Abstract:
The orthodontic appliance for correction of Class II or III malocclusions attaches to the maxillary arch on an archwire adjacent to the first molar and to the mandibular arch on an archwire in the cuspid or bicuspid area, and applies a low continuous force through the use of two plunger piston type devices, whether the mouth is open or closed. Dual acting piston cylinders are connected together, with first and second piston connecting rods extending in opposing directions from the piston cylinders. A first mounting element is provided at the exterior end of the first piston connecting rod for mounting the first piston connecting rod to at least one of the maxillary teeth, and a second mounting element is provided at the exterior end of the second piston connecting rod for mounting the second piston connecting rod to at least one of the mandibular teeth, for providing a continuous biasing force between the maxillary and mandibular teeth for treatment of malocclusions.

Description:
RELATED APPLICATIONS 
     This is a continuation in part of Ser. No. 09/459,003 filed Dec. 10, 1999 now U.S. Pat. No. 6,162,051. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to orthodontic appliances, and more particularly concerns a Class II or III malocclusion correction device that applies low continuous force through the use of dual plunger piston type devices, whether the mouth is open or closed. The appliance attaches to the maxillary arch at the first molar and to the mandibular arch on the archwire in the cuspid or bicuspid area, either unilaterally or bilaterally. 
     2. Description of Related Art 
     Orthodontic appliances, such as brackets, buccal tubes and the like, are typically applied to teeth by adhering the appliances to the surface of the teeth. Such appliances typically include archwire portions for receiving an archwire and ligature elastic bands to provide corrective forces to straighten and reposition the teeth. Headgear mounting tubes can also be attached to the maxillary arch at about the first molar, for the mounting of corrective headgear to straighten and reposition the teeth. Such orthodontic appliances typically include a base portion adapted to conform to the shape of the teeth to which they are applied. 
     A Class I malocclusion typically occurs when the bite is satisfactory in that the upper or maxillary teeth line up with the lower or mandibular teeth, but individual teeth are crooked, crowded or turned. A Class II malocclusion, also called an “overbite,” or “buck teeth,” occurs when the upper teeth project beyond the lower teeth. A Class III malocclusion, also called an “underbite,” occurs when the lower teeth project beyond the upper teeth. Orthodontic appliances can be used to exert a force between an individual&#39;s upper and lower sets of teeth to aid in correction of such malocclusions. While coil springs have been used to apply force for adjustment of malocclusions, coil springs can be uncomfortable for patients and can require the wearing of embarrassing and uncomfortable headgear, are subject to wear and breakage, and can limit the degree of a patient&#39;s jaw movement. 
     There thus remains a need for a malocclusion correction device that is ideal for a non-compliant patient, allows flexibility in jaw movement, can be used on either left or right sides of a patient&#39;s teeth, and can even be used unilaterally. It would be desirable to provide a malocclusion correction device for correction of Type II or III malocclusions, that eliminates the need for headgear, aids in midline correction, does not limit the patient&#39;s range of motion of the lower jaw, and applies a constant force whether the patient&#39;s mouth is open or closed, providing for a more predictable treatment time. The present invention meets these needs. 
     SUMMARY OF THE INVENTION 
     Briefly, and in general terms, the present invention provides for an orthodontic appliance for correction of Class II or III malocclusions, that allows a full range of motion and flexibility of jaw movement, applies a low continuous force through the use of two plunger piston type devices, whether the mouth is open or closed. The appliance of the present invention attaches to the maxillary arch at the first molar and to the mandibular arch on the archwire in the cuspid or bicuspid area, either unilaterally or bilaterally. The appliance can be used for either the left and right sides of the teeth of a patient, and can be used on one side alone, if desired. The appliance of the present invention eliminates the need for the use of headgear for correction of Class II or III malocclusions, and can used as an aid in midline corrections. With the orthodontic appliance of the invention, the duration of a course of orthodontic treatment for correction of Class II or III malocclusions can be more predictable than was heretofore possible. 
     The present invention accordingly provides for an orthodontic appliance for correction of Class II or III malocclusion of maxillary teeth and mandible teeth, with dual piston cylinders connectable between the maxillary teeth and mandible teeth. The orthodontic appliance comprises a first piston cylinder and a second piston cylinder connected together, with each piston cylinder having first and second ends. The first piston cylinder includes a first piston connecting rod slidably connected within the first piston cylinder and extending from the first end of the first piston cylinder, and the first piston cylinder biases the first piston connecting rod in a direction along the longitudinal axis. The second piston cylinder includes a second piston connecting rod slidably connected within the second piston cylinder and extending from the first end of the second piston cylinder, and the second piston cylinder biases the second piston connecting rod in a direction along the longitudinal axis of the second piston connecting rod, with the exterior ends of the first and the second piston connecting rods extending in opposing directions. In a presently preferred aspect, a first archwire is connected to the maxillary teeth, and a second archwire is connected to the mandible teeth. A first mounting element is connected to the exterior end of the first piston connecting rod for mounting the first piston connecting rod to the first archwire connected to the maxillary teeth, and a second mounting element is connected to the exterior end of the second piston connecting rod for mounting the second piston connecting rod to the second archwire connected to the mandibular teeth. 
     In a presently preferred embodiment, the first piston connecting rod is biased to extend toward the exterior end of the first piston connecting rod, and the second piston connecting rod is biased to extend toward the exterior end of the second piston connecting rod. In another presently preferred aspect of the invention, the first mounting element is connected to the exterior end of the first piston connecting rod by a ball and socket joint so as to be rotatable with respect to the first piston cylinder, and the second mounting element is connected to the exterior end of the second piston connecting rod by a ball and socket joint so as to be rotatable with respect to the second piston cylinder. In another presently preferred aspect, the first and second mounting elements comprise locking fasteners connectable to the first and second archwires, respectively. 
     In one currently preferred embodiment, the first piston cylinder comprises a first piston cylinder housing, a first compression spring disposed in the first piston cylinder dwelling, the interior end of the first piston connecting rod being connected to the first compression spring, the first piston connecting rod being slidable within the first piston cylinder housing along the longitudinal axis of the first piston connecting rod, the first compression spring biasing the first piston connecting rod to extend away from the first compression spring; and the second piston cylinder comprises a second piston cylinder housing, a second compression spring disposed in the second piston cylinder housing, the interior end of the second piston connecting rod being connected to the second compression spring, the second piston connecting rod being slidable within the second piston cylinder housing along the longitudinal axis of the second piston connecting rod, the second compression spring biasing the second piston connecting rod to extend away from the second compression spring. 
     These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of the orthodontic appliance according to the present invention; 
     FIG. 2 is a sectional view of the orthodontic appliance of FIG. 1; 
     FIG. 3 is an illustration of a deployment of the orthodontic appliance of FIG. 1 between maxillary and mandibular sets of teeth, with the mouth closed; 
     FIG. 4 is an illustration of a deployment of the orthodontic appliance of FIG. 1 between maxillary and mandibular sets of teeth, with the mouth open; 
     FIG. 5 is a plan view of an alternate embodiment of the orthodontic appliance according to the present invention; 
     FIG. 6 is a sectional view of the orthodontic appliance of FIG. 5; 
     FIG. 7 is an illustration of a deployment of the orthodontic appliance of FIG. 5 between maxillary and mandibular sets of teeth, with the mouth closed; and 
     FIG. 8 is an illustration of a deployment of the orthodontic appliance of FIG. 5 between maxillary and mandibular sets of teeth, with the mouth open. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As is illustrated in the drawings, the invention is embodied in an orthodontic appliance  10  for correction of Class II or III malocclusion of maxillary teeth  12  and mandibular teeth  14 , as is illustrated in FIGS. 3 and 4. The orthodontic appliance advantageously employs dual acting pistons  16 ,  18  connected together in tandem, to bias the maxillary and mandibular teeth in the desired directions for treatment of a malocclusion. 
     Referring to FIGS. 1 and 2, the dual acting pistons include a first piston cylinder  20  having a housing  21  with a first end  22 , and a second end  24 , with a first compression spring  26  disposed in the first piston cylinder. Connected to the first compression spring is a first piston connecting rod  28  extending from a slot  29  in the first end of the first piston cylinder, the first piston connecting rod having a longitudinal axis  30 , an exterior end  32 , and an interior end  34 . The interior end of the first connecting rod is connected to the first compression spring, and is slidable within the piston cylinder housing relative to the first piston cylinder along the longitudinal axis of the first piston connecting rod. 
     The dual acting pistons also include a second piston cylinder  40  having a housing  41  with a first end  42  and a second end  44 , with a second compression spring  46  disposed in the second piston cylinder. A second piston connecting rod  48  is connected to the second compression spring, and extends from a slot  49  in the first end of the second piston cylinder, the second piston connecting rod having a longitudinal axis  50 , an exterior end  52 , and an interior end  54 . The interior end of the second connecting rod is connected to the second compression spring, and the second piston connecting rod is slidable within the second piston cylinder housing along the longitudinal axis of the second piston connecting rod. 
     The second piston cylinder is preferably connected adjacent to the first piston cylinder, with the first end of the first piston cylinder adjacent to the second end of the second piston cylinder, and the second end of the first piston cylinder adjacent to the first end of the second piston cylinder, with the exterior ends of the first and the second piston connecting rods extending in opposing directions. Alternatively, the first and second piston cylinders could be connected end to end. In a presently preferred embodiment, the first compression spring biases the first piston connecting rod to extend away from the first compression spring, and the second compression spring biases the second piston connecting rod to extend away from the second compression spring, as depicted in the figures, to bias the first and second connecting rods apart; although the first and second compression springs could alternatively be configured to bias the first and second connecting rods together. 
     A first mounting element  60  is connected to the exterior end of the first piston connecting rod for mounting the first piston connecting rod to at least one of the maxillary teeth. In a currently preferred aspect, the first mounting element is connected to the exterior end of the first piston connecting rod by a ball and socket joint  62 , including a ball  64  disposed within a socket  66  at the exterior end of the first piston connecting rod, so that the first piston connecting rod is rotatable with respect to the first piston cylinder. In another presently preferred aspect, the first mounting element comprises an annealed wire  68  connectable to a headgear buccal tube  70 , shown in phantom in FIGS. 3 and 4, to allow bending of the annealed wire gingivally and distally, as needed for adjusting the orthodontic appliance for effectiveness and comfort. Such a headgear buccal tube is described in U.S. Pat. No. 6,053,729, which is incorporated by reference herein. As is illustrated in FIGS. 3 and 4, the first mounting element is preferably attached to at least one of the maxillary teeth, such as by adhesive, and is currently preferably attached to the maxillary arch at the first molar  72 . 
     A second mounting element  80  is connected to the exterior end of the second piston connecting rod for mounting the second piston connecting rod to at least one of the mandibular teeth. In another presently preferred aspect, the second mounting element is connected to the exterior end of the second piston connecting rod by a ball and socket joint  82 , including a ball  84  contained within a socket  86  at the exterior end of the second piston connecting rod, so that the second piston connecting rod is rotatable with respect to the second piston cylinder. In a presently preferred aspect, the second mounting element is a locking fastener  88 , such as a clamp that can be a slotted member with an Allen screw, as illustrated, or a forked or bifurcated member, for example, that can be closed around an arch wire  90  as shown in FIGS. 3 and 4, or other appliance, and typically to be attached to the mandibular arch on an archwire connected to the teeth by orthodontic brackets  92 , in the cuspid or bicuspid area. As is illustrated in FIGS. 3 and 4, the orthodontic appliance of the invention can thus be used for continuously biasing the mandibular teeth and jaw forward while continuously biasing the maxillary teeth and jaw backward to correct a Class II malocclusion, whether the mouth of the patient is open or closed. 
     In an other presently preferred embodiment illustrated in FIGS. 5-8, the invention is embodied in an orthodontic appliance  110  for correction of Class II or III malocclusion of maxillary teeth  112  and mandibular teeth  114 , as is illustrated in FIGS. 7 and 8. The orthodontic appliance advantageously employs dual acting pistons  116 ,  118  connected together in tandem, to bias the maxillary and mandibular teeth in the desired directions for treatment of a malocclusion. 
     Referring to FIGS. 5 and 6, the dual acting pistons include a first piston cylinder  120  having a housing  121  with a first end  122 , and a second end  124 , with a first compression spring  126  disposed in the first piston cylinder. Connected to the first compression spring is a first piston connecting rod  128  extending from a slot  129  in the first end of the first piston cylinder, the first piston connecting rod having a longitudinal axis  130 , an exterior end  132 , and an interior end  134 . The interior end of the first connecting rod is connected to the first compression spring, and is slidable within the piston cylinder housing relative to the first piston cylinder along the longitudinal axis of the first piston connecting rod. 
     The dual acting pistons also include a second piston cylinder  140  having a housing  141  with a first end  142  and a second end  144 , with a second compression spring  146  disposed in the second piston cylinder. A second piston connecting rod  148  is connected to the second compression spring, and extends from a slot  149  in the first end of the second piston cylinder, the second piston connecting rod having a longitudinal axis  150 , an exterior end  152 , and an interior end  154 . The interior end of the second connecting rod is connected to the second compression spring, and the second piston connecting rod is slidable within the second piston cylinder housing along the longitudinal axis of the second piston connecting rod. 
     The second piston cylinder is preferably connected adjacent to the first piston cylinder, with the first end of the first piston cylinder adjacent to the second end of the second piston cylinder, and the second end of the first piston cylinder adjacent to the first end of the second piston cylinder, with the exterior ends of the first and the second piston connecting rods extending in opposing directions. Alternatively, the first and second piston cylinders could be connected end to end. In a presently preferred embodiment, the first compression spring biases the first piston connecting rod to extend away from the first compression spring, and the second compression spring biases the second piston connecting rod to extend away from the second compression spring, as depicted in the figures, to bias the first and second connecting rods apart; although the first and second compression springs could alternatively be configured to bias the first and second connecting rods together. 
     A first mounting element  160  is connected to the exterior end of the first piston connecting rod for mounting the first piston connecting rod to at least one of the maxillary teeth. In a currently preferred aspect, the first mounting element is connected to the exterior end of the first piston connecting rod by a ball and socket joint  162 , including a ball  164  disposed within a socket  166  at the exterior end of the first piston connecting rod, so that the first piston connecting rod is rotatable with respect to the first piston cylinder. In a presently preferred aspect, the first mounting element is a locking fastener  168 , such as a clamp that can be a slotted member with an Allen screw, as illustrated, or a forked or bifurcated member, for example, that can be closed around an arch wire  170  as shown in FIGS. 7 and 8, or other appliance, and typically to be attached to the maxillary arch on an archwire connected to the teeth by orthodontic brackets  192 , in the adjacent to the first molar  172 . 
     A second mounting element  180  is connected to the exterior end of the second piston connecting rod for mounting the second piston connecting rod to at least one of the mandibular teeth. In another presently preferred aspect, the second mounting element is connected to the exterior end of the second piston connecting rod by a ball and socket joint  182 , including a ball  184  contained within a socket  186  at the exterior end of the second piston connecting rod, so that the second piston connecting rod is rotatable with respect to the second piston cylinder. In a presently preferred aspect, the second mounting element is also a locking fastener  188 , such as a clamp that can be a slotted member with an Allen screw, as illustrated, or a forked or bifurcated member, for example, that can be closed around an arch wire  190  as shown in FIGS. 7 and 8, or other appliance, and typically to be attached to the mandibular arch on an archwire connected to the teeth by orthodontic brackets  192 , in the cuspid or bicuspid area. As is illustrated in FIGS. 7 and 8, the orthodontic appliance of the invention can thus be used for continuously biasing the mandibular teeth and jaw forward while continuously biasing the maxillary teeth and jaw backward to correct a Class II malocclusion, whether the mouth of the patient is open or closed. 
     While the present invention has been described and shown as designed for use in moving the mandibular teeth and jaw forward while moving the maxillary teeth and jaw backward to correct a Class II malocclusion, it should be readily appreciated that the mounting of the device can be reversed and arranged to affix the second mounting element in the frontal area of the maxillary teeth, and to affix the first mounting element in the back area of the mandibular teeth, to reverse the direction of the force exerted on the maxillary and mandibular teeth, for correction of a Class III malocclusion. 
     It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.