1. An orthodontic yoke comprising: an elongated member having a distal end and a proximal end; a first split loop secured to said distal end of said member; a tubular element having a distal end and a proximal end, said proximal end of said elongated member received in said tubular member and extending therethrough; and a second split loop secured to said tubular element adjacent the proximal end thereof.
2. In an orthodontic appliance for transmitting forces to teeth of a patient, said appliance having orthodontic bands secured to said teeth, orthodontic brackets secured to said orthodontic bands and an arch wire received in said orthodontic brackets and secured thereto by ligatures, the improvement of an orthodontic yoke comprising: an elongated member; a tubular element, said elongated member received in said tubular element and extending out each end thereof; means for mounting said yoke for sliding movement along said arch wire; and means for eliminating movement of said elongated member in relation to said tubular element.
3. In an orthodontic appliance for transmitting forces to teeth of a patient, said appliance having orthodontic bands secured to said teeth, orthodontic brackets secured to said orthodontic bands and an arch wire received in said orthodontic brackets and secured thereby by ligatures, the improvement of an orthodontic yoke comprising:
The present invention relates to orthodontic appliances generally and specifically to an adjustable yoke to be used in combination with such appliances for transmitting forces to desired teeth for the purpose of either moving those teeth into a desired position or maintaining them in an existing position.
It has been common practice for sometime to employ various appliances for the purpose of moving teeth in relationship to each other. Such appliances have been widely used to straighten or correct the spacing of both upper and lower teeth.
Common practice has been to affix to a plurality of teeth a series of orthodontic bands each of such bands encircling and cemented to a given tooth. Each band has an orthodontic bracket secured thereto and on the buccal or labial surface thereof. A wire commonly referred to as an arch wire is received in each of the brackets along the outer surface of the teeth and is secured to each bracket by a ligature such as a thin tie wire or the like. In order to move one or more teeth, pressure is applied at a given location along the arch wire. In the past, a yoke composed of a wire fabricated or bent to form loops at either end to fit over the arch wire was employed to transmit forces supplied by rubberbands or extra oral forces, such as headgear, to the desired location. In order to make the yoke cooperate with the appliance and, for example, to distally move a molar, it was necessary to cut the yoke wire to the desired size and thread the yoke over the arch wire prior to attaching the arch wire to the brackets. The procedure of customizing and attaching the yoke is difficult and time consuming in that a wire must be cut and bent to an exact size and the arch wire must be removed and replaced after threading it through the loops on the yoke.
With the present invention, an adjustable yoke is provided so that the length of the yoke can be quickly and easily established and the yoke can be applied to the arch wire without removing the arch wire from the brackets.
It is my invention to provide a yoke consisting of a wire of finite length having a split loop secured at one end. The other end of the wire is received in one end of a sleeve or tubular member which sleeve has a split loop secured to its other end. The length of the yoke is defined by the amount of wire that is fed through the sleeve. After determining the length of the yoke desired, the total length of the yoke can be fixed by merely crimping the sleeve at one or more places thereby preventing the wire from sliding therethrough. The split loop at the end of the wire (the distal end of the yoke) may then be slipped over the already positioned arch wire and crimped to close the loop. Similarly the loop at the end of the sleeve (the mesial end of the yoke) can be placed over the arch wire and crimped. A finite length of the wire portion of the yoke is allowed to extend through the sleeve portion in order to provide a hook element at the proximal end of the yoke. Once the yoke has been positioned on the arch wire with the distal loop bearing against the molar to be distally driven, forces applied by a rubberband or the like can be attached to the yoke at the hook to supply the driving force. Where the forces are to be applied intermaxillary, one end of the rubberband is slipped over a hook on the distal end of the lower arch wire, for example, and the other end is placed over a hook on the mesial position or the upper arch wire, under tension, thereby transmitting the forces supplied by the rubberband throughout the length of the yoke to the upper molar to be distally driven. By reversing this arrangement the yoke can be employed to drive a lower molar.
The yoke of the subject invention will find application where it is necessary to stabilize one or more teeth when others are being driven by a combination of intra and inter oral or extra oral forces.
Further understanding of the present invention will be had with reference to the drawings wherein:
FIG. 1 is an elevational view of the yoke of the subject invention secured to teeth with the application of intermaxillary force.
FIG. 2 is a partial plan view of the same invention.
FIG. 3 is an elevational view of the yoke of the present invention illustrating the telescoping aspect of the wire and sleeve.
Common numerals will be used in all figures of the drawings. Referring to FIGS. 1, 2 and 3, the yoke 10 is comprised of a sleeve element 11 being of sufficient inside diameter to receive wire 12. Sleeve 11 includes a split loop 14 secured at one end thereof. Wire 12 has a split loop 16 secured at one end thereof. Once the desired length of yoke 10 is established, sleeve 11 is crimped in one or more places with a pliers or the like in order to fix the position of wire 12 in sleeve 11 and to allow a portion of wire 12 to extend completely through sleeve 11 to form hook 13. Hook portion 13 of wire 12 may be previously annealed to facilitate bending in order to form a more pronounced hook configuration.
Prior to the affixation of yoke 10 to the appliance A there has been provided a series of orthodontic bands 18 which encircle certain teeth of the patient. Orthodontic bands 18 are provided with orthodontic brackets 17 which are located on the buccal or labial surfaces of the teeth. Brackets 17 are adopted to receive arch wires 19. Arch wire 19 is secured to brackets 17 by means of ligatures 21. Yoke 10 is made to cooperate with arch wire 19 by placing split loop 16 over said arch wire at a position whereby split loop 16 bears against band 18 or bracket 19 on the tooth to be driven. Split loop 14 is positioned over arch wire 19 at a point where it will not exert any force against any teeth. When the desired spacing between split loop 16 and 14 is achieved, sleeve 11 is crimped around wire 12 and split loops 14 and 16 are closed. The end of wire 12 emanating from sleeve 11 defines hook 13. Yoke 10 may be contoured slightly to conform to the curvature of arch wire 19.
In the preferred embodiment of the invention yoke 10 is stainless steel. Wire 12 is 0.036 inches in diameter. Sleeve 11 has a 0.036 inch inside diameter and split loops 14 and 16 are 0.019 × 0.026 and may be soldered, welded or brazed to wire 12 and sleeve 11. In some instances split loops 14 and 16 may be formed from short lengths of tubing, for example 1/4-inch. Although stainless steel may be preferred it is important that the material and size of the components provide suitable corrosion resistance and be sufficiently pliable so that yoke 10 can be bent to the curvature of the teeth or arch wire 19 and so that sleeve 11 can be crimped about wire 12.
The foregoing discussion has been made for purposes of illustration it being understood that those skilled in the art will modify the yoke herein discussed while remaining within the scope and spirit of the invention.