US3438132A - Orthodontic method and apparatus - Google Patents

Description

April 15, 1969 J. M. RUBIN ORTHODONTIC METHOD AND APPARATUS Sheet Filed May 2, 1966 FIG. 2

April 15, 1969 J. M. RUBIN ORTHODONTIC METHOD AND APPARATUS Sheet Filed May 2, 1966 w mm EU R N United States Patent O 3,438,132 ORTHODONTIC METHOD AND APPARATUS James M. Rubin, 141 W. 17th St., New York, N.Y. 10011 Filed May 2, 1966, Ser. No. 546,690 Int. Cl. A61c 7/00 U.S. Cl. 3214 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates generally to an orthodontic method and apparatus and is more specifically concerned with a novel and improved method for straightening malposed teeth, and apparatus for accomplishing same.

In orthodontics, the most common method of straightening malposed teeth is by the use of an arch-wire which applies a force to a tooth to be straightened by cooperation with a bracket secured to the tooth through a tooth band. The arch-wire is anchored to other teeth through suitable brackets and is deflected so as to apply a light force to the tooth to be straightened. As the tooth straightens, the arch-wire is bent to ditferent positions in order to continue the application of a straightening force to the tooth until straightening is completed. Such procedure requires that the arch-wires be physically deformed from its generally smooth curvature in order to be in a position to engage the bracket attached to the malposed tooth. The amount of force applied will depend on the degree of distortion of the arch-wire and since the bending of the archwire is manually accomplished by the orthodontist, it becomes most difiicult to accurately control or evaluate the forces being applied.

In the straightening of teeth, it is preferred to apply only a light force to avoid root absorbt-ion and injury to bone and tissue. As the tooth moves under the light force, adjustments are made during monthly visits and the tooth is slowly brought to the proper position. It is known that excessive force should be avoided, but the delicate operation to be performed in a patients mouth and the inability to evaluate the forces applied make it substantially impossible to control the forces and maintain them at a minimum.

Accordingly, it is the object of the instant invention to provide a method for straightening teeth wherein the force applied to a malposed tooth may be controlled with reasonable accuracy.

Another object of the invention is to provide a method for straightening a malposed tooth wherein greater uniformity of operation will result.

A further object of the invention is to provide a method for straightening a malposed tooth in which the increase in the force applied to a malposed tooth during periodic checkups may be accurately controlled within limits, regardless of the skill of the orthodontist.

Still another object of the invention is to provide improved apparatus for the straightening of malposed teeth.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Generally speaking, in accordance with the invention, a malposed tooth is straightened as the result of forces ice applied through an arch-wire whose position generally remains constant throughout treatment and whose connection to the tooth is varied at desired intervals to constantly provide the desired straightening force to the tooth. Suitable apparatus is provided for controlling the cooperation of the arch-Wire with the tooth whereby the desired forces are controlled by suitable selection of appropriate apparatus rather than by physical deformation of the arch-wire.

The invention accordingly comprises the feature-s of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view of a set of teeth with arch-Wire and brackets attached;

FIG. 2 is a perspective view of a tooth having apparatus of the instant invention mounted thereon;

FIG. 3 is an exploded perspective view, at an enlarged scale, of the clip and block of FIG. 2;

FIG. 4 is a perspective view of another block forming part of a block set;

FIG. 5 is a plan view of a block and chip engaged with an arch-wire;

FIG. 6 is a perspective view of another block in the set;

FIG. 7 is a perspective view of another form of apparatus mounted on a tooth;

FIG. 8 is a perspective view of a block constructed in accordance with a modified embodiment of the invention;

FIG. 9 is a plan view of the block of FIG. 8 in engagement with an arch-wire; and

FIG. 10 is a sectional, elevational view taken along line 1010 of FIG. 8.

Referring to FIG. 1, there is shown a representation of a set of teeth with the six middle teeth being the anterior teeth, the next two on each side being the bicuspids and the last one on each side being molars. The teeth, designated as 11, are shown to indicate the environment of the invention and thus no attempt has been made to accurately depict the configuration of each tooth. One of the anterior teeth is malposed and it is the malposed tooth 12 which requires straightening. Each tooth is surrounded by a band 13 having an arch-wire bracket 14 secured thereto for receiving an arch-Wire 15. The arch-wire forms a smooth are along the outside of the teeth and the correctly located teeth acts as anchors for correcting the position of the malposed tooth. A straightening force will be applied to the malposed tooth through the bracket and band by the arch-wire. Since a reactive force will likewise be applied to each of the other teeth, plural anchors are desirable to minimize the forces applied to each of the anchor teeth 'whereby repositioning of the anchor teeth will be negligible. It is important to note that the archwire of FIG. 1 follows a smooth arc and is not deflected inwardly proximate to the malposed tooth. This is contrary to generally accepted orthodontic procedures and is basic to the substantial advantages derived from the invention hereafter described.

Referring to FIG. 2, tooth 12 has band 13 secured therearound in a manner well known in the art. Arch wire bracket 14 consists of a clip 16 and a block 17 which will be hereafter described in greater detail. Received through block 17 is the arch-wire 15.

Referring to FIG. 3, clip 16 is channel-shaped with the legs of the channel being perpendicular to the base thereof. Base 18 is formed with an inwardly extending tongue 19 substantially centrally of the base and parallel to the longitudinal axis of the channel-shaped clip. One leg 21 is also formed with an inwardly extending longitudinal tongue 22 and a detent button 23.

Block 17 preferably has a square cross section and is formed with a detent slot 24 in one face adapted to receive tongue 22 and a cup shaped depression 25 adapted to receive detent button 23. A slot 26 is provided in block 17 for receiving arch-wire l5 and is positioned to receive tongue 19.

Referring to FIG. 2 and 3, clip 16 is permanently affixed to band 13 such as by Welding. When inserting the arch-wire into the patients mouth, it is given a smooth curvature by the orthodontist and located generally within each of the clips. Block 17 is then set in place with the,

arch-wire in slot 26 and the block is resiliently held in the clip by cooperation between the tongue and slots and button 23 and depression 25.

At this point, it is appropriate to consider the relative sizes of the various components in order to understand the method to be hereafter described in connection with such miniature apparatus. The dimensions are given by way of example and are by no means limiting. The length of block 17 is .110" with its height and width .060" each. Clip 16 has inside dimensions such as to closely embrace the block and the leg of the clip may be bent slightly inwardly toward one another in order to provide for good frictional engagement with the block when the legs are deflected on assembly. Note that all such elements are normally fabricated of stainless steel or other suitable material.

The outside diameter of tongues 19 and 22 are each .016 and project as semi-circles. Detent slot 24 is formed as a semi-circle of the same diameter. The width of slot 26 is also .016" with the base of the slot formed as a semi-circle. The diameter of the arch-wire used in this example would be .016", this being the diameter of the commonly used wire in the light wire technique. The minimum depth of slot 26 would be .032" in order for it to receive the arch-wire as well as a .016" diameter tongue. Blocks will be provided with slots of greater depth. Slot 26 may have a depth as great as .048" or greater and blocks having slots of varying depths would be provided for carrying out the invention as will hereafter become apparent. By way of example, the block shown in FIG. 4 has a slot 26 with a minimum depth of .032".

The orthodontic method of the instant invention and the apparatus used in conjunction therewith may now be understood. Referring again to FIG. 1, malposed tooth 12 requires repositioning in the labial or buccal direction as indicated by the arrow. Each of the other teeth act as anchors and a tooth band 13 and clip 16 is aflixed to each as well as to the malposed tooth. Arch-wire is smoothly formed and a block 17 is selected for each of the anchored teeth. The blocks selected for the anchored teeth have slots 26 with a .032 depth. This is proper since the anchor teeth are correctly aligned and thus a space of .016" will be provided for the arch-wire of same diameter when the block is assembled in the clip with tongue 19 in the slot. In this manner, the arch-wire will smoothly follow the arch of the teeth and be anchored at a plurality of points without exerting forces as between the anchored teeth.

The block provided for cooperation with the clip mounted on the malposed tooth should not have a slot of minimum depth since the assembly of such block through the clip would cause an excessive labial force to be applied to the malposed tooth. As is known in the art, a light force should be applied in order that the tooth is caused to move slowly over a period of time. If the tooth is malposed by .052" for example, a block having a .048 slot would be assembled to the clip of the malposed tooth so as to apply a small corrective force to the tooth. As the tooth moves labially over a period of time, the force applied to it by the block having the deep slot becomes less and, at the next visit, a block having a slot of smaller depth, .044" for example, would be substituted for the block with the deeper slot. Thus the tooth would again be placed under a small corrective forse so that further straightening may occur. As the tooth is straightened over a period of time, the block is continually changed for a block having a slot of smaller depth so that a light pressure is maintained until the tooth has been brought to the proper position.

It is important to note that a deformation from its smooth arch was not imparted to the arch-wire and thus the arch-wire was not manipulated throughout the corrective cycle. Each block caused a slight deflection of the resilient arch-wire so as to apply a small force to the tooth. Each time the block is changed, the force applied to the tooth will be proportional to the decrease in slot depth and thus will be substantially predetermined so that corrective forces can be applied while controlling the amount of such forces.

This is in contradistinction to current practice wherein the amount of force applied depends substantially on the feel of the orthodontist. While he knows that small forces are desirabe, prior to the instant method, there was no way to accurately determine that the forces will remain small but of sufiicient magnitude to effect movement of the malposed tooth.

In other words, with applicants method and apparatus, the forces applied to a malposed tooth may be accurately controlled. As the tooth moves under a force in the direction of application of the force and the force thereby decreases, the force can be subsequently slightly increased by merely removing a block and substituting another block therefor. Thus once the arch-wire is in place, it need not be constantly remanipulated since it is the remanipulation of the arch-wire which introduces the possibility for human errors and inaccuracies. Thus in prior techniques, error and inaccuracy in developing corrective forces was introduced on each visit wherein a change of corrective action took place. With applicants method, manipulation of the arch-wire could conceivably be limited to the single instance of commencement of treatment. Thereafter, the forces are changed by substitution of blocks and the initial forces can also be controlled by suitable selection of the original block. The orthodontist would be supplied with a set of blocks having slots of varying depths. In the example cited, the smallest slot would be .032" deep and the deepest slot .048" deep with intermediate blocks having slots which vary in depth at increments of .004". Note that tongue 19 could be omitted, or replaced by a central dimple which may be of semi-spherical configuration having an outside diameter of about .005" to increase the range of slot depth. With the dimple, the arch-wire when engaged with the clip, would establish a point contact therewith.

A tooth requiring rotation on its vertical axis for straightening would also be accomplished with blocks having horizontally oriented slots. As shown in FIG. 5, arch-wire 15 extends through slot 26. With the tooth rotated on its vertical axis the arch-wire would make contact with the base of the slot at one end of the block and with tongue 19 at the other end of the slot to thereby apply a rotative force to the tooth as indicated by the arrow in FIG. 5. As correction of the tooth position tages place, blocks having shallower slots would be substituted for those with deeper slots in accordance with the method described above.

If the tooth requires uprighting or tipping, the block would be oriented to place slot 26 in a generally vertical plane wherein the arch-wire would engage the base of the slot at one end of the block and tongue 22 at the other end of the block as shown in FIG. 6. In this manner a rotating force would be applied to the tooth in a vertical plane in the same manner that a rotating force in the horizontal plane is applied by the arrangement shown in FIG. 5. Again, as straightening takes place, the blocks would be changed to control the corrected forces applied to the malposed tooth.

In certain malposition situations, torquing of the tooth is required. A malposed tooth requiring torquing would have its longitudinal axis inclined from the vertical in a labial-lingual direction, for example. Torqing is accomplished by use of an edge-wise arch-wire having a rectangular cross section. As shown in FIG. 7, the malposed tooth 12 surrounded by a band 13 having a clip 16 attached thereto is adapted to receive a block 31 having a vertically directed slot 32 therein. The slot receives a rectangular arch-wire 33 whereby the cooperation between the walls of the rectangular arch-wire and the walls of the slot provide a torquing force to upright the tooth. In accordance with the instant invention, a set of blocks 31 would be provided, having slots of various widths. For example, with rectangular arch-wire having a width of .016", a typical set of blocks would include a block having a slot width of .016", and block having a slot width of .018, a block having a slot width of .020 and a block having a slot of .022. When the tooth is badly malposed, the block having the largest width slot would be utilized to avoid the application of excessive torquing forces to the tooth. As the tooth moves, blocks having narrower width slots would be substituted in the same manner as heretofore described.

In certain orthodontic applications, it is desirable to have point contact between the arch-wire and the engaging bracket. The instant invention is capable of providing true point contact utilizing apparatus such as shown in FIGS. 8 through 10. A block 41 is provided with a longitudinal aperture or slot having a substantially knife edge bearing surface whereby, when engaged with an archwire of circular cross section, the engagement area substantially approaches a single point as shown in FIG. 9.

The longitudinal aperture in this embodiment is formed as a pair of intersecting semi-cones. The outer ends 43 of the aperture are located in opposed block ends and appear, in plan view, as semi-circles opening tangentially outwardly through a side of the block as best seen in FIG. 10. The longitudinal axis of each of the semi-cones is not perpendicular to its respective base and thus the axes intersect at an angle. The bearing edge thus occurs in a plane parallel to the block ends and passing through the intersection of the axes as indicated at 44 in FIGS. 8 through 10. In section (FIG. 10) the bearing surface is semi-circular and opens tangentally outwardly through one side of the block. The intersecting semi-cones thereby form a slot for receiving the arch-wire with the hearing surface at the intersection being closest to the side of the block through which the slot extends.

The point contact method also utilizes blocks of r varying apertures. If, for example, a .016" arch-wire is to be used, the diameter of each semi-circular cutout in a block end would be .048". The point on the semi-circle furthest from the block side through which the slot extends would also be .048". These representative dimensions Would be identical for all blocks in a set.

The diameter and location of the bearing surface at the intersection would vary from block to block. In each case, the diameter of the semi-circle and the distance from the block side through which the slot extends to the furthest point on the semi-circle would be equal. In this embodiment a clip 16 would be used which preferably omitted tongue 19 and thus the block in the set used for a normally placed tooth would have an intersecting diameter of .016. If the tooth is slightly malposed the intersecting diameter might be .018 or .020" while for a badly malposed tooth the intersecting diameter might be .0 36. This embodiment could also be used with a clip having a dimple as heretofore described. In any event the intersecting diameter would always be less than the base diameters of the semi-cones in order that a bearing surface 44 would occur as an edge in a plane. Thus, in accordance with the instant technique, as the position of the tooth is corrected, a block having a larger intersecting diameter would be replaced by one of smaller intersecting diameter and the replacement procedure would continue until the tooth is completely straightened.

It should also be understood that the aforesaid invention can be used in conjunction with other orthodontic techniques and apparatus, the proper selection being well within the skill of those in the art.

What is claimed is:

1. Orthodontic apparatus for use with an arch-wire comprising a clip having a base'for attachment to a tooth band and a plurality of blocks, each of said blocks adapted for cooperation with said clip for retention thereby, each of said blocks being provided with a slot defining a surface for engagement by the arch-wire, said slot opening inwardly and being closed by said base, the location of the surface of each block being at variant with the location of the surface on all other blocks.

2. Orthodontic apparatus as claimed in claim 1 wherein said surface is formed as a slot extending longitudinally of said block from one side thereof, the depth of the slot in each block being different than the depth of the slots in all other blocks.

3. Orthodontic apparatus as claimed in claim 2 wherein the width of each slot is substantially equal to the width of the arch-wire to be received therein.

4. Orthodontic apparatus as claimed in claim 1 Wherein said surface is formed as a slot extending longitudinally of said block from one side thereof, the width of the slot in each block being dilferent than the width of the slots in all other blocks.

5. Orthodontic apparatus as claimed in claim 4 Wherein the slots in all blocks are of substantially equal depth.

6. Orthodontic apparatus as claimed in claim 1 wherein said surface is formed at the intersection of two partially cone-shaped apertures having their base ends at opposite ends of said block and their intersecting ends centrally of said block, said cone-shaped apertures opening outwardly through one side of said block along the length thereof to define a longitudinally extending slot, the depth of the slot at the intersection in each block being diiferent than the depth in all other blocks.

7. Orthodontic apparatus as claimed in claim 1 wherein said clip is formed as a channel-shaped member, said channel-shaped member being formed with a tongue, and each of said blocks being formed with a detent slot adapted for cooperation with said tongue when said block is assembled with said clip.

References Cited UNITED STATES PATENTS 2,908,974 10/1959 Stifter 3214 ROBERT PESHOCK, Primary Examiner.

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