US1743138A - Film holder - Google Patents

Description

Jan. 14,- 1930.

Filed March 14, 1927 //v VENT'OE." 6'. .5. J/ODGJON.

firroemers.

Patented Jan. 14, 1930 EDWARD S. I-IODGSON, OF EAST ST. LOUIS, ILLINOIS FILM HOLDER Application filed March 14, 1927. Serial No. 175,412.

lhis invention relates generally to improvements in dental implements, and particularly to an improved means for supporting a radio-sensitive film pack in a persons mouth while a radiograph of a tooth or teeth of said person is being made.

Prior to this invention, it was a common practice for the patient to hold the film pack in his mouth with his fingers while a radio graph was being made, but this method was found to be very unsatisfactory because it frequently resulted in the production of imperfect radiographs due to the fact that the film pack was not held in the proper position with relation to the tooth or teeth being radiographed. To obtain the best results in making radiographs, the ray projected toward the film by the X-ray apparatus should approach said film as close as possible at a right angle to the plane of the sensitized face of the film. This tends to avoid distortion of the impression on the film of the tooth or teeth being radiographed, as it is obvious that if the ray did not approach the film pack at or near a right angle to the plane thereof, the impression of the tooth or teeth being radiographed would be undesirably elongated or foreshortened.

Ordinarily, the plane of the film is at an angle to the long axis of the tooth being radiographed, and it has been the practice in the past to position the X-ray apparatus so that the ray passing therefrom was projected at an approximate right angleto the plane of the film. However, to do this, it was neces sary for the dentist to first observe the position of the film within the patients mouth and then position the X-ray apparatus so that the ray projected therefrom impinged on the film at the proper angle, and it frequently was difficult to properly position these parts relative to each other so that the best results were obtained. A source of a great amount of difficulty encountered heretofore in making 4 radiographs of upper molar teeth was the presence of the cheek bone, or more properly, the zygomatic arch, which is in such position in the human head that if the ray from the X-ray apparatus is not projected accurately 59 with respect to the film, said ray will be com pelled to penetrate said zygomatic arch before it impinges on the film. The result of this is that the impression on the film will be shaded where the rays pass through the zygomatic arch, whereby an imperfect radiograph is produced.

By the use of the implement disclosed herein the X-ray apparatus may be accurately positioned with respect to the film pack within the patients mouth, and as a result, the angle 0 of the ray projected from the X-ray apparatus is such that it is not necessary for said ray to penetrate the zygomatic arch, and, therefore, clearer and undistorted radio-- graphs are obtained.

Another important object of the invention arises from its adaptability for use in making duplicate radiographs intended for use with a stereoscope. It is well known that when a ,7 stereoscope is to be used in viewing radio- 79 graphs, two radiographs must be made which are almost exact duplicates of each other. These radiographs are made one at a time, and it is obvious that if the film on which the second radiograph is to be made is not in exactly the same position within the patients mouth as was the first film, and also if the patients head and the ray projected from the X-ray apparatus are not in exactly the same relative positions during the making of both radiographs, said radiographs will not be stereoscopic. By the use of the present in-' vention, all of these parts are arranged in their proper and corresponding positions during the making of both radiographs, and, therefore, said radiographs will be very well adapted for use with a stereoscope.

Figure 1 is a perspective of my improved implement showing a film pack associated I therewith in dotted lines;

Figure 2 is a front elevation of my improved implement with the, extension piece thereof removed, a portion of a human head being illustrated by dotted lines;

Figure 3 is a View on a reduced scale showing the'manner of employing my improved implement when radiographs for use with a stereoscope are being made;

Figure 4 is a plan view of a modified form m0 of my invention;

' Figure 5 is a side elevation of the form or the invention shown in Fig. 4t, portions of a human head being illustrated by dotted lines.

The main portion of my improved implement is preterabl 'stampedfrom a plate of suitable material as a unitary structure, and comprises a fiat body 1 having an integral lateral extension 2 at one of its ends. The extension 2 comprises a portion 3 located immediately adjacent to the main body portion 1 and inclined downwardly at an angle with respect thereto, as shown clearly in Fig. 2, and an integral portion a suitably bent downwardly and upwardly upon itself to produce a recess or socket 5 adapted to receive the film pack 6, The extension 2 is of such width that it will properly support the film pack 6, and also the depth of the recess or socket 5 is such with relation to the thickness of the film pack, which is ordinarily provided with a backing of sheet lead, that said film pack will be trictionally gripped in said recess or socket. By referring to Fig. 2, it will be observed that the portion 4 of the extension 2 and the film pack supported thereby are arranged at an angle With respect to the long axis A of the tooth T being radiographed, this being necessary because of the formation of the human mouth, which prevents thelilm being arranged in a position more nearly parallel with the long axis of the tooth T. i

As already stated herein, it is desirable that the ray from the 'X-ray apparatus should impinge on the film 6 at a right angle to the plane of the sensitive face of said film to prevent distortion of the impression of the tooth being radiographed, but by referring to Fig. 2, it will be seen that if this were done, said ray would have to pass through the zygomatic arch, which is'designated by the reference character Z in the view mentioned, whereby the resultant radiograph would have an undesirable shaded portion. It is, therefore, an important object of this invention to provide means whereby radiographs may be made without undue distortion while, at thesame time, the angle of the ray is such that it will not be compelled to pass through the zygomatic arch. I a

To accomplish this purpose, I provide the main portion of my improved implement with an integral angle plate 7 which extends laterally slightly and upwardly from the edge of the flat body 1 at which the lateral extension 2 is located, said angle plate being located at the end of said flat body 1 opposite to the end thereof at which said lateral extension 2 is located. The angle plate 7 is arranged at an angle to the perpendicular or, in other words, to the long'axis of the tooth being radiographed, which, in Fig. 2, is the tooth T, and when the implement isin use, the angle of the plate 7 is'approximately onehalf of the angle between the film 6 and the long axis of the tooth T.

In the use of the portion of my improved implement thus far described, a film 6 is arranged in the recess or socket 5 and the end portion of the flat body 1 at which said film is supported is introduced into the patients mouth so that the film will be immediately adjacent to the tooth to be radiographed, in

which position said tooth and a correspond ingly positioned tooth of the opposite jaw will grip the flat body 1 at a point adjacent to the lateral extension 2, as shown in Fig. 2. Because of the location of the angle plate 7 on the fiat body 1, said angle plate will be located outside of the patients mouth when the implement is in use, as shown in Fig. 3, and to position the X-ray apparatus so that the ray thereof is at the proper angle with respect to the film, it is only necessary that the angle of said ray is at an approximate right angle to the plane of the angle plate 7. It is obvious, of course, that as the angle plate 7 is outside of the mouth of the patient,

it will be a simple matter to position the I Xray apparatus so that the ray projected therefrom is at the proper angle with respect to the plane of the angle plate, and, therefore, because of the slight angle between the angle plate and the. film and between the angle plate and the long axis of the tooth being radiographed, there will be no; undue.

distortion of the the film.

When my improved implement is used in making radiographs intended for use with a stereoscope, the main portion of the imple ment is used just as has been already described; that is to say, the film 6 is arranged in the recess impression of said tooth on its ends which is adapted to receive an end portion 10 of the fiat body 1, whereby said extension piece is supported by said flat body 1. The extension piece 8 is pret. erably stamped from a single piece of mate-V rial, the socket portion thereofbeing formed by integral portions which are bent to form same. ilso, the extension piece is tapered to a point at its outer end for a purpose to j be hereinafter set forth. 7

It is well known that when radiographs are made for use with a stereoscope, duplicate radiographs must be produced, and in the use of my improved implement for in layer form on the opposite faces of the flat body 1 adjacent to the position of the lateral extension 2. The end portion of the 5 and the end of the fiat body 1 at which the lateral extension 2 is arranged this purpose, a suitable plastic material 11 is arranged fiat body 1 is then arranged in the patients mouth as already explained, and in gripping said fiat body with the teeth, the patient will make impressions of the teeth in the layers of the plastic material. The extension piece or indicator 8 is then a-lined with some fixed object such, for instance, as a dental instrument 12, arranged on a suitable support, such as the shelf 18 in Fig. 3. The first radiograph is then made in the manner already described according to which the angle plate 7 is used to regulate the angle of the ray projected from the X-ray apparatus. The fiat body 1 is then removed from the patients mouth for the purpose of removing the exposed film and a new film is inserted in the recess 5, after which the end portion of the fiat body 1 is introduced in the patients mouth so that the teeth will correspond with the impressions made in the plastic compound 11 during the making of the first radiograph. The patients head, which in all probability has been moved after the making of the first radiograph, is then moved to a position where the extension piece 8 is again in alinement with the instrument 12 which, of course, has not been moved. When this has been done, it is apparent that the parts will be in the same relative positions which they were in during the making of the first radiograph, and, therefore, the second radiograph will be practically a duplicate of the first.

I have described the manner of using my improved implement in connection with teeth of the upper jaw, but it is obvious that when teeth of the lower jaw are to be radiographed, the same style implement with the recess 5 and plate 7 at slightly different angles and pointing downward, is used, the frictional grip between the portion 4 and the film being sufiicient to prevent accidental displacement of the film when the instrument is in this position. Also, it is plain that right and left instruments must be used for the opposite sides of the mouth.

In Figs. 4 and 5, I illustrate a form of my improved implement which is intended for use in anterior work. This form of the implement includes a flat body 1' adapted to be introduced into the mouth in a horizontal position and has associated with it a portion suitably bent upon itself to produce a recess or socket 5 adapted to receive a film 6. This form of the invention also includes an integral angle plate 7 which, when the implement is in use, is located outside of the patients mouth. In the use of this form of the invention, a film is arranged in the recess 5 and the flat body 1' is introduced into the patients mouth, after which the X-ray appa-- ratus is so positioned that the ray projected therefrom and which impinges on the film is at an approximate right angle to the plane of the angle plate 7. The angle plate 7' of the form of the invention shown in Figs. 4

and 5 is provided with an angularly arranged end portion 10 which is adapted to receive one of the extension pieces 8 when this form of the invention is used for making radiographs for stereoscopic purposes.

It will be noted that when my improved implement is in use, the film is held in a fiat condition and is not curved, and therefore, the likelihood that the impression will be distorted because of a curved condition of the film is eliminated.

I claim 1. A holder for a radio-sensitive film pack comprising a body portion, an element formed integral with said body portion at an end thereof, said element comprising a portion extended laterally from said body portion which is mounted at an angle with respect thereto, and a portion bent upon itself to provide a recess adapted to receive a film pack, the last mentioned portion being arranged at an angle to said body portion and to said laterally extended portion, and a plate formed integral with said body portion at a point adjacent to the end thereof opposite to that at which said element is located, said plate being mounted at an angle with respect to said body portion and to the recessed portion of said element.

2. A holder for a radio-sensitive film pack comprising a body portion, an element formed integral with said body portion at an end thereof, said element being bent upon itself to provide a recess adapted to receive a film pack and being mounted at a predetermined angle with respect to said body portion, a plate formed integral with said body portion at a pointadjacent to the end thereof opposite to that at which said element is located, said plate being mounted at an angle with respect to said body portion and to said element, and a position-indicating piece detachably supported by said body portion at the end thereof adjacent to said plate.

In testimony whereof, I have hereunto set my hand.

EDWARD S. HODGSON.

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