Orthodontic appliance

An orthodontic appliance (10) for distalizing an upper molar (12) includes a main support shaft (50) disposed in the archwire receptacle (22) of a molar tooth bracket (20). A slide shaft (52) extends from the main support shaft (50) and movably supports a slide collar (56). The slide collar (56) is tied via a tensile ligature (66) to the bracket (34) of a secondary tooth (14), such as a premolar. A biocompatible and corrosion resistant compression spring (64) is operatively disposed between the slide collar (56) and the slide shaft (52). The compression spring (64) is prevented from buckling by a guide pin (60) extending centrally through the compression spring (64). The guide pin (60) is attached at one end to the slide collar (56) and the other end passes through a guide tube (58) extending rigidly from the slide shaft (52). A mesial support ligature (68) extends between the slide collar ( 56) and an archwire (38) to prevent inadvertent dislocation of the appliance (10).

TECHNICAL FIELD 
The subject invention relates to an orthodontic appliance, and more 
specifically, to a distalizing appliance for forcibly displacing a tooth. 
BACKGROUND ART 
Orthodontics is the branch of dentistry concerned with correcting and 
preventing irregularities of the teeth and poor occlusion. During 
orthodontic treatments, teeth are fitted with braces and moved into proper 
alignment, etc., by forcibly controlling movement of the teeth with the 
brace hardware and various appliances. Frequently, during the orthodontic 
treatment, it is necessary to distalize a primary tooth, e.g., an upper 
molar relative to a secondary tooth, e.g., a premolar or bicuspid. Such 
distalization of the primary tooth creates space between the two teeth, 
and more importantly moves the primary tooth into a desired posterior 
position. 
Distalizing appliances for moving the primary tooth relative to a second 
tooth are known in the art. For example, head gear is perhaps the best 
known such orthodontic appliances for distalizing a primary tooth relative 
to the secondary tooth. With head gear, the orthodontic bracket fitted to 
the upper molar brace is provided with a head gear tube. The head gear 
wire is inserted into the head gear tube and tensile forces are exerted on 
the head gear wire by a strap extending behind the patient's neck. Head 
gear are extremely effective in distalizing the upper molars, however are 
plagued with certain disadvantages. For example, the head gear apparatus 
is traditionally uncomfortable, causing discomfort to the patient's neck 
and sometimes mouth. Further, head gear can be unsightly due to the 
external components. Also, and most importantly, the use of head gear 
requires patient cooperation. Thus, if the patient declines to wear the 
head gear appliance because of comfort, or concern for appearance, the 
upper molars will not be distalized. 
Other orthodontic appliances have been proposed as an alternative to such 
head gear. For example, U.S. Pat. No. 4,595,361 to Blechman et al, issued 
Jun. 17, 1986, discloses an orthodontic appliance including repelling 
magnets disposed between the primary and secondary teeth for distalizing 
the primary tooth. In each of the several embodiments disclosed in 
Blechman et al, one magnet is supported in a head gear tube in the bracket 
of the primary tooth brace. For this reason, additional orthodontic 
appliances cannot be used on the primary tooth at the same time as the 
Blechman et al appliance. Accordingly, the Blechman et al appliance cannot 
be used simultaneously with head gear to further accelerate distalization 
of the primary tooth. 
Another example of a molar distalizing appliance may be had in U.S. Pat. 
No. 5,064,370 to Jones, issued Nov. 12, 1991. The Jones patent discloses a 
compression spring distalizing appliance in lieu of the Blechman et al 
magnets. The bracket on the primary tooth brace includes a head gear tube 
and a standard archwire receptacle fixedly supported thereon. The 
compression spring of the distalizing appliance is carried on a main 
support shaft which engages the primary tooth brace through both the head 
gear tube and the archwire receptacle. In other words, all available tubes 
and/or receptacles in the bracket of the primary tooth brace are employed 
during treatment with the Jones appliance. Therefore, additional 
appliances, such as head gear, cannot be used simultaneously with the 
Jones distalizing appliance. 
SUMMARY OF THE INVENTION AND ADVANTAGES 
The subject invention contemplates an orthodontic appliance for distalizing 
a primary tooth, such as an upper molar. The appliance comprises a primary 
brace means for fixed attachment to a primary tooth. A central archwire 
receptacle is provided in the primary brace means. A secondary brace means 
is included for fixed attachment to a secondary tooth adjacent the primary 
tooth. A distalizer means is operatively disposed between the primary 
brace means and the secondary brace means for forcibly distalizing the 
primary brace means relative to the secondary brace means. A primary 
support means extends between the distalizer means and the primary brace 
means for engaging the primary brace means exclusively within the archwire 
receptacle thereby unencumbering any additional receptacles in the primary 
brace means to attach further orthodontic appliances. 
The primary support means of the subject invention extends from the 
distalizer means and attaches to the primary brace means only in the 
archwire receptacle. Therefore, if the primary brace means further 
includes a head gear tube, that head gear tube will remain open even with 
the distalizer means operatively connected such that head gear can be worn 
simultaneously with the distalizer means of the subject invention. Thus, 
the primary tooth can be distalized or moved in some other manner at a 
much more rapid rate than heretofore available with the prior art 
distalizing appliances since, according to the subject invention, the 
distalizer means is supported exclusively within the archwire receptacle, 
thereby unencumbering a head gear tube (if any) and any other auxiliary 
tubes. Conversely, if no head gear tube or auxiliary tube is present, the 
distalizer means can still be used effectively by way of the archwire 
receptacle connection, where prior art appliances can not be used at all.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to the figures, wherein like numerals indicate like or 
corresponding parts throughout the several views, an orthodontic appliance 
according to the subject invention is generally shown at 10. The appliance 
10 is of the type for distalizing a primary tooth 12, such as an upper 
molar, relative to a secondary tooth 14, such as a premolar or bicuspid. 
The appliance 10 includes a primary brace means, generally indicated at 16 
in FIGS. 1, 6 and 7, for fixed attachment to the primary tooth 12. In 
typical fashion, however in no way imperative, the primary brace means 16 
includes a metallic band 18 surrounding and cemented to the primary tooth 
12, with a bracket 20 extending outwardly from the band 18. Alternatively, 
although not shown, the bracket 20 can be cemented directly to the surface 
of the primary tooth 12. As best shown in FIGS. 1 and 3, the bracket 20 
includes a central archwire receptacle 22, a head gear tube 24 occlusally 
adjacent to and larger than the archwire receptacle 22, and an auxiliary 
tube 26 gingivally adjacent to the archwire receptacle 22. An interiorly 
extending hook 28 projects gingivally from the bracket 20. Referring to 
FIG. 3, the cross-sectional shape of the archwire receptacle 22 is shown 
to be generally rectangular, and likewise the auxiliary tube 26. The head 
gear tube 24, however, is generally circular cross section and 
significantly larger than the archwire receptacle 22. 
A secondary brace means, generally indicated at 30 in FIGS. 1, 6 and 7 is 
provided for fixed attachment to the secondary tooth 14, which is adjacent 
the primary tooth 12. The secondary brace means 30 includes a band 32 
surrounding the secondary tooth 14, and a bracket 34 extending outwardly 
from the band 32. Alternatively, although not shown, the bracket 34 can be 
cemented directly to the surface of the secondary tooth 14. The bracket 34 
is provided with an archwire receptacle 36 for receiving a standard 
archwire 38. 
In typical fashion, the archwire 38 is received laterally into the archwire 
receptacle 36 of the secondary brace means 30, with a band or metallic wire 
secured over the bracket 34 to retain the archwire 38 in the receptacle 36. 
However, the archwire 38 is received axially, or lengthwise, into the 
archwire receptacle 22 of the primary brace means 16. As best shown in 
FIGS. 6 and 7, the archwire 38 is connected to the brackets 40 extending 
from the face of the adjacent teeth 42. However, the archwire 38 
terminates posterior the secondary brace means 30 for reasons to be 
described subsequently. 
Distalizer means, generally indicated at 44, is operatively disposed 
between the primary brace means 16 and the secondary brace means 30 for 
forcibly distalizing the primary brace means 16 relative to the secondary 
brace means 30. That is, the distalizer means 44 reacts against the 
primary brace means 16 to force the primary tooth 12 rearwardly, or 
posteriorly, while preferably maintaining the secondary brace means 30 and 
in the secondary tooth 14 in a stationary position. 
Primary support means, generally indicated at 46, extends between the 
distalizer means 44 and the primary brace means 16 for engaging the 
primary brace means 16 exclusively within the archwire receptacle 22 
thereby unencumbering the additional head gear tube 24 and auxiliary tube 
26 so that further orthodontic appliances may be attached to the primary 
base means 16. Accordingly, a standard head gear appliance, as illustrated 
in phantom at 48 in FIG. 1, can be worn simultaneously with the distalizer 
means 44 to further and more rapidly distalize the primary tooth 12. In 
like manner, other types of orthodontic appliances may be attached to the 
molar bracket 20, e.g., via the auxiliary tube 26 and/or the hook 28, 
simultaneously with the distalizer means 44 and a head gear appliance 48. 
The primary support means 46 includes a main support shaft 50 having a 
generally rectangular cross-section. Ideally, the main support shaft 50 is 
fabricated from the same material as the archwire 38, with both members 
having the same cross-sectional configuration. The main support shaft 50 
is fixedly connected, such as by brazing, to the distalizer means 44 and 
extends therefrom in offset fashion for insertion snugly within the 
archwire receptacle 22 of the primary brace means 16. The distalizer means 
44 further includes a slide shaft 52 fixed to the main support shaft 50 by 
any well known means, such as soldering, brazing, welding or cementing. 
The slide shaft 52 is of metallic construction having a generally flat, 
elongated rectangular cross section as shown in FIG. 4. The slide shaft 52 
includes a distal end having a mesial dog leg bend 54 to prevent lip and 
cheek irritation. A slide collar 56 is slideably disposed on the slide 
shaft 52 between the dog leg 54 and the connection at the main support 
shaft 50. 
A guide tube 58 is fixedly connected to the slide shaft 52 and the main 
support shaft 50 adjacent the connection therebetween. An elongated 
metallic guide pin 60 extends from the slide collar 52 and is slideably 
disposed through the guide tube 58. Thus, as the slide collar 56 moves 
along the slide shaft 52, the guide pin 60 slides within the guide tube 
58. As best shown in FIG. 5, the guide pin 60 has a circular 
cross-section. 
Biasing means, generally indicated at 62 in FIGS. 1, 2, 5, 6 and 7, is 
operatively disposed between the main support shaft 50 and the slide 
collar 56 for biasing the primary brace means 16 toward the desired 
distalized position. The biasing means 62, more particularly, comprises a 
compression spring 64 disposed between the slide collar 56 and the guide 
tube 58. The compression spring 64 is coiled around the guide pin 60 so as 
to prevent buckling. Preferably, the compression spring 64 is fabricated 
from a nickel-titanium alloy, however stainless steel or other corrosion 
resistant and biocompatible materials may be used. 
In order to prevent excessive bending moments applied to the main support 
shaft 50, a tensile ligature 66 extends from the distalizer means 44 and 
operatively engages the secondary brace means 30. That is, as best shown 
in FIGS. 1, 2, 6 and 7, the tensile ligature 66 extends around the slide 
shaft 52 and over the slide collar 56 and then loops rearwardly about the 
archwire 38 and the bracket 34 in the secondary brace means 30. By tightly 
drawing the tensile ligature 66, the compression spring 64 is activated or 
compressed to apply a distalizing force against the primary brace means 
16, as best shown in FIG. 6. 
To further prevent displacement of the distalizer means 44, a mesial 
support ligature 68 extends from the distalizer means 44 and is fixed 
relative to archwire 38. As perhaps best shown in FIGS. 6 and 7, the 
tensile ligature 66 and the mesial support ligature 68 are preferably 
formed of a single continuous wire strand which is first looped and 
twisted to form the tensile ligature 66 and then immediately feed around 
the archwire 38 and twisted to form a twisted end 70. The twisted end 70 
of the mesial support ligature 68 is preferably tucked between the dog leg 
54 of the slide shaft 52 and the archwire 38 to prevent gum or cheek 
irritation. The mesial support ligature 68 is required in the preferred 
embodiment due to the relatively thin main support shaft 50 engaged only 
in the archwire receptacle 22 of the primary brace means 16. Thus, when 
the patient is chewing food or some other external force is applied 
laterally to the distalizer means 44, the mesial support ligature 68, as 
well as a tensile ligature 66 and the main support shaft 50 prevent 
inadvertent displacement of the appliance 10. 
The subject appliance 12 is installed simply by feeding the main support 
shaft 50 into the rectangular archwire receptacle 22 of the primary brace 
means 16. Accordingly, to provide clearance for the main support shaft 50, 
the archwire 38 is severed immediately behind the secondary brace means 30, 
as shown in FIGS. 6 and 7. Frequently, the primary brace means 16 is formed 
on a molar tooth 12, such that the primary brace means 16 is also fitted 
with a head gear tube 24 and possibly an auxiliary tube 26 for attaching 
additional orthodontic appliances. The distalizing means 44 is connected 
to the primary brace means 16 so that the head gear tube 24 and the 
auxiliary tube 26 remain unobstructed to receive additional orthodontic 
appliances, such as a head gear apparatus 48, which may be employed 
simultaneously with the distalizer means 44. 
To activate the distalizer means 44, a thin malleable wire is looped around 
the archwire 38 and the bracket 34 of the secondary brace means 30 and then 
extended and twisted over the slide collar 56 and the slide shaft 52 in a 
tightening manner so as to activate, or compress, the compression spring 
64. The same wire forming the tensile ligature 66 is then wrapped around 
the archwire 38 next to one of the adjacent teeth 42 with the ends of the 
wire tied off along a twisted end 70, as shown in FIG. 6. 
As shown in FIG. 7, the distalizer means 44 applies a rearward, or 
posterior distalizing force against the primary tooth 12 so that the 
primary tooth 12 is distalized from the secondary tooth 14. In FIG. 7, the 
slide collar 56 is shown at its full length of travel by way of engagement 
with the dog leg 54, such that the primary tooth 12 will not be further 
distalized without reactivating the compression spring 54. 
In order to reactivate the compression spring 64 from that shown in FIG. 7, 
the tensile ligature 66 and the mesial support ligature 68 are removed and 
discarded. A new malleable wire is looped and drawn around the bracket 34 
of the secondary brace means 30 and the archwire 38, and then twisted and 
tightened around the slide shaft 52 and slide collar 56 in the same manner 
as discussed above, thereby compressing the compression spring 64. The wire 
is then looped around the archwire 38 to form the mesial support ligature 
68 and tied off at the twisted end 70 thereby reactivating the distalizer 
means 16 to further forcibly urge the primary tooth 12 posteriorly in the 
mouth. 
The primary advantage of the subject invention resides in the solitary, or 
exclusive and independent support of the distalizer means 44 within the 
archwire receptacle 22 of the primary brace means 16, thereby leaving open 
and unencumbered the head gear tube 24 and the auxiliary tube 26, as well 
as the hook 28. Thus, even with the distalizer means 44 in place, a head 
gear system 48 and any other appropriate orthodontic appliance connected 
to either the auxiliary tube 26 or the hook 28 may be simultaneously 
employed to further and more rapidly move the teeth into proper occlusal 
alignment. 
The invention has been described in an illustrative manner, and it is to be 
understood that the terminology which has been used is intended to be in 
the nature of words of description rather than of limitation. 
Obviously, many modifications and variations of the present invention are 
possible in light of the above teachings. It is, therefore, to be 
understood that within the scope of the appended claims wherein reference 
numerals are merely for convenience and are not to be in any way limiting, 
the invention may be practiced otherwise than as specifically described.