The invention relates generally to orthodontics and, more particularly, to self-ligating orthodontic brackets, and orthodontic bracket systems including self-ligating orthodontic brackets and orthodontic hand tools for use with the self-ligating orthodontic brackets and.
Orthodontic brackets represent principal components of all corrective orthodontic treatments devoted to improving a patient's occlusion. In conventional orthodontic treatments used for cosmetic enhancement of teeth, brackets are affixed to the patient's teeth and an archwire is engaged into a slot of each bracket. The archwire applies corrective forces that coerce the teeth to move into correct positions. The archwire forms a track to guide movement of the brackets and the associated teeth to desired positions for correct occlusion.
Self-ligating orthodontic brackets have been developed that eliminate the need for ligatures by relying on a movable member, such as a slide, a cover, or a spring clip, for capturing the archwire within the bracket's archwire slot. Self-ligating orthodontic brackets provide greater patient comfort, shorter treatment time, reduced patient chair time, and more precise control of tooth translation. Traditional ligatures (e.g., elastomeric ligatures or metal wires) are also difficult to apply to each individual bracket, which is simplified by self-ligating types of orthodontic brackets. Elastomeric ligatures, which may be susceptible to decay and deformation, may also contribute to poor oral hygiene. Self-ligation also reduces the risks of soft-tissue injury to the patient's mouth arising from the presence of wire ligatures.
Conventionally, doctors use an explorer type tool or a “pen” type opening tool to pull the movable member relative to the bracket body to provide an opened position in which the archwire slot is accessible to remove the archwire. The opening tool applies a force directly to the movable member that initiates movement of the movable member toward the opened position. While resident in the patient's mouth, self-ligating orthodontic brackets are prone to calculus buildup. In particular, depending upon the amount of calculus buildup and its location, it may become difficult to initiate movement of a closed movable member relative to the bracket toward the opened position using a conventional opening tool. Specifically, the calculus buildup may require the application of a relatively large force to initiate movement of the movable member. This force is transferred from the bracket to the tooth of the patient, which results in patient discomfort. Consequently, the doctor may have to resort to replacing the bracket, if the movable member cannot be opened, or to using a plier-type device to force the movable member to the opened position. In either instance, the patient may experience significant discomfort as the unbalanced force is transferred from the bracket to the tooth.
Accordingly, there is a need for a self-ligating orthodontic bracket, as well as a system including a self-ligating orthodontic bracket and an orthodontic hand tool for use with the self-ligating orthodontic bracket, characterized by respective constructions that cooperate to minimize the force transmitted to the tooth of the patient when opening the bracket and overcome these and other deficiencies of conventional orthodontic hand tools and self-ligating orthodontic brackets.
In another embodiment of the invention, an orthodontic bracket is provided for use with an orthodontic hand tool having a tip. The orthodontic bracket is adapted to couple an archwire with a tooth. The orthodontic bracket comprises a bracket body configured to be mounted to a tooth. The bracket body includes an archwire slot and a first contact point. A movable member is coupled with the bracket body for movement relative to the archwire slot between an open position in which the archwire is insertable into the archwire slot and a closed position in which the movable member retains the archwire in the archwire slot. The movable member includes a second contact point. The first contact point is positioned on the bracket body such that the tip of the orthodontic hand tool can be placed in a contacting relationship with the first contact point on the bracket body and a contacting relationship with the second contact point on the movable member.
In another embodiment of the invention, an orthodontic bracket system is provided for use in coupling an archwire with a tooth. The orthodontic bracket system comprises an orthodontic hand tool having an elongate shaft and a tip projecting from the elongate shaft. The orthodontic bracket system further comprises an orthodontic bracket configured to be mounted to the tooth. The orthodontic bracket includes a bracket body with an archwire slot and a movable member coupled with the bracket body for movement relative to the archwire slot between an open position in which the archwire is insertable into the archwire slot and a closed position in which the movable member retains the archwire in the archwire slot. The bracket body includes a first contact point and the movable member including a second contact point. The first contact point is positioned on the bracket body such that the tip of the orthodontic hand tool can be placed in a contacting relationship with the first contact point on the bracket body and a contacting relationship with the second contact point on the movable member. When the elongate shaft is tilted or rotated relative to the bracket body, the first portion of the tip applies a first force to the first contact point on the bracket body and the second portion of the tip applies a second force to the second contact point on the movable member effective to move the movable member relative to the bracket body.
Because of the construction of the orthodontic bracket and hand tool, a doctor can apply significant leverage in opening the movable member with the orthodontic hand tool because equal and opposite reactionary forces act on the movable member and bracket body of the self-ligating bracket. This reduces patient discomfort when the movable member is opened to access the archwire slot because the amount of force transferred to the patient's tooth is minimized or negligible.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the principles of the embodiments of the invention.
With reference to
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With reference to
In alternative embodiments, the movable member 25 may have a different construction, such as a locking member, a latch, a hinged latch, a ligation cover, a shutter member, a retaining clip, a movable cover, a clip, a spring clip, or any other type of retention device recognized by a person having ordinary skill in the art.
If orthodontic bracket 20 is mounted to a tooth in the maxilla, the movable member 25 may open in the occlusal direction. If orthodontic bracket 20 is mounted to a tooth in the mandible, the movable member 25 may open in the gingival direction. However, the movable member 25 for different brackets 20 applied to either jaw or arch may open in any combination of directions. When attached to a patient's tooth, the orientation of the bracket 20 may differ from the orientation shown in the drawings as understood by a person having ordinary skill in the art.
The bracket body 21, base 22, and movable member 25 are constructed using known fabrication methods from conventional materials, including but not limited to a metal like titanium or a ceramic. The bracket body 21, base 22, and movable member 25 may be constructed of different materials or any combination of conventional materials familiar to a person having ordinary skill in the art.
The base 22 is configured to be adhesive bonded to a buccolabial surface of a tooth (not shown) in any conventional manner such as, for example, with an appropriate orthodontic cement or glue. The base 22 may have a contoured profile that corresponds to the curved contour of the patient's tooth surface to which the base 22 is bonded and may carry optional structure (not shown), such as a bond pad, for enhancing the strength of the adhesive bond with the patient's tooth surface.
The bracket body 21 includes a pair of sidewalls 26 (one not shown) that are substantially parallel to each other and that are oriented generally in gingival-occlusal planes when the base 22 is secured to the tooth. The bracket body 21 also includes sidewalls 28. Sidewalls 26, 28 converge to define bracket body corners, which may be chamfered or curved to facilitate smooth junctions.
The bracket body 21 includes an integral body extension 30 that projects outwardly beyond sidewall 28 in either an occlusal or gingival direction when the base 22 is secured to the tooth. The bracket body 21 includes another body extension 32 that projects beyond the opposite sidewall 28 in the opposite direction to the body extension 30. The body extensions 30, 32 may define tie wings providing attachment points to, for example, apply torsional forces to the tooth to which the orthodontic bracket 20 is attached or if the tooth is severely malpositioned during the initial treatment stages.
With continued reference to
The bracket body 21 includes a contact point, which in the representative is constituted by a receptacle or recess 40 formed on one side of the archwire slot 23. The recess 40 has an opening that faces in the labial direction. In the embodiment shown, the recess 40 is a blind opening that is bounded by a base surface 47 and a sidewall 42 with an opening 43 that confronts a portion 27 of the movable member 25. The sidewall 42 intersects the labial surface 44 and extends into the bracket body 21 from the labial surface 44 to the base surface 47. The recess 40 is positioned in the labial surface 44 such that the tip 12a can contact the sidewall 42 and the movable member 25 when the tip 12a is inserted into the recess 40 and the movable member 25 is in the closed position.
The recess 40 has a cross sectional profile defined by dimensions W3 and L2. The dimensions and shape of the recess 40 are selected such that the tip 12a can be inserted into the recess 40 and moved for moving the movable member 25 from the closed position toward the open position. In this regard, the dimension W3 of the recess 40 may be greater than the dimension W1 of the first section 15a of the tip 12a and dimension L2 of the recess 40 may be greater than dimension L1 of the first section 15a. The recess 40 is recessed into the labial surface 44 of the bracket body 21 by a depth or dimension, which may be between about 0.3 mm and about 3.0 mm. When viewed in the labial direction, the recess 40 has a cross-sectional profile that is generally rectangular. The dimension L2 of the recess 40 and dimension L1 of the first section 15a may selected such that, when the tip 12a is rotated relative to the recess 40 in the bracket body 21 by a given angle, the movable member 25 is moved to the open position. For example, the dimensions L2 and L1 may be matched such that tip 12a may be rotated relative to the recess 40 by, for example, about 90° to move the movable member 25 from the closed position to the open position without attempting to force the movable member 25 to travel beyond the normal open position in which the archwire 24 is exposed. By constraining the range of motion for the movable member 25, a load is not imposed on the bracket's spring pin (not shown). The spring pin (not shown) in the bracket 20 represents a hard stop for the movable member 25 during the opening procedure. An appropriate selection of the dimension L1 places control limits of the slide opening procedure on the tool 10 and not on the spring pin.
Recess 40 is a concavity in the representative embodiment that is recessed into the labial surface 44 such that the sidewall 42 and base surface 47 of the recess 40 are non-coplanar with the adjacent portion of the labial surface 44. The lack of co-planarity permits the tip 12a to be engaged with the recess 40 for the application of force to the movable member 25 and bracket body 21 used to move the movable member 25 relative to the bracket body 21 without transferring substantial force to the patient's tooth. In alternative embodiments, the recess 40 may be replaced by a different type of contact point, such as a flat or curved tab, that projects from the nearby portion of the labial surface 44 of the bracket body 21. The tip 12a of orthodontic hand tool 10 contacts the projecting feature for the application of force to the contact point on the movable member 25 and to the projecting feature on the bracket body 21 so that the movable member 25, when in its closed position, can be moved relative to the bracket body 21 without transferring substantial force to the patient's tooth. In an alternative embodiment, the recess 40 may be defined in one of the sidewalls 26, 28 of the bracket body 21.
With reference to
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As the orthodontic hand tool 10 is rotated, the tip 12a and one or more of the sidewalls 16a-16d and 19a-19d also contact the sidewall 42 bounding the recess 40. Consequently, the bracket body 21 and the movable member 25 share the reactionary forces from tip 12a so that the force transferred to the tooth is minimized, which reduces patient discomfort from the act of opening the movable member 25. In other words, when opening the movable member 25, the tip 12a applies equal and opposite forces to the bracket body 21 via the contacted sidewall 42 and the contacted portion 27 of movable member 25.
As noted above, the movable member 25 includes spaced-apart arms 45. As the movable member 25 is moved toward the open position in the direction of arrow B, the arms 45 of the movable member 25 are retained by respective guides 46 formed in the bracket body 21. The guides 46 constrain the movement of the movable member 25 as the movable member 25 is moved relative to the bracket body 21 between the closed and open positions.
In an alternative embodiment and as shown in
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In another alternative embodiment and as shown in
The closing mechanism 50 has a first section 51 with grooves 52 and 53 dimensioned and shaped for engaging the archwire 24 (
The closing mechanism 50 is designed so that the first section 51 and the second section 54 are movable toward each other under a force applied by hand in the direction shown by arrows E and F to move the movable member 25 from the open position to the closed position. Simultaneously, the archwire 24 is held by the grooves 52 and 53 substantially stationary within the archwire slot 23. The first section 51 and the second section 54 are biased relative to each other such that the spring bias force increases as the first section 51 and the second section 54 approach each another under a hand applied or manual force. A contoured arched space 60 between the grooves 52, 53 is dimensioned and shaped to accommodate a portion of the bracket body 21 that that the grooves 52 and 53 are disposed on opposite sides of (i.e., straddle) the bracket body 21.
In alternative embodiments, either closing mechanism 50 or tip 12a may be replaced by a different type of structure (not shown) commonly used in the fields of orthodontics and dentistry to perform procedures within a patient's mouth. These structures, which are recognized by a person having ordinary skill in the art, may function to probe, measure and hold various pieces of mouth tissue or orthodontic hardware. These structures assist the practitioner in grasping, holding, moving, and replacing various objects within a patient's mouth. Exemplary alternative structures include, but are not limited to, a mirror, a file, an explorer, a scraping tool, a ruler, etc.
With reference to
Tip 76 includes a pair of substantially planar or flat sidewalls 82, 83 that taper so as to converge at respective side edges bounding a planar end surface 86. Contoured sidewalls 84, 85, which are disposed between sidewalls 82 and 83, likewise converge toward the end surface 86 and define side edges of the end surface 86. The sidewalls 82-85 are symmetrically arranged about the longitudinal axis 78. The area and lengths of the side edges of the end surface 86 are selected such that the tip 76 can be partially inserted into the recess 40 defined in the bracket body 21. The depth of recess 40 and the penetration depth of the tip 76 into the recess 40 may each be between about 0.5 mm and about 2.0 mm. When so inserted and contingent upon the insertion depth, the end surface 86 may have either a contacting relationship or a proximate relationship with the base surface 47 of the recess 40. One of the sidewalls 82, 83 confronts the portion 27 of the movable member 25 and the other of the sidewalls 82, 83 confronts the sidewall 42 of the recess 40.
In the representative embodiment, the end surface 86 is substantially rectangular (i.e., a planar quadrilateral with opposite side edges of equal lengths and with four right angle corners). The end surface 86 of tip 76 may have other closed geometrical shapes, such as a quadrilateral, a trapezoid (a quadrilateral with two sides parallel), or a square (a rectangle in which all sides have equal length). In each of these alternative shapes, the side edges of the end surface 86 intersected by the substantially flat sidewalls 82, 83 are approximately linear.
Each of the sidewalls 82, 83 of tip 76 includes a respective contrast region 88, 90 created by a laser marking process that discolors the material constituting the orthodontic hand tool 70. Alternatively, the contrast regions 88, 90 may be formed by applying a colored coating to the sidewalls 82, 83. The contrast regions 88, 90 have a width that is significantly smaller than their length. The coloration of the contrast regions 88, 90 is chosen to promote visual perception by the human eye and to contrast with the other adjacent sidewalls 84, 85. This permits a clinician to readily identify the orientation of the sidewalls 82-85 of tip 76 so that the orthodontic hand tool 70 can be oriented to align the sidewalls 84, 85 with the short sides of the sidewall 42 bounding the recess 40. In this oriented condition, one of the sidewalls 82, 83 can be juxtaposed with portion 27 of the movable member 25 and the other of the sidewalls 82, 83 is proximate to the long side of the sidewall 42 bounding the recess 40. The length of the sidewalls 82, 83 may also be selected to promote their identification by the clinician when the hand tool 70 is used. In an alternative embodiment, the contrast regions 88, 90 may be omitted from the construction of the hand tool 70.
Orthodontic hand tool 70 is used in a manner similar to tool 10 (
The clinician then rotates the handle 72 about the longitudinal axis 78, which serves to rotate the tip 76 in a direction 92. As the tip 76 is rotated, sidewalls 82, 84 of the tip 76 contact portion 27 of the movable member 25 and sidewalls 83, 85 of the tip 76 contact the sidewall 42 of recess 40. This dual action transfers reactionary forces to the first and second contacts points and, thereby, substantially limits the force applied to the patient's tooth when the movable member 25 is opened. After the movable member 25 is opened, the clinician removes the tip 76 from the recess 40. The archwire 24 is then accessible for removal from the archwire slot 23.
With references to
The orthodontic hand tool 100 generally includes an elongate shaft or handle 104 with a proximal end (not shown) and a distal end 106, a tip 108 that projects from the distal end 106, and a longitudinal axis 109 extending along the handle 104 and tip 108. Orthodontic hand tool 100 may be constructed of conventional materials familiar to a person having ordinary skill in the art.
Tip 108 includes sidewalls 110-113 that taper so as to converge at respective side edges bounding a planar end surface 114. Sidewalls 110, 111 may include contrast regions 88, 90 (
The tip 108 includes a pair of projections or prongs 116, 118 that project outwardly from end surface 114. A centerline of each of the prongs 116, 118 is approximately perpendicular to a plane containing the end surface 114. The prongs 116, 118 may project between about 0.5 mm and about 2.0 mm from the plane containing the end surface 114. The prongs 116, 118, which are positioned in a flanking relationship on opposite sides of the longitudinal axis 109, are spaced apart from each other by a gap. As the handle 104 is rotated about the longitudinal axis 109, the prongs 116, 118 rotate in respective circular orbits about the longitudinal axis 109.
The orthodontic hand tool 100 is used to manipulate the movable member 25 of the orthodontic bracket 102. As best shown in
Orthodontic hand tool 100 is used in a manner similar to tools 10 (
As the tip 108 is rotated, prong 116 is confined in recess 126 and prong 118 is free to move within the slot 124. Prong 118 applies a force against the sidewall of the slot 124 that urges the movable member 25 from the closed position toward the opened position. Prong 116, which remains confined within recess 126, applies a counter-balancing force to the bracket body 21. After the movable member 25 is opened, the clinician removes the prongs 116, 118 from the slot 124 and recess 126. The archwire 24 is then accessible for removal from the archwire slot 23.
With references to
Tip 138 includes a pair of substantially planar or flat sidewalls 140, 142, which are similar to sidewalls 82, 83 (
The proximal end 134 of the handle 132 includes the closing mechanism 50 (
Orthodontic hand tool 130 has a composite construction consisting of inserts or posts carrying the functional features that are disposed inside the material forming the handle 132, wherein the inserts and handle are composed of different types of materials. For example, the handle 132 may be formed from a cured polymer resin the tip 138 and the closing mechanism 50 may be formed from a metal and partially embedded in the cured polymer resin. In this instance, the tip 138 and the first and second sections 51, 54 of the closing mechanism 50 are coupled with respective posts 150, 152, 154, which are anchored within the polymer material of the handle 132. The posts 150, 152, 154 are concealed inside of the handle 132. The orthodontic hand tool 130 may be formed, for example, by an injection molding process with the tip 138 and the first and second sections 51, 54 of the closing mechanism 50 inserted into the mold before molten polymer injection. Because of its composite construction, the weight of the orthodontic hand tool 130 may be reduced in comparison to an all-metal construction.
Sidewalls 140, 142, which are flat, extend along the handle the handle 132 of the tool 130. The flat edges defined by the sidewalls 140, 142 on the handle 132 provide a tactile and visual indicator on the orientation of the tool tip 138, which improves the ease of use for the clinician.
While the invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in considerable detail in order to describe the best mode of practicing the invention, it is not the intention of applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the spirit and scope of the invention will readily appear to those skilled in the art. The invention itself should only be defined by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 60/946,853, filed Jun. 28, 2007. This application claims the benefit of U.S. Provisional Application No. 61/020,245, filed Jan. 10, 2008. This application is related to application Ser. No. ______, entitled “ORTHODONTIC HAND TOOLS FOR USE WITH A SELF-LIGATING ORTHODONTIC BRACKET AND METHODS FOR USING SUCH ORTHODONTIC HAND TOOLS” and filed as Attorney Docket No. ORM-315US2 on even date herewith. The disclosure of each of these applications is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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60946853 | Jun 2007 | US | |
61020245 | Jan 2008 | US |