US2532200A - Orthodontal instrument - Google Patents

Description

Nov. 28, 1950 B. E. SMITH ORTHODONTAL INSTRUMENT Filed Aug. 6, 1948 IN V EN TOR. Bariozzl I'. Smz

ATTORNEYS Patented Nov. 28, 1950 I ED STAT ES PAT OF F 'HCEL QRTHQDONTAL INSTRUMENT Barton E; Smith, Massillon,,0,hio

ApplicationAugust -(i, 1948, SerialNo. 423388 1. Claim. 1,

The invention relates. generally to, an instrument for facilitating the operation, of straight.- ening irregular teeth, gandzmore particularly to-an instrument for making ligatures to connect in,- dividual irregular teeth to an edgewise'anch 'exe tending along the row of teeth in. which the irregular teeth are located;

Conventional practice in straightening irregular. teeth-by using a so-called edgewise; arch consists in: mounting a wire arch alongsidethe row of? teeth by cementing metal bands on several-of the: teeth and attaching the wire arch to; the band. llhe, teeth which are the farthest outof linemay be connected to the arch by attaching a finee wireligature to metal band on, such: a tooth and; then tying the wire under tension to the arch to pull the toot-h toward? the arch. The straightening operationusually extendsover a period of many months, depending upon the; degreeof irregularity, and the process is one of gradually pulling the irregularteeth into line;

For this purpose, it is customary'to start out with a: Wire: arch "of considerable resiliency such asa wire .015" in diameter, and tie'each of the several irregular teeth to: the arch with, a fine wireligature. Under tension the resiliency of the arch wire preventspulling the teeth too se- 18128137 591- as to cause painor injury; After a suitable time. the arch wire is changed to a slightly larger diameter which is, less resilient; and the diameter ofthe wire may best-eppedup slightly three or four times at periods of several months each to gradually pullthe irregular teeth intoline, The lastwire, or in some cases, the last two.- wires, preferably are rectangular in cross section and of the order of .022" 303 1028 in cross section, and positioned edgewise to the teeth, that is, with the longest dimension, at right angles to the teeth.

With the -exception of a few teeth which are quite far out of line at the beginning of the straightening process, all of the: teeth being straightened are provided withmetalabands which have grooved brackets thereon for receiving the arch wire, and these brackets are secured to the archwire by looping the, ligature wire over the archwi're and underthe brackets and then twisting the ligature wire under tension to malre a very tight connection The operation of looping and tying: the ligature wire around the band bracket and" arclrurire is a tedious and exacting one with the ordinary instruments which thed'entist has at his disposal. Consequently, the dentist. nat orally tends to avoid changing the size of the arch wire: any oftener than is necessary so asto eliminate as; much as possible the tediousstyingoperation, with the result that frequently. the straightening operation. is not carried out properly by changing: the size of the arch wire at short: enough intervals to: be most. beneficial" to the patient;

It is an object of the present nvention to provide: a l-novel. and improved ligature tying instrument for quickly: and easily securing. irregular teeth to an. edgewise arc-h;

Another object is to. provide a. novel ligature tying instrumentzfor use in straightening irregular teeth, which instrument is designed to-be easyon the patient, aswell' as beneficial to him.

Another object is to provide a novel ligature tying: instrument which so facilitates. the attaching of irregular teeth to an edgewise arch as to insure the performance of a proper and gradual, process of straightening the teeth.

A further; object is to provide a ligature tying instrument; for use in connection with an edgewise arch, which instrumentlis of substantially the same size, and: shape as other ordinary in strumentsv in. constant use to which the dentist is accustomed.

A still further object is to provide a novel ligature tying instrument for use in straightening teeth, which is adapted to be prepared beforehand with a loop of ligature wire by an assistant for quick and easy use by the dentist inthe tying operation.

These and other objects are accomplished by the parts, constructions, arrangementsand combinations which comprise the present invention,

r the nature of which is set forth in the following general statement, and a preferred embodiment of which is set forth in the following description and illustrated in the accompanying drawings, and which is particularly and distinctly pointed out and set forth in the appended claims forming part hereof.

in general terms, the improved instrument comprising the present invention preferably includes an instrument having an elongated shank with a handle swiveled on the rearportion thereof, the front end of the instrument being provided with a pair of side-by-side holes extending from the front end substantially longitudinally of the instrument a short distance and opening out through the top thereof, said holes being adapted to have threaded therethrough the ends of a loop of ligature Wire formed at the front end of the instrument and preferably shaped in a forming die, there being a post spaced: from the holes for anchoring theendsof the ligature wire and a groove on the underside of the front end of the instrument for engaging the arch wire and pressing it into the band bracket groove when the ligature wire is being applied to connect the arch wire to a band bracket surrounding an irregular tooth.

Referring to the drawing forming part hereof in which a preferred embodiment of the invention is shown by way of example;

Figure 1 is a top plan elevation of the improved instrument on a somewhat enlarged scale, showing the ligature wire formed in a loop at the front end of the instrument and the ends of the loop wrapped around the anchor post;

Fig. 2 is a bottom plan elevation thereof;

Fig. 3 is a fragmentary perspective View showing the manner of forming the wire loop in a forming die adapted for shaping the loop to facilitate the subsequent tying operation;

Fig. 4 is a fragmentary side elevational view showing the bend in the loop produced by the forming tool;

Fig. 5 is a fragmentary plan view showing the arch wire of the edgewise arch mounted alongside a row of teeth with a loop of ligature wire held by the novel tool in position to connect the arch to a band bracket;

Fig. 6 is a side elevation of the edgewise arch in position on a row of teeth; and

Fig. '7 is anenlarged sectional view as on line l-l, Fig. 6, showing the manner of connecting the loop of ligature wire to a band bracket on a tooth.

Similar numerals refer to similar parts throughout the several views of the drawing.

The novel instrument includes a front handle portion 8 which may have a reduced elongated shank 9 extending axially rearward therefrom with a flanged end piece it secured on the outer end of the shank. Preferably, a handle sleeve II is swiveled on the shank 9 between the front handle portion 8 and the end piece it, and the handle portions 8 and ii ar preferably both provided with longitudinal flats to make them octagonal in cross section, for example, for facilitating gripping the handle portions the fingers. Moreover, the handle portions 8 and 55 may be knurled if desired, for the same purpose.

The front end of the handle portion 8 is preferably tapered radially inward as indicated at E2, and a head portion indicated generally at it projects axially forward therefrom. As shown in the drawings, the head portion 53 is flattened substantially throughout its length, and the front end M of the head portion is preferably flared laterally outward to increase its width to some extent.

The head end M is provided with two side-byside holes l 5 which extend through the front end thereof in a substantially longitudinal direction and open outwardly through the upper side of the head portion as best shown in Figs. 1 and 3. These holes 55 are adapted to have threaded therethrough the two ends is of a loop i? of fine ligature wire which may be formed in front of the head end i i of the instrument. The head portion i3 is provided with an anchor post id which is preferably secured to the rear end of the head it, and the post 53 provides an anchor for the two ends 55 of the loop, the end portions being twisted around the shank of the post and then the loose ends remaining may be wrapped around the rear end of the head portion, as indicated in the drawing. As shown in Fig. 2, the underside of the head portion M is preferably provided with a longitudinal groove l 9 for a purpose to be described.

Referring to Figs. 5 and 6, a portion of the lower denture of a set of human teeth is indicated generally at 20 with an edgewise arch 2| mounted along the outer surface of the row of teeth. The arch is anchored at 22 to a bracket secured on a metal band 23 which is cemented on one of the molars, and the other end of the arch would be similarly secured to a molar on the other side of the lower denture; The individual teeth are attached to the arch 2| by metal bands cemented to the teeth and having brackets thereon for detachably engaging the band; Since these bands and brackets are all essentially the same except for the bands being shaped to fit individual teeth, only one set of them will be described.

The metal band 25 is cemented to the tooth 26 in a usual manner, and the band has a small metal bracket 2'5 secured to its outer side. The bracket 2? has a central groove 28 with overhanging upper and lower wings or flanges 29, and the groove 28 is adapted to detachably receive the arch wire 2! which is shown as being rectangular in cross section, although a round wire may be used during the earlier stages of the straightening process, as previously described.

Assuming the tooth 26 to be irregular or out of alignment, the process of straightening the tooth is gradually to pull it toward the arch 2|, by ti htly securing the bracket 2! to the arch wire under tension. Obviously, if the arch wire is of small enough diameter to be considerably resilient, the arch wire will give slightly inward so that the pull on the tooth will not be too great in the earlier stages of the straightening process.

The conventional method of securing the arch wire to the bracket 2'! is to tie a loop of ligature wire around the arch wire and under the wings 2d of the bracket and then outwardly around the arch wire and twist the ends of the ligature together to tighten the loop. Since the ligature wire is very fine and the loop and bracket are both small, it is a very delicate and tedious operation properly to secure these loops, especially while working in the mouth of the patient.

In using the novel instrument in tying the loop of ligature wire around each bracket 2! to secure it tightly to the arch wire 2i, the loop I! is first formed in a piece of ligature wire and the loose ends i t of theloop are threaded through the holes i5 and tightly wrapped around the post .58 for anchoring the loop. The dentist then holds the handles 8 and H in this hand in an accustomed manner and laces the groove 59 on the underside of the head in en agement with the arch wire 22 adjacent to the bracket 27 to be tied. in the manner ndicated in Fig. 5. The sides of the loop H are then under the wings 25 and the dentist may then null on the instrument and at the same time rotate the handle portion 8 in his thumb and forefinger to twist the ends of the loop tightly toget er and tie the bracket to the arch wire under tension. The twisted ends of the loop are then snipped off as indicated at 3'3. and the twisted ends may then be bent or tucked under the arch wire the bracket to be out of the way of the patients tongue and lips.

In order to facilitate engaging the sides of the loop ll under the wings 28 of the loop, the loop may be pro-bent as indicated in Fig. 4, and for this purpose a forming tool or die indicated generally at 35 is preferably provided. This die is adapted to form the loop I l of proper size and also to bend the sides downwardly as indicated at I1 so that they can easily be engaged under the wings 29 when the loop is held in position adjacent a bracket 21, by slightly rotating the instrument so as to engage one side I? under one wing 29 and then the other side under the other wing.

The forming die 3| preferably includes a base 32 having an upright post 33, and a mandrel 34 projects upwardly from the post and has an outer periphery substantially equivalent to the inner periphery of the loop I T to be formed. When the loop I! is positioned over the mandrel 34, a die piece 35 which is slidably connected at 36 to the post 33 may be brought down over the mandrel, and the die piece has depending flanges 3! on opposite sides which engage the sides of the loop I! and bend them downwardly into the die sockets 38 on each side of the base of the mandrel 34 to form the bent sides 11.

The forming die 3| is preferably secured on a suitable working table or the like, and may eonveniently be used to form the loop I! and then bend the same, by first placing the ligature wire loop I! around the mandrel 34, then threading the ends 16 through the holes I5 and anchoring the free ends of the loop around the post I 8. The die piece 35 is then forced downwardly to bend the sides of the loop as shown at IT, whereupon the loop may be removed from the mandrel and the instrument is prepared or loaded with a loop in readiness to make the connection between the band bracket 21 and the arch wire 2 I.

By having several of the novel instruments on hand, the operation of attaching a number of band brackets on irregular teeth to an arch wire is made very rapid and easy, because an assistant can load the instruments in advance with the ligature wire, having the sides of its loop bent into proper form, and then hand the loaded in-- strument to the dentist who merely slips the sides of the loop under the Wings 29 of a bracket and tightens the loop under tension by twisting the front end of the instrument. The twisted ends are then cut off and tucked in between the arch and the tooth. For facilitating this last operation, one or both sides of the head portion [4 may be provided with a short groove or slot 40 which is adapted to engage the twisted ends of the ligature wire for bending the same into an out-of-the-way position.

The use of the novel ligature tying instrument, especially in connection with the loop forming die, as previously described herein, not only makes the tying operation more rapid and easy for the dentist, but also makes it easier on the patient because it shortens the time and eliminates the awkwardness of the tying operation in the mouth. Moreover, since the tying operation is so simple and rapid, the dentist is much less apt to delay changing the arch wire and retying the irregular teeth thereto at the proper stages in the straightening operation. Accordingly, the straightening operation is performed with a minimum amount of pain or injury and with a maximum amount of benefit to the patient.

In the foregoing description, certain terms have been used for brevity, clearness and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiment of the improved construction illustrated and described herein is by way of example, and the scope of the present invention is not limited to the exact details of construction.

Having now described the invention, the construction, the operation and use of a preferred embodiment thereof, and the advantageous new and useful results obtained thereby; the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claim.

I claim:

In combination, an orthodontal ligature tying instrument for connecting an edgewise arch to a band bracket secured on an irregular tooth, and a loop forming die, said ligature tying instrument including a head at one end having a pair of side-by-side holes extending through the front of the head and opening out through the side thereof, an anchor element on said instrument for attaching the ends of a loop of ligature wire formed in front of said head and threaded through said holes, and said loop forming die including a mandrel for fitting within said loop and a movable die element for engaging the sides of the loop and bending them downwardly.

BARTON E. SMITH.

REFERENCES @ITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 806,300 Sorenson Dec. 5, 1905 1,299,102 Angle Apr. 1, 1919 2,268,755 Li Jan. 6, 1942

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