Description

ORTHODONTIC SCREW

Technical Field

[1] The present invention relates to an orthodontic screw, and more particularly, to an orthodontic screw in which an orthodontic elastic member can be fastened and fixed to a head of the orthodontic screw in a desired direction to prevent the elastic member from being inadvertently unfastened from the screw when straightening irregular teeth. Background Art

[2] PCT Publication No. WO 01/37752 Al, entitled "Anchor Screw for Orthodontic

Treatments," discloses an orthodontic screw having a reduced diameter portion formed at a head thereof such that an orthodontic elastic member or metal wire can be fastened to the head of the screw. FIG. 9 shows the orthodontic screw disclosed in the above publication. Referring to FIG. 9, an orthodontic metal wire F is fastened to a reduced diameter portion 6 of the screw to apply a force to teeth to be corrected. Further, a through hole 5 in which the orthodontic metal wire can be inserted is formed.

[3] However, in a case where an orthodontic metal wire or elastic member such as an elastic string or a tensile spring is fastened to the reduced diameter portion of the above orthodontic screw, it may be unfastened from the orthodontic screw if a force is applied to the metal wire or elastic member in a direction not perpendicular to an axial direction of the screw (i.e., in a direction toward the head). In addition, it is difficult to apply a tensile force to the metal wire or elastic member in a desired direction even though the metal wire or the elastic member has been properly fastened to the orthodontic screw. Further, since it is difficult to insert the metal wire into the through hole during the medical treatment, it takes much time to perform the medical treatment. Due to the above disadvantages, the conventional orthodontic screw formed with a reduced diameter portion at a head thereof cannot provide effective medical treatment. Disclosure of Invention

Technical Problem

[4] An object of the present invention is to provide an orthodontic screw capable of solving the aforementioned problems. Another object of the present invention is to provide an orthodontic screw capable of preventing an orthodontic metal wire or elastic member fastened to a head of the screw from being unfastened from the head of the screw. A further object of the present invention is to provide an orthodontic screw capable of allowing a force to be applied, in a desired direction, to the orthodontic metal wire or elastic member fastened to the head of the screw.

Technical Solution

[5] An orthodontic screw of the present invention includes a threaded portion formed with a screw thread at an outer circumferential surface thereof, and a head extending from the threaded portion and formed with a rotating means for tightening or loosening the screw. Further, the head of the screw includes a fastening portion with a reduced diameter spaced apart from an end of the head in an axial direction of the screw, a hooking portion extending from the fastening portion and having a diameter greater than that of the fastening portion, and at least one hooking groove formed on an outer circumferential surface of the hooking portion in the axial direction of the screw such that an orthodontic elastic member fastened to the fastening portion is tightly hooked to the hooking groove. The hooking portion has a diameter greater than that of the fastening portion such that an orthodontic metal wire or elastic member is not unfastened from the fastening portion. Furthermore, the hooking groove prevents the metal wire or elastic member from being unfastened from the fastening portion and fixes the orthodontic metal wire or elastic member to apply a force to the orthodontic metal wire or elastic member in a desired direction.

[6] In addition, as the rotating means for allowing the screw to be rotated and then screwed into or unscrewed from the alveolar bone, a tightening portion with a polygonal section may be provided at a position where the hooking portion and the threaded portion are connected with each other. In such a case, a maximum diameter of the hooking portion may be smaller than a minimum diameter of the tightening portion such that a tool for rotating the screw receives the hooking portion therein. Further, at least one insertion groove is preferably formed on an upper surface of the hooking portion such that an orthodontic linear member (a ligature wire) can be inserted and fixed in the groove from the upper surface of the hooking portion. Furthermore, catching protrusions may also be formed at both sides of the at least one hooking groove formed in the hooking portion to prevent the orthodontic elastic member from being unfastened from the groove and easily control a direction in which an orthodontic force is applied.

[7] Moreover, the orthodontic screw of the present invention may be provided with a screw rotating means which is formed at an upper surface of the hooking portion and also used as a means for fixing an orthodontic ligature wire thereto. That is, at least one insertion groove serving as the rotating means may be formed on the upper surface of the hooking portion such that a screwdriver is inserted in the groove to tighten or loosen the screw and an orthodontic linear member is inserted and fixed in the groove from the upper surface of the hooking portion. Brief Description of the Drawings

[8] FIG. 1 is a perspective view of an orthodontic screw according to an embodiment of the present invention.

[9] FIG. 2 is a front view showing the orthodontic screw of FIG. 1.

[10] FIG. 3 is a plan view showing the orthodontic screw of FIG. 1.

[11] FIGS. 4a and 4b are plan views showing various examples of hooking grooves formed in a hooking portion of the orthodontic screw according to the present invention. [12] FIG. 5 is a perspective view of an orthodontic screw according to another embodiment of the present invention. [13] FIG. 6 is a schematic view illustrating a state where an orthodontic linear member is inserted and fixed in the hooking portion of the orthodontic screw of FIG. 5. [14] FIG. 7 is a perspective view showing an orthodontic screw according to a further embodiment of the present invention. [15] FIG. 8 is a schematic view illustrating an operating state of the orthodontic screw of

FIG. 1.

[16] FIG. 9 is a plan view showing a conventional orthodontic screw.

[17] <Explanation of Reference numerals for Main Portions in Drawings>

[18] 100 orthodontic screw 10 threaded portion

[19] 20 head 21 hooking portion

[20] 22 fastening portion 23 tightening portion

[21] 25 hooking groove 25a catching protrusion

[22] 26 first insertion groove 27 second insertion groove

[23] 30 alveolar bone 31 teeth

[24] 40 orthodontic elastic member 41 bracket

[25] 50 orthodontic linear member 51 wire

Best Mode for Carrying Out the Invention [26] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. [27] FIG. 1 is a perspective view of an orthodontic screw according to an embodiment of the present invention, FIG. 2 is a front view of the orthodontic screw shown in FIG. 1, and FIG. 3 is a plan view of the orthodontic screw shown in FIG. 1. [28] The orthodontic screw 100 of this embodiment includes a threaded portion 10 and a head 20. [29] A screw thread 11 is formed on an outer circumferential surface of the threaded portion 10 which in turn is screwed and fixed into the maxilla/mandible or alveolar bone such that the orthodontic screw 100 cannot be unfastened or loosened, i.e. can be supported and maintained, during the medical treatment. One end of the threaded

portion 10 is formed into a sharp conical shape such that it can be screwed into the maxilla/mandible or alveolar bone. In addition, a conical seating portion 12 is formed at the other end of the threaded portion 10 such that the screw 100 can be stably placed onto the gingiva. The seating portion 12 is brought into close contact with the gingiva to prevent foreign substances such as food from penetrating between the threaded portion and the gingiva.

[30] The head 20 is formed with a cylindrical tightening portion 23 which extends from the seating portion 12 of the threaded portion 10 and serves as a rotating means for tightening or loosening the orthodontic screw 100. Further, a fastening portion 22 with a predetermined length and a reduced diameter is formed at a position spaced apart from an end of the head 20. by a distance in an axial direction of the screw. A hooking portion 21 with a diameter greater than the fastening portion 22 is formed between the other end of the head 20 and the fastening portion 22. In addition, the tightening portion 23 has a hexagonal section and has a minimum diameter greater than a maximum diameter of the hooking portion 21 such that the screw can be tightened or loosened using a tool without any interference with the hooking portion 21.

[31] The fastening portion 22 is used to apply an orthodontic force to teeth to be corrected in such a state where an orthodontic elastic member 40 is fastened thereto as shown in FIG. 8. It is described in this embodiment that the fastening portion 22 take the shape of a circular cylinder, but the present invention is not limited thereto. Further, the hooking portion 21 is used to prevent the orthodontic elastic member 40 fastened to the fastening portion 22 from being unfastened (removed) and also has a diameter greater than the diameter of the fastening portion 22.

[32] The orthodontic screw 100 of this embodiment is formed with four hooking grooves

25 on an outer circumferential surface of the hooking portion 21 at a constant interval. The hooking grooves 25 serve to prevent the orthodontic elastic member 40 from being unfastened (removed) from the fastening portion 22 as well as to fix the orthodontic elastic member 40 such that a force can be applied to the elastic member in a desired direction.

[33] As described above, the orthodontic screw 100 of this embodiment is configured in such a manner that the threaded portion 10 is tightly screwed into the alveolar bone and the head 20 formed at the other end of the threaded portion 10 includes the fastening portion 22 and the hooking portion 21 formed with the hooking grooves 25. Therefore, the orthodontic elastic member 40 can be installed in a desired direction and then cannot be unfastened or removed from (i.e., can be fixed or held to) the orthodontic screw after the installation. Accordingly, an orthodontic force can be effectively applied to teeth to be corrected.

[34] FIGS. 4a and 4b are plan views showing various examples of the hooking grooves

formed in the hooking portion of the orthodontic screw according to the present invention, which are different from the hooking grooves 25 of the previous embodiment shown in FIG. 1 only in view of their shapes.

[35] Each of the hooking grooves 25 shown in FIG. 4a is formed with catching protrusions 25a at both ends thereof to surround the orthodontic elastic member 40 inserted in the relevant hooking groove 25 such that the orthodontic elastic member 40 cannot be unfastened, thereby ensuring the stable orthodontic treatment.

[36] Further, FIG. 4b shows hooking grooves 25 each of which takes the shape of a polygon such that the orthodontic elastic member cannot be easily unfastened. Each of the hooking grooves 25 has three surfaces in this example, but it may also have other polygonal shapes with four surfaces, five surfaces or the like.

[37] FIG. 5 is a perspective view of an orthodontic screw according to another embodiment of the present invention, and FIG. 6 is a schematic view illustrating a state where an orthodontic linear member is inserted and fixed in the hooking portion of the orthodontic screw of FIG. 5.

[38] The embodiment of FIG. 5 is different from that of FIG. 1 in view of their upper shapes of the hooking portion 21. That is, a rotating means for the orthodontic screw 100 is formed on an upper surface of the hooking portion 21 and insertion grooves 26 and 27 are also formed on the upper surface of the hooking portion 21 such that the orthodontic linear member 50 can be inserted and fixed in the insertion grooves as shown in FIG. 6. The first and second insertion grooves 26 and 27 are cut out crosswise to a predetermined depth. Further, the orthodontic screw of this embodiment can be easily tightened or loosened either by using the tightening portion 23 or by inserting a regular or Phillips head screwdriver into a plurality of the insertion grooves 26 and 27 formed on the upper surface of the hooking portion 21.

[39] Referring to FIG. 6, the orthodontic screw of this embodiment can provide an orthodontic force to the teeth to be corrected by fastening the elastic member to the fastening portion and also by inserting the orthodontic linear member 50 into the first insertion groove 26 and then maintaining the orthodontic linear member 50 using a wire 51 in a state where it is inserted in the groove. In particular, since the hooking grooves 25 are provided in the hooking portion 21 of the screw of this embodiment, the orthodontic linear member 50 can be firmly fixed by causing the wire 51 to be placed on one end of the orthodontic linear member 50 and pass through the hooking grooves 25 formed at one side of the hooking portion 21 downwardly and upwardly and then to be placed on the other end of the orthodontic linear member 50 and to pass through the hooking grooves 25 formed at the other side of the hooking portion 21 downwardly and upwardly and then by causing both ends of the wire 51 to be twisted together.

[40] FIG. 7 is a perspective view of an orthodontic screw according to a further

embodiment of the present invention, which is different from that of FIG. 1 in that no tightening portion 23 is employed and the insertion grooves 26 and 27 with a cross shape are formed on the upper surface of the hooking portion 21.

[41] The orthodontic screw 100 of this embodiment can be tightened or loosened by inserting a screwdriver into the cruciform insertion grooves 26 and 27 formed on the upper surface of the hooking portion 21. As shown in FIG. 6, the orthodontic linear member 50 can be fixed to the orthodontic screw. By using the orthodontic screw of this embodiment, time and costs required for processing the tightening portion 23 can be reduced.

[42] FIG. 8 is a schematic view illustrating an operating state of the orthodontic screw shown in FIG. 1. As shown in FIG. 8, when intending to straighten irregular teeth, brackets 41 are attached to the teeth 31 and are connected with each other using a wire 42. Then, one end of an orthodontic elastic member 40 is fixed to the wire 42, while the other end of the orthodontic elastic member 40 is fastened and fixed to the head 20, i.e. the fastening portion 22, of the orthodontic screw 100 screwed and fixed into the maxilla/mandible and the alveolar bone 30. The orthodontic elastic member 40 fixed to the fastening portion 22 of the orthodontic screw 100 screwed and fixed as described above can apply a tensile force to the wire 42 by pulling the wire 42 fixed to the brackets 41 attached to the teeth 31. Accordingly, if a predetermined force is applied to the bracket 41, the force can be applied to the teeth 31 to straighten the irregular teeth. At this time, even though the orthodontic elastic member 40 fastened to the fastening portion 22 is installed in a direction toward the head 20 of the screw 100 (i.e. in such a direction that a force is applied at an angle inclined from a direction perpendicular to the axial direction of the screw toward the head 20), the orthodontic elastic member 40 cannot be easily unfastened but can be maintained at a fixed state because it is inserted and hooked into the hooking groove 25. Further, since a plurality of hooking grooves 25 are formed along the outer circumferential surface of the hooking portion 21, the orthodontic elastic member 40 for straightening the irregular teeth can be fixed to the orthodontic screw in a desired direction to apply a certain force to the teeth in the desired direction. Industrial Applicability

[43] According to the present invention, an orthodontic screw formed with hooking grooves at its head having a reduced diameter is provided such that an orthodontic metal wire or elastic member fastened to the head of the orthodontic screw cannot be unfastened and a force can also be applied to the orthodontic metal wire or elastic member in a desired direction. Therefore, the orthodontic screw of the present invention can be used to provide more effective orthodontic treatment.

[44] The preferred embodiments of the present invention illustrated above and shown in the accompanying drawings should not be construed to limit the spirit of the present invention. The scope of the present invention should be defined only by the appended claims, and the present invention can be changed or modified in various ways within the spirit of the present invention by those skilled in the art. Thus, such changes or modifications will be included in the scope of the present invention if they are apparent to those skilled in the art.