Orthodontic Appliance With Hook

FIG. 1 is a top plan view of a known ceramic orthodontic appliance having an integral hook member.

FIG. 2 is a top perspective view of another known ceramic orthodontic appliance having an integral hook member.

FIG. 3 is a top plan view of another known orthodontic appliance having an integral hook member.

FIG. 4 is a side plan view of the appliance of FIG. 3.

FIG. 5 is a top perspective view of an orthodontic appliance embodying the present invention.

FIG. 6 is a cross-sectional view of the appliance of FIG. 5 taken along the line A--A.

FIG. 7 is a side plan view of two of the orthodontic appliances of FIG. 5 mounted to a patient's teeth, one being coupled to an auxiliary appliance.

FIG. 8 is another side plan view of two orthodontic appliances of FIG. 5 mounted to a patient's teeth, one being coupled to an auxiliary appliance.

FIG. 9 is a top perspective view of another orthodontic appliance embodying the present invention.

FIG. 10 is a top plan view of another orthodontic appliance embodying the present invention.

In FIGS. 5 and 6, an orthodontic appliance embodying the present invention is indicated generally by the reference numeral 10. The orthodontic appliance 10 comprises a bracket portion 12 and a base portion 13. The bracket portion 12 defines an archwire slot 14 therein for receiving an archwire (not shown). The base portion 13 defines on the bottom thereof a tooth-abutting surface 16. The surface 16 is shaped generally to fit the morphology of a tooth, and has formed therein a plurality of indentations 18, for receiving adhesive material for mounting the appliance to a tooth.

Although the tooth-abutting surface 16 is shown with indentations, it may also take the shape of a number of known tooth-abutting surfaces. For example, the surface 16 may be smooth, or may have grooves formed therein. The appliance 10 is made of a ceramic material, such as a single crystal or polycrystalline aluminum oxide. The present invention is not limited to ceramic appliances, however, but may equally be employed in metal orthodontic appliances or appliances made of other materials, such as plastic.

The appliance 10 further includes a pair of split, or twin edgewise tie-wings 22, extending along one side of the bracket portion 12 and projecting outwardly therefrom. The tie-wings 22 are coupled to one another by a first web portion 24 extending along the adjacent edge of the archwire slot 14. A pair of hooked tie-wings 26 extend along the bracket portion 12 on the side opposite the tie-wings 22, and project outwardly therefrom. A second web portion 28 extends between the hooked tie-wings 26 along the adjacent edge of the archwire slot 14.

Each hooked tie-wing 26 defines on an interior side thereof a hook-shaped surface 30. The opposing hooked surfaces 30 define therebetween a round aperture 32 having a radius R. The two surfaces 30 meet at about the middle of the web portion 28 and thus form a single curved surface defined substantially by the radius R. The center of the radius R is located about midway between the mesial and distal edges of the bracket portion 12.

As shown in FIG. 6, the inside perimeter of the round aperture 32 substantially coincides with the plane of the gingival side of the bracket portion 12. Therefore, either hook-shaped tie-wing 26 is not likely to fracture if a strong impact force is applied thereto. A narrow opening 33 is defined between the tips of the two hooked tie-wings 26. The opening 33 is wide enough to permit an elastic, ligature wire, or auxiliary force transmitting member to be passed therethrough and seated against either hook-shaped surface 30. However, the opening 30 is narrow enough to prevent such members from becoming dislodged when, for example, the teeth are brushed or the patient is chewing food. In one embodiment of the appliance 10, the width of the opening 33 is about equal to the radius R of the aperture 32.

The free end of each hooked tie-wing 26, which is generally the gingival end, is formed with a rounded contour to facilitate the attachment of ligature, elastics, coil springs, or other force transmitting members thereto. The rounded ends are also provided to avoid any sharp corners that might cause discomfort by impinging on the tissue in a patient's mouth. Another advantage of the rounded free ends is that they avoid the formation of points of concentrated stress that tend to easily fracture.

The appliance 10 is mounted to a tooth by applying adhesive material to the tooth-abutting surface 16. Ordinarily, the appliance 10 is oriented on the tooth so that the hooked tie-wings 26 are placed on the gingival side of the tooth. The hooked tie-wings 26 can then serve substantially the same purposes as hooks or posts on known orthodontic appliances. For example, ligature or elastics can be wrapped or fitted over either of the hooked tie-wings 26, and seated on the respective hook-shaped surface 30. The hooked end of a coil spring, or other auxiliary appliance, can also be coupled to one of the hooked tie-wings 26, and seated against the respective hook-shaped surface 30, to transmit the auxiliary force thereto.

In FIGS. 7 and 8, two orthodontic appliances 10 are shown mounted to teeth T1 and T3 with an archwire 36 ligated thereto. A molar tube 38 having a gingival hook 40 is mounted to the molar T2 and ligated to the archwire 36. An elastic ring 42 is coupled between the distal hooked tie-wing 26 on the cuspid T1 and the hook 40 on the molar tube 38. The elastic ring 42 therefore applies a distally directed force to the cuspid T1, as indicated by the arrow in FIG. 7. In FIG. 8, a hook 44 is coupled to the archwire 36. An elastic ring 42 is coupled between the mesial hooked tie-wing 26 on the bicuspid T3 and the hook 44. The elastic ring 42 therefore applies a mesially directed force to the bicuspid T3, as indicated by the arrow in FIG. 8.

Therefore, as illustrated in FIGS. 7 and 8, it is possible to use an orthodontic appliance 10 to selectively shift a tooth in different directions. Although not illustrated, it is also possible to connect an elastic ring 42, or other auxiliary appliance, between the hooked tie-wings 26 of two adjacent appliances 10. Because the elastic ring 42 is seated within the round aperture 32, and against one of the hook-shaped surfaces 30, the problem of the elastic ring becoming dislodged from the bracket is ordinarily avoided. The hook-shaped curvature of the surface 30 and the relatively narrow opening 33 function to prevent the elastic ring from becoming accidentally dislodged during treatment.

Because the same appliance 10 may be used for applying forces in more than one direction, the orthodontist does not have to purchase different types of ceramic appliances depending upon the direction in which the force of the appliance is to be applied. Therefore, an orthodontist using the appliance 10 will usually be able to retain a smaller inventory of ceramic appliances on hand. Another advantage of the present invention is that the hooked tie-wings 26 have proven to be sturdier than the hooks that are formed on known ceramic appliances, such as by extending one tie-wing outwardly into a hooked-shape, as shown in FIG. 1. The appliance 10 is therefore less likely to fracture.

Yet another advantage of the present invention is that the hooked tie-wings 26 are shaped to be functionally similar not only to hooks or posts used in known appliances, but also to tie-wings, such as the tie-wings 22. As shown in FIG. 5, the hooked tie-wings 26 have a similar profile to the ordinary twin edgewise tie-wings 22. Therefore, like the tie-wings 22, the hooked tie-wings 26 can be used to ligate an archwire seated in the archwire slot 14 to rotationally control the tooth. On the other hand, known ceramic appliances that do not have a split tie-wing shape, such as the appliance of FIG. 2, will likely inhibit rotational control of the tooth.

It should also be noted that because the hooked tie-wings 26 have a profile similar to that of the split tie-wings 22, the hooked tie-wings ordinarily will not cause further discomfort to the patient. On the other hand, known appliances having tie-wings with hooks or posts projecting outwardly therefrom, are more likely to impinge the tissue in a patient's mouth.

In FIG. 9, another orthodontic appliance embodying the present invention is indicated generally by the reference numeral 10. The appliance 10 of FIG. 9 is similar to the appliance 10 of FIGS. 5 and 6 and, therefore, like reference numerals are used to indicate like elements. The appliance 10 of FIG. 9 is different in that neither the split tie-wings 22, nor the hooked tie-wings 26, are coupled by web portions. Instead, a channel 34 is formed between the split tie-wings 22 and the hooked tie-wings 26, which extends across the appliance in a direction substantially perpendicular to the axial direction of the archwire slot 14.

The hooked surfaces 30 define therebetween a round aperture 32 having a radius R. The two hooked surfaces 30 are therefore defined by the radius R. The center of the radius R is located about midway between the mesial and distal edges of the bracket portion 12. However, the channel 34 extends through the aperture 32. The width of the opening 33 between the tips of the tie-wings 26 is preferably about equal to the radius R. The channel 34 facilitates ligating an archwire to either the split tie-wings 22, or the hooked tie-wings 26. However, it should be noted that the round aperture 32 in the appliance of FIGS. 5 and 6 can also be used to achieve the results of a split tie-wing appliance. The hooked tie-wings 26 in FIG. 9 can otherwise be used in the same manner as the hooked tie-wings described above in relation to FIGS. 5 and 6.

In FIG. 10, another orthodontic appliance embodying the present invention is indicated generally by the reference numeral 10. The appliance 10 of FIG. 10 is similar to the appliance 10 of FIGS. 5 and 6. Therefore, like reference numerals are used to indicate like elements. The appliance 10 of FIG. 10 is different in that the mesial and distal edges of the appliance are slanted at an angle relative to the longitudinal (or mesial-distal) axis of the archwire slot 14. The appliance 10 is called a cuspid bracket, because its shape is particularly suitable for the treatment of cuspids. Accordingly, as will be recognized by those skilled in the art, the orthodontic appliance of the present invention can take a variety of shapes and relative dimensions.