Patent Application
20160220331
Malocclusions between the upper and lower dentition of a patient generally fall within three classes, which may be skeletal in nature, dental in nature, or a combination of both. Class I malocclusions, otherwise known as neutroclusion, are those in which there is a normal antero-posterior relationship between the maxillary arch and mandibular arch, and there is a Class I molar as defined by Dr. Edward H. Angle, but misalignment of teeth exists. This malocclusion is commonly corrected with braces applied to the teeth for gradual realignment. Class II malocclusions, otherwise known as distoclusion, are those in which the mandibular arch or lower jaw is posteriorly positioned in relationship to the maxillary arch, and the mandibular first molar is distally positioned in relationship with the maxillary first molar. In this type of malocclusion an “overbite” (in layman's terms) condition exists and may be corrected by either moving the lower jaw forward orthopedically or surgically, moving the mandibular dentition forward, moving the upper teeth posteriorly, or a combination of these to obtain a proper bite. Corrective appliances are utilized to produce these desired outcomes. Class III malocclusions, otherwise known as mesioclusion, occur when the mandibular arch or lower jaw is positioned too far anteriorly with respect to the upper arch and the mandibular first molar is mesially positioned in relationship with the maxillary first molar. This condition, often referred to as an underbite, may be corrected with the use of braces, rubber bands, protraction facemask therapy, and/or, in some cases, through surgery.
The present invention generally relates to appliances for treating Class II or Class III malocclusions or, overbite and underbite conditions, respectively. In the past, rubber bands, springs, or Herbst-type pistons extending between upper and lower sets of brackets have been used to move the dentition into alignment. Over time, this corrective movement will permanently realign the upper and lower teeth of the patient through dental movement and/or proper bone growth. External headgear attached to the braces of the patient has been used for similar purposes. One main disadvantage with rubber bands and external headgear is that they each require cooperation on the part of the patient. In other words, the patient is required to regularly maintain the rubber bands or headgear in place. Patients may choose not to apply the corrective appliances because they are unsightly or uncomfortable or may forget to apply them. In either case, the lack of diligence in using the corrective appliances reduces the effectiveness of the treatment.
Class III malocclusions can be the most challenging to correct. It would therefore be advantageous to provide a method and apparatus for underbite correction that negates the need for surgery and eliminates the issue of patient non-compliance. Most of the current corrective orthodontic devices are designed for Class I and Class II malocclusions. There are very few dental appliances currently available for specifically correcting Class III malocclusions. Most devices used to correct Class III malocclusions are actually designed for Class II and are simply installed in a modified manner for correction of an underbite.
U.S. Pat. No. 6,358,046 describes an orthodontic appliance for correction of Class II or III malocclusions that attaches to the maxillary arch at the first molar and to the mandibular arch on the archwire in the cuspid or bicuspid area, and applies a low continuous force through the use of two plunger piston type devices with compression springs disposed in the piston cylinders.
U.S. Patent Publication No. 2012/0070797 describes an orthodontic correction system for Class II and Class III malocclusions, having a variable length alignment assembly useful in providing corrective orthodontic forces to a patient's dentition and/or jaw via hinges that attach the alignment assembly between maxillary and mandibular archwires.
U.S. Patent Publication No. 2014/0242534 describes a mandibular attachment structure having a force member connecting the mandibular and maxillary portions of the assembly. The structure includes bands dimensioned to encircle corresponding lower molars on opposite sides of the tongue, and threadless couplers each of which is removably or releasably affixed to a buccal side of a corresponding band. The pressing connection is maintained by cooperating a hook at the end of the force member and a hook at the end of a threadless coupler.
Heretofore, orthodontic devices for the correction of Class II and Class III malocclusions are cumbersome and tedious to install, have exposed components that are uncomfortable for the wearer, and include elements prone to breakage. Additionally, the prior art devices are designed to be installed exclusively to an archwire, or exclusively to a molar band. It would be advantageous to provide a bite correction device that is simple, reliable, and comfortable for the patient. It would also be advantageous to provide a bite correction device that is versatile, yet easy to install.
In view of the above problems and limitations of the prior art, one purpose of the present invention is to provide a method and apparatus for correcting Class II and Class III malocclusions. More specifically, the present invention relates to an orthodontic bite corrector that may be installed on either an archwire or an orthodontic band. Preferably, the bite corrector is comprised of a coil spring wrapped around a push rod, the coil spring and a portion of the push rod being contained within a spring housing. A mechanism of attachment is also provided on both the rod and the housing.
Another aspect of the present invention is to provide an apparatus that may be installed in a manner to provide movement of the teeth, movement of the jaw, or both. To effect tooth movement, the bite corrector may be attached to a desired position along the length of a maxillary and mandibular archwire. To effect tooth plus jaw movement, the bite corrector may be attached to an orthodontic band secured around upper and lower teeth.
Typically, known devices used to correct Class II malocclusions attach at the upper first molar and distal to or behind the lower canine. However, in correction of Class II malocclusions, the present invention is capable of attaching distal to the upper canine and at the lower first molar, an arrangement opposite that of typical devices. In correction of Class III malocclusions, known devices typically attach at the lower first molar and distal to the upper canine, whereas in the correction of Class III malocclusions, the present invention is capable of attaching at the upper first molar and distal to the lower canine, an arrangement opposite that of typical devices.
Yet another aspect of the present invention is to provide a spring activated bite correction device wherein the majority of corrective forces are the result of spring expansion, rather than spring compression. In other words, the present invention will bring the ends of the appliance closer together, whereas, prior art inventions work to move the ends of the appliance farther apart. Once the bite corrector has been installed in the desired manner and position, the natural opening and closing of the mouth facilitates activation of the spring and correction of the bite. As the mouth opens, the rod is pulled outward from the housing, thus compressing the spring. As the mouth closes, the spring rebounds and expands, thus pulling the rod inward into the housing. This spring expansion pulls the rod further inside the housing, thus, in correction of Class III malocclusions, moving or pulling the mandibular teeth and lower jaw back, while simultaneously moving or pushing the maxillary teeth and upper jaw forward. This mechanism of action works contrary to current spring activated orthodontic devices in which the spring is pulled to expansion during mouth opening and compressed upon mouth closure; thus supplying the corrective forces mainly during spring compression. This latter mechanism results in strain on the spring and frequent device failure or breakage. The design of the present invention preserves the integrity of the spring, resulting in a more reliable and effective device.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
The present invention provides a method and apparatus for correcting Class II and Class III malocclusions, dental asymmetries, and/or dental related skeletal abnormalities. This appliance may be installed independently or fitted to a patient's currently installed orthodontic appliance such as brackets, archwires, dental bands, and the like. Preferably, the present invention may be used to correct a Class III malocclusion, otherwise known as an underbite. In an underbite, the mandible (lower jaw) has outgrown the maxilla (upper jaw and palate), resulting in the lower jaw protruding beyond the upper jaw such that the upper and lower teeth do not align with one another. To correct this misalignment, the therapeutic goal is to move the maxillary teeth forward and the mandibular teeth back, such that they are in correct alignment with one another. An additional therapeutic goal is to promote growth of the upper jaw, if possible. Although growth of the lower jaw cannot be stopped or prevented, in some patients, especially children and younger patients, it may be possible to facilitate forward movement of the maxilla.
In a preferred embodiment, the orthodontic bite corrector 11 comprises a push rod 12, a spring housing 13, a coil spring 14, and a mechanism 15 of installing or attaching the appliance to the teeth or preexisting braces. The coil spring 14 may be wrapped around the push rod 12, whereby the spring 14 and the portion of the push rod 12 contacting the spring 14 are enclosed in the housing 13.
Depending on the type of correction needed and the skeletal development of the patient, the corrector 11 may be installed in a manner to provide either a more dental effect (movement of the teeth) or a more skeletal effect (movement of the jaw). To provide more dental movement, the bite corrector 11 may have a spring 14 that expresses lower forces consistent with tooth movement and may be attached to a desired position along the length of a maxillary and mandibular archwire 19, as shown in
In addition to the above-described methods of attachment, it is contemplated that the bite corrector 11 may also be connected to alternative types of fasteners such as a temporary anchorage device (TAD) to produce a more skeletal effect. TADs are commonly used temporary implants that function as an anchor. In this case, the fastener, or TAD, would secure the appropriate portion of the bit corrector 11 directly to the bone, rather than to a threaded receptacle. Anchorage devices such as TADs are common in the field of orthodontics, and any person skilled in the art would have knowledge of how to install and use these temporary anchorage devices. In the present invention, TADs could be placed on the buccal aspect of the bone, preferably one mesial to the maxillary first molar on each side and one distal to the mandibular canine on each side, for a total of four TADs. In another arrangement, two TADs could be used. The device 11 could be connected to TADs on the maxilla and attached to teeth on the mandible to provide mostly mandibular tooth movement; alternatively, the device could be connected to TADs on the mandible and attach to teeth on the maxilla to provide more maxillary tooth movement.
Once the bite corrector has been installed in the desired manner and position, the natural opening and closing of the mouth facilitates activation of the spring 14 and correction of the bite. When the mouth is closed, ideally the spring 14 and push rod 12 are positioned such that there is room in the housing 13 for both spring expansion and spring compression. This positioning is best illustrated by
For the best correction result, it is desirable to maintain optimal spring resistance. It is also contemplated that in some cases the extent of the bite correction may reach a point where the spring 14 is fully expanded and in its “resting state”, yet the teeth are still not fully aligned. As previously stated, during the correction process the rod 12 is pulled inward as the spring 14 expands, thus moving the lower teeth back and bringing the upper teeth forward. When the teeth or jaw have been moved to a point where the spring housing 13 no longer has room to accommodate any further inward pulling of the rod 12, the spring 14 may need to be reactivated. Spring reactivation may be accomplished several ways depending on the amount of spring resistance needed. The upper archwire attachment mechanism 15 may be moved distal to its present location, the lower archwire attachment mechanism 15 may be moved mesial to its present location, or both the upper and lower attachment mechanisms 15 may be moved accordingly. For example, if the mesial attachment mechanism 15 is secured on the archwire 19 behind the lower canine bracket, it may be moved and secured on the archwire 19 in front of the lower canine bracket, thus pulling the rod outward from the housing, compressing the spring 14, and lengthening the appliance. Alternatively, a stop of varying millimeter lengths may be crimped onto the archwire 19 to slightly increase the distance of the correction device from its previous attachment location. These methods, in turn, “reset” the bite corrector 11 and allow it to resume its intended function.
Although the bite corrector 11 of the present invention has been described herein in terms of correcting a Class III malocclusion, it should be noted that this bite corrector 11 is also designed to correct a Class II malocclusion, also known as an overbite. The assemblies described herein may remain the same, while the appliance 11 itself may be installed in a reverse arrangement. For example, in a Class II embodiment, the distal attachment of the spring housing 13 may become a mesial or anterior attachment, and the mesial attachment of the push rod 12 may become a distal or posterior attachment. For instance, the spring housing 13 may be secured to the maxillary archwire 19a in a mesial/forward position near the upper canine, whereas the push rod 12 may be secured to the mandibular archwire 19b in a distal/back position near the lower molars. Alternatively, the push rod 12 may be secured distally to a lower orthodontic band 26 (preferably molar) via a fastener 27; whereas the spring housing 13 may be secured mesially to an upper orthodontic band 26 such as a bicuspid band, or a molar band with an extension wire (similar to the lower extension bar 32 described in
As the present device allows for various changes and numerous embodiments, particular embodiments will be illustrated in drawings and described in detail in the written description. However, this is not intended to limit the present invention to particular modes of practice, and it is to be appreciated that all changes, equivalents, and substitutes that do not depart from the spirit and technical scope of the present invention are encompassed in the present invention. In the description of the present invention, certain detailed explanations of related art are omitted when it is deemed that they may unnecessarily obscure the essence of the invention.
The terms used in the present application are merely used to describe particular embodiments, and are not intended to limit the present invention. An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. In the present application, it is to be understood that the terms such as “including” or “having,” etc., are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof may exist or may be added.
Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those with ordinary knowledge in the field of art to which the present invention belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have the meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present application.
