Abstract:
An orthodontic fixture system includes a tap, a screw, a tool, and fixation wire. In a method of orthodontic fixation, a user manipulates the tool to drive the tap and screw. The tap is configured to first make a threaded hole in only a proximal wall of an alveolus bone. The screw is configured for firm insertion in the proximal wall of the alveolus bone through the hole made with the tap and to abut an inner surface of the distal wall of the alveolus bone in a non-damaging manner. The screw and fixation wire include cooperating structures to enable a user to readily apply both tension and torsional forces via mutual engagement of the screw and fixation wire and thus to one or more orthodontic elements attachable to patient teeth.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of pending U.S. application Ser. No. 12/466,205 filed May 14, 2009 entitled Orthodontic System and which claims priority to Taiwanese Application 097212214 filed Jul. 10, 2008. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention relates to methods of orthodontic fixation and orthodontic fixture systems. More particularly, the invention relates to methods of orthodontic fixation employing an orthodontic fixture system including a tap, a screw including a fixation aperture, fixation wire, and installation tools. 
       BACKGROUND OF INVENTION 
       [0003]    In a standard process for affixing an orthodontic fixation, a slit is made in gingival tissue with a knife, and a portion of the gingival tissue is flipped open. A hole is made in the alveolus bone with an electric dental engine. With the dental engine, a threaded body of a screw is then driven in the alveolus bone through the hole while a platform, neck and head of the screw extend outside the alveolus bone. An orthodontic wire and/or a spring are used to apply traction, for example to pull a tooth towards the orthodontic screw. 
         [0004]    In a shortened process, the step of making a slit in the gingival tissue and the step of flipping open a portion of the gingival tissue of the standard process are sometimes omitted. That is, a hole is directly made in the gingival tissue and the alveolus bone with the threaded body then driven in with an electric dental engine. 
       SUMMARY OF INVENTION 
       [0005]    Embodiments are based at least in part on a new appreciation and understanding that a depth in the alveolus bone reached with the threaded body is critical. If the depth is insufficient, the threaded body will lack adequate support and be too weak to sufficiently pull the tooth via the orthodontic wire and/or the spring. If the depth is excessive, the threaded body might be driven into and through the alveolus bone so as to extend from the alveolus bone from the opposite side because of the high speed of the electric dental engine. 
         [0006]    With the shortened process described above, there is also greater risk of necrosis of adjacent portions of the gingival tissue because it might be shredded with the orthodontic screw driven with the electric dental engine operated at high speed. 
         [0007]    In both of the standard and shortened processes, the forces that can be exerted on the tooth with the orthodontic wire and/or the spring supported on the orthodontic screw are inadequate for at least certain applications. For example, torque cannot be readily exerted on the tooth with the existing orthodontic screw alone. 
         [0008]    Accordingly, embodiments include methods of orthodontic fixation and orthodontic systems including a tap, a screw, fixation wire, and installation tools. A user can manipulate the tool to drive the tap and screw. The tap is configured to make a non-through hole in an alveolus bone. The screw is configured for firm insertion in the alveolus bone through the non-through hole made with the tap. 
         [0009]    Other objectives, advantages and features of the invention will be apparent from the following description referring to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]    The invention will be described via the detailed schematic illustration of embodiments referring to the drawings. 
           [0011]      FIG. 1  is a schematic view of an orthodontic fixture system according to one embodiment. 
           [0012]      FIG. 2  is a side view of a tap of the orthodontic fixture system of  FIG. 1 . 
           [0013]      FIG. 3  is a side view of a screw of the orthodontic fixture system shown in  FIG. 1 . 
           [0014]      FIG. 4  is a partial, perspective view of the screw shown in  FIG. 3 . 
           [0015]      FIG. 5  is a partial, perspective view of a screw according to another embodiment. 
           [0016]      FIG. 6  is a partial, perspective view of a screw according to another embodiment. 
           [0017]      FIGS. 7A and 7B  are schematic side views of embodiments of a tap and of a spring tied to a screw respectively and orthodontic fixation methods thereof. 
           [0018]      FIG. 8  shows a patient&#39;s teeth subjected to orthodontia with the spring and screw shown in  FIG. 7B  and orthodontic fixation methods thereof. 
           [0019]      FIG. 9  is shows a patient&#39;s teeth subjected to orthodontia with a first wire and the screw shown in  FIG. 5  and orthodontic fixation methods thereof. 
           [0020]      FIG. 10  is a perspective view of a first wire and a fixation wire connected to the screw shown in  FIG. 5  and orthodontic fixation methods thereof via corresponding anatomical structure not shown for improved visibility. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0021]    Reference will now be made to the drawings. All drawings are schematic in nature and are not to scale and in some views illustrates anatomical structure also in a schematic nature. Referring to  FIG. 1 , an orthodontic fixture system  1  includes a tap  11 , a selection of screws  12 , a tool  13 , and fixation wire  14  according to one embodiment. The orthodontic fixture system  1  is configured for methods of orthodontic fixation of a patient&#39;s teeth. In various embodiments, tool  13  is a screwdriver or wrench configured to engage the tap  11  and screw  12  so as to apply a rotation force and optionally also a longitudinal force. The tool  13  is manually driven in some embodiments and in other embodiments is powered, which can include electrical power from a utility service or batteries. An engagement surface of the tool  13  is configured to cooperatively engage with associated taps  11  and screws  12 . 
         [0022]    Referring to  FIG. 2 , embodiments of the tap  11  include a threaded body  114 , a platform  113  on the threaded body  114 , a head  111  and a neck  112  between the platform  113  and the head  111 . The diameter of the neck  112  is smaller than diameters of the platform  113  and the head  111 . The neck  112  is made by making a groove around the tap  11 . The threaded body  114  includes a thread  1141  formed thereon and a blade  1143  formed at a tip  1142  thereof. The tap  11  thus comprises a cutting and threading capability, for example so as to form a threaded hole or passage in bone tissue upon suitable driving force from the tool  13 . In some embodiments, the tap  11  includes a fixation aperture  115  transversely defined in the platform  113 . 
         [0023]    The tap  11  is preferably made of a hard and tough material suitable for use in the animal body. In some embodiments, the tap  11  is made of stainless steel and in other embodiments is made of a titanic alloy. The tap  11  is preferably made of non-toxic materials, however need not be made of biocompatible materials in all embodiments as the tap  11  is not necessarily configured for extended residence within an animal body, but only for relatively brief use during execution of methods of orthodontic fixation as will be described in greater detail below. In some embodiments, the tap  11  is configured for multiple uses and includes the ability to be cleaned and sterilized between uses. 
         [0024]    Referring to  FIG. 3 , embodiments of the screw  12  include a threaded body  124 , a platform  123  on the threaded body  124 , a head  121  and a neck  122  between the platform  123  and the head  121 . The diameter of the neck  122  is smaller than diameters of the platform  123  and the head  121 . The neck  122  is made by making a groove around the screw  12 . A fixation aperture  125  is transversely defined in the platform  123 . The fixation aperture  125  is a through hole configured to receive fixation wire  14  in a manner that will be described in greater detail below. The threaded body  124  includes a thread  1241  formed thereon and a rounded tip  1242  thereof. 
         [0025]    The screw  12  is preferably made of biologically compatible materials, such as stainless steel or biologically compatible titanium alloys. The screw  12  is configured for extended residence in the animal body. In one embodiment, a variety of screws  12  are provided of varying dimensions and/or materials. In some embodiments, screws  12  are provided in various lengths to accommodate differing dimensions of a corresponding patient&#39;s anatomical structure. In some embodiments, screws  12  are provided in various materials, for example to accommodate a patient&#39;s allergy to certain materials. Embodiments of orthodontic fixation methods include selecting an appropriate screw  12  from a plurality of different screws  12  appropriate to a particular application. 
         [0026]    Referring to  FIG. 4 , embodiments of the head  111  of the tap  11  include a dome  111   a  on the top while the head  121  of the screw  12  includes a dome  121   a  on the top according to one embodiment. A corresponding tool  13  would have complementary mating engagement structures. 
         [0027]    Referring to  FIG. 5 , the head  111  of the tap  11  include a circular disc and similar is the head  121  of the screw  12  according to another embodiment. Radial slits are defined in the head  111 , thus dividing the head  111  into blocks  111   b . Radial slits are defined in the head  121  of the screw  12 , thus dividing the head  121  into blocks  121   b . A corresponding tool  13  would have complementary mating engagement structures. 
         [0028]    Referring to  FIG. 6 , the head  111  of the tap  11  is a hexagonal disc and similar is the head  121  of the screw  12  according to another embodiment. Radial slits are defined in the head  111 , thus dividing the head  111  into blocks  111   c . Radial slits are defined in the head  121 , thus dividing the head  121  into blocks  121   c . A corresponding tool  13  would have complementary mating engagement structures. 
         [0029]    In the embodiments illustrated and described with respect to  FIGS. 2-5 , the fixation apertures  115  and  125  are generally rectangular cross-section through-going holes. Flat interior surfaces of the fixation apertures  115  and  125  of these embodiments are arranged substantially parallel or perpendicular to a longitudinal axis of the tap  11  or screw  12 . The fixation apertures  115  and  125  are oriented in a different direction in the embodiment illustrated and described with respect to  FIG. 6  than in other embodiments. More particularly, in the embodiment of the fixation apertures  115  and  125  illustrated and described with respect to  FIG. 6 , flat interior surfaces of the fixation apertures  115  and  125  are rotated from substantially parallel or perpendicular to a longitudinal axis of the tap  11  or screw  12  along a generally transverse axis of the tap  11  or screw  12 . 
         [0030]    In one embodiment of a method of orthodontic fixation as shown in  FIG. 7A , a dentist employs an appropriate embodiment of tool  13  to apply a rotation force and, optionally, also a longitudinal inwards force so as to drive the tap  11  by the head  111   b  or  111   c , thus making an at least partially threaded hole  30  in the alveolus bone with the blade  1143  and thread  1141  of the threaded body  114  of the tap  11 . While penetrating a proximal wall  21  of the alveolus bone, the dentist encounters resistance. On penetrating the proximal wall  21  of the alveolus bone, the dentist feels a drop in the resistance. Now, the dentist removes the tap  11  from the alveolus bone, with greatly reduced risk of penetrating a distal wall  40  of the alveolus bone with the tap  11 . The contour of the partially threaded hole  30  in the alveolus bone corresponds generally to the outer contour or envelope of the tap  11  at its furthest penetration into the alveolus bone. 
         [0031]    Referring to  FIG. 7B , in one embodiment, the dentist employs the tool  13  to drive the screw  12  by the head  121   b  or  121   c , thus driving the threaded body  124  of the screw  12  into and through the proximal wall  21  of the alveolus bone generally into the partially threaded hole  30  previously made with the blade  1143  and the thread  1141  of the tap  11 . While driving the threaded body  124  of the screw  12  into the marrow  50  of the alveolus bone, the dentist encounters resistance. On reaching the distal wall  40  of the alveolus bone, the dentist feels marked growth in the resistance. Now, the dentist ceases advancing the screw  12 . It is difficult for the dentist to unintentionally penetrate the distal wall  40  of the alveolus bone with the rounded tip  1242  of the threaded body  124  of the screw  12  as the screw  12  lacks the cutting blade  1143  of the tap  11 . 
         [0032]      FIG. 7B  also shows that in one embodiment the dentist attaches wire formed into a spring  26  to the portion of the screw  12  exposed outside the proximal wall  21  of the alveolus bone. In one embodiment, the spring  26  is attached to the neck  122  of the screw  12 .  FIG. 7B  also shows that in one embodiment the dentist advances the screw  12  sufficiently that the rounded tip  1242  engages in non-damaging contact with the distal wall  40  of the alveolus bone. This embodiment provides the advantage that the installed screw  12  engages with both the proximal wall  21  and the distal wall  40  of the alveolus bone. In this embodiment, the screw  12  is supported at two opposite and displaced ends via engagement with the proximal wall  21  and the distal wall  40  and thus obtains improved structural support to better resist off-axis forces from the spring  26 . 
         [0033]    Referring to  FIG. 8 , a first wire  24  is provided. The first wire  24  is square in a cross-sectional view so that it can be used as a twist wire for exerting a torque. Moreover, the first wire  24  is elastic so that it can be used as a tensile wire for exerting a tensile force. Furthermore, the first wire  24  is made of an appropriate rigidity so that it can be bent to obtain a desired direction of a tensile force. 
         [0034]    In one embodiment of a method of orthodontic fixation, the dentist attaches several orthodontic elements  23  to a patient&#39;s teeth  22  and connects the first wire  24  to the orthodontic elements  23 , thus connecting the orthodontic elements  23  to one another. Then, the dentist ties an end of a spring  26  to one of the orthodontic elements  23  and another end of the spring  26  to the neck  122  of the screw  12 , thus pulling the teeth  22  towards the screw  12 . 
         [0035]    Referring to  FIG. 9 , in another embodiment of a method of orthodontic fixation, the dentist attaches the orthodontic elements  23  to the teeth  22 . Then, the dentist ties an end of the first wire  24  to the orthodontic elements  23  and another end of the first wire  24  to a selected one of the blocks  121   b . The greater the number of blocks  121   b , the easier a desired direction of the first wire  24  can be reached. The dentist pulls and bends the first wire  24  before tying it, thus providing a tensile force in a desired direction. Hence, the dentist pulls the teeth  22  towards the screw  12  without having to use any spring. 
         [0036]    Referring to  FIG. 10 , in one embodiment of a method of orthodontic fixation, the screw  12  is affixed as previously described and a first wire  24  is tied to the head  121   b  of the screw  12 . One end of a fixation wire  14  is connected to one or more orthodontic elements  23  and the fixation wire  14  is twisted as extending from the one or more orthodontic elements  23 . An opposite end of the fixation wire  14  is driven through the fixation aperture  125  of the screw  12  and tied to a selected one of the blocks  121   b.    
         [0037]    In this embodiment, the fixation wire  14  is rectangular in cross-section. In other embodiments, the fixation wire  14  is triangular, oblong, or other sectional shapes, according to the requirements of particular applications. The fixation wire  14  is sized and configured to extend longitudinally through the fixation aperture  125 , however to resist rotation or turning within the fixation aperture  125  via material impingement and interference therewith. A rectangular cross-section of the fixation wire  14  and appropriate dimensions enable a torsional force to be applied to the fixation wire  14  via engagement with the screw  12 . In a like manner, the orthodontic element  23  also comprises a fixation aperture  135  which is sized and configured to receive an end of the fixation wire  14 , but resist rotation of the fixation wire  14  with respect to the fixation aperture  135 . Thus, a torque is exerted on teeth  22  attached to the orthodontic elements  23  via the one or more orthodontic elements  23  with the fixation wire  14  as engaged with the fixation aperture  125  of the screw  12 . 
         [0038]    Embodiments of methods of orthodontic fixation and orthodontic fixture systems  1  exhibit several advantages. Firstly, there is greatly reduced risk of necrosis of the gingival tissue. This is because the dentist manually drives the tap  11  into the alveolus bone through the gingival tissue with the tool  13  and can stop the tap  11  before shredding any portion of the gingival tissue. 
         [0039]    Secondly, there is greatly reduced risk of breaching the threaded body  71  because the tap  11  is configured to make the partially threaded hole  30  in the proximal wall  21  of the alveolus bone and the marrow  50 , but not impinge on or damage the distal wall  40 . The screw  12  of selectable lengths is driven through the proximal wall  21  into the marrow  50  of the alveolus bone and stopped on reaching the distal wall  40  of the alveolus bone. 
         [0040]    Thirdly, appropriate depth in the alveolus bone reached with the screw  12  is facilitated because the screw  12  is stopped on the moment when the rounded tip  1243  of the screw  12  is abutted against the distal wall  40  of the alveolus bone. The support of the screw  12  by both the proximal and distal walls  30 ,  40  of the alveolus bone is more reliable than the support of a screw by only the first wall  21  and marrow  50  of the alveolus bone. At the same time, there greatly reduced risk of penetrating the distal wall  40  of the alveolus bone with the rounded tip  1243  of the screw  12 . 
         [0041]    Fourthly, a torque can be exerted on the teeth  22  via orthodontic elements  23  using the fixation wire  14  together with the screw  12 .