CA1259866A

CA1259866A - Interdental immobilization device

Info

Publication number: CA1259866A
Application number: CA000578613A
Authority: CA
Inventors: Boris Divis; Colin Mccolgan
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-09-27
Filing date: 1988-09-27
Publication date: 1989-09-26
Also published as: USRE34249E

Abstract

TITLE

INTERDENTAL IMMOBILIZATION DEVICE

APPLICANT

Boris Divis M.D.
Colin McColgan INVENTOR

Boris DIVIS M.D.
Colin McCOLGAN

ABSTRACT

An interdental immobilization device consists of a fixture of at least three components, a screw member, one cone and a nut. The cone has an aperture from base through apex so that the screw may slip therethrough, and the screw has a threaded helical shaft which threadingly mates with the nut.
The screw and the cone have the means for anchoring the screw to the cone. The cone is slipped onto the screw and anchored thereon and the screw is pushed through from inside the mouth, through the gum between adjacent teeth, and then engaged onto the threaded nut whereby the fixture is secured between two adjacent teeth. Using plurality of these fixtures, staggered and spatially disposed along both upper and lower jaw, when they are interjoined with wire or elastic the lower jaw is effectively immobilized to the upper jaw.

Description

This invention relates to an interdental immobilization device.
From time to time, it is necessary to immobilize the human jaw.
This will be necessary when fractures of mandible occur or when (sparingly) one wishes to have their mouth fixed shut so as to avoid eating, and hence losè weight.
The existing method of the prior art uses a pliable metal strip with projecting hooks known as an archbar and several fine wires and rubber bands. The metal strip is secured tightly to the teeth of the upper jaw by passing a wire around the base of a tooth and through the gum and over each side of the tooth and also over the metal strip. At this point both ends of the wire are outside the mouth and are twisted together to hold the metal strip urgingly against the outside surEace of the teeth. The twisted wire is then cut to a length of approximately 1/8 to 1/4 inch and bent backward towards the gum and preferably placed in between two adjacent teeth to prevent irritation on the inside of the lips.
This is repeated spatially around eight to twelve teeth of the upper ]aw and the same is repeated over the lower jaw.
The metal strip has the projecting hooks spatially disposed on its outside surface and over these hooks small rubber bands or wires are then attached between those hooks of the meta] strip attached to the teeth of the lower jaw and those hooks oE the upper jaw. This techni~ue has been published at pages 301 through 303 in Surgery of the Upper Respiratory System (Vol 1-2nd Edition) by William W.
Montgomery M.D., Published by Lea & Febiger, Copyright 1~79.
This particular prior art technique, which is extremely common in North America, and around the world has several disadvantages. The most dominant disadavantage is that during twist tightening of the wires, the wires can easily snap and the whole process must be repeated hence adding to the length of the installation procedure. It is not uncommon for this - procedure to take between 1 and 2 hours of operating theatre time since a general anesthetic for the patient is always needed.

~2~ 66 After approximately two days of use, the wires need to be retightened and retwisted as they have a tendency to loosen ofE and sometimes break. If they break during tightening, th0 patient must be re-anesthetized again within the operating theatre and new wires inserted as before. Further, the patient must be anesthetized for wire removal after the jaw has mended.
With the recent scare of AIDS and HEPATITIS B, there is a constant danger of trauma to the surgeons hands from the ends of the wire and hence exposure to the patient's body fluids and blood since the passing of the wire between the teeth, always ruptures the gum and the gum bleeds.
We have conceived of a fixture which can be placed and bolted between the teeth. The fixture exposes an anchoring surface, which preferably is cylindrical, onto which the rubber bands or wires may be attached so as to fix the lower and upper jaw into rigid position.
The fixture according to the invention has several advantages over the prior art; namely, (a) anesthetic is generally required only on the installation of the fixture;
(b) the fixture may be tightened by the simple expedient of turning down a nut on a screw as there is no wire and -therefore wire twisting with the appendant possibility of wire breakage cannot occur; thus, the step for re-installation of possibly broken wires in an operating theatre environment with the patient anesthetized is avoided; and, ~c) the fi~ture is easily removed generally without the patient being re-anesthetized.
The invention, in its preferred embodiment, contempla-tes ; -therefore; a truncated cone, a screw, and a nut; the nut and cone defining a screw accommodating channel. The channel through the truncated cone extends from the flat bottom of the cone through the apex and the cone preferably is a near upright conic. The screw has a threaded shaft while the nut a channel that threadingly mates with the shaft.

~ :25~1~66 ; In yet a further alternative embodiment of the invention two cones rather than one cone may be used.
In one variant of the nut, the internal diameter of the channel is smooth bored and slightly smaller in diameter than that of the threaded shaft. In the preferred embodiment of this variant, the nut is composed of a plastic material such as nylon and has a shorter major bore diameter larger than that of the screw that steps into a longer minor bore with diameter slightly smaller than that of the threaded shaft.
The length of the minor bore is substantially greater than that of the major bore. In an alternative embodiment of the - nut, the nut has a helically threaded channel of constant diameter which threadingly mates with the screw and in this embodiment the nut is preferably composed of a metal such as stainless steel.
In yet a urther embodiment of the threaded shaEt, the shaft has means to index itself into one o the cones as well as to protrude beyond the cone as a bent tip so when fixed between the teeth the bent tip stands as a protrusion in ~he crevice deEined by these adjacent teeth.
The invention therefore contemplates a fixture Eor interdental immobilization comprising:
(a) an interconnecting engagement member with engagement means;
(b) a first and a second anchor member adapted to be spatially disposed and fixedly attached to the engagement member;
(c) a capture region; and, (d) means for adjustably locating said anchor members relative to each other and for carrying the capture region, the capture region baing adapted to carry selected interconnecting elements to interconnect said fixture with a second such fixture relatively disposed at a pre-determined distance.
Particularly, in its preferred embodiment the fixture comprises:

1 259 8~D6 (a) an elongated screw member carrying a first anchor means and having an attachment means;
(b) a second anchor means;
~c) a capture region;
(d) locating means for fixedly locating said second anchor means along said longitudinal member at a pre-determined spatial position and for locating the capture region thereon.
More specifically, there i5 an "L" shaped screw with a distal arm and a threaded shaft and a pointed tip thereon a proximate arm wherein the proximate arm extends through an obtuse angle into a straight inclined piece that acts as a protrusion. This screw protrudes through an anchor member which in one embodiment is a truncated cone~ The screw and cone are stainless steel in the preferred embodiment while the second anchor means, in the preferred embodiment includes a capture region and is composed of nylon with a smaller major bore stepping into a smaller minor bore si~ed a diameter smaller than that of the screw so that the screw can tap into the minor bore a helical thread for matingly securing the nut onto the screw. The screw also carries a capture region which in its preferred embodiment i5 a circumferential shoulder which acts as a bearing surface for interjoining a plurality of said fixtures located spatially between teeth of the upper and lower jaw.
The invention wil~ now be described by way of example and reference to the accompanying drawings in which:
Figure 1 is a perspective assemb-y view of the preferred embodiment of the invention.
Figure 2 is a perspective assembly view of an alternative embodiment of the invention.
Figure 3 is a section through the embodiment according to figure 1 showing its implantation adjacent a tooth shown in phantom;
(a) figure 3A is a partial section of a longer screw in the nut of figure 3 showing how the screw distal end is severed after implantation.

Figure 4 is a perspective view of the Eirst step according to the prior art.
Figure 5 is a plan view of the brace according to the prior art secured by wire to teeth.
Figure 6 illustrates the securing of the upper and lower jaw according to the prior art.
Figure 7 corresponds to figure 4 as it relates to the implantation of devices according to the invention.
Figure 8 is a perspective view showing the implantation of the preferred embodiment of the invention between teeth as viewed from the inside of the mouth and hence is a view along VIII-VIII of ~igure 7.
~igure 9 is a partial perspective view of a jaw indicating the mode of securing the upper and lower jaws according to the invention.
Figure 10 is cross-sectional view of one embodiment of the nut.
Figure 11 is a cross-sectional view of another embodiment of nut according to the invention.
Referring to figure 1, the fixture 10, according to the invention, consists of a U shaped screw member 11 with an upstanding proximate arm 12 that is bent through an obtuse angle 12' to terminate as a forwardly inclined straight piece 12". The screw member 11 carries a longitudinal shaf-t 13 with its distal end tapering to a point at 14. Part of the shaf-t 13 is helically threaded as a~ 15. A truncated conic member, or cone 16 consists of a flat bottom 19 through which extends a slot 20 and the cone defines therethrough a channel 18 which - passes through the apex oE the cone and hence truncates it as shown in figures 1 and 2. The channel 18 is a diameter slightly larger than the diameter of the shaft 13 so as to allow free passage therethrough. This is more clearly seen in the sectional figure 3. The slot 20 is outwardly tapered at 20' at the identical obtuse angle as at 12' so that the proximate arm 12 may appropriately index within the slot 20 and the bend 12' and straight distal piece 12" mate against the inclined or beveled surface of slot 20' allowing the end of the distal piece 12' to protrude into the crevice defined by the bodies of two adjacent teeth.
The nut 17 in one of the preferred embodiments, that is shown in figures 1 and 10, is formed of nylon and the channel 21 is a stepped smooth walled channel, as more clearly seen in figure 10, with a shorter major bore 21C and a longer minor bore 21CR; the major bore interfacing with the apex thereof.
Also, the nut 17 may be profiled as seen in figures 1 and 3 so as to provide an outter hexagonal gripping surface 22H sized greater than the diameter of the cylindrical shoulder 23 through which it steps into a truncated conical section 24.
The face of the nut obverse to the truncated conic 24 is conically recessed at 25 as more clearl~ seen in figure 3 (see also figures 10 and 11). If the tip 14 of the screw 13 extends into the conical recess 25 aEter the physician has placed the fixture 10 between teeth, as will be disclosed hereafter, the physician has room to insert a pair of diagonal cutters 30 (see figure 3A) or the like into the recess 25 and to snip off the protruding segment of shaft 13 and the tip 14 which are collectively shown as SR so as not to cause abrasion to the inner skin of the mouth.
Referring to figures 3 and 8, in application, the screw 11 is fitted to slip through cone 16 with the proximate arm 12 indexing into the slot 20. The screw 11 is pushed between the base of two adjacent teeth 50 (502 and 503 in figure 8) and the point 14 assists in the penetration of the screw 11 from the inside of the mouth through the gum mass between said teeth 502 and 503 to the outside gum surface. The nut 17 is then, if hexagonally formed as in figure 1, put into a socket wrench and threaded onto the screw 11 so as to urge against the adjacent teeth 502 and 503 as well as the adjacent gum mass. If the profiled nut of figure 1 having the hexagonal surface 22H is nylon, and has the stepped ~ore channel, shown in figure 10, the tapered tip 14 of the screw 11 indexes into the opening face of the major channel 21C and as the nut is rotated, the screw 11 itself taps a helical thread into the wall of the minor bore 21CR of the nylon nut of figures 1, 3 . .

and 10 and secure anchoring is thereby acheived. As the nut 17 is turned tighter, the cone 16 and the conic section 24 of the nut 17 are drawn toward each other and a tight fit is acheived. If there be any loosening off at a later time it is simple to just slightly turn down the nut with the socket wrench.
This step is repeated to locate, as shown in figure 71 a plurality of fixtures 10 mounted between teeth along the lower jaw. The steps are repeated in relation to the upper jaw.
The shoulder cylindrical surface 23 of the nut 17 is used as the capture region for anchoring wire W, which is laced between top and bottom fixtures as shown in figure 9.
In this way, the lower jaw is immobilized to the upper jaw.
This wrapping may just be accommodated by weaving or wrapping of wire W or if preferred, elastic loops Wl may be used.
Referring to figure 2, a further alterna-tive embodiment consists of two identical truncated stainless steel conics shown as 16' and 16". The screw 11 has but a proximate straight arm 12 and that arm indexes into the slot ~0 of the truncated conic 16'. The nut 17 is fashioned without a tapered conic section 24 and hence a flat bearing as shown and for reason, a second conic 16" identical to that of 16' is used as the bearing member for the nut. Similarly, as disclosed relative to ~igure 1, the screw 11, the conics 16' and 16" and nut 17 may be installed between the teeth. This particular embodiment is less favourable to that of figures 1 and 10 since there are 4 rather than 3 discreet components to the fixture 10 and the nut is stainless steel as that of figure 11 but profiled as in figure 2 without the conic surface 24.
Referring to figure 3A the length of the screw 11 may be structured quite long so as to accommodate various depths (thicknesses of teeth). In that instance, the tip 14 of the screw 11 protrudes well beyond the face of the conical recess 25 of the nut as shown in figures 3 and 3A. This overhang extent SR may be cut off with a pair of wire cutters 30 as 9~;16~

shown in figure 3A. This provides means for reducing the length of the screw each time that the nut 17 is turned down on the teeth to tighten the fixture. Abrasion to the inner lip and cheek is thus avoided~
Returning now to figure 10, when the nut is composed of nylon, the channel may be a two step bore as shown that is a shorter major bore ?1C that steps into a longer ~inor bore 21 CR. The thread 15 of the screw 11 may be modified (though not required) near its tip 14 with a cup at 14C and a protruding piece 14I which ~ooperatively act as a "tap". When the nylon nut 10 is turned down on this end taped threaded shaft of the screw 11' the screw 11' self taps the minor bore 2lCR -to form a mating thread therein securing the nut 17 thereon.
In the preferred embodiment of figures 1, 3, and 10, the screw 11, and cone 16, are s-tainless steel and the nut 17 is made of nylon. We have found that a cone base diameter of approximately 5 m.m. and a cone height of 3 m.m. is satisfactory with an angle of 40. This means that the hexagon diameter 22H of the nut 17 is preferrably about 7 m.m. while the shoulder portion 23 diameter is about 5 m.m.
~ith a depth of shoulder of about 2 m.m~ to allow adequate space for winding of wire or elastics Wl between respective shoulders of fixtures in a manner as seen in figure 9. In this respect the preEerred length of the screw is about 12 m.m. with the screw arm 12 having a length of approximately

2.5 m.m. and protrusion 12l' of about 2.5 m.m. and an outside bend diameter at 12' of 0.8 m.m. In this respect, slot 20 cut into the face of the base of the cone has a preferred depth of approximately 1 m.m. and a preferred width of between 0.8 and 1 m.m.
In a variant of the nut 17, it may be stainless steel as shown in figures 1 and 11. In this instance, the central channel 21 is a uniform helically threaded channel 21N shown in figure 10. The stainless steel nut may be profiled with either the hexagonal surface 22H of figure 1 or with a cylindrical knurled surface 22N and of figure 2, It should be noted, that if the formed screw 11 of figure 1 is used, the proximate arm tip of the straight piece 12" protrudes beyond the conic 16 (as shown in figure 3) into the crevice defined by the bodies of two adjacent teeth (see figure ~) and anchors the screw preventing its rotation and the corresponding rotation of the conic 16 in figures 1, 3, and 8, as the nut 17 is initially turned down. If the screw 11 is of the unmodified shape, as shown in figure 2, the screw 11 and the conic 16' of that finger is a tendency that they rotate on the initial turning down of the nut 17 irrespective of which profile 22H or 22N the nut has. This empediment is amplified when the step bore nylon nut of figure 10 is used on the screw 11 of figure 2 or figure 10, while if the stainless steel nut 17 of figure 11 is used i.e., having a uniform threaded channel 21~ the problem is less pronounced.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A fixture for interdental immobilization comprising:
(a) an interconnecting engagement member with engagement means;
(b) a first and a second anchor member adapted to be spatially disposed and fixedly attached to the engagement member;
(c) a capture region; and, (d) means for adjustably locating said anchor members relative to each other and for carrying the capture region, the capture region being adapted to carry selected interconnecting elements to interconnect said fixture with a second such fixture relatively disposed at a pre-determined distance.

2. The fixture as claimed in claim 1 wherein the interconnecting engagement member is a shaft and said first and second anchoring members are truncated conic regions, each including attachment means for engaging the engagement means of the interconnecting engagement member (a).

3. The fixture as claimed in claim 1 when the interconnecting engagement member is a threaded shaft and said first anchor member is a truncated conic defining a channel through which said shaft extends and wherein said second anchor means is integral with said adjustably locating means (d) and includes means for engagement with said shaft whereby to position said first and second anchor means relative to each other.

4. The fixture as claimed in claim 3 wherein said means (d) for locating includes a bearing surface adapted to locate said means (d) and said second anchor means relative to said first anchor means.

5. A fixture for interdental immobilization comprising:
(a) an elongated screw member carrying a First anchor means and having an attachment means;
(b) a second anchor means;

(c) a capture region;
(d) locating means for fixedly locating said second anchor means along said elongated screw member at a pre-determined spatial position and for locating the capture region thereon.

6. A fixture for interdental immobilization comprising:
(a) an elongated screw member having a first and a second attachment means;
(b) a first anchor means;
(c) a second anchor means;
(d) a capture region;
(e) locating means for fixedly locating said first and second anchor means along said elongated screw member at a pre-determined spatial position and for locating the capture region thereon.

7. The fixture as claimed in claim 6, wherein said first and second anchor means are conic regions.

8. The fixture as claimed in claim 7, wherein one conic region is a truncated conic.

9. The fixture as claimed in claim 5, 6 or 7, wherein the elongated screw member is "L" shaped having a distal arm with a threaded shaft and pointed tip thereon and a proximate arm.

10. The fixture as claimed in claim 8, wherein the elongated screw member is "L" shaped having a distal arm with a threaded shaft and pointed tip thereon and a proximate arm.

11. The fixture as claimed in claim 5, 6 or 7, wherein the elongated screw member is "L" shaped having a distal arm with a threaded shaft and pointed tip thereon and a proximate arm, wherein the proximate arm extends through an obtuse angle into a straight inclined piece that acts as a protrusion;

12. The fixture as claimed in claim 5, 6 or 7, wherein the elongated screw member is "L" shaped having a distal arm with a threaded shaft and pointed tip thereon and a proximate arm, wherein the tip includes means for tapping a thread into a uniform channel of smaller diameter.

13. The fixture as claimed in claim 7 or 8 wherein, the elongated screw member is "L" shaped having a distal arm with a threaded shaft and pointed tip thereon and a proximate arm, wherein said conics and screw are stainless steel.

14. The fixture as claimed in claim 5, 6 or 7, wherein the locating means is a nut adapted to threadingly engage said screw member.

15. The fixture as claimed in claim 5 f 6 or 7, wherein the locating means is a nut adapted to threadingly engage said screw member, wherein the nut is made of plastic and has a major bore stepping into a minor bore of diamater less than the diameter of the screw.

16. The fixture as claimed in claim 5, 6 or 7, wherein the locating means is a nut adapted to threadingly engage said screw member, wherein the nut is made of plastic and has a major bore stepping into a minor bore of diamater less than the diameter of the screw, wherein the nut defines a shoulder that acts as the capture region and has a cross-sectional area larger than the cross-sectional area of the capture region adjacent thereto.

17. The fixture as claimed in claim 5, 6 or 7, wherein the locating means is a nut adapted to threadingly engage said screw member, wherein the nut is made of plastic and has a major bore stepping into a minor bore of diamater less than the diameter of the screw, wherein the nut defines a shoulder that acts as the capture region and has a cross-sectional area larger than the cross-sectional area of the capture region adjacent thereto, having a recess whose apex communicates with a channel on the side obverse to that of the capture region.