Abstract:
A screw-type orthodontic anchor having an upper member with a pair of slots formed therein with the slots being of different depths. A head portion disposed below the upper member with a collar or cap enveloping the upper member and having a protrusion formed on the inner surfaces thereof which is positioned in a hole extending through the head portion.

Description:
BACKGROUND OF THE INVENTION 
     In orthodontics, anchors are inserted into the of maxilla or mandible bone. The anchors are screwed into the bone with an upper portion protruding from the gum in order to anchor various orthodontic appliances for the purpose of moving teeth in the desired direction. These types of anchors are independent of the teeth and allow the use of multiple orthodontic devices which are attachable to a single anchor. 
     BRIEF SUMMARY OF THE INVENTION 
     An orthodontic anchor for placement in the maxillary or mandible bone includes a body portion with an elongated screw portion extending downwardly therefrom and a hexagonal head portion extending upwardly therefrom. An upper member is secured to the upper surface of the head portion with a pair of grooves formed therein and with one of the grooves being deeper than the other for the reception of one or more rectangular wires. A collar is disposed around the head portion or, alternatively, a cap envelopes the upper member and the head portion with a projection formed on the inner surface of the collar and cap for insertion into a hole formed in the head portion so as to interlock the collar and cap with respect to the anchor. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view of the orthodontic anchor according to this invention; 
         FIG. 2  is an exploded view of the upper portion of the anchor shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view taken along the line  3 - 3  in  FIG. 1 ; 
         FIG. 4  is an elevational view showing an application of the orthodontic anchor; 
         FIG. 5  is an exploded view of the upper portion of the anchor showing a modification of the invention; and 
         FIG. 6  is a perspective view of a further modification of the orthodontic anchor cap element shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the drawings and with particular reference to  FIG. 1 , the orthodontic anchor according to this invention is depicted and includes tapered body portion  1  with elongated screw portion  2  integrally joined thereto and extending downwardly therefrom. Self-tapping screw tip  3  is formed on the bottom of screw portion  2  remote from body portion  1 . For the purpose of tightening and loosening the anchor, hexagonal head portion  4  extends upwardly from body portion  1 . To complete the basic elements of the anchor, slotted upper member  5  is formed on the upper surface of head portion  4  remote from body portion  1 . Slotted upper member  5  includes deep groove  6  and shallow groove  7  disposed at right angles, as best shown in  FIGS. 2 and 5 . Grooves or slots  6  and  7  are formed by a pair of spaced vertical sidewalls which are suitable for the reception and placement of two rectangular wires. Since groove  6  is deeper than groove  7 , any undesirable contact between the two rectangular wires is eliminated. The anchor, according to this invention, is also adaptable to the use of only one rectangular wire. Although the size of grooves  6  and  7  may vary in accordance with orthodontic requirements, it has been determined that suitable dimensions are 0.036×0.022 mm for deep groove  6  and 0.028×0.022 mm for shallow groove  7 . 
     For the purpose of attaching various orthodontic appliances to the anchor in accordance with this invention, hexagonal collar  8  is dimensioned to fit snuggly over hexagonal head portion  4 . Protrusion  9  is formed on the inner surface of collar  8  and is sized so as to enter hole  10  when collar  8  is positioned around head portion  4  into the position shown in  FIG. 1 . By this means, collar  8  is securely interlocked with respect to head portion  4  so that undesirable separation therefrom is prevented. Also, hole  10  extends completely through head portion  4  so that an orthodontic wire or other suitable device is attachable to the anchor in the absence of collar  8 . In addition, hook  11  extends from collar  8  for the purpose of the attachment of various orthodontic devices such as a wire, spring, elastomeric band, etc. 
     A modification of the orthodontic anchor is shown in  FIG. 5  wherein hexagonally-shaped cap  12  is adapted to completely envelope upper member  5  of the anchor and fit snugly about head portion  4 . Projection  9  is formed on the inner surface of cap  12  and is adapted to slide into hole  10  in the same manner as described in connection with the structure shown in  FIG. 3 . In  FIG. 6 , multiple slots  13  are formed in the downwardly extending wall of cap  12  which facilitate placement of cap  12  when a rectangular wire is disposed within slot  6  or  7  so that the rectangular wire is disposed within slots  13  when cap  12  is disposed in its fully seated position. Of course, suitable orthodontic tubes and wires are attachable to cap  12  by an suitable means such as welding, glue and the like. 
     In  FIG. 4 , one application of this invention is shown wherein spring  14  is attached to conventional bracket  15  at one end and to the anchor at the other end. As the patient&#39;s tooth realignment progresses, various orthodontic devices can be secured to the anchor and are easily changed without the necessity to relocate the anchor. 
     In addition, in accordance with this invention, a set including the anchor and collars, which are compatible with a patient&#39;s particular requirements, are packaged with a screwdriver in a sterile or nonsterile package. This particular set is suitable for a single application and can be easily ordered online by the orthodontist and simply discarded after use. By this means, extensive conventional orthodontic anchor sets which are expensive and reused are eliminated.