Abstract:
Pliers adapted to lock wires within thermoformed dental appliances following the partial enclosure of wires during the thermoforming process.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to dental instruments. More specifically, the invention is directed to pliers which aid in locking specially configured wires within thermoformed dental appliances. 
   DESCRIPTION OF RELATED ART 
   In the field of orthodontics thermoformed appliances are used extensively. There is a desirability of enclosing wires within the thermoplastic materials. Enclosed wires can have such functions as stabilizing the thermoformed material or providing an attachment for devices attached to the teeth, such as Adams clasps. The problem is the vacuum pressure thermoformed process does not readily enclose the wires. A two-step process for enclosing the wires may be used for thermoformed materials. Liquid acrylic may be placed around the wire just prior to vacuum pressure forming the thermoplastic material over the wire. This process is not possible for polypropylene due to the fact that it does not adhere to acrylic. U.S. Pat. No. 4,798,534 by Breads describes a process of holding the wire away from a model surface which enhances the wire being enclosed in the thermoplastic material. In pending U.S. Pub. No. 20030219690 an arcuate wire is described enclosed in polypropylene thermoformed appliances wherein repeated curves in the wire extending away from the dental model surface are used to achieve the locking of the wire. The enclosure of the curved sections of the arcuate wire is not consistent which leads to the present invention. 
   What is needed are orthodontic pliers that complete the enclosure of the thermoformed material around the curved portions of the arcuate wire, or, in a more general sense, around a partially enclosed wire. Further, this protrusion produced by the pliers must not protrude upon the patient&#39;s gums or teeth. 
   U.S. Pat. No. 340,896 describes an orthodontic band contouring plier with curved male and female jaws. The pliers are distinguishable for being limited to producing a curvature to an orthodontic band. 
   U.S. Pat. No. 634,493 discloses a patent with two parallel jaws. 
   U.S. Pat. No. 1,304,720 discloses a plier for holding band material. The pliers are distinguishable by having a first straight jaw with a hole in it and a curved male jaw which enters the hole of the first jaw when the plier is closed. No joint is formed. 
   U.S. Pat. No. 1,316,409 discloses a plier for extracting a cotter pin. The pliers are distinguishable by having male and female jaws. 
   U.S. Pat. No. 3,727,316 discloses parallel jaws with notches for guides to bend wires. There are no male jaws. 
   U.S. Pat. No. 3,911,583 issued on Oct. 14, 1975, to Robert Hoffman describes dental pliers having an upper jaw having upwardly and inwardly tapered concave shaped sides and front for forming gripping edges in removing metal bands cemented to teeth and the removal of cement on teeth. The pliers are distinguishable for being limited to removal of cemented dental bands and cement. 
   U.S. Pat. No. 5,084,935 issued on Feb. 4, 1992, to Ferdinand Kalthoff describes a multiple-purpose wire shaping and cutting tool. It further describes means of forming certain commonly known wire shapes used in the orthodontic profession. There are opposing convex and concave surfaces on its inner jaws in order for the tool to perform its intended function. One handle has a hole while the other handle has a disc-shaped guide for forming labial bows in a wire. 
   U.S. Pat. No. 5,197,880 issued on Mar. 30, 1993, to Leeland M. Lovaas describes a tool for crimping a metal endodontic file. The tool has opposing convex and concave surfaces on its inner jaws to perform its intended function. Unlike the present invention, the inner surfaces of the jaws are parallel to one another when the tool is in its closed position. The file crimping tool of  FIG. 8  is distinguishable because the tool cannot be used for the enclosing of wires in thermoplastic retainers. 
   U.S. Pat. No. 5,538,421 issued on Jul. 23, 1996, to Thomas E. Aspel describes an assortment of dental pliers comprising a lower jaw longer or shorter than the upper jaw for removing orthodontic brackets, bands, buttons, cleats, bonding materials, and braces from teeth. The pliers are distinguishable for being limited to jaws designed for cutting and removing unwanted dental materials from the patient&#39;s teeth and to prevent luxation (tipping) of the tooth to minimize pain while using the pliers. 
   U.S. Pat. No. 5,588,832 issued on Dec. 31, 1996, to Farrokh Farzin-Nia describes a method of fabricating orthodontic pliers and the stainless steel or titanium alloy pliers made by the process. The manufacturing process of making these pliers minimizes the grinding and cutting of the pliers once the two nearly identical halves are made into the two scissor parts. The orthodontic pliers are distinguishable for having conventional needle-nose jaws. 
   U.S. Pat. No. 6,293,790 describes pliers for crimping an encapsulated expansion screw wherein the jaw arms are equal in length and similar in having an arcuate shape. This is unlike the present invention in that it does not produce a butt joint. The arcuate shape produces a point of the material which will not complete the enclosure of an embedded wire. 
   None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. 
   SUMMARY OF THE INVENTION 
   The present invention is crimping pliers used in orthodontics. It is the object of this invention to provide a plier-type hand tool for orthodontists and orthodontic technicians which has the means of improving the enclosure of a wire within a thermoformed orthodontic appliance. The goal is to press the two layers of thermoplastic material together into a butt joint, completing the enclosure of the wire. The crimping pliers are comprised of two elongated components that are subapically and pivotally joined with a pivot pin. Each of these elongated pieces is irregular in shape, equal in length and possesses symmetrical opposing jaws relative to each other. Each jaw portion of the crimping pliers ends with a right angled extension extending towards the opposite jaw. The right angled extensions end with jaw tips which are mutually parallel and fit together when the plier jaws are closed. A butt joint is formed when two layers of thermoplastic material are placed between the parallel jaw tips and the plier jaws are closed. In the preferred embodiment the pliers are designed to complete the enclosure of a partially embedded, specially formed, 0.045″ wire. The 045″ wire is arcuate in form and is placed in the palatal and lingual portion of the thermoformed orthodontic appliance. The 0.045 wire has repeated arc type bends which extend away from surface of the patient&#39;s mouth or the inner surface of the retainer. The purpose of these bends is to facilitate the enclosure of the wire by the thermoplastic material during the vacuum pressure-forming process. Each parallel jaw tip is the shape of a half circle. The arc portion of the half circle faces the handles of the pliers and is shaped to conform to the inner arc of the wire. The pliers are designed to reach over the partially enclosed wire in the arc areas and press the thermoformed material together in the inner part of the arc. The flat surface faces the tissue surface of the appliance or the apex of the pliers. The importance of the flat surface is to produce a protrusion of the thermoplastic material that will not protrude upon the patient&#39;s soft tissue or teeth when the orthodontic appliance is worn. In another embodiment of the above pliers the jaws of the pliers turn 60° from the long axis of the pliers in the axial direction of the pivot pin. 
   It is another object of this invention to provide an orthodontic crimping plier to enclose a wire which has been vacuum-formed over, but lies on the surface of the dental model. In this embodiment the pliers are similar to the above pliers except the parallel jaw tips are rectangular in shape, the longitudinal dimension of the rectangular tip is in the longitudinal direction of the 0.045″ wire. The object is to enclose the wire and not protrude upon the patient&#39;s soft tissue and teeth. In this embodiment the jaws may be either straight or turn 60°. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the orthodontic crimping pliers; 
       FIG. 1A  is a perspective view of the orthodontic crimping pliers with a thermoformed dental retainer; 
       FIG. 2A  is a prospective view of the pliers of  FIG. 1  in an open position; 
       FIG. 2B  is a perspective view of the end of the jaw extension of the pliers of  FIG. 1  in relation with a curved portion of an imbedded wire; 
       FIG. 3  is side plan view of the pliers of  FIG. 1  in an open position; 
       FIG. 4  is a top plan view of the pliers of  FIG. 1 ; 
       FIG. 5  is a cross-sectional view of the pliers of  FIGS. 1 through 18  and  18 ; 
       FIG. 6  is a perspective view of  FIG. 5  with the side plan view of the pliers in  FIG. 1  enclosing the wire with the thermoplastic material; 
       FIG. 7  is a cross-sectional view of the thermoplastic material pressed over the wire in  FIG. 6 ; 
       FIG. 8  is a top plan view of the pliers in  FIG. 1  in another embodiment with a 60° bend in the jaws of the pliers; 
       FIG. 9  is a prospective view of the pliers of  FIG. 8 ; 
       FIG. 10  is a prospective view of another embodiment of the orthodontic crimping pliers in an open position; 
       FIG. 10A  is a prospective view of the end of the orthodontic crimping pliers shown in  FIG. 10 ; 
       FIG. 11  is a perspective view of the pliers of  FIG. 10  in a closed position pressing the thermoplastic material over the embedded wire; 
       FIG. 12  is a top plan view of the pliers in  FIG. 10 ; and 
       FIG. 13  is a top plan view of the pliers of  FIG. 10  in another embodiment with the jaws bent 60°. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention is a pair of orthodontic crimping pliers for enclosing wires within thermoplastic retainers. Referring to  FIGS. 1 ,  2 A,  2 B,  3 ,  4 ,  6 ,  8 ,  9 ,  10 ,  10 A,  11 ,  12 , and  13  the orthodontic crimping pliers are comprised of a first handle  1  continuous with a first jaw  4 , a second handle  2  continuous with a second jaw  3  and a pivot pin  5  joining the two jaw/handle combinations together pivotally.  FIGS. 1 and 1A  depict the orthodontic crimping pliers with a thermoplastic retainer  10  with an embedded wire  11 . The embedded wire  11  is depicted with repeating curves  12  which curve away from the inner surface of the retainer  10 . The curved wire  11  areas  12  are designed to facilitate the enclosure of the wire  11  by the thermoplastic material  21  during the vacuum-pressure thermoforming process. The pliers in  FIGS. 1 ,  2 A,  2 B,  3 ,  4 ,  6 ,  8  and  11  are designed to fit the wire arc  12  and press the thermoplastic material  21  in the curved area  12 . In  FIG. 5  the wire  12  is shown prior to full enclosure  20  and in  FIGS. 6 ,  7  and  11  the wire  12  is shown enclosed  24  in  FIGS. 6 and 7 .  FIG. 1  depicts the jaws  3  and  4  having right angle extensions  6  and  7  each extending towards the opposing jaw and ending in a tip. The tip of each right angle jaw  6  and  7  has a flat surface  13  and  14  with a half circle shape as shown in  FIGS. 2A and 2B , the curved portion  15  of the half circle facing the handles  1  and  2  of the pliers. The curved portion  15  of the half circle, as shown in  FIG. 2B , is designed to conform to the curvature of the curved portion  12  of the 0.045″ wire  11  as shown in  FIG. 2B . The inner flat surfaces of the half circles  13  and  14  conform to the inner surface or tissue side of the retainer  10 . When the handles  1  and  2  are squeezed, as in  FIG. 3 , the flat surfaces  13  and  14  are closed over the thermoplastic material  21  to enclose the 0.045″ wire  11  wherein the gap  20  in  FIG. 5  is closed or pressed  24  as in  FIGS. 6 ,  7  and  11 .  FIG. 4  shows a top view of the pliers wherein the pliers have the jaws  3  and  4  in the same axial direction as the handles  1  and  2 . 
     FIG. 7  is an enlargement of  FIG. 6  depicting the retainer material  21  enclosing the wire  11  The pliers have pressed  24  the retainer  10  material  21  enclosing the wire  11 .  FIG. 8  shows another embodiment of the orthodontic crimping pliers of  FIGS. 1 ,  2 A and  2 B, the jaws  3  and  6  bending  28  60° from the longitudinal direction of the handles  1  and  2  in the axial direction of the pivotal pin  5 .  FIG. 9  depicts the pliers in  FIG. 8  from a different perspective. The 60° angled jaws  3  and  4  in  FIGS. 8 and 9  allow easier access to certain areas of the retainer  10 . 
   Referring to  FIGS. 10 ,  11  and  12 , another embodiment of the pliers is shown wherein the flat surfaced  30  and  31  tips of the right angled jaw extensions which press the retainer material  21  are rectangular in shape wherein the length of the rectangle is in the longitudinal direction of the wire  11  when the pliers are used to lock the retainer material  21  over the wire  11  as shown in  FIG. 11 . The rectangular designs of the flat surfaces  30  and  31  are useful for locking a straight wire which is at the level of the inner surface of the retainer without protruding the retainer material  21  into the tissue of the patient while wearing the retainer  10 .  FIG. 12  depicts the top view of this embodiment with the jaws  3  and  4  in the same longitudinal direction as the handles  1  and  2 . 
     FIG. 13  depicts another embodiment wherein the pliers of  FIGS. 10 ,  11  and  12  have jaws  3  and  4  with a 60° bend from the longitudinal axis of the handles  1  and  2  of the pliers and in the axial direction of the pivotal pin  5 . This embodiment enables access to certain areas of the retainer. 
   The invention has been described with specific embodiments. However, the intent of the invention is to provide orthodontic crimping pliers that complete the enclosure of a partially enclosed wire within a thermoformed orthodontic appliance. The orthodontic crimping pliers produce a butt joint of the thermoplastic material which prevents the enclosed wire from being dislodged from the thermoplastic material.