Abstract:
A screw tap type device for loosening or extracting a wisdom tooth is provided. The device comprises a screw tap with a plurality of longitudinal cavities in the external screw thread, creating cutting teeth which create a strong frictional grip with a rough dentine wall of a previously drilled tapered tunnel of a wisdom tooth. A user can then twist the device to exert axial bodily dislocating force for easy loosening or extraction of the wisdom tooth.

Description:
PRIOR RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/169,731, filed Apr. 16, 2009, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a screw tap type device for loosening or extracting a wisdom tooth. The tip of the screw tap comprises eight cavities formed on the outer surface of the screw tap. The remaining portions of the original screw thread form cutting teeth to provide sharp contact points between the screw tap and a tapered tunnel of the wisdom tooth previously prepared by drilling. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is difficult to surgically extract a third molar, or a wisdom tooth, especially when it is a mesially-impacted lower wisdom tooth. Application of extraction forceps is difficult in deep seated angle of mandible, as the beaks of the forceps could hardly grip the remaining crown as the coronal surface must be deliberately sliced off mesially at an inclined angle to create space for maneuver. Application of elevators is also difficult as a pivot anchorage point for side lifting could hardly be found, even when the surrounding distal and buccal bones have been excessively relieved. Once the mesially sliced wisdom tooth is tightly gripped upon, movement can be facilitated and loosening or extraction of the wisdom tooth can be achieved readily. 
         [0004]    It is a goal of the present invention to provide a screw tap type device for loosening or extracting mesially impacted lower wisdom teeth. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention, providing a device for loosening or extracting a wisdom tooth, has been achieved by the methods and devices disclosed herein. In one aspect, a device with a handle for easy user control, a shaft which one of its ends is attached to the handle, and a screw tap which is attached to the other end of the shaft. The device comprises a plurality of turns of external screw thread and a plurality of longitudinal cavities formed in the external screw thread. The longitudinal cavities disconnect the external screw thread into pieces of discontinuous screw thread, or cutting teeth, which function as contact points with high adhesive force between the device and the wall of a previously drilled tapered tunnel of the wisdom tooth. In one embodiment, the handle, shaft and screw tap all constitute one single piece of equipment with no detachable parts. In some embodiments, the device comprises 12 turns of external screw thread and 8 longitudinal cavities forming 96 cutting teeth. 
         [0006]    In another aspect, disclosed herein is a device with a handle for easy user control, a shaft which one of its ends is attached to the handle, and a screw tap which is attached to the other end of the shaft. The screw tap has an upper portion, which comprises a cylindrical protrusion constituting means for attaching the screw tap to the shaft, and a lower portion which comprises a plurality of turns of external screw thread and a plurality of longitudinal cavities formed in the external screw thread. In one embodiment, the device comprises 12 turns of external screw thread and 8 longitudinal cavities forming 96 cutting teeth. 
         [0007]    In another aspect, disclosed herein is a device with a male hexagonal key and a spherical end with a female hexagonal slot and a screw tap. In one embodiment, the male hexagonal key is attached to a dental handpiece at one end, and is inserted into the female hexagonal slot at the other end. In another embodiment, the spherical end comprises at least a pair of flat facets opposite of each other on a horizontal plane, constituting means for gripping with fingers or other dental equipment. In a further embodiment, at the end of the spherical end furthest away from the female hexagonal slot, a screw tap comprising a plurality of turns of external screw thread and a plurality of longitudinal cavities formed in the external screw thread is attached. In a further embodiment, the spherical end comprises 4 flat facets equally distanced from each other on a horizontal plane, constituting means for gripping with fingers or other dental equipment. In a further embodiment, the spherical end comprises 12 turns of external screw thread and 8 longitudinal cavities forming 96 cutting teeth. 
         [0008]    In another aspect, described herein is a method of loosening or extracting a wisdom tooth by drilling a tapered tunnel into the wisdom tooth, inserting into the tapered tunnel a screw tap which comprises a plurality of turns of external screw thread and a plurality of longitudinal cavities formed in the external screw thread, engaging the screw tap with the wisdom tooth by twisting, tightening, and gripping and wobbling either with fingers or with other dental equipment such as forceps. In one embodiment, the screw tap comprises 12 turns of external screw thread and 8 longitudinal cavities forming 96 cutting teeth. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0009]    Additional advantages and details of the invention are explained based on exemplary embodiments with reference to the drawings. The following are shown: 
           [0010]      FIGS. 1   a ,  1   b  and  1   c  depict a side elevation view, an enlarged detail view and a front view, respectively, of the screw tap type device according to the present invention. 
           [0011]      FIG. 2  depicts a side view of a mesially impacted lower wisdom tooth. 
           [0012]      FIG. 3  depicts a side view of a mesially impacted lower wisdom tooth with its coronal surface of the crown sliced off. 
           [0013]      FIG. 4  depicts a side view showing an example of a process for drilling a tapered tunnel into a wisdom tooth. 
           [0014]      FIG. 5  depicts a side view of a mesially impacted lower wisdom tooth after drilling. 
           [0015]      FIGS. 6   a  and  6   b  depict a side view and an enlarged detail view, respectively, showing an example of an application of the invention. 
           [0016]      FIG. 7  depicts a side view of a distally impacted lower wisdom tooth. 
           [0017]      FIGS. 8   a ,  8   b  and  8   c  depict a perspective view, a top view and a side view, respectively, of another embodiment of the invention. 
           [0018]      FIGS. 9   a  and  9   b  depict a perspective view and a side view, respectively, of another embodiment of the invention. 
           [0019]      FIG. 10  depicts a cross sectional view showing an example of a process of the application of another embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    A device for loosening or extracting a wisdom tooth according to the present invention will be described below with reference to the figures. 
         [0021]    As illustrated in  FIG. 1   a , the screw tap type device shown generally comprises a shaft  2 , which one of its end is attached to a handle  1 , and the other end is attached to a screw tap  3 . The handle, shaft and screw tap all constitute one single piece of equipment  15  with no detachable parts. As illustrated in  FIGS. 1   b  and  1   c , the screw tap comprises  12  turns of external screw thread and 8 longitudinal cavities  4  formed in the external screw thread. The longitudinal cavities  4  disconnect the external screw thread into 96 pieces of discontinuous screw thread, or cutting teeth  5 . 
         [0022]    In  FIG. 2 , a side view of a mesially impacted lower wisdom tooth  6  is shown. The coronal crown of the wisdom tooth  7  is pressed against the second molar  8 . Further obstructions creating difficulty in gripping by dental equipment include obstructions from the buccal bone  9  and the distal bone  10 . 
         [0023]    As illustrated in  FIG. 3 , to create space for maneuver in the distal and buccal regions, a portion of the buccal bone  9  and the distal bone  10  are commonly trimmed by conventional slow speed surgical burs. Further, the coronal crown of the wisdom tooth  7  is commonly sliced off at an inclined angle by a conventional high speed diamond bur to create space in the mesial region. 
         [0024]    As illustrated in  FIG. 4 , a tapered tunnel may be prepared by a conventional high speed handpiece  11  with a large diamond beads-chained high speed bur  12  mounted thereon. The unconventional beads-chained bur  12  is excellent in this embodiment because, as illustrated in  FIG. 5 , it is capable of creating a rough dentine wall  13  which enhances the frictional grip anchorage by the screw tap  3 . The tapered tunnel  14  is close to the dimensions of the screw tap  3 , and tilted at an angle from the occlusal axis of the wisdom tooth  6 . 
         [0025]    As illustrated in  FIGS. 6   a  and  6   b , the screw tap type device  15  comprising the handle  1 , shaft  2  and screw tap  3  is inserted into the prepared tapered tunnel  14 . The 96 cutting teeth  5  created by the longitudinal cavities  4  in the external screw thread contact with the rough dentine wall  13  of the tapered tunnel  14 , and establish a strong frictional grip. Once the frictional grip is established, the user may twist the device with moderate force to initiate first bodily movement of the wisdom tooth  6 . Once the first bodily movement of the wisdom tooth  6  is created, extraction shall be accomplished with much greater ease. 
         [0026]    In another embodiment of the invention, as illustrated in  FIG. 7 , the device is used for a distally impacted lower wisdom tooth  17 . To create space for maneuver, a portion of the buccal bone  18  and the distal bone  19  are commonly trimmed by conventional slow speed surgical burs. Further, the coronal crown of the distally impacted wisdom tooth  20  is commonly sliced off at an inclined angle by a conventional high speed diamond bur to create space in the distal region. A tapered tunnel  21  may be prepared by a conventional high speed handpiece  11  with a large diamond beads-chained high speed bur  12  mounted thereon as illustrated in  FIG. 4 . 
         [0027]    In another aspect of the invention, as illustrated in  FIGS. 8   a ,  8   b  and  8   c , a spherical end  22  is attached to a screw tap  30 . On the spherical end  22 , at the end furthest away from the point of attachment between the spherical end  22  and the screw tap  30  is a female hexagonal slot  24 . A male hexagonal key  23 , as illustrated in  FIGS. 9   a ,  9   b  and  10 , is inserted into the female hexagonal slot  24  at one end, and is attached to a deliver bur  25  at the other end, whereas the deliver bur  25  is in turn mounted on a slow speed high torque handpiece  26 . The spherical end  22  also comprises 4 flat facets  27  equally distanced from each other on a horizontal plane. As illustrated in  FIG. 10 , the 4 flat facets  27  constitute means for gripping with fingers  28  or grappled by a forcep  29  to twist, tighten and wobble the device at desirable positions for extraction despite of its implant angle. 
         [0028]    In some embodiments, the screw tap  3  or  30  comprises a plurality of turns of external screw thread. In some embodiments, the screw tap  3  or  30  comprises 12 turns of external screw thread. 
         [0029]    In some embodiments, the screw tap  3  or  30  comprises a plurality of longitudinal cavities  4  or  31 , respectively, formed in the external screw thread. In some embodiments, the screw tap  3  or  30  comprises 8 longitudinal cavities  4  or  31 , respectively, formed in the external screw thread. 
         [0030]    In some embodiments, the screw tap  30  and the spherical end  22  constitute  145  one single piece of equipment with no detachable parts. 
         [0031]    In some embodiments, the male hexagonal key  23  and the female hexagonal slot  24  are in other suitable but non-spherical polygonal shapes, such as trigonal, tetragonal, pentagonal, heptagonal or octagonal, or other shapes such as straight-shaped, cross-shaped, star-shaped or other shapes suitable for the purpose of fitting the male hexagonal key  23  into the female hexagonal slot  24 . In some embodiments, the male hexagonal key  23  and the female hexagonal slot  24  are in the shape of a polygon with more than 2 and fewer than 7 sides. In some embodiments, the male hexagonal key  23  and the female hexagonal slot  24  are in the shape of a hexagon. 
         [0032]    In some embodiments, the screw tap  3  or  30  is coated with a material which has the effect of hardening the service of the screw tap  3  or  30 . In some embodiments, the screw tap  3  or  30  is coated with titanium nitride for providing a hardened surface. 
         [0033]    In some embodiments, the spherical end  22  comprises at least a pair of flat facets  27  opposite of each other on a horizontal plan. In some embodiments, the spherical end  22  comprises 4 flat facets  27  equally distanced from each other on a horizontal plane. 
         [0034]    As various changes could be made in the methods and devices disclosed herein without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying figures shall be interpreted as illustrative and not in a limiting sense. For example, the methods and devices may be used for extracting lower or upper wisdom teeth, intact or fractured wisdom teeth, and mesially or distally impacted wisdom teeth.