US3888007A

US3888007A - Orthodontic face bow

Info

Publication number: US3888007A
Application number: US461855A
Authority: US
Inventors: Donald F Chittenden
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-04-18
Filing date: 1974-04-18
Publication date: 1975-06-10
Anticipated expiration: 1992-06-10

Abstract

The orthopedic face bow includes an outer bow forming an elongated loop at its central portion. An inner bow has its central portion soldered to a central underside portion of the elongated loop and a center piece having upper and lower channels formed therein is positioned within the elongated loop so that the lower side walls of the lower channel eclipse the soldered connection portion of the inner bow to the outer bow. The floor of the upper channel in turn, defines fulcrum surfaces to distribute stresses in cooperation with the end loop portions when the extending ends of the outer bow are bent inwardly.

Description

United States Patent 11 1 Chittenden ORTHODONTIC FACE BOW [76] Inventor: Donald F. Chittenden, 1365 N.

Armel Dr., Covina, Calif. 91722 22 Filed: Apr. 18, 1974 21 Appl. No.: 461,855

[52] U.S. Cl 32/14 D [51] Int. Cl. A6lc 7/00 [58] Field of Search 32/14 D; 128/146 [56] References Cited UNITED STATES PATENTS 3,137,941 6/1964 Andrews 32/14 D 3,311,978 4/1967 Haas et a1. 32/14 D Primary Examiner-Robert Peshock Attorney, Agent, or Firm-Pastoriza & Kelly June 10, 1975 57 ABSTRACT The orthopedic face bow includes an outer bow forming an elongated loop at its central portion. An inner bow has its central portion soldered to a central underside portion of the elongated loop and a center piece having upper and lower channels formed therein is positioned within the elongated loop so that the lower side walls of the lower channel eclipse the soldered connection portion of the inner bow to the outer bow. The floor of the upper channel in turn, defines fulcrum surfaces to distribute stresses in cooperation with the end loop portions when the extending ends of the outer bow are bent inwardly.

7 Claims, 5 Drawing Figures ORTHODONTIC FACE BOW This invention relates generally to orthodontic devices and more particularly to an improved face bow construction.

BACKGROUND OF THE INVENTION Conventional prior art face bows normally include an outer bow and an inner bow of lesser radius of curvature having its central portion fixed to the central portion of the outer bow. The inner bow is positioned about a patients teeth in his mouth and engages the patients posterior molars. The outer bow, in turn. passes about opposite sides of the patients face and terminates in hook portions for receiving some type of force supplying means such as an elastic band. The arrangement is such as to exert inward pressure on the inner end portions of the inner bow to urge the patients teeth in a rearward direction. These devices are sometimes referred to as dental retractors.

A major problem encountered with such appliances is the tendency for the outer bow to break off from the inner bow or in itself fracture as a consequence of constant flexing or inward bending of the outer ends. Normally. the central portion of the inner bow is silversoldered to the central portion of the outer bow and by making a fairly long solder path, the securement of the members together can be strengthened. On the other hand, the silver-solder itself is unsightly and tarnishes quickly.

Efforts in the past to solve the tendency for the outer bow to break or become disconnected from the inner bow have included the formation of a loop in the central portion of the outer bow, curved portions of the loop tending to distribute the stress and thus decreasing the tendency of breakage under flexing or bending conditions of the outer ends. With only a loop portion formed. however, the stress tends to become concentrated at the sharp turn portion of the loop and thus the problem is still present.

Other efforts towards strengthening such appliances have involved providing a sheath or surrounding of the connected portions of the inner loop to the outer loop. While such a sheath will strengthen the connection. stress still is concentrated at the exit points of the outer bow from the sheath. In fact. the stiffening resulting from the provision ofa surrounding sheath can even aggravate the problem.

In addition to the foregoing. such orthodontic face bows as are presently available are generally unsightly and uncomfortable for the patient. A specific problem with respect to discomfort is the sharp and jagged ends of the inner and outer bows which can seriously injure a patient's gums. Moreover. the usual stops provided adjacent to the ends of the inner bows for applying pressure to the patients teeth generally take the form of solder enlargements wherein again rapid tarnishing of the solder takes place and any type of adjustment of the stop positions is difficult BRIEF DESCRIPTION OF THE PRESENT INVENTION With the foregoing consideration in mind, a basic ob ject of the present invention is to provide an improved orthodontic face bow construction wherein the foregoing problems are substantially overcome.

More particularly, the present invention comprises an outer bow with an elongated loop formed at its central portion. An inner bow in turn has its central portion secured such as by silver soldering to a central underside portion of the elongated loop. A center piece in turn is provided with upper and lower channels. the lower channel receiving the underside of the elongated loop and the central portion of the inner bow in a manner such that its lower side walls completely eclipse the silver soldered connection not only inhibiting the tarnishing but also contributing towards an esthetic appearance.

The upper channel in turn encompasses in a side-byside relationship the upper portion of the elongated loop and the floor of this upper channel defines fulcrum surfaces which cooperate with the loops in distributing stress.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing as well as further features and advantages of this invention will be understood by now referring to a preferred embodiment of the face bow as shown in the accompanying drawings in which:

FIG. 1 is a perspective view of the orthodontic face bow of this invention:

FIG. 2 is an enlarged perspective view of the center piece body only utilized in the face bow of FIG. 1;

FIG. 3 is a front elevational view of the face bow looking in the direction of the arrows 33 of FIG. 1;

FIG. 4 is a plan cross section through the immediate inside wall surfaces of the center piece taken in the direction of the arrows 4-4 of FIG. I; and.

FIG. 5 is across section in the direction ofthe arrows 55 of FIG. 1.

DETAILED DESCRlPTlON OF THE PREFERRED EMBODlMENT Referring first to FIG. 1, the orthopedic face bow in cludes an outer bow l0 defining an elongated loop 1] at its central portion and terminating at its outer ends in integrally formed hooks l2 and 13.

An inner bow member [4 of lesser radius of curvature than the outer how has a central portion secured to a central underside portion of the elongated loop. This securement will become clearer as the description proceeds. It will be noted that the inner bow member 14 includes half loops formed near its outer ends as indicated at 15 and 16. These half loops serve as "stops" in lieu of soldered enlargements or the like as have characterized prior art devices. The position along the bow at which the half loops are formed is selectable thereby enabling the stop positions to be adjusted. The

extreme ends

17 and 18 of the inner how 14 as well as the extreme ends of the hooks l2 and [3 on the outer bow 10 are all smoothly radiused to avoid the presence of any sharp. jagged points.

The assembly is completed by the provision of a center piece 19 which fits within the elongated loop 11.

Referring now to FIG. 2, details of the center piece will be described. Aa shown. this center piece comprises a body having an upper and lower channel formed on its top and bottom surfaces as indicated at 20 and 21 respectively so as to define a general H- shape in cross section. It will be noted that the floor 22 of the upper channel 20 is convex between its

exit end portions

23 and 24. This concave shape accommodates the general curvature of the central top portion of the elongated loop when the center piece is assembled within the loop as shown in H6. 1.

Referring to the front view of FIG. 3. the central top portions of the loop are indicated at 11d and lle in side-by-side relationship within the upper channel of the center piece 19. lt will be noted in this view that these portions exiting from the upper channel in the center piece are jogged slightly as at 25 and 26 so that the further end portions of the outer bow lie in a plane passing between the upper portions of the elongated loop to include the line of contact indicated at 27 of the portions in side-byside relationship. This plane is per pendicular to the plane of the drawing of FIG. 3.

Referring now to H6. 4. further details of the structure will be evident. As shown. the ends of the elongated loop designated 11a and 11h extend beyond the

exit end portions

23 and 24 of the upper channel in the center piece 19. Further. it will be noted that the convex configuration of the floor of the channel accommodates in surface contact the general curvature of this upper central portion of the elongated loop as described heretofore.

In FIG. 4, the securement of the central portion of the inner bow 14 designated 28 to the central underside portion of the elongated loop llc is shown at 29 and as stated may constitute silver solder. It will also be clear that these respective portions lie one above the other within the lower channel of the center piece 19 in such a manner that the lower side walls of this lower channel will eclipse the soldered connection as in the view of FIG. I.

The foregoing physical arrangement will also be clear from FIG. 5 wherein the side-by-side upper loop portions [Id and 111: within the upper channel 20 of the center piece 19 is shown and the one above the other position of the lower central portion of the loop and central portion of the inner bow 11c, and 28 respectively within the channel 21 is shown.

The width ofthe lower channel 21 of the center piece 19 as shown in FIG. Sis such that the plane ofthe inner bow 14 can be adjusted to form a desired angle with the plane of the outer bow prior to soldering to the lower loop portion of the outer bow Thus. in assembling the device. the inner bow may be positioned as indicated by the dotted lines at 14'. ln this example, the plane of the inner bow forms an angle below the plane of the outer bow. However. the plane of the inner bow could form a similar angle above the plane of the outer bow if desired. Once a suitable relationship has been established. the parts are soldered as described and the center piece then attachedOPERATlON Referring specifically to FIG. 4. the manner in which the described structure lessens the risk of breaking of the outer bow or disconnection of the outer bow from the inner how will become evident. As shown in FIG. 4, when the outer ends of the outer bow 10 are bent or flexed inwardly as often occurs. the portions of the upper loop 11d and lle at the points they pass from the exit ends of the upper channel will bear down on the channel floor surface portions adjacent these ends. These portions are indicated at 23 and 24 in FIG. 2 and serve as fulcrum surfaces for the outer bow portions. These fulcrum surfaces in addition to the end loop portions llu and 11b of the elongated loop. which portions as described are spaced from the exit ends ofthe center piece. distributes the stress along the end loop portions in such a manner that large stress concentrations at any one point are avoided. Thus. it will be understood that the upper loop portions are simply resting in the upper channel and are free to move therein and rock on the convex surface in such a manner to effect the desired stress distribution. The end loop portions 11a and llb themselves can circumferentially expand as necessary to accommodate bending movements Under bending of the outer extending ends of the outer bow inwardly. the loop portions and central top portions will assume the positions illustrated in dotted lines in FIG. 4 wherein the fulcrum action will be evident. Because the flexing is taken up along a substantial distance of the end loops. there is very little stress communicated to the soldered portion 29in the lower channel of the center piece. Thus the risk of breakage is minimized.

From the foregoing description. it will be evident that the center piece really serves a dual function. First. it will provide the desired fulcrum surfaces to distribute stress in cooperation with the end loop portions. Second, it serves to-eclipse and protect the soldered con nection of the inner bow to the under side central por tion of the elongated loop of the outer bow.

The foregoing basic feature in combination with the further features of rounding off the extreme ends of the respective bows results in a greatly improved orthodontic face bow. The outer and inner bows themselves will normally comprise stainless steel wire and thus tarnish ing of these portions is minimal. By providing the half loops in the outer stainless steel wire portions of the inner bow 14 as described to serve as stops. the presence of silver solder is avoided and thus the associated problems of tarnishing are avoided. With respect to the single silver solder connection at the central portion of the bows. as described the center piece eclipses and protects this connection so that an overall esthetically pleasing device as well as an hygienic device results.

What is claimed is:

1. An orthopedic face bow comprising. in combination:

a. an outer bow member defined forming an elongated loop at its central portion;

b. an inner bow having its central portion secured to a central underside portion of said elongated loop; and.

c. a rigid centerpiece having a lower channel with a floor portion passing through said elongated loop. the central portion of the inner bow and lower central portion of the loop lying in said channel so that the lower side walls eclipse the securement portion of the inner bow to the outer bow the upper surface of said center piece defining the opposite side of the floor of said lower channel. including portions servicing as fulcrum surfaces when the extending ends of the outer bow are flexed inwardly.

2. An orthopedic face bow comprising. in combination:

a. an outer bow member defining an elongated loop at its central portion and terminating at its outer ends in integrally formed hooks;

b. an inner bow member having a central portion soldered to a central underside portion of said elongated loop; and

c. a center piece comprised of a body having an upper and lower channel formed on its top and bottom surfaces respectively so as to define a general Hshape in cross section. the upper portions of said elongated loop lying in the upper channel in sideby-side relationship and the lower portion of the loop and a central portion of the inner bow member lying in said lower channel. one above the other, the lower side walls of said lower channel eclipsing the soldered connection of the inner bow to the loop. the end loop portions of the loop ex tending beyond the ends of the channels in the center piece to provide flexibility and accommodate bending of the outer bow, the floor of the upper channel of said center piece adjacent the exit ends of the channel defining fulcrum surfaces for the respective upper loop portions when bending occurs so that stress in the loop is distributed about said end loop portions to minimize the risk of breaking of the outer bow and breaking its soldered connection to said inner bow 3. A face bow according to claim 2, in which the floor of said upper channel is convex between its exit ends to accommodate the general curvature of the central top portion of the elongated loop and increase the area of said fulcrum surfaces.

4. A face bow according to claim 2, in which said (ill inner bow member includes half loops formed near its outer ends to serve as stops, the position along the bow at which the half loops are formed being selectable thereby enabling the stop positions to be adjusted.

5. A face bow according to claim 2, in which the ex treme ends of the outer and inner bows are all radiuscd to avoid the presence of any sharp. jagged points.

6. A face bow according to claim 2. in which portions of the outer loop exiting from the upper channel in the center piece are jogged slightly so that the further end portions of the outer bow lie in a plane passing between said upper portions of said elongated loop to include the line of contact of the portions in side-by-side relationship.

7. A face bow according to claim 2, in which the width of the lower channel of said center piece is such that the plane of the inner bow can be adjusted to form a desired angle with the plane of the outer bow prior to soldering to the underside central loop portion of the outer bow and insertion within said lower channel.

Claims

1. An orthopedic face bow comprising, in combination: a. an outer bow member defined forming an elongated loop at its central portion; b. an inner bow having its central portion secured to a central underside portion of said elongated loop; and, c. a rigid centerpiece having a lower channel with a floor portion passing through said elongated loop, the central portion of the inner bow and lower central portion of the loop lying in said channel so that the lower side walls eclipse the securement portion of the inner bow to the outer bow the upper surface of said center piece defining the opposite side of the floor of said lower channel, including portions servicing as fulcrum surfaces when the extending ends of the outer bow are flexed inwardly.

2. An orthopedic face bow comprising, in combination: a. an outer bow member defining an elongated loop at its central portion and terminating at its outer ends in integrally formed hooks; b. an inner bow member having a central portion soldered to a central underside portion of said elongated loop; and c. a center piece comprised of a body having an upper and lower channel formed on its top and bottom surfaces respectively so as to define a general H-shape in cross section, the upper portions of said elongated loop lying in the upper channel in side-by-side relationship and the lower portion of the loop and a central portion of the inner bow member lying in said lower channel, one above the other, the lower side walls of said lower channel eclipsing the soldered connection of the inner bow to the loop, the end loop portions of the loop extending beyond the ends of the channels in the center piece to provide flexibility and accommodate bending of the outer bow, the floor of the upper channel of said center piece adjacent the exit ends of the channel defining fulcrum surfaces for the respective upper loop portions when bending occurs so that stress in the loop is distributed about said end loop portions to minimize the risk of breaking of the outer bow and breaking its soldered connection to said inner bow.

3. A face bow according to claim 2, in which the floor of said upper channel is convex between its exit ends to accommodate the general curvature of the central top portion of the elongated loop and increase the area of said fulcrum surfaces.

4. A face bow according to claim 2, in which said inner bow member includes half loops formed near its outer ends to serve as stops, the position along the bow at which the half loops are formed being selectable thereby enabling the stop positions to be adjusted.

5. A face bow according to claim 2, in which the extreme ends of the outer and inner bows are all radiused to avoid the presence of any sharp, jagged points.

6. A face bow according to claim 2, in which portions of the outer loop exiting from the upper channel in the center piece are jogged slightly so that the further end portions of the outer bow lie in a plane passing between said upper portionS of said elongated loop to include the line of contact of the portions in side-by-side relationship.