Orthodontic implant structure and orthodontic implant jig

An orthodontic implant structure (2) that is used by being implanted in bone in an oral cavity includes a first screw (6, 6B) having a screw body (6b) and an engaging portion (14), a plate securing implement (12, 13), a second screw, and a base plate having a first surface (4p) and a second surface (4q) and in which a first attachment hole (24A, 24B) and a second attachment hole (26) are formed.

TECHNICAL FIELD

The present invention relates to an orthodontic implant structure and an orthodontic implant jig. Priority is claimed on Japanese Patent Application No. 2015-161298, filed Aug. 18, 2015, the content of which is incorporated herein by reference.

BACKGROUND ART

In recent years, an orthodontic method in which a specific tooth is fixed in place, and this fixed tooth is then connected to a tooth that is to be moved (namely, to a tooth that is to undergo orthodontic treatment), and the tooth to undergo orthodontic treatment is then moved by being pulled has been used as a method of performing orthodontic treatment. In this orthodontic method, since the fixed tooth and the tooth to be moved are pulling on each other, there are cases when the fixed tooth is also moved in the direction of the tooth to be moved. Therefore, for example, a threaded implant on which a circular cylinder-shaped thread portion is formed is implanted in a bone of the jaw portion. A plate and wires and the like are fixed to this implant, and an end portion of this plate and wires and the like are fixed to a tooth. As a result, movement of the fixed tooth is suppressed, and orthodontic treatment can proceed.

For example, in Patent Document 1, an orthodontic implant structure is disclosed in which a base plate is fixed in place using two screws that are screwed into a bone such as the jawbone or the like inside the oral cavity at a predetermined distance from each other. In the orthodontic treatment in which this implant structure is used, an upper structure is screwed onto the fixed base plate, and orthodontic treatment is performed on a row of teeth via this upper structure.

CITATION LIST

Patent Document

SUMMARY OF INVENTION

Technical Problem

However, the inventors of the present application discovered that, in a conventional orthodontic implant structure, since the base plate is directly supported by being pressed against a bone such as the jawbone (hereinafter, this may be referred to simply as ‘a bone’) or the like inside the oral cavity using a plurality of screws, with the passage of time, this bone sinks in the direction in which it is being pressed. If the bone sinks in this way, a gap gradually appears between the base plate and the bone. The base plate may consequently become unstable, and excessive play may be generated therein. In addition, if the base plate does become unstable, the straightening force applied to a row of teeth by the upper structural bodies, plates, and wires and the like that are connected to the base plate is reduced, and the effectiveness of the orthodontic treatment is decreased.

The present invention was conceived in order to solve the above-described problem, and it is an object of the present invention to provide an orthodontic implant structure that is able to stably support a base plate. It is a further object of the present invention to provide an orthodontic implant jig that is used in this type of orthodontic implant structure.

Solution to Problem

In order to achieve the aforementioned objects, a first aspect of the present invention is an orthodontic implant structure that is used by being implanted in a bone inside an oral cavity, and that includes a first screw having a screw body that is implanted in a bone and an engaging portion that is formed by forming a thread in a head portion of the screw body, a plate securing implement that is capable of being screwed into a thread, a second screw that is implanted in a bone and has a head portion, and a base plate having a first surface that is disposed facing the bone and a second surface that is disposed on an opposite side from the first surface, the base plate in which a first attachment hole and a second attachment hole are formed, the first attachment hole with which the engaging portion is capable of being engaged from the first surface, and the second attachment hole into which the second screw is capable of being inserted from the second surface and locking the head portion of the second screw.

In the orthodontic implant structure according to this first aspect, the base plate is attached by implanting the first screw in a bone such as a jawbone or the like, and engaging the first attachment hole from the first surface with the engaging portion that is protruding from this bone. In addition, by screwing the plate securing implement from the second surface of the base plate into the thread of the first screw that has been placed inside the first attachment hole, the base plate is fixed to the first screw. As a result, the base plate is directly supported in the direction from the first surface towards the second surface not by bone, but by the engaging portion of the first screw (and by the plate securing implement). In contrast, by inserting the second screw from the second surface of the base plate through the second attachment hole, and implanting the portion thereof that protrudes from the front of the first surface in the direction of insertion into a bone such as a jawbone or the like, the base plate is directly supported by the head portion of the second screw in the direction from the second surface towards the first surface. Accordingly, according to the above-described orthodontic implant structure, the first screw and the second screw are prevented from coming loose from the bone, but are instead firmly fixed to the bone. In addition, the base plate is not directly supported by bone, but is instead stably supported by the first screw and the second screw, and is stabilized above the bone.

A second aspect of the present invention is the orthodontic implant structure according to the first aspect, wherein the first screws is provided with a stopper that protrudes in a radial direction that is orthogonal to the screw axial direction at a position closer in the screw axial direction to the thread portion than the engaging portion. According to the orthodontic implant structure of this second aspect, since the base plate is gripped in the thickness direction thereof by the stoppers and by small screws, the base plate is supported even more stably.

A third aspect of the present invention is the orthodontic implant structure according to the first or second aspects, wherein a seating surface whose diameter becomes wider moving from the first surface towards the second surface is formed in the second attachment hole, and the head portion of the second screw has an abutting surface that abuts against the seating surface. According to the orthodontic implant structure of this third aspect, since the abutting surface abuts against the seating surface when the second screw in inserted from the second surface towards the first surface, the support provided to the base plate by the head portion of the second screw in a direction from the first surface towards the second surface is strengthened.

A fourth aspect of the present invention is the orthodontic implant structure according to any one of the first through third aspects, wherein the base plate is formed having a plate shape, and the base plate is provided with the first attachment hole, the second attachment hole, and an attachment portion to which an upper structure that is used for orthodontic treatment is removably attached, and a notch portion that enables a plate portion to be bent in a desired direction are formed between the first attachment holes or second attachment hole and the attachment portion.

According to the orthodontic implant structure of this fourth aspect, since the plate portion can be bent in a desired direction around the portion of the plate portion where the notch portion is formed between the first attachment hole or second attachment hole and the attachment portion, the position and orientation of the attachment portion changes in accordance with the orientation resulting from this bending. Namely, the position and orientation of the attachment portion can be freely altered so as to match the attitude desired for the upper structure that is attached to the attachment portion. Because of this, the position of the attachment portion can be easily adjusted so as to match the configuration and application of the upper structure even after the base plate has been fixed to the jawbone inside the oral cavity. For example, since the position of the attachment portion can be easily altered even if the position where the base plate is fixed deviates from the predetermined position, it is sufficient if the base plate is only fixed in an approximate position and there is no need for the base plate to be fixed in a precise position relative to the upper structure. Accordingly, these tasks are simplified, work efficiency is improved, and both labor and time are reduced. Moreover, by changing the formation positions, the orientation, and the number of formation locations and the like of the notch portions in the plate portion, the base plate can be bent to any desired configuration. Furthermore, since the upper structure can be positioned in a desired attitude without the number of parts used having to be increased, unlike the case of a conventional structure, there is no increase in structural complexity, and a reduction in cost can also be achieved.

A fifth aspect of the present invention is the orthodontic implant structure according to the fourth aspect, wherein the notch portion is formed by reducing the width of a predetermined location of the plate portion. According to the orthodontic implant structure of this fifth aspect, it is easier for the plate portion to be bent around the location where the width of the plate portion has been made smaller.

A sixth aspect of the present invention is an orthodontic implant jig that is fixed indirectly to bone using first screws, a plate securing implement, and a second screw, wherein the orthodontic implant jig has a first surface that is disposed facing the bone, and a second surface that is disposed on an opposite side from the first surface, and a first attachment hole with which the engaging portion is capable of bring engaged from the first surface and enabling the plate securing implement to be screwed into the thread provided in the engaging portion, and a second attachment hole into which the second screw is capable of being inserted from the second surface and locking the head portion of the second screw in place are formed in the orthodontic implant jig. According to the orthodontic implant jig of this sixth aspect, since the orthodontic jig is not supported directly by bone, but is instead supported directly by the first screw and the second screw, the orthodontic jig is fixed stably without any play therein. Accordingly, the upper structure, plates, and wires and the like can be stably supported by and fixed to this orthodontic jig.

Advantageous Effects of Invention

According to the orthodontic implant structure of the present invention, it is possible to stably support a base plate. Moreover, according to the orthodontic jig of the present invention, this orthodontic jig can be used in the orthodontic implant structure, so that the effectiveness of orthodontic treatment performed using an upper structure, a plate, and wires and the like can be increased.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an orthodontic implant structure (referred to below simply as an implant structure) to which the present invention has been applied is described with reference to the drawings. Note that the drawings used in the following description are schematic views, and length, width, and thickness proportions and the like therein may not necessarily match those of an actual product, and may differ when appropriate.

FIG. 1throughFIG. 4are views representing an implant structure2according to an embodiment to which the present invention has been applied (hereinafter, this is referred to as ‘the present embodiment’).FIG. 1is a perspective view,FIG. 2is a side view,FIG. 3is a plan view, andFIG. 4is a cross-sectional view across a line P-P shown inFIG. 3.

As is shown inFIG. 1, the implant structure2is provided with a first screw6, a small screw12, a second screw8, a base plate (i.e., an orthodontic implant jig)4, an upper structure10, and a small screw40. The implant structure2is used by being implanted in the bone (not shown in the drawings) of a jaw portion inside an oral cavity. Specifically, the implant structure2is used in the following manner in order to move a tooth in a predetermined direction. Namely, the first screw6and the second screw8are implanted in bone, and the base plate4is supported on the first screw6and the second screw8. The upper structure10is then connected and fixed to the base plate4, and the implant structure2is placed inside the oral cavity. An orthodontic bracket or the like (not shown in the drawings) is then adhered via brazing or the like to the upper structure10, and the orthodontic bracket is connected to a predetermined tooth (not shown in the drawings) via orthodontic wire, elastic, and springs and the like (not shown in the drawings).

FIG. 5is a perspective view of a first screw6. The first screw6is a component that is formed from a highly biocompatible material such as, for example, titanium or a titanium alloy or the like. The first screw6has a first head portion6a, and a first screw body6bthat protrudes in a screw axial direction D6from the first head portion6aand is implanted in bone. Here, the first head portion6acorresponds to a first screw head portion of the present application, and the first screw body6bcorresponds to a screw body.

The first head portion6ahas an engaging portion14in which a female thread is formed. This female thread is open on an upper surface (i.e., side) of the first head portion6a, and is formed on a side wall of a recessed portion that is formed extending from this upper surface in the screw axial direction D6so as to penetrate an internal portion of the head portion6ain a direction towards the first screw body6b. Note that the depth (i.e., the length) of this female thread in the screw axial direction D6from the upper surface of the first head portion6ais not particularly restricted provided that the entirety of a male thread of the small screw (i.e., plate securing implement)12(described below) is able to be screwed into this female thread. In the present embodiment, a distal end in the penetration direction of the female thread does not reach the interior of the first screw body6b, however, a bottom end of the recessed portion in the depth direction from the upper surface of the first head portion6adoes reach as far as the interior of the first screw body6b.

In the present embodiment, the entire first head portion6aforms the engaging portion14(seeFIG. 4), and is formed in the shape of a hexagonal column. The configuration of the engaging portion14when looked at in plan view is not particularly restricted. However, if, for example, the configuration of the engaging portion14when looked at in plan view is polygonal, then if the inner circumferential configurations of first attachment holes24A and24B (described below: seeFIG. 1andFIG. 10) in the base plate4are also formed as polygonal shapes so as to match the polygonal engaging portion14, the corner portions of the respective polygonal shapes mutually lock each other in place so that any rotation of the base plate4in the circumferential direction of the engaging portion14is effectively suppressed.

A male thread is formed on an outer circumferential portion of the first screw body6b. The length in the screw axial direction D6of the first screw body6bis not particularly restricted provided that, when the first screw6is implanted in bone, it is stably supported by this bone. In the first screw body6b, the end portion that protrudes in the screw axial direction D6from the first head portion6ahas a tapered shape. In the present embodiment, an internal angle of the tapered portion of this protruding end portion is set to 120 degrees. However, the internal angle of the tapered portion of the protruding end portion is not particularly restricted and may be set to any appropriate angle.

A stopper16is provided on the first screw6at a position that is closer to the first screw body6bin the screw axial direction D6than the engaging portion14. The stopper16is formed so as to protrude from an end portion of the first screw body6bthat is close to the first head portion6ain a radial direction D7that is orthogonal to the screw axial direction D6. Looking at a cross-section of the stopper16taken in the screw axial direction D6, an upper surface16uof the stopper16, which is closer to the engaging portion14, is parallel to the radial direction D7, while a lower surface16dof the stopper16, which is closer to the first screw body6b, is sloped such that, as it approaches a base end portion from a distal end portion that is enlarged in the radial direction D7, it gradually moves closer to a distal end6cin the implanting direction of the first screw body6b. As a result of the stopper16being formed in this shape, the first screw body6bcan be easily implanted in bone, while any stress felt by the patient receiving the orthodontic treatment is alleviated. Note that the stopper16of the present embodiment is formed so as to protrude in the radial direction D7from the entire first screw body6bin the circumferential direction thereof, namely, is formed in a toroidal shape. However, the shape of the stopper16is not particularly restricted. For example, the stopper16may also be formed such that it protrudes from only a portion in the circumferential direction of the first screw body6b.

The small screws12are components that are formed from a highly biocompatible material such as, for example, titanium or titanium alloy or the like. As is shown inFIG. 4, the small screws12are able to be screwed into the female thread that is formed in the engaging portions14of the first screws6, and have a head portion12a, and a small screw body12bthat protrudes in an axial direction D12from the head portion12a.

A groove22having the shape of a plus sign when seen in plan view (hereinafter, these may be referred to as plus groove: seeFIG. 3) are formed in the head portion12ain order that a tool or the like may be inserted therein when the small screw12is being attached to the first screw6. A central upper end portion of the head portion12athat is in contact with the plus groove22is beveled. Note that the configuration of the head portion12aand groove22is not particularly restricted provided that the configuration does not impede the handling of the small screw12and the ease of attaching them to the first screw6.

A male thread that is capable of being screwed into the female thread that is formed in the first head portion6aof the first screw6is formed on an outer circumferential portion of each small screw body12b. The length in the axial direction D12of the male thread that is formed on the small screw body12bis not particularly restricted provided that the base plate4(described below) can be stably supported between the head portion12aof the small screw12and the stopper16of the first screws6.

FIG. 6throughFIG. 8are views representing the second screw8.FIG. 6is a perspective view,FIG. 7is a perspective view as seen from a different direction from that inFIG. 6, andFIG. 8is a side view. The second screw8is a component that is formed from a highly biocompatible material such as, for example, titanium or titanium alloy or the like. The second screw8has a second head portion8a, and a second screw body8bthat protrudes in a screw axial direction D8from the second head portion8aand is implanted in bone. Here, the second head portion8acorresponds to a second screw head portion of the present application.

The second head portion8ahas an abutting surface18. The abutting surface18is provided extending around an entire side wall in the circumferential direction of the second head portion8a. As is shown inFIG. 6throughFIG. 8, the second head portion8ais provided with the same diameter as the second screw body8bin a join position where it joins to the second screw body8b, and is formed such that the diameter thereof expands as it moves in the screw axial direction D8away from the second screw body8b.

The plus groove22is formed in the second head portion8ain order that a tool or the like may be inserted therein when the second screw8is being implanted in bone. A central upper end portion of the second head portion8athat is in contact with the plus groove22is beveled. Note that the configuration of the second head portion8aand grooves22is not particularly restricted provided that the handling of the second screw8and the ease of implanting it in bone are not impeded.

A male thread is formed on an outer circumferential portion of the second screw body8b. The length in the screw axial direction D8of the second screw body8bis not particularly restricted provided that, when the second screw8is being implanted in bone, it is stably supported by this bone. In the second screw body8b, the end portion that protrudes in the screw axial direction D8from the second head portion8ahas a tapered shape. In the present embodiment, an internal angle of the tapered portion of this protruding end portion is set to 120 degrees. However, the internal angle of the tapered portion of the protruding end portion is not particularly restricted and may be set to any appropriate angle. In the present embodiment, in order to stabilize the second screw body8by screwing it into bone as deeply as possible, the male thread that is formed on the outer circumferential portion of the second screw body8bis formed right up to the end portion of the second portion8athat is next to the second screw body8b.

FIG. 9throughFIG. 12are views representing the base plate4.FIG. 9is a perspective view,FIG. 10is a plan view,FIG. 11is a side view, andFIG. 12is a cross-sectional view across a line D-D shown inFIG. 10. The base plate4is a component that is formed from a highly biocompatible material such as, for example, titanium or a titanium alloy or the like. As is shown inFIG. 9throughFIG. 12, the base plate4is formed in an elongated shape (i.e., is formed as a belt-shaped object) having a predetermined thickness, and has a first surface4pthat is disposed facing in the longitudinal direction towards a bone such as the jawbone or the like inside an oral cavity, and a second surface4qthat is disposed on the opposite side from the first surface4p.

A plurality of (i.e., a total of three in the example given in the present embodiment) attachment holes in the form of first attachment holes24A and24B and a second attachment hole26are formed a predetermined distance apart from each other in the longitudinal direction in an end portion4cwhich is located at one end in the longitudinal direction of the base plate4. In the present embodiment, the two first attachment holes24A and24B and the second attachment hole26, which is disposed between the two first attachment holes24A and24B, are located in a portion that occupies substantially half of the base plate4in the longitudinal direction of the base plate4, and that includes the end portion4c. Note that the locations of the first attachment holes24A and24B and the second attachment hole26are not particularly restricted.

The first attachment holes24A and24B are formed such that the engaging portions14of the first screws6are able to engage therein from the first surface4p. In the present embodiment, an inner periphery of the first attachment hole24A is formed in a hexagonal shape, which is the same cross-sectional shape as the shape of the first head portion6a(namely, in the present embodiment, as the shape of the engaging portion14) of the first screw6when this is seen in plan view, so that the engaging portion14is able to be engaged in the first attachment hole24A. In addition, an inner periphery of the first attachment hole24B is also formed in a hexagonal shape when seen in plan view, however, the inner periphery of the first attachment hole24B is formed as an elongated hole whose sides that extend in parallel with the longitudinal direction of the base plate4are elongated. In this way, by forming the first attachment hole24B as an elongated hole extending in the longitudinal direction of the base plate4, even in cases in which the distance between the two first screws6and6is not constant, or in cases in which the two first screws6and6are unable to be implanted with their respective screw axial directions D6aligned in parallel with each other, by engaging the engaging portion14of one first screw6in the first attachment hole24A, and then engaging the engaging portion14of the other first screw6in the first attachment hole24B within the range of the elongated hole, it is possible to attach the base plate4to the two first screws6.

An edge portion25that protrudes within the aperture is provided on an inner peripheral edge of the first attachment holes24A and24B that is closer to the second surface4q. Each edge portion25is sandwiched between the engaging portion14and the head portion12aof the small screw12(seeFIG. 4) when the male thread that is formed on the small screw body12bof each small screw12is screwed into the female thread that is formed in the engaging portion14of each first screw6.

The second attachment hole26is formed such that the second screw body8band the second head portion8aof the second screw8are inserted in that sequence from the second surface4qinto the second attachment hole26, and the second head portion8ais anchored within this hole. In the present embodiment, the second attachment hole26becomes gradually wider in diameter moving from the first surface4ptowards the second surface4qso as to conform to the outer shape of the second head portion8aof the second screw8. Accordingly, a seating surface27whose diameter becomes gradually wider moving from the first surface4ptowards the second surface4qis formed on a side wall of the second attachment hole26. The abutting surface18of the second screw8is able to abut against the seating surface27.

As is shown inFIG. 2,FIG. 11, andFIG. 12, in the present embodiment, the portion in the longitudinal direction of the base plate4where the second attachment hole26is formed is indented slightly so as to protrude in the direction in which second screw body8bprotrudes when the second screw8is inserted into the second attachment hole26. The protrusion height of the portion where the second attachment hole26is formed is substantially equivalent to the thickness of the stopper16of the first screw6. As a result of this indentation being formed in this manner, when the base plate4is being supported by the first screws6and the second screw8, the first surface4pin the portion where the second attachment hole26is formed and the lower surface16dof the stopper16of the first screws6(in other words, a virtual line L1shown inFIG. 2) abut against an upper surface of the bone, and this enables the base plate4to be easily positioned. Note that the base plate4shown inFIG. 2is just one example thereof, and it is also possible for the base plate4to not be indented.

In the present embodiment, in the longitudinal direction of the base plate4, the width of the base plate4becomes narrower between the first attachment hole24A and the second attachment hole26, and also between the first attachment hole24B and the second attachment hole26. As a result, a lightening of the weight of the base plate4can be achieved. Moreover, it is also easy to bend the base plate4between the first attachment hole24A and the second attachment hole26, and between the first attachment hole24B and the second attachment hole26. In addition, notch portions30and30are formed opposite each other on either side of the axis of the base plate4in an end portion4din the longitudinal direction of the base plate4where the first attachment holes24A and24B and the second attachment hole26are not formed. An attachment portion32that is used to attach the upper structure10(described below) to the base plate4is provided on the end portion4d.

The pair of notch portions30and30are formed by cutting substantially circular arc-shaped notches in peripheral edges of the base plate4towards a center in a width direction thereof such that the width of the base plate4is shortened from the two sides thereof. According to this structure, by fixing the first attachment holes24A and24B and the second attachment hole26of the base plate4, and then applying force in a first bending direction D41, which is indicated by an arrow inFIG. 10, to a portion of the base plate4that includes the attachment portion32so as to rotate this portion around the position where the notch portions30are formed, the portion of the base plate4that includes the attachment portion32can be easily bent in the first bending direction D41. In the same way, by applying force in a second bending direction D42, which is indicated by an arrow inFIG. 10, to a portion of the base plate4that includes the attachment portion32so as to rotate this portion around the position where the notch portions30are formed, the portion of the base plate4that includes the attachment portion32can be easily bent in the second bending direction D42.

Although not shown in the drawings, it is also possible to provide a notch portion in the first surface4por the second surface4qof the base plate4that is formed by reducing the plate thickness of the base plate4over the entire width direction thereof.

By fixing the substantially half portion of the base plate4shown inFIG. 9throughFIG. 12where the first attachment holes24A and24B and the second attachment hole26are formed, and then applying force to this substantially half portion that includes the attachment portion32such that this substantially half portion that includes the attachment portion32is bent in a third bending direction D43, which is indicated by an arrow inFIG. 11, and then by additionally fixing the substantially half portion that includes the attachment portion32, and then applying force to the distal end portion that includes the attachment portion32such that this distal end portion that includes the attachment portion32is bent in a fourth bending direction D44, which is indicated by an arrow inFIG. 11, this base plate4can be formed into a crank-shaped base plate4that, as is shown inFIG. 1throughFIG. 4, is bent substantially perpendicularly at two locations in the longitudinal direction thereof. However, it is also possible for the base plate4to be bent after it has been supported and fixed in position above the bone in the shape shown inFIG. 9throughFIG. 12using the first screws6, the small screws12, and the second screw8.

The attachment portion32is provided so as to protrude outwards for a predetermined length from the second surface4qof the base plate4. Moreover, as is shown inFIG. 10, when seen in plan view, the attachment portion32is formed in a star shape having a plurality (eight in the example illustrated for the present embodiment) of projections at equidistant intervals in a circumferential direction thereof. A through hole that penetrates through the attachment portion32is formed in the center of the attachment portion32, and this through hole penetrates right through the base plate4. A female thread is formed on a side wall of the through hole in the attachment portion32. The portion of the base plate4where the attachment portion32is provided is formed having an expanded diameter when seen in plan view. Note that the attachment portion32may also be provided such that it protrudes outwards for a predetermined length from the first surface4pof the base plate4. It is also possible, moreover, for a plurality of the attachment portions32to be provided.

As is shown inFIG. 1throughFIG. 4, the upper structure10is a component that is formed from a highly biocompatible material such as SUS (stainless steel) or the like. As is shown inFIG. 1throughFIG. 4, the upper structure10of the present embodiment is a belt-shaped object having a predetermined thickness.

A base portion11is provided in the center in the longitudinal direction of the upper structure10. An insertion hole23whose shape corresponds to the star-shaped projection of the attachment portion32that is provided on the base plate4is formed in the base portion11. As a consequence, when the insertion hole23in the upper structure10is inserted into the attachment portion32of the base plate4, the angle of the upper structure10relative to the base plate4at the time of this insertion is kept the same. In the present embodiment, since the attachment portion32is formed substantially in a star shape having eight projections when seen in plan view, the mounting angle of the upper structure10relative to the base plate4can be adjusted at 45 degree angular intervals.

Note that the shape of the upper structure10is not particularly restricted provided that it is able to be mounted onto the mounting portion32of the base plate4. For example, it is also possible for the upper structure10to extend in only one direction from the attachment portion32, for example, such as if the upper structure10were to be attached to the attachment portion32of the base plate4with the base portion11being provided on an end portion on one side in the longitudinal direction of the upper structure10. Moreover, it is also possible to additionally provide the upper structure10with a structure in which an orthodontic bracket or the like (not shown in the drawings) is adhered via brazing or the like to the upper structure10, and orthodontic wire, elastic, and springs and the like (not shown in the drawings) are then connected to this orthodontic bracket or the like.

The small screw40is a component that is formed from a highly biocompatible material such as, for example, titanium or titanium alloy or the like. The small screw40is able to be screwed into the female thread that is formed in the attachment portion32of the base plate4, and has a head portion40a, and a small screw body40bthat protrudes in an axial direction D40from the head portion40a.

The grooves22are formed in the head portion40ain order that a tool or the like may be inserted therein when the small screw40is being attached to the attachment portion32of the base plate4. A central upper end portion of the head portion40athat is in contact with the plus grooves22is beveled. Note that the configuration of each head portion40aand grooves22is not particularly restricted provided that the handling of the small screw40aand the ease of attaching it to the attachment portion32are not impeded.

A male thread that is capable of being screwed into the female thread that is formed in the attachment portion32of the base plate4is formed on an outer circumferential portion of the small screw body40b. In the present embodiment, the length in the axial direction D40(seeFIG. 2andFIG. 4) of the male thread that is formed on the small screw body40bis shorter than the depth in the thickness direction of the base plate4(namely, in a direction heading from the second surface4qtowards the first surface4p) of the female thread that is formed in the attachment portion32of the base plate4. Note that the length of this male thread in the axial direction D40is not particularly restricted provided that the small screw40is able to be stably supported on the base plate4.

Next, a method used to implant the implant structure2in a bone (not shown in the drawings) such as a jawbone within an oral cavity (hereinafter, this may be referred to simply as an ‘implanting method’) will be described with reference toFIG. 1throughFIG. 4.

When implanting the implant structure2in bone, firstly, anchor positions (in other words, implanting positions for the first screws6and the second screw8) for the implant structure2in a bone of the jaw (for example, a central portion in the palatine bone of the upper jaw or the like) inside the oral cavity of a patient requiring orthodontic treatment are determined. Next, using a tool such as a specialized screwdriver (not shown in the drawings), a predetermined number (two in the present embodiment) of the first screws6are implanted in the bone in the screw axial direction D6at a predetermined distance from each other while being rotated. The screwing operation at this time is ended when the lower surface of the stopper16of the first screws6is at a position where it is in contact with bone or with an adhesive film. At this time, since the stopper16is abutting against bone or against the surface of an adhesive film, the first screws6can be prevented from sinking into the bone.

Next, the first attachment hole24A of the base plate4is engaged with the engaging portion14of one of the first screws6out of the two first screws6that have been implanted, and the first attachment hole24B is engaged with the engaging portion14of the other first screw6. The base plate4is then positioned with the first surface4pfacing the bone. At this time, even if, for example, the respective screw axial directions D6of the two first screws6are not parallel with each other, the base plate4can be attached to the two first screws6within the range of the longitudinal direction of the first attachment hole24B. As a consequence, a high-precision screw implanting operation is unnecessary thereby enabling the operation to be simplified.

Next, using a tool such as a specialized screwdriver (not shown in the drawings) or the like, the male thread formed on the small screw body12bof each small screw12is screwed into the female thread that is formed in the engaging portion14so as to fix the base plate4in position. As a result, the base plate4is supported by the first screws6. Note that, as is described above, even if the respective screw axial directions D6of the two implanted first screws6are not mutually in parallel, since the base plate4is formed from titanium or the like, the base plate4can be suitably bent. As a consequence of this, the positions of the first attachment holes24A and24B can be adjusted to match the engaging portions14.

Next, using a tool such as a specialized screwdriver (not shown in the drawings) or the like, the second screw body8bof the second screw8is inserted from the second surface4qinto the second attachment hole26in the base plate4. The second screw body8bof the second screw8is then implanted in the screw axial direction D8while the portion thereof that is protruding from the first surface4pis being rotated. The screwing operation at this time is ended when the abutting surface18of the second screw8is at a position where it is abutting against the seating surface27of the second attachment hole26.

Next, the insertion hole23in the upper structure10is inserted into the attachment portion32of the base plate4. Thereafter, using a tool such as a specialized screwdriver (not shown in the drawings) or the like, the male thread formed on the small screw body40bof the small screw40is screwed into the female thread that is formed in the attachment portion32so as to fix the upper structure10to the base plate4. Thereafter, an orthodontic bracket or the like (not shown in the drawings) is adhered via brazing or the like to the upper structure10, and orthodontic securing implements such as orthodontic wire, elastic, and springs and the like (not shown in the drawings) are connected to this orthodontic bracket or the like. The tooth or row of teeth that are to undergo orthodontic treatment are then joined to these orthodontic securing implements. By performing the above-described steps, the implant structure2can be implanted in a bone (not shown in the drawings) such as the jawbone or the like inside an oral cavity, and the tooth or row of teeth that are to undergo orthodontic treatment can be fixed to the implant structure2.

For example, if the treatment involves moving a tooth by pulling it from a different direction, or if the tooth to be moved is changed, then it is sufficient to simply loosen the small screw40, or, alternatively, it is sufficient to alter the placement angle of the upper structure10relative to the base plate4, more specifically, by extracting the small screw40from the attachment portion32and removing the upper structure10to a location above the attachment portion32, and then altering the original placement angle of the upper structure10relative to the star-shape of the attachment portion32to a more appropriate placement angle, and then reattaching the upper structure10from above onto the attachment portion32at this new appropriate placement angle.

According to the implant structure2of the above-described present embodiment, if the first screws6are implanted in a bone such as a jawbone or the like, and the first attachment holes24A and24B are then engaged from the first surface4pwith the engaging portions14which are protruding from this bone, then the base plate4can be attached to the first screws6. In addition, if the male thread of each small screw12is screwed from the second surface4qof the base plate4into the female thread of each first screw6, then the base plate4is fixed to the first screws6. In this manner, the base plate4is gripped between the first screws6and the small screws12, and is supported not by bone, but directly by the first screws6. In contrast, by inserting the second screw8from the second surface4qof the base plate4through the second attachment hole26, and implanting the portion thereof that protrudes from the front of the first surface4pin the direction of insertion into a bone such as a jawbone or the like, the base plate4is pressed by the second head portion8aof the second screw8from the second surface4qin the direction of the first surface4p, and is also directly supported by the second screw8. In this type of structure, the first screws6and the second screw8are prevented from coming loose from the bone, and are instead firmly fixed to the bone. In addition, the base plate4is not directly supported by bone, but is instead stably supported by the first screws6and the second screw8. Because of this, any play can be eliminated from the base plate4.

As has been described above, since the base plate4is not supported directly by bone, but is instead stably supported directly by the first screws6and the second screw8, the upper structure10, plates, and wires and the like can be stably fixed to the base plate4.

According to the implant structure2of the present embodiment, as a result of the stoppers16being provided on the first screws6, the base plate4is gripped in the thickness direction thereof between the stoppers16of the first screws6and the head portions12aof the small screws12. Because of this, the base plate4can be supported more stably.

Moreover, according to the implant structure2of the present embodiment, the second screw8is provided with the abutting surface18, and when the second screw8is inserted from the first surface4pthrough the base plate4towards the second surface4q, the abutting surface18abuts against the seating surface27. As a consequence, the surface area of the contact between the second screw8and the base plate4when the base plate4is pressed by the second head portion8aof the second screw8from the second surface4qin the direction of the first surface4pis increased. Because of this, the support provided to the base plate4by the second screw8is made more stable and stronger in the direction in which the base plate4is pressed from the second surface4qtowards the first surface4p.

Moreover, according to the implant structure2of the present embodiment, since the notch portions30are formed in the base plate4, the plate portion can be bent in any desired direction around the portion where the notch portions30are formed. Accordingly, by changing the position and orientation of the attachment portion32in accordance with the orientation of this bend, the attachment portion32can be set in the attitude desired for the upper structure. Namely, the position of the attachment portion32can be easily adjusted so as to match the configuration and application of the upper structure10even after the base plate4has been fixed to a bone. Accordingly, since the task of attaching the base plate4is simplified, work efficiency is improved, and both labor and time taken can be reduced. Moreover, by changing the formation positions, the orientation, and the number of formation locations and the like of the notch portions30in the plate portion, the base plate can be bent to any desired configuration. Furthermore, the upper structure can be positioned in a desired attitude without the number of parts used having to be increased, unlike the case of a conventional structure. Consequently, there is no increase in the structural complexity of the implant structure2, and a reduction in cost can also be achieved.

Moreover, according to the implant structure2of the present embodiment, since the plate portion of the base plate4has a simple elongated configuration, not only are the manufacturing and processing of the base plate4simplified, but the handling thereof when the implant structure2is being fixed to a bone can be made even easier. Moreover, according to the implant structure2of the present embodiment, since the notch portions30are formed in the base plate4by narrowing the width thereof, the plate portion can be easily bent around the locations where the width of the plate portion is formed more thinly.

By engaging the first attachment holes24A and24B from the first surface4pwith the engaging portions14of the first screws6that are protruding from the bone, and screwing the male thread on the small screw12into the female thread in the first screws6from the second surface4q, the base plate (i.e., the orthodontic implant jig)4of the above-described present embodiment is not supported by bone, but is supported above the bone by the first screws6and the small screws12. Moreover, as a result of the second screw8being inserted from the second surface4qthrough the second mounting hole26, and the portion that protrudes from the front of the first surface4pin the insertion direction being implanted in bone, the base plate4is pressed from the second surface4qin the direction of the first surface4p, and is also directly supported by the second screw8. Namely, according to the base plate4of the present embodiment, since the base plate4is not supported directly by bone, but is instead stably supported directly by the first screws6and the second screw8, the various effects described above can be achieved.

A preferred embodiment of the present invention has been described above in detail, however, the present invention is not limited to this specific embodiment and various alterations and modifications and the like may be made thereto insofar as they do not depart from the spirit or scope of the present invention as described in the Claims.

FIG. 13AthroughFIG. 13Care views showing variant examples of the first screws6and plate securing implements (namely, the small screws12), withFIG. 13Abeing a side view representing a first screw6B,FIG. 13Bbeing a side view representing a nut (i.e., a plate securing implement)13, andFIG. 13Cbeing a cross-sectional view showing a cross-section when a cut is made in a parallel direction to the screw axial direction D6of the first screw6B through the center of the first screw6B while looking at the base plate4, which has been fixed by the first screw6B and the nut13, in plan view. Note that inFIG. 13AthroughFIG. 13C, component elements of the first screw6B and the nut13that have similar functions to those of component elements of the first screw6and the small screw12are given the same descriptive symbols as those component elements of the first screw6and the small screw12and a description thereof is omitted.

As is shown inFIG. 13A, a male thread is formed on the first head portion6aof the first screw6B. In contrast, as is shown inFIG. 13B, a female thread is formed in the nut13that is used instead of the small screw12of the above-described embodiment as a plate securing implement. In a structure of this type, as is shown inFIG. 13C, the base plate4is attached to the first screw6B by implanting the first screw body6bof the first screw6B in bone, in the same way as in the above-described embodiment, and engaging the first attachment hole24A (or the first attachment hole24B) from the first surface4pwith the engaging portion14which is protruding from this bone. The base plate4is then fixed to the first screw6B by screwing the female thread of the nut13onto the male thread on the first head portion6aof the first screw6B from the second surface4qof the base plate4. In this way, the base plate4is gripped between the first screw6B and the nut13, and is supported not by bone, but directly by the first screw6B. Accordingly, according to the structure of the first variant example, in the same way as in the above-described embodiment, the first screws6and the second screw8are prevented from coming loose from the bone, but are instead firmly fixed to the bone. In addition, the base plate4is not directly supported by bone, but is instead stably supported by the first screw6B and the second screw8. Because of this, any play can be eliminated from the base plate4.

FIG. 14AthroughFIG. 14Eare views showing variant examples of the base plate4, and are plan views showing a first variant example through to a fifth variant example of the base plate4. As is shown in these drawings, the number and locations respectively of the first attachment holes, the second attachment hole, and the attachment portion32that are formed in the base plate4of the present invention are not particularly restricted, and may be suitably altered in accordance with the content of the orthodontic treatment. For example, as is shown inFIG. 14A, it is also possible for the attachment portion32, the first attachment hole24A, the second attachment hole26, and the first attachment hole24B to be formed in that sequence in the longitudinal direction from one end portion4dof a base plate4A of the first variant example towards another end portion4cthereof. Additionally, as is shown inFIG. 14B, it is also possible for the first attachment hole24A, the attachment portion32, the first attachment hole24B, and the second attachment hole26to be formed in that sequence in the longitudinal direction from the one end portion4dof a base plate4B of the second variant example towards the other end portion4cthereof. Additionally, as is shown inFIG. 14C, it is also possible for the first attachment hole24A, the second attachment hole26, the attachment portion32, the second attachment hole26, and the first attachment hole24B to be formed in that sequence in the longitudinal direction from the one end portion4dof a base plate4C of the third variant example towards the other end portion4cthereof. Additionally, as is shown inFIG. 14D, it is also possible for the first attachment hole24B, the second attachment hole26, the attachment portion32, the first attachment hole24B, and the second attachment hole26to be formed in that sequence in the longitudinal direction from the one end portion4dof a base plate4D of the fourth variant example towards the other end portion4cthereof. Furthermore, as is shown inFIG. 14E, it is also possible for a base plate4E of the fifth variant example to extend in two mutually orthogonal directions. The first attachment hole24B, the attachment portion32, and the first attachment hole24A are formed in that sequence in the direction of the long axis shown inFIG. 14Efrom the one end portion4dtowards the other end portion4cin a first portion that extends in a first direction (i.e., in the direction of the long axis) out of the aforementioned two directions. On the other hand, the second attachment hole26, the attachment portion32which is shared with the first portion, and the second attachment hole26are formed in that sequence in the direction of the short axis shown inFIG. 14E, which is orthogonal to the direction of the long axis, from one end portion towards another end portion in a second portion that extends in a second direction (i.e., in the direction of the short axis) out of the aforementioned two directions. In this way, the base plate4may be formed in shapes other than an elongated shape. The shape of the base plate4when seen in plan view is not particularly restricted, and may be suitably altered in accordance with the orthodontic treatment.

Namely, in the implant structure of the present invention, as a result of the base plate4being supported from below by the first screws6and6B, and the first screws6and6B and the base plate4being fixed in place by the plate securing implements12and13, and the base plate4being supported from above by the second screw8, thereby enabling the upper structure10to be attached to the base plate4via the attachment portion32, the above-described effects are obtained. In addition, the design parameters of the base plate4, the first screws6, and the second screw8and the like are able to be freely altered in accordance with the contents of the orthodontic treatment.

INDUSTRIAL APPLICABILITY

According to the orthodontic implant structure of the present invention, it is possible to stably support a base plate. Moreover, according to the orthodontic jig of the present invention, this orthodontic jig can be used in the orthodontic implant structure, so that the effectiveness of orthodontic treatment performed using an upper structure, a plate, and wires and the like can be increased.

REFERENCE SIGNS LIST