Orthodontic archwires

Abstract

To provide an arch wire for orthodontics that can reduce pain and discomfort during orthodontic treatment by using a low-rigidity wire. [Solution] The orthodontic archwire 10 has a loop portion 30 formed in a predetermined shape to enable loop mechanics, and is made of a superelastic material selected from the group consisting of nitinol, titanium-molybdenum alloy (TMA), and gum metal, which have a Young's modulus of 100 GPa or less. When the loop portion is activated, a force that slowly returns to its original shape acts continuously on the target tooth, physiologically promoting tooth movement and reducing pain during treatment, and further reducing the risk of complications due to excessive force, such as root resorption and damage to periodontal tissue.

Description

[Technical Field]

[0001] This invention relates to an orthodontic arch wire, specifically to an orthodontic arch wire that uses a low-rigidity wire to reduce pain and discomfort during orthodontic treatment. [Background technology]

[0002] The multi-bracket method has been one of the most common orthodontic treatment methods for correcting the alignment of teeth. For example, Patent Document 1 discloses an orthodontic method in which an orthodontic bracket is attached to the crown (the surface of each tooth), and mechanical tension (a restoring force such as pushing, pulling, or twisting) of an arch wire attached to each adjacent orthodontic bracket is applied to each tooth, gradually moving the position of each tooth to the proper alignment.

[0003] In orthodontics using this type of multi-bracket method, two methods are generally known: sliding mechanics and loop mechanics, and the appropriate method is selected depending on the stage and purpose of treatment.

[0004] Sliding mechanics involves passing a wire through brackets attached to the teeth, and applying force to the wire using rubber, coil springs, etc. The brackets then slide along the wire, allowing the teeth to move.

[0005] On the other hand, loop mechanics is a method in which a wire is bent vertically to form various loop shapes, such as an omega loop, a box loop, or a keyhole loop, and the loops are activated by opening and closing to apply force to the teeth and move them. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5624094 Summary of the Invention [Problem to be solved by the invention]

[0007] The arch wires used in the multi-bracket method are generally made of stainless steel. Stainless steel wires are highly rigid and easy to process, which has the advantage that, for example, in the loop mechanics described above, each loop shape can be easily formed by bending it depending on the case.

[0008] On the other hand, stainless steel wires have high rigidity, so they exert a strong force on the teeth. If such a strong force is continuously exerted on the teeth, it can cause pain in the teeth or put a continuous load on the tooth root, which can lead to the risk of root resorption.

[0009] These problems can be solved by using low-rigidity wires, and in recent years, low-rigidity wires have been devised using materials such as Nitinol, an alloy of nickel and titanium, Gummetal, a titanium alloy, or TMA, an alloy of titanium and molybdenum.

[0010] However, due to its characteristics, low-rigidity wires are generally only used in sliding mechanics. This is because there is a fixed idea in the industry that low-rigidity wires have lower rigidity than stainless steel wires, making it difficult to bend them vertically in loop mechanics, such as in omega loops. Therefore, orthodontic treatment using low-rigidity wires has not been adopted in orthodontic loop mechanics to date, and orthodontic treatment using stainless steel wires remains the mainstream.

[0011] The present invention was devised in consideration of the above points, and aims to provide an orthodontic arch wire that can reduce pain and discomfort during orthodontic treatment by using a low-rigidity wire. [Means for solving the problem]

[0012] In order to achieve the above object, the orthodontic archwire of the present invention is made of a low-rigidity wire having a Young's modulus of 100 GPa or less.

[0013] Here, by using a low-rigidity wire with a Young's modulus of 100 GPa or less for orthodontic archwires, it is possible to continuously apply a sustained, weak force to the teeth. This physiologically promotes tooth movement, reduces pain during treatment, and reduces the risk of complications caused by excessive force, such as root resorption and periodontal tissue damage. Furthermore, combining such a low-rigidity wire with brackets reduces friction between the wire and brackets, promoting more efficient tooth movement.

[0014] Furthermore, when the Young's modulus exceeds 100 GPa, even a slight deformation of the wire generates a large force, which causes sudden and excessive force to be applied to the tooth, resulting in pain and discomfort in the tooth and periodontal tissue, as well as an increased risk of complications such as root resorption and damage to the periodontal tissue.

[0015] Furthermore, when the low-rigidity wire is selected from the group consisting of nitinol, titanium-molybdenum alloy (TMA), and gum metal, these materials have low rigidity, and as described above, can reduce pain during treatment and various risks in orthodontic treatment.

[0016] Furthermore, when a low-rigidity wire is used as a loop mechanics to promote tooth movement and a loop of a predetermined shape is formed in the low-rigidity wire, the loop formed in the wire can be expanded (activated) to apply force to the teeth, utilizing the force of the wire returning to its original shape. In this case, because the wire is low-rigidity, a weak force is continuously applied to the teeth, which, as mentioned above, reduces pain during treatment and prevents complications such as root resorption.

[0017] Furthermore, when the loop portion is selected from the group consisting of omega loop, V loop, L loop, keyhole loop, T loop, and box loop shapes, the optimal loop shape is selected from these loop portion shapes depending on the case, purpose of treatment, or timing of treatment.

[0018] For example, the Omega Loop is primarily used to close gaps after tooth extraction or to prevent molars from being pulled forward by forming it on the end of a wire, while the V Loop is used to pull front teeth backward, and the L Loop is used to achieve three-dimensional tooth movement by combining multiple loop sections.

[0019] Keyhole loops are keyhole-shaped loops that are used to move specific teeth more efficiently. T-loops offer the most control of loop mechanics and are ideal for fine-tuning the balance between front and back teeth. Box loops are used to pinpoint the position of specific teeth, such as to correct misalignment of teeth up and down, in and out, or when a single tooth is significantly misaligned. [Effects of the Invention]

[0020] The orthodontic arch wire of the present invention is easy to install, and by using a low-rigidity wire, it can reduce pain and discomfort during orthodontic treatment. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a diagram showing an orthodontic appliance according to an embodiment of the present invention attached to teeth. FIG. [Figure 2] 1 is a diagram showing an example of a loop portion formed in an orthodontic wire according to an embodiment of the present invention. FIG. [Figure 3] 1A to 1C are diagrams showing a processing procedure for an orthodontic wire according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The orthodontic arch wire according to the embodiment of the present invention will be described below with reference to the drawings to help understand the present invention. In the following description, we will assume that the canine tooth T3 is moved to the gap S after the first premolar T4 has been extracted.

[0023] First, an orthodontic appliance 1 including an orthodontic arch wire 10 according to an embodiment of the present invention will be described with reference to Fig. 1. As shown in Fig. 1, the orthodontic appliance 1 according to this embodiment is mainly composed of brackets 20 attached in contact with the crowns Tc of each tooth T of the patient, and the orthodontic arch wire 10 inserted into grooves formed in the brackets 20.

[0024] The brackets 20 are made from stainless steel, titanium, ceramics, etc., and come in different shapes depending on the anterior teeth T1 to T3, including the target teeth to be moved, and the molars T5 to T7, which will serve as anchor teeth, and are positioned so that they abut against the crowns Tc on the tongue side of the patient.

[0025] Here, bracket 20 does not necessarily have to be made from stainless steel, titanium, ceramics, etc. Any material may be used as long as it is medically confirmed to be safe and will not deteriorate, corrode, or break even in the harsh environment of the oral cavity.

[0026] Furthermore, the bracket 20 does not necessarily have to be positioned so as to abut the lingual crown Tc of the patient. For example, it may be positioned so as to abut the labial crown. For the sake of convenience, the embodiment of the present invention will be described based on an embodiment in which the bracket 20 abuts the lingual crown Tc.

[0027] Furthermore, it is not necessary to use brackets 20 with different shapes for the anterior teeth T1 to T3 and the molars T5 to T7. Brackets 20 of the same shape can be used for all teeth T, and brackets of different shapes can also be used for each tooth T.

[0028] As shown in Fig. 1(b), the bracket 20 has a groove 21 formed therein that is generally concave in cross section and opens obliquely downward. The orthodontic arch wire 10 is inserted into this groove 21, and the orthodontic arch wire 10 can be adjusted to correct the patient's teeth with a biasing force according to the initial shape.

[0029] The orthodontic archwire 10 has a substantially rectangular cross section, and is bent into a substantially U-shape in plan view so as to fit the dentition of the patient, as shown in Fig. 1(a). A loop portion 30 is formed by bending in the vertical direction at the position of the target tooth, and the orthodontic archwire 10 as a whole is configured to be able to perform loop mechanics.

[0030] Here, the cross-sectional shape of the orthodontic arch wire 10 does not necessarily have to be rectangular. For example, it may be circular, elliptical, or another shape. However, from the viewpoint of applying torque to the target teeth, it is preferable that the cross-sectional shape of the orthodontic arch wire 2 be rectangular.

[0031] The loop portion 30 is an omega loop, which has a semicircular shape resembling the omega symbol, and by expanding (activating) the loop portion 30, it is possible to apply force to the teeth by utilizing the force of the wire trying to return to its original shape.

[0032] Here, it is not necessary to adopt an omega loop as the loop portion 30. For example, as shown in Figure 2, various shapes such as a V loop (Figure 2(a)), an L loop (Figure 2(b)), a keyhole loop (Figure 2(c)), a T loop, a box loop, etc. can be adopted, and the optimum shape can be selected depending on the case, the purpose of treatment, the timing of treatment, etc., and further, it is also possible to use a combination of loop portions 30 of these shapes.

[0033] The material of the orthodontic archwire 10 is Nitinol, an alloy material made of nickel (Ni) and titanium (Ti), and its Young's modulus is 40 to 90 GPa.

[0034] In this way, by using nitinol as the material for the orthodontic arch wire 10, when the loop portion 30 is activated, a force that slowly returns to its original shape due to its superelasticity is continuously applied to the target tooth, thereby physiologically promoting tooth movement, reducing pain during treatment, and further reducing the risk of complications caused by excessive force, such as root resorption and periodontal tissue damage. Furthermore, friction between the orthodontic arch wire 10 and the brackets 20 is reduced, promoting more efficient tooth movement.

[0035] However, the material for the orthodontic arch wire 10 is not necessarily limited to nitinol. As a result of research by the inventor, it was found that a material with a Young's modulus of 100 GPa or less is suitable for achieving the objectives of applying a moderate force to the teeth, reducing pain during treatment, and reducing the risk of complications such as root resorption. Specifically, in addition to nitinol, titanium-molybdenum alloy (TMA) or gum metal made of a titanium alloy is also suitable.

[0036] Furthermore, if a material with a Young's modulus of over 100 GPa is used, a sudden force will be applied to the tooth, which may cause pain during treatment or increase the risk of complications such as root resorption.

[0037] Next, a method for processing the orthodontic archwire 10 according to this embodiment will be described with reference to FIG.

[0038] [Preparing orthodontic wires] First, prepare the orthodontic wire 10 to be used in orthodontic treatment. The orthodontic wire 10 is linear from one end to the other.

[0039] [Loop processing] Next, as shown in FIG. 3(b), a loop portion 30 is formed by bending the treatment piece vertically at an arbitrary position (in this embodiment, at a position corresponding to a gap S formed by tooth extraction in the patient).

[0040] [Curving] After the loop portion 30 is formed, as shown in Figure 3(c), one end and the other end of the orthodontic arch wire 10 are formed into an approximately straight line to correspond to the molar dentition of the patient, and the entire orthodontic arch wire 10 is curved to correspond to the anterior dentition (Figure 3(d)).

[0041] The orthodontic arch wire 10 processed through the above steps has the brackets 3 attached thereto, and is then attached to the teeth T of the patient by adhesive means such as resin.

[0042] It is not necessary to process the orthodontic archwire 10 in the above-described procedure, and the order of these processing steps can be changed as appropriate.

[0043] The above is a detailed description of the orthodontic arch wire 10. In the above embodiment, the orthodontic arch wire is mainly described as being applied to loop mechanics, which forms a loop in the orthodontic arch wire to move the teeth, but the orthodontic arch wire 10 of this embodiment can also be applied to sliding mechanics.

[0044] As described above, the orthodontic arch wire according to the present invention can reduce pain and discomfort during orthodontic treatment by using a low-rigidity wire. [Explanation of symbols]

[0045] 1 Orthodontic appliances 10 Orthodontic archwire 20 Bracket 21 Groove 30 Loop section C. Midline of the dental arch S Gap T tooth T1 central incisor T2 lateral incisor T3 canine T5 premolar T6 and T7 molars Tc dental crown Tr tooth root

Claims

1. The wire is made of low-rigidity wire with a Young's modulus of 100 GPa or less. Orthodontic archwire.

2. The low-rigidity wire is Selected from the group consisting of Nitinol, titanium molybdenum alloy (TMA), and gum metal 2. The orthodontic archwire according to claim 1.

3. the low stiffness wire is used as a loop mechanics to facilitate tooth movement; The low-rigidity wire has a loop portion formed thereon having a predetermined shape.

3. The orthodontic arch wire according to claim 1 or 2.

4. The loop portion is selected from the group consisting of an omega loop, a V loop, an L loop, a keyhole loop, a T loop, and a box loop.

4. The orthodontic arch wire according to claim 3.

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