterior crossbite.

[0056] Treatment Goals: 1. Promote maxillary length and width growth. 2. Inhibit excessive mandibular growth. 3. Correct reverse overbite. Treatment Plan: 1. Rapid expansion with a maxillary spiral expander, combined with anterior traction, to promote transverse and sagittal development of the maxilla. Treatment Process: The treatment process is as follows: 1. The child was fitted with a maxillary support spiral expander in conjunction with anterior traction for two weeks. The parents reported that the child had redness, swelling and pain in the chin area, and that scarring had appeared on the chin. The parents also reported that the child was unable to cooperate with the fitting.

[0057] 2. The treatment plan was changed, the chin support was removed, and an intraoral mandibular pad and connecting rod were added. After 5 months, the patient's parents reported significant improvement in the redness and swelling of the child's chin, and a marked reduction in discomfort. The results of the oral and maxillofacial examination are as follows: Soft tissue lateral view: The depression in the middle third of the child's face has improved, and the upper lip is located in front of the lower lip; Frontal view of soft tissue: Improvement in nasal side depression, increased fullness; Chin: Redness and scarring have mostly healed. Intraoral lateral occlusion: anterior teeth overbite 0.5mm, bilateral molar relationship and mesial relationship improved.

[0058] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A forwardly towed auxiliary device, characterized in that It includes a support column (1) and a connecting rod (2). The support column (1) is connected to the teeth; one end of the connecting rod (2) is connected to the support column (1), and the other end is connected to the front traction face frame; blind holes or through holes are opened on the support column (1).

2. The front-hauled auxiliary device according to claim 1, characterized in that The anchorage column (1) is located on the outside of the personalized mandibular connecting pad. The anchorage column (1) is integrally formed with the personalized mandibular connecting pad or the anchorage column (1) is bonded to the personalized mandibular connecting pad.

3. The front-hauled auxiliary device of claim 1, wherein, The anchorage column (1) is set on a fixing strip. The anchorage column (1) and the fixing strip are integrally formed. The fixing strip is bonded to the outer side of the tooth row.

4. The front towed auxiliary device according to claim 1, characterized in that, At least two anchorage posts (1) are provided on one side of the mandible. The anchorage post (1) in front of the dentition has a through hole, and the anchorage post (1) in the back of the dentition has a blind hole.

5. The front towed auxiliary device according to claim 1, characterized in that, A blocking protrusion (4) is designed on the connecting rod (2) as a support part to assist the distal movement of the molar.

6. The front towed auxiliary device according to claim 1, characterized in that, The end of the connecting rod (2) is a straight rod or has a bent structure, and the bent structure and the support column (1) limit each other.

7. The front towed auxiliary device according to claim 1, characterized in that, A cross-shaped connector is provided at the connection point between the connecting rod (2) and the front traction frame. A fastening screw is provided on the cross-shaped connector to enable the connecting rod (2) to move left, right, up, and down at one end outside the opening.

8. The front towed auxiliary device according to claim 1, characterized in that, The connecting rod is connected to the front traction frame by a snap-fit ​​mechanism.

9. The front towed auxiliary device according to claim 1, characterized in that, The personalized mandibular connecting jaw pad was modeled using oral scan data and fabricated using 3D printing.

10. A corrective system for Class III facial profile and molar distalization in children, characterized in that, It includes a front traction frame and an auxiliary device for front traction as described in any one of claims 1-9.

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