An embedded tooth traction device

Abstract

The present application relates to the field of dental correction tools, in particular to a device for traction of impacted teeth. The device is composed of a traction hook and an appliance. The traction hook is adhered to the crown of the impacted tooth to be tractioned. The traction hook is composed of an adhesive accessory and a ligature wire. One end of the ligature wire is fastened to the adhesive accessory, and the other end of the ligature wire is free and curved into a hook. The appliance is composed of an elastic traction wire and a retaining device. One end of the elastic traction wire is embedded in the retaining device, and the other end of the elastic traction wire is curved and connected to the free curved end of the ligature wire of the traction hook. The device can reasonably adjust the traction direction of the impacted teeth in three-dimensional space, and can correct the impacted teeth in different dentition periods. The device has low requirements for the anchorage teeth, is simple to manufacture, low in price, and has remarkable effects.

Description

Technical Field

[0001] This invention relates to the field of orthodontic tools, and to a dental orthodontic device, particularly to an impacted tooth traction device. This device is also suitable for the treatment of severely misaligned teeth. Background Technology

[0002] Impacted teeth are teeth that have passed their eruption period but remain embedded in the jawbone due to obstruction from nearby teeth, bone, or soft tissue. They cannot be observed directly with the naked eye and require imaging examinations for detection. The prevalence of impacted teeth is reported to be approximately 13.7%–16.5% in international studies and approximately 7.33%–9.61% in large-scale domestic case studies, making it a common and frequently occurring disease in oral clinics. The causes of impacted teeth are complex. Common pathological factors include abnormal tooth germ position, premature loss of deciduous teeth, infection of deciduous teeth, and trauma leading to abnormal eruption pathways of the permanent teeth, as well as systemic factors such as malnutrition, rickets, osteosclerosis, and endocrine disorders.

[0003] Impacted teeth can cause various harms to oral health. Impacted teeth and the oral and maxillofacial inflammations and tumors they induce are among the most common diseases in oral and maxillofacial surgery. Impacted teeth can lead to widening of interdental spaces, tooth rotation, ectopic placement, and other deformities, easily causing tooth decay and periodontitis, and may even induce jawbone tumors. Impacted teeth can cause pressure symptoms on adjacent teeth; for example, if a second molar is compressed by an impacted third molar, root resorption can occur, causing pain and secondary pulpitis and periapical periodontitis. The occurrence of impacted teeth not only reduces the number of permanent teeth but also causes dentition abnormalities, abnormal dental arch morphology, malocclusion, and inflammation and root resorption of adjacent tissues, affecting the patient's facial aesthetics, chewing function, and mental health.

[0004] Currently, there are generally two options for treating impacted teeth: one is surgical extraction. However, direct extraction of impacted teeth, which are closely related to important structures such as the inferior alveolar nerve and blood vessel bundle, the maxillary sinus cavity, and the nasopalatine nerve, carries a high risk. Furthermore, extraction can sometimes lead to incomplete dentition, affecting the patient's aesthetics, occlusion, and chewing function. The other option is traction, which involves pulling the impacted tooth into the oral cavity and then performing conventional orthodontic treatment to correct it to its proper position. Even if extraction is still necessary after traction, the risk and difficulty of the extraction surgery are reduced because the impacted tooth is now away from important nerves and blood vessels, significantly increasing safety.

[0005] Surgical exposure combined with orthodontic traction is one of the best treatment methods. The conventional orthodontic procedure consists of four steps: 1) widening the eruption gap to ensure unobstructed eruption of the impacted tooth; 2) surgically creating a window to expose the crown of the impacted tooth; 3) attaching traction attachments, such as brackets, lingual clips, and traction hooks; 4) applying orthodontic traction force to pull the impacted tooth out and align the teeth. Among these, traction of impacted teeth has the longest treatment duration and is the most challenging, and it is currently the focus of clinical research on impacted teeth.

[0006] The common method for traction of impacted teeth is to use removable or fixed orthodontic appliances. If fixed appliances are used, the remaining teeth in the dentition must be able to withstand the fixed treatment. Initial alignment of the dentition is necessary to allow for the use of large-sized archwires and to stabilize the anchor teeth. Traction of impacted teeth needs to be delayed for several months. During this period, the position and morphology of the impacted teeth in children may change. If multiple consecutive teeth are impacted, the increased free distance of the master archwire increases its elasticity, requiring greater force to traction the impacted teeth, which exacerbates this trend and can easily lead to tilting of adjacent teeth used as anchors. If opposing teeth are used for traction, it can easily cause elongation of the opposing teeth. Fixed appliances typically align the impacted teeth directly into the dentition, resulting in a single direction of traction force. Furthermore, the use of fixed appliances is limited in children with mixed dentition and multiple loose deciduous teeth. Fixed appliances also increase the difficulty of oral cleaning, increasing the risk of caries; additionally, there are emergencies such as bracket dislodgement and archwire irritation of soft tissues, requiring high patient compliance, especially in children. Although removable orthodontic appliances are bulky, uncomfortable, and can affect pronunciation, they allow for immediate traction and provide sufficient anchorage using the hard palate and alveolar bone, making them suitable even when there aren't enough healthy teeth in the dentition for support. Furthermore, the appliances can be removed for brushing and rinsing, which helps maintain oral hygiene and prevent cavities and inflammation of the oral soft tissues. Therefore, removable orthodontic appliances are more suitable for young children with poor brushing skills and those in the mixed dentition stage. They can also provide early treatment for impacted teeth, reducing the harm caused by impacted teeth.

[0007] In addition to having sufficient tissue to counteract the reaction force of the traction force and ensure the magnitude of the traction force, it is also necessary to adjust the direction of the traction force to control the eruption path of the impacted tooth, so that the impacted tooth can avoid obstacles and move to the correct position.

[0008] In traditional traction orthodontic treatment, the traction force primarily originates from the restoring force generated by the deformation of the archwire or rubber band. When using fixed appliances, the impacted tooth is ligated to the archwire, and the traction force stems from the restoring force generated by the archwire's deformation. Removable appliances often use rubber bands to connect the impacted tooth to the appliance's hooks, utilizing the elasticity of the rubber bands to pull the impacted tooth. The distance between the appliance's connection point (traction site) and the impacted tooth affects the magnitude of the traction force; a larger distance results in greater deformation of the archwire or rubber band, leading to a stronger traction force. Both archwires and rubber bands require sufficient distance between the impacted tooth and the traction site. If there is insufficient space in the patient's mouth for the appliance's traction hooks to move away from the impacted tooth, the archwire or rubber band will deform less, resulting in a weaker traction force. Furthermore, the direction of the traction force is determined by the location of the appliance's traction site; the impacted tooth, after being pulled, erupts towards the traction site. In some cases, it is difficult to balance the size of the orthodontic force when the traction point is oriented appropriately. If the impacted tooth needs to be moved to the labial or buccal side, the traction point is best on the labial side. However, because the space between the gum and the labial and buccal soft tissues is narrow, it is difficult to increase the distance between the traction point and the impacted tooth. Therefore, three-dimensional traction of impacted teeth has always been a clinical challenge.

[0009] To address this issue, the present invention designs the following orthodontic appliance, which has low requirements for anchorage teeth, can be used in different dentition stages, has flexible and varied traction force magnitude and direction, is simple to manufacture, convenient for patients to wear and apply force, and is safe and efficient. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides an impacted tooth traction device that can adjust the traction direction in three-dimensional space, can be used in different dentition stages, and has very low requirements for anchorage teeth.

[0011] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0012] An impacted tooth traction device comprises a traction hook and an orthodontic appliance. The traction hook is adhered to the crown of the impacted tooth to be tractioned. The traction hook consists of an adhesive attachment and a ligature wire. One end of the ligature wire is attached to the adhesive attachment, and the other end is free and bent into a hook. The orthodontic appliance consists of an elastic traction wire and a retention device. One end of the elastic traction wire is embedded in the retention device and bent at the end, which facilitates stability. The other end of the elastic traction wire can be bent or not bent and is detachably connected to the bent hook at the other end of the ligature wire on the traction hook. The function of the ligature wire is to pass through the gingival tissue and connect the adhesive attachment and the elastic traction wire. As the impacted tooth erupts, its length can be shortened as needed.

[0013] Furthermore, the elastic traction wire can also be combined with a clear aligner, using the clear aligner as a retention device. In other words, the retention device can be replaced by a clear aligner.

[0014] Furthermore, the elastic traction wire is bent into loops at the point where it extends from the retention device. There are 1-2 loops to adjust the required elasticity. The number of loops depends on the required traction force and the desired gentleness. The number of loops formed by the elastic traction wire at the point where it extends from the retention device is determined by the required elastic force for traction of the impacted tooth; typically, one loop is used. One end of the loop extends outward to form a traction section. The length and angle of this traction section can be adjusted according to the required direction of the impacted tooth.

[0015] Furthermore, the elastic traction wire is made of elastic Australian wire, orthodontic stainless steel archwire, or nickel-titanium wire.

[0016] Preferably, the elastic traction wire is Australian wire. The elasticity and hardness of Australian wire fall between those of stainless steel and nickel-titanium wire. It is less hard and more elastic than stainless steel archwire, but harder and more resilient than nickel-titanium wire. A free section of Australian wire provides sufficient hardness to prevent deformation, while also allowing for bending to increase elasticity, thus effectively controlling the direction of tooth movement and adjusting the elastic force. Therefore, Australian wire is the optimal choice for this device.

[0017] Furthermore, the structure of the retention device mainly depends on the direction of the traction force required to pull the impacted tooth and the height and integrity of the crowns of the other teeth in the dentition containing the impacted tooth. The basic principle of retention device design is to ensure at least three-point balance, where the elastic traction wire and traction hook form one retention point, and the other two retention points should be located in different quadrants of the same dental arch, ensuring sufficient retention force while also considering aesthetics and comfort.

[0018] Furthermore, if the traction force is directed towards the palatal or maxillary side, when the dentition is in the early stage of mixed dentition or when tooth damage is severe, the retention device can be a full-coverage occlusal splint to increase the contact area between the appliance and oral tissues, thereby increasing retention force. One end of the elastic traction wire is embedded in the lingual position within the full-coverage occlusal splint near the impacted tooth. When the dentition is in the permanent dentition stage or the late stage of mixed dentition and the teeth are healthy and intact, the retention device consists of a base and 2-3 single-arm clips. The single-arm clips are used to fix the base, and one end of the elastic traction wire is embedded in the lingual position within the base near the impacted tooth.

[0019] Furthermore, if the direction of the traction force is towards the palate or jaw, the retention device may be a Nance holder.

[0020] Furthermore, the single-arm card can be replaced with an arrow card, and a double-curved lip bow can be added if necessary.

[0021] Furthermore, if the traction force is biased towards the labial side, and the dentition is in the early stage of mixed dentition or when tooth damage is severe, the retention device can be a full-coverage occlusal splint, with one end of the elastic traction wire embedded in the labial portion of the splint. When the dentition is in the permanent dentition stage or the late stage of mixed dentition and the teeth are healthy and intact, the retention device consists of a baseplate, two or more single-arm clips, and a double-curved labial arch. One end of the elastic traction wire is bonded to the crossbeam to the curve of the double-curved labial arch using self-curving plastic, and the position of the double-curved labial arch does not obstruct the impacted teeth to be corrected. This is because when the crown height of the remaining teeth in the dentition is insufficient, such as in the early stage of mixed dentition, when the dentition is dominated by deciduous teeth and permanent teeth have not fully erupted, or when tooth damage is severe, such as multiple teeth having severe caries, it leads to difficulties in appliance retention. In such cases, using a full-coverage occlusal splint as a retention device can increase retention force. When multiple permanent teeth have erupted in the dentition and the teeth are healthy and intact, such as in the permanent dentition stage or the late mixed dentition stage, the retention device consists of a baseplate, two or more single-arm clips, and a double-curved labial arch. The elastic traction wire is made of self-curing plastic bonded to the curve of the double-curved labial arch. The position of the double-curved labial arch does not obstruct the impacted tooth to be corrected.

[0022] For patients in the early stages of mixed dentition or with severe tooth damage, a full-coverage occlusal splint is recommended. This splint utilizes the entire dentition (excluding impacted teeth) as anchorage teeth, effectively dispersing the anchorage force and preventing excessive stress on adjacent teeth, which could lead to movement or misalignment. Furthermore, in the early stages of mixed dentition, using a retention device consisting of a baseplate, two or more single-arm clasps, and a double-curved labial arch may not be feasible because the molars may not have fully erupted. Therefore, a full-coverage occlusal splint is preferable in the early stages of mixed dentition or when tooth damage is severe. However, in the permanent dentition stage and the later stages of mixed dentition, a full-coverage occlusal splint may affect the joint. If sufficient healthy teeth provide retention, a single-arm clasp and baseplate device can be used for retention.

[0023] Furthermore, the adhesive accessories often use tongue-side fasteners and brackets.

[0024] For bonding the traction hook, firstly, the mucosa of the impacted tooth is cut open, part of the alveolar bone is removed, and part of the crown of the impacted tooth is exposed. The bonding attachment (lingual buckle or bracket) is bonded to the crown of the impacted tooth, and then the ligature wire is tied to the bonding attachment with the other end of the ligature wire bent. The mucosa is then sutured, and the free end of the ligature wire is extended into the oral cavity.

[0025] A fully enclosed occlusal splint is used, with one end of the elastic traction wire embedded within it. The entire dentition, alveolar bone, and mucosa serve as anchorage tissue, bearing the reaction force of the traction. If the patient is in the permanent dentition stage, a double-curved labial arch is installed, avoiding the impacted tooth. One end of the elastic traction wire is bonded to the double-curved labial arch using self-curing plastic. The elastic traction wire is bent back into a loop at the point where it protrudes from the retention device, and the extended free archwire connects to the traction hook for the impacted tooth.

[0026] When using the appliance, install the traction hook and then wear the appliance. Different appliance devices are selected depending on the direction the impacted tooth needs to be pulled. When traction of the impacted tooth is required, connect the bent end of the ligature wire on the traction hook to the traction end of the elastic traction wire on the appliance. If not, separate the bent end of the ligature wire on the traction hook from the traction end of the elastic traction wire on the appliance, as shown by the dotted line in the figure. After connecting the traction hook to the elastic traction wire, the elastic traction wire deforms and generates a restoring force, creating tension on the traction hook. This causes the impacted tooth to be pulled in different directions—palatal, labial, and occlusal—thus gradually pulling the impacted tooth in the desired direction, achieving the purpose of traction. The elastic traction wire bends back into a loop at the point where it extends out of the retention device, allowing for adjustment of the wire's direction and position in three dimensions to obtain a suitable traction point.

[0027] The core feature of this patented design is that the orthodontic archwire is placed on a removable orthodontic appliance, utilizing the elasticity of the archwire to pull on impacted teeth. It eliminates the need for specialized traction hooks, the distance between the traction hook and the impacted tooth, and the influence of the hook's position on the traction force, resulting in minimal irritation to soft tissues. There is no need to use or replace rubber bands, simplifying the procedure for patients. The orthodontic archwires used in fixed orthodontic appliances (such as Australian wire, nickel-titanium wire, and stainless steel wire) are characterized by high elasticity, small diameter, and gentle, lasting force. Furthermore, depending on the type and size of the archwire, its elasticity varies to meet different force requirements. In addition, the archwire is easily molded (Australian wire, stainless steel wire) and can be bent into different shapes and lengths as needed. Traction wires made from orthodontic archwires can also be bent into hooks, possessing inherent elasticity and easily deforming under stress. Even at a distance from the impacted tooth, they can still be hooked. The elastic traction wire connects to the impacted tooth, reducing the distance and even allowing it to adhere closely to the mucosa. This results in minimal irritation to oral tissues. Furthermore, once the elastic traction wire is attached to the impacted tooth, it tends to return to its original shape after deformation. The resulting restoring force acts on the impacted tooth, which is the traction force for pulling the impacted tooth. The direction of the restoring force is the direction of the traction force for the impacted tooth; it can be towards the jaw, the labial or palatal side, or even towards the gingiva, thus pulling the impacted tooth in three dimensions.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1) This invention creatively changes the innovative approach by placing the orthodontic archwire on a removable appliance, utilizing the elasticity of the archwire to traction impacted teeth. It eliminates the need for specialized traction hooks, disregards the distance between the traction hook and the impacted tooth, and eliminates the influence of the hook's position on the traction force, resulting in minimal soft tissue irritation. It also eliminates the need for using and replacing rubber bands, simplifying patient operation. This device overcomes the drawbacks of existing technologies that use rubber bands as the elastic traction material, such as the inability to apply force when the distance between the impacted tooth and the anchorage tooth is small; and the need for frequent replacement even when rubber bands can be used. Furthermore, it avoids the problem of difficulty in placing traction hooks when the impacted tooth is too close to surrounding tissues.

[0030] 2) This invention designs a traction device based on the direction of the traction force required for traction of impacted teeth, which can provide traction force in multiple directions such as palatal, labial, and maxillary, thus solving the problem of three-dimensional traction direction control for impacted teeth in different positions.

[0031] 3) This invention achieves intermittent traction of impacted teeth through the detachable connection between the ligature wire on the traction hook and the elastic traction wire, allowing patients to remove and put on the orthodontic appliance themselves, which is beneficial to oral hygiene, facilitates cleaning of the orthodontic appliance, and increases safety.

[0032] 4) This invention uses different retention devices for different dentition stages, which effectively solves the problem of insufficient anchorage while taking comfort into account.

[0033] 5) This device cleverly utilizes the adjustable length and curvature of the elastic traction wire and ligation wire. When pulling out an impacted tooth, if the traction ligation wire extends too far beyond the gum line, it can be shortened and re-bent, increasing traction force while avoiding irritation to oral tissues. During impacted tooth traction, the traction angle can be adjusted as needed, facilitating subsequent treatment adjustments and increasing the success rate and efficiency of impacted tooth traction.

[0034] 6) This device is suitable for traction and correction of impacted teeth in different dentition stages and locations. For patients in the mixed dentition stage, or those with missing or temporarily unerupted posterior teeth, a full-coverage occlusal splint can provide sufficient anchorage. This device has lower anchorage requirements and a wider range of applications, making it suitable for early orthodontic treatment of impacted teeth in children, promoting root growth and reducing root deformities. For cases in the permanent dentition stage or with sufficient anchorage, a single-arm clasp or arrow clasp with a baseplate can be used as a retention device.

[0035] 7) Australian wire, stainless steel archwire, and nickel-titanium wire are usually combined with brackets for fixed orthodontic treatment and are rarely used on removable orthodontic appliances. This invention breaks this limitation by using the elastic archwire used on fixed orthodontic appliances alone and combining it with removable orthodontic appliances, which facilitates subsequent multiple adjustments and treatments.

[0036] 8) In this device, the elastic traction wire is bent into a loop at the position where it extends out of the base plate. The direction and angle of the elastic traction wire can be reasonably adjusted as needed, thereby adjusting the magnitude and direction of the orthodontic force in three-dimensional space. This allows the impacted tooth to avoid obstruction and interference from surrounding tissues, reduces the resistance of impacted tooth traction, and improves the success rate of traction.

[0037] 9) This device uses readily available materials, is inexpensive, simple to manufacture, easy to clean, and practical.

[0038] Figure descriptions and reference numerals

[0039] Figure 1 This is a schematic diagram of a device for traction of impacted teeth in the late mixed dentition or permanent dentition stage, which pulls the teeth towards the palatal or occlusal side. The fixed base uses an arrow clip.

[0040] Figure 2 This is a schematic diagram of a device for traction of impacted teeth in the late mixed dentition or permanent dentition stage, which pulls the teeth towards the palatal or occlusal side. The fixed base uses a single-arm clip.

[0041] Figure 3 A schematic diagram of a device for traction of impacted teeth in the early stage of mixed dentition towards the palatal or occlusal side, showing a fully enclosed occlusal pad;

[0042] Figure 4 A schematic diagram of a device for pulling impacted teeth labially in the late stage of mixed dentition or permanent dentition, wherein a single-arm clasp is used to fix the base.

[0043] Figure 5 A schematic diagram of a device for pulling impacted teeth labially during the late stage of mixed dentition or permanent dentition, in which the fixed base uses an arrow clip;

[0044] Figure 6 A front view of a device for pulling impacted teeth labially during the late mixed dentition or permanent dentition stage;

[0045] Figure 7 A schematic diagram of the structure of a traction device for impacted teeth in the early stage of mixed dentition, which pulls the teeth labially; a fully enclosed occlusal pad.

[0046] Among them, 1-traction hook, 2-orthodontic appliance, 11-adhesive attachment, 12-ligature wire, 12a-one end of ligature wire, 12b-the other end of ligature wire, 21-elastic traction wire, 22-retention device, 21a-one end of elastic traction wire, 21b-the other end of elastic traction wire, 21c-ring, 221-single arm clip, 222-base, 223-arrow clip, 224-double curved lip arch, 225-full-coverage jaw pad. Detailed Implementation

[0047] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following technical solutions.

[0048] Example 1

[0049] like Figure 1-7 As shown, an impacted tooth traction device comprises a traction hook 1 and an orthodontic appliance 2. The traction hook 1 is attached to the crown of the impacted tooth to be tractioned. The traction hook 1 consists of an adhesive attachment 11 and a ligature wire 12. One end 12a of the ligature wire is attached to the adhesive attachment 11, and the other end 12b of the ligature wire is free and bent into a hook. The orthodontic appliance 2 comprises an elastic traction wire 21 and a retention device 22. One end 21a of the elastic traction wire is embedded in the retention device 22 and bent at the end. The other end 21b of the elastic traction wire may be bent or not bent, and is detachably connected to the bent hook of the other end 12b of the ligature wire on the traction hook. The elastic traction wire 21 can also be combined with a clear aligner, using the clear aligner as the retention device 22. The elastic traction wire 21 is bent into a loop 21c at the point where it extends out of the retention device 22. There are 1-2 loops to increase elasticity, and the number of loops depends on the required traction force and gentleness. The elastic traction wire 21 is made of elastic Australian wire, orthodontic stainless steel archwire, or nickel-titanium wire. The structure and shape of the retention device 22 mainly depend on the direction of the traction force required to pull the impacted tooth and the height and integrity of the crowns of the other teeth in the dentition where the impacted tooth is located.

[0050] like Figures 1-3 As shown, if the traction force is directed towards the palatal or maxillary side, when the dentition is in the early stage of mixed dentition or when tooth damage is severe, the retention device 22 can be a full-coverage occlusal pad, with one end 21a of the elastic traction wire embedded in the lingual position within the full-coverage occlusal pad 225 near the impacted tooth. When the dentition is in the permanent dentition stage or the late stage of mixed dentition and the teeth are healthy and intact, the retention device 22 consists of a base and 2-3 single-arm clips 221. The single-arm clips are used to fix the base 222, and one end 21a of the elastic traction wire is embedded in the lingual position within the base 222 near the impacted tooth. The retention device 22 can be replaced with a Nance base. The single-arm clips 221 can also be replaced with arrow clips 223, and if necessary, a double-curved labial arch 224 can also be added.

[0051] like Figure 4-7 As shown, when the direction of the traction force is labial, and the dentition is in the early stage of mixed dentition or when tooth damage is severe, the retention device 22 can be a full-coverage occlusal pad 225, and the elastic traction wire... ofOne end 21a is embedded in the labial portion of the full-coverage occlusal pad 225. When the dentition is in the permanent dentition stage or the late mixed dentition stage and the teeth are healthy and intact, the retention device 22 consists of a base 222, two or more single-arm clips 221, and a double-curved labial arch 224. One end 21a of the elastic traction wire is bonded to the crossbeam to the curve of the double-curved labial arch 224 using self-curving plastic. The position of the double-curved labial arch 224 does not obstruct the impacted tooth to be corrected. The adhesive attachments 11 mostly use lingual clips or brackets.

[0052] A fully enclosed jaw splint is used, with one end of the elastic traction wire embedded within it. The entire dentition, alveolar bone, and mucosa serve as anchorage tissue, dispersing the reaction force from the traction. If the patient is in the permanent dentition stage, a double-curved labial arch is installed, avoiding the impacted tooth. One end of the elastic traction wire is bonded to the double-curved labial arch using self-curing plastic. The elastic traction wire is bent back into a loop at the point where it protrudes from the retention device, and the extended free end is detachably connected to the impacted tooth ligation wire.

[0053] When using the device, install the traction hook and wear the orthodontic appliance. Select the appropriate traction device based on the desired direction for the impacted tooth. When traction is needed, connect the bent end of the ligature wire on the traction hook to the traction end of the elastic traction wire on the appliance. If not needed, separate the bent end of the ligature wire from the traction end of the elastic traction wire on the appliance, as shown by the dotted line in the diagram. When the traction hook is connected to the elastic traction wire, the restoring force generated by the deformation of the elastic traction wire pulls the impacted tooth, subjecting it to traction in different directions such as palatal, labial, and maxillary, thus gradually pulling the impacted tooth in the desired direction. The elastic traction wire bends back into a loop at the point where it extends from the retention device, allowing adjustment of the position and direction of the free end to change the magnitude and direction of the traction force. The direction and length of the traction ligature wire can also be adjusted to coordinate with the magnitude and angle of the force applied by the elastic traction wire.

Claims

1. A device for traction of impacted teeth, characterized in that: The device consists of a traction hook (1) and an orthodontic appliance (2). The traction hook (1) is attached to the crown of the impacted tooth to be tractioned. The traction hook (1) consists of an adhesive attachment (11) and a ligature wire (12). One end (12a) of the ligature wire is attached to the adhesive attachment (11), and the other end (12b) of the ligature wire is free and bent into a hook. The orthodontic appliance (2) consists of an elastic traction wire (21) and a retention device (22). One end (21a) of the elastic traction wire is embedded in the retention device (22) and bent at the end. The other end (21b) of the elastic traction wire is detachably connected to the bent hook of the other end (12b) of the ligature wire on the traction hook. The elastic traction wire (21) is bent into a loop (21c) at the point where it extends out of the retention device (22). There are 1-2 loops (21c) to increase elasticity. The number of loops depends on the magnitude and gentleness of the required traction force. If the direction of the traction force is palatal or maxillary, when the dentition is in the early stage of mixed dentition or the tooth is severely damaged, the retention device (22) can be a full-coverage occlusal pad, and one end (21a) of the elastic traction wire is embedded in the lingual position of the full-coverage occlusal pad (225) near the position of the impacted tooth; when the dentition is in the permanent dentition stage or the late stage of mixed dentition and the tooth is healthy and intact, the retention device (22) is composed of a base and 2-3 single-arm clips (221), the single-arm clips are used to fix the base (222), and one end (21a) of the elastic traction wire is embedded in the lingual position of the base (222) near the position of the impacted tooth; When the direction of traction is labial, and the dentition is in the early stage of mixed dentition or when the tooth is severely damaged, the retention device (22) can be a full-coverage occlusal pad (225), and one end (21a) of the elastic traction wire is embedded in the labial part of the full-coverage occlusal pad (225); when the dentition is in the permanent dentition stage or the late stage of mixed dentition and the tooth is healthy and intact, the retention device (22) consists of a base (222) plus two or more single-arm clips (221) and a double-curved labial arch (224), and one end (21a) of the elastic traction wire is bonded to the crossbeam to the curve of the double-curved labial arch (224) using self-curing plastic, and the position of the double-curved labial arch (224) does not obstruct the impacted tooth to be corrected.

2. The impacted tooth traction device according to claim 1, characterized in that: The elastic traction wire (21) is combined with the invisible aligner, and the invisible aligner is used as a retention device (22).

3. The impacted tooth traction device according to claim 1, characterized in that: According to claim 1, the impounded tooth traction device is characterized in that the elastic traction wire (21) is made of elastic Australian wire or nickel-titanium wire.

4. The impacted tooth traction device according to claim 1, characterized in that: The structure and shape of the retention device (22) mainly depend on the direction of the traction force required to pull the impacted tooth and the height and integrity of the crowns of the other teeth in the dentition where the impacted tooth is located.

5. The impacted tooth traction device according to claim 1, characterized in that: The retaining device (22) is replaced by a Nance holder.

6. The impacted tooth traction device according to claim 1, characterized in that: The single-arm card (221) is replaced with an arrow card (223), and a double-curved lip bow (224) is added.

7. The impacted tooth traction device according to claim 1, characterized in that: The adhesive attachment (11) uses a tongue-side buckle or bracket.

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