Dental fixing element

The element is adapted to be fitted as an annular band around a tooth and to be secured to a dental appliance to hold the same in position. The fixing element comprises a strip metal element having two end portions, which are adapted to overlap in said annular band, two slide-snap fastener parts which are respectively carried by said end portions and selectively interengageable in a plurality of positions which determine respective diameters of said annular band, and one of the fastener parts including a bracket which is provided with a longitudinal groove for slidably receiving an orthodontic appliance. The bracket carries a clamping device which projects over the longitudinal groove, and is selectively and angularly movable to positions for slidable and clamping engagement with the orthodontic appliance received in the longitudinal groove.

This invention relates to a strip metal element for dental purposes, 
specifically for use as a fixing and supporting element, which is intended 
to be fitted around a tooth and to be connected to an orthodontic or 
prosthetic appliance to hold it in position. 
It is known to use pre-shaped strip metal elements for dental purposes, 
specifically for use as a fixing and supporting element, which is intended 
to be fitted around a tooth and connected to an orthodontic or prosthetic 
appliance to hold it in position. These elements are usually made in that 
a piece of metal strip is formed to an annular band, which is slidably 
fitted over the tooth for fixation. Even if a very large number of such 
annular bands in different shapes are available for teeth which differ in 
size and shape, a satisfactory fit cannot be ensured so that clearance 
spaces between the tooth and the annular band must be filled with cement. 
In the course of time, this cement filling is washed out and remains of 
food deposit in this region and initiate caries. To adapt the annular band 
to the anatomic shape of the tooth, the dentist must turn inwardly the 
outer edge of the annular band. This requires a high dexterity and takes 
much time, just as the remaining work of adaptation. 
It is an object of the invention to facilitate the adaptation of the 
preformed strip metal element to the tooth, to reduce the number of such 
pre-shaped strip metal elements which must be kept in stock, and to 
optimize the fixation of the strip metal elements to the tooth. In a strip 
metal element for orthodontic purposes, specifically for use as a fixing 
and supporting element, which is intended to be applied around a tooth and 
connected to an orthodontic or prosthetic appliance to hold it in 
position, this object is accomplished in that the end portions of the 
strip metal element have preferably beveled surfaces and are adapted to 
overlap and provided with slide-snap fastener parts which permit of an 
adjustment of the strip metal element to fit around the tooth. The 
fastener parts at the ends of the strip metal element can first be 
interengaged in a preliminary position, in which the element can easily be 
slipped over the tooth, and the fastener can then be tightened so that the 
thin-walled, pliable strip metal element conforms to the shape of the 
tooth. When the strip metal element is tightened by means of suitable 
forceps, the strip metal element will automatically hug the tooth so that 
no clearance space is left. 
Specifically, the outer end portion of the strip may consist of a tongue 
which is formed with struck-out, inclined toothlike lugs, which are 
slidably movable through an eyelet formed in the other end portion of the 
strip metal element to a position which determines the diameter of the 
resulting annular band. 
In another embodiment of the slide-snap fastener providing for an 
adjustment of the strip metal element, one end portion of the strip metal 
element is provided with a serrated plug-in tongue and the other end 
portion is provided with a keeper having a receiving passage and locking 
shoulders so that the manipulation and fitting also on the buccal side of 
the tooth are facilitated. 
Another object of the invention is to save space in that the slide-clamp 
fastener constitutes also a bracket for an adjustable connection of 
orthodontic arches. 
A further object of the invention is to provide an improved bracket adapted 
to be secured to an orthodontic or prosthetic appliance in a selected 
position. 
In the adjustable strip metal element comprising end portions that are 
adapted to overlap and provided with slide-snap fastener parts, the 
overlapping end portions may have beveled surfaces and the strip metal 
element may have thinner portions adapted to contact the tooth on its 
mesial and distal sides. This feature eliminates the need for separating 
the teeth from each other at the lateral points of contact. The strip 
metal element may be shaped so that it flares toward its proximal edge 
when the fastener has been closed so that the tightening of the element 
causes the same to adapt itself snugly to the root of the tooth and no 
cement is required in this region.

As is apparent from FIG. 1, the known pre-shaped strip metal elements for 
fixing orthodontic or prosthetic appliances to teeth consist of annular 
bands 1, which are slidably fitted over a tooth to which the appliance is 
to be fixed. For this purpose, such annular bands must be available in a 
very large number of shapes and sizes. Nevertheless, a close fit of the 
annular bands is not ensured so that clearance spaces are liable to remain 
and must be filled with cement, which promotes caries. 
The annular band 2 according to the invention, shown in FIG. 2, has been 
made from a strip metal element 3, which is shown in FIG. 3 and has 
overlapping end portions 4, 5 which comprise parts of a slide-snap 
fastener, as is shown in FIG. 4. The outer end portion 4 of the strip 
metal element terminates in a tongue 6, which is formed with struck-out 
inclined toothlike lugs 7 and can be inserted into an eyelet passage 8 
formed in the second end portion 5 to a position which determines the 
diameter of the resulting annular band for a close adaptation to the shape 
and size of the tooth. This adaptation will be promoted by the use of a 
suitable forceps for tightening the band. 
Particularly from the enlarged view shown in FIG. 4 it is apparent that the 
struck-out inclined toothlike lugs 7 constitute resilient barbs which when 
the tongue 6 is inserted into the eyelet passage 8 lock the tongue against 
being pulled back. It is apparent that the bridgelike portion 9 defining 
the eyelet passage has a resilient angled portion 10, which is adapted to 
interfit with each of the toothlike lugs. The end portion 5 terminates in 
a tip 11, which is beveled on the inside toward its extremity so that a 
formation of a clearance space in this region is avoided. 
FIG. 5 is an enlarged view showing another embodiment of a slide-snap 
fastener. One end portion 12 of the strip metal element is formed with 
side teeth 13, which are insertable into a covered recess 14, which is 
formed in the second strip end portion 16 and provided with mating teeth 
15. The end portion 12 is insertable into the opening 14 to a position 
which determines the diameter of the resulting annular band. The recess 14 
is covered by a strip portion 17. In the position shown in FIG. 5, a space 
18 is left for further adjustment. It is apparent that the side teeth 13 
constitute barbs, which during the insertion into the recess 14 interlock 
with the teeth 15 thereof to prevent a pulling back of the end portion 12. 
From the exploded view of FIG. 6, a plug-in tongue 20 is apparent, which is 
provided with side teeth 21 and with a central slot 23, which permits of a 
resilient interengagement of the teeth as the tongue 20 is inserted, also 
a handle 24 for inserting the tongue 20, and a keeper 25 which is formed 
with a passage 26 for receiving the tongue 20 and with a transverse slot 
27 for receiving a locking member 28, which is formed with mating teeth 
29, which present locking shoulders that have seeking edges and are 
adapted to interengage with the teeth 21 of the tongue 20 as the same is 
inserted. 
In the embodiment shown in FIGS. 7 to 9, the plug-in tongue 20 and the 
keeper part 25 are mounted on the ends of the strip metal element 30 and 
are interengaged to close said element in the form of an annular band. The 
band is applied to an incisor in such a manner that the slide-snap 
fastener is disposed on the buccal side of the tooth, as is shown in FIG. 
7 for teeth Z. 
In the embodiment shown in FIGS. 7 and 8 the keeper 25 constitutes also a 
bracket, which slidably receives the arch 31 in a longitudinal groove 32 
and is provided with a rotatable clamping member 33, which has radial arms 
for clamping the arch 31 in the groove 32. The clamping arms of the 
clamping member 33 differ in thickness. FIG. 7 shows the annular band 30 
fitted around a tooth Z. 
FIG. 9 shows another keeper 25, which also constitutes a bracket, to which 
the orthodontic arch 31 is connected by loops 34 of a tying element, which 
extends in side grooves 35 of the bracket. Such an arrangement is required 
when the incisors are set back to such an extent that the orthodontic arch 
used to straighten the teeth cannot be clamped in the manner shown in 
FIGS. 7 and 8. Just as in FIG. 7, the annular band is fitted around a 
tooth. A second bracket is indicated, which may be fixed, e.g., to the 
next tooth. 
It is also apparent from FIGS. 7 to 9 that the tip of the inner end portion 
of the band has a beveled inside surface 36 tapering to the extremity and 
that the annular bands 30 have thinner portions 37 and 38 for contacting 
the teeth on their mesial and distal sides. As a result, it is not 
necessary to insert rubber wedges or wires between the teeth to separate 
them before the annular band 30 can be fitted and there is no need to 
apply cement to the annular band at the extremity of its inner end 
portion. Such cement was previously required and when it had been washed 
out the tooth was liable to be attacked by remains of food retained in 
this region. The annular band 30 may flare toward its proximal edge 39 so 
that the tightening of the annular band 30 causes the same to fit closely 
around the root of the tooth and leaves also in this region no clearance 
space which would have to be filled with cement. Such cement was required 
in the previous practice and was liable to be washed out so that the tooth 
was then attacked by remains of food retained in this region and caries 
was thus prmoted. 
To improve the grip on the orthodontic arch, two brackets according to the 
invention may be mounted one beside the other on a strip metal element. In 
that case, only one of these brackets may be used as a keeper part of the 
slide-snap fastener whereas both brackets serve to hold the orthodontic 
arch in position. In another embodiment, two brackets may be arranged one 
over the other and may serve as keeper parts of the slide-snap fastener 
and, if desired, to hold orthodontic arches in position.