Dental X-ray irradiation indicating device

Abstract: A dental X-ray irradiation indicating device (19) which permits accurate indication of a location to be X-­ rayed and also permits photographing of an image substantially with the exact size. The device comprises a supporting member (11), an arm means (14) extending from the supporting member, and an indicating member (15) mounted on the arm means by way of a mounting member (16), whereby the indicating member is positioned in an opposing relationship to an intra-oral X-ray film package (6) which is held in a predetermined angular position in an oral cavity of a patient. When an intra-oral X-ray photograph is to be taken, an X-ray is irradiated with reference to the indicating member of the device.

Description: This invention relates to a dental X-ray irradiation indicating device according to the preamble of claim 1. When an X-ray photograph of a tooth is to be taken, a dental or intra-oral X-ray film package (hereinafter referred to only as film package) is positioned inside of the tooth (on the side adjacent the tongue) for an object of photographing, and an X-ray is irradiated upon the tooth from the outside. In such X-ray photographing, it is necessary to hold a film package at the specific position during photographing. A conventional supporting device for holding a film package in position is described below with reference to FIG. 1 which is a sectional view of an oral cavity in which the supporting device is used. Referring to FIG. 1, reference symbol 1a and 1b denote each a tooth, 1a₁ and 1b₁ denote each an occlusal surface, 2 denote gums, 3 a tongue, and 4 a cheek. Reference numeral 5 denotes a supporting device adapted to be bitten between the teeth 1a and 1b, and the supporting device 5 is made of a comparatively soft or flexible substance and has a shape of a parallelepiped having a rectangular cross section. Reference numeral 6 denotes a film package adhered to an end face of the supporting device 5, and 7 an X-ray film enclosed in the film package 6. The supporting device 5 and the film package 6 are initially prepared independently of each other. In preparation for X-ray photographing, the supporting device 5 is adhered to a predetermined location of the film package 6, and then the film package 6 is inserted into the oral cavity and positioned at such a position as to allow an X-ray photograph of the tooth 1a to be taken. Then, the supporting device 5 is bitten between the teeth 1a and 1b so as to hold the film package 6 at the position. An X-ray is subsequently irradiated from the outside of the cheek 4 toward the tooth 1a as indicated by an arrow mark X. Consequently, an X-ray image (latent image) of the tooth 1a is produced on the X-ray film 7. The film package 6 is then taken out of the oral cavity, and the envelope or cover of the film package 6 is torn away to take out the X-ray film 7. The X-ray film 7 is then developed and fixed to produce a visible X-ray image of the tooth 1a on the X-ray film 7. In such X-ray photographing as described above, however, it is not possible to accurately discriminate, from outside, the position of the X-ray film 7 and hence the position of the tooth 1a for an object of photographing, and it is quite impossible to discriminate the slope with which the X-ray film 7 is inclined by the gums contacting therewith. Accordingly, in conventional X-ray photographing, a photographer takes aim roughly at the position of the X-ray film 7 or the tooth 1a and directs an X-ray to the location. An X-ray image of the tooth 1a can be obtained even by such rough means because the X-ray diffuses to some degree. It is very troublesome, however, to take aim at the position of the X-ray film 7 or a tooth for an object of photographing from outside each time a photograph is to be taken. Besides, when the X-ray is stopped down in order to obtain a clearer X-ray image, mere taking aim may not permit accurate irradiation of the X-ray, and actually it is difficult to obtain a clear X-ray image. Further, normally the X-ray film 7 is inclined with respect to a vertical line interconnecting the upper and lower teeth 1a and 1b due to presence of the gums 2 as described above. In this instance, it is almost impossible to produce an image of the tooth 1a with the exact size on the X-ray film 7. There is the possibility, therefore, that the diagnosis and/or treatment depending upon the X-ray image may lack in accuracy. EP-A-0 119 300 to wich the preamble of claim 1 refers, describes a dental aiming device provided with a film holding means having a projection formed thereon, a film holder having plural indentations which are selectively fitted on the projection and an alignment ring having three bores which are selectively fitted on an aligning arm. This known dental aiming device is also complex in construction and insofar rather expensive. Moreover, it is necessary to choose one of the plural indentations, one of the three bores and the direction of the alignment ring in accordance with the tooth to be X-rayed. DE-A-30 06 608 discloses an X-ray source having a conical free end like a cone. Such an X-ray source was used several years ago. In recent years, however, a cylindrical X-ray source having a flat front face has been used predominantly. An aiming bar has aiming guides in the form of short lugs. These aiming guides are suited for an old X-ray source, but are not suitable for a cylindrical X-ray source. With the latter X-ray source, the flat front face of the X-ray source must be positioned at a right angle with respect to the lugs. However, this positioning is difficult and requires both time and labour. It is an object of the present invention to provide a dental X-ray irradiation indicating device which permits accurate indication of a location to be X-rayed. It is another object of the present invention to provide a dental X-ray irradiation indicating device which permits photographing of an image substantially with the exact size. These objects are achieved by the features of claim 1. FIG. 1 is a sectional view of part of an oral cavity in which a conventional supporting device is used; FIG. 2 is a fragmentary perspective view of a dental X-ray irradiation indicating device showing a first embodiment of the present invention; FIGS. 3(a), 3(b) and 3(c) are a perspective view, a front elevational view and a side elevational view, respectively, of an indicating member of the device shown in FIG. 2; FIG. 4 is a front elevational view of the dental X-ray irradiation indicating device shown in FIG. 2 on which the indicating member shown in FIGS. 3(a), 3(b) and 3(c) is mounted; FIG. 5(a) is a plan view of part of an oral cavity upon photographing of a tooth using the dental X-ray irradiation indicating device of FIG. 2, and FIG. 5(b) is a sectional view taken along line Vb-Vb of FIG. 5(a); FIGS. 6(a) and 6(b) are diagrammatic representations illustrating an inclination of the indicating member shown in FIGS. 3(a) to 3(c); FIGS. 7(a) and 7(b) are a front elevational view and a side elevational view, respectively, of an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device showing a second embodiment of the present invention; FIG. 8(a) is a front elevational view of an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device showing a third embodiment of the present invention, and FIGS. 8(b) and 8(c) are enlarged sectional views taken along line VIIIb-VIIIb and line VIIIc-VIIIc of FIG. 8(a), respectively, and FIG. 8(d) is an enlarged sectional view taken along line VIIId-VIIId of FIG. 8(c); FIG. 9(a) is a front elevational view of an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device showing a fourth embodiment of the present invention, and FIGS. 9(b) and 9(c) are enlarged front elevational views of pivotally connecting portions of the indicating member shown in FIG. 9(a) and FIG. 9(d) is a side elevational view of the pivotally connecting portion shown in FIG. 9(c); FIGS. 10(a) and 10(b) are a plan view and a side elevational view, respectively, showing a example of coupling structure between a supporting member and an arm; FIGS. 11, 12, 13 and 14 are plan views showing further examples of coupling structure between a supporting member and an arm; and FIG. 15(a) is a plan view of a supporting structure for a film package, and FIG. 15(b) is a side elevational view as viewed in the direction of an arrow mark XXXIVb in FIG. 15(a). Referring first to FIGS. 2 to 4, there is shown a dental X-ray irradiation indicating device according to a first embodiment of the present invention. The dental X-ray irradiation indicating device is generally denoted at 10 and includes a supporting member 11 in the form of a parallelepiped having a rectangular cross section and made of a comparatively soft material such as, for example, foamed polyethylene, sponge or rubber. The supporting member 11 has an adhering portion or face 12 for adhering a film package thereto. A bonding agent is applied to the adhering portion 12 of the supporting member 11 in advance, and when an X-ray photograph is to be taken, a film package 6 is adhered to the adhering portion 12 as shown in phantom in FIGS. 2 and 4. The supporting member 11 further has a pair of upper and lower bite faces or portions 13a and 13b adapted to be bitten by upper and lower opposing teeth when an X-ray photograph is to be taken. An arm 14 having a substantially L-shape in plan extends from the supporting member 11. The arm 14 has a portion 14a extending laterally from an end of the supporting member 11 and having a face in the common plane with a face of the supporting member 11 opposite the adhering face or portion 12, another portion 14b contiguous to the portion 14a and extending in a direction substantially perpendicular to the portion 14a, and a mounting portion 14c at the other end of the portion 14b. An indicating member 15 is removably mounted on the mounting portion 14c of the arm 14. The indicating member 15 has a generally ring-like configuration as seen in FIGS. 3(a) to 3(c). The indicating member 15 has a first indicating portion or element 15a providing a lower half of a circle, the other upper half of which is shown by a broken line in FIG. 3(b). The indicating member 15 further has a second indicating portion or element 15b providing an upper half of another circle, the other lower half of which is shown by a broken line in FIG. 3(b). A pair of parallel connecting portions or elements 15c connect the opposite ends of the first and second indicating portions 15a and 15b to each other to complete the indicating member 15. A pair of mounting members 16 are securely mounted at or near connecting portions of the indicating member 15 between the first indicating portion 15a and the connecting portions 15c and each has a rectangular through-hole 17 formed therein. The indicating member 15 is mounted on the arm 14 with the mounting portion 14c of the latter fitted in the through-hole 17 of one of the mounting members 16 thereon. Each of the mounting members 16 has a pair of opposite mounting faces 16a and 16b or 16c and 16d. It is to be noted that the mounting face 16b is opposite the mounting face 16a though not shown in any of FIGS. 2 to 4 but shown in FIG. 5(a). The first and second indicating portions 15a and 15b of the indicating member 15 are connected in an inclined relationship to each other by a predetermined angle denoted at α in FIG. 3(c). In particular, the plane defined by the second indicating portion 15b is inclined by an angle α with respect to the plane defined by the first indicating portion 15a (that is, the plane of FIG. 3(b)). It is to be noted that the angle α, which will be hereinafter described, is shown in a rather exaggerated manner in FIG. 3(c). Further, the axes of the through-holes 17 in the mounting members 16 extend perpendicularly to the plane defined by the first indicating portion 15a of the indicating member 15. A method of taking an X-ray photograph using the dental X-ray irradiation indicating device 10 of the present invention will be described subsequently with reference to FIGS. 5(a) and 5(b). When an X-ray photograph is to be taken, at first a film package 6 is mounted on the adhering portion 12 of the supporting member 11 as shown in phantom in FIG. 2 by means of a bonding agent applied to the adhering portion 12. Then, one of the mounting members 16 is selected depending upon at which location a tooth for an object of photographing is in a pair of rows of teeth, and the mounting portion 14c of the arm 14 is fitted into the through-hole 17 of the selected mounting member 16 to mount the indicating member 15 on the supporting member 11. In the case shown in FIGS. 5(a) and 5(b), the indicating member 15 is mounted such that the mounting face 16b of the upper mounting member 16 in FIG. 5(a) is fitted with the mounting portion 14c of the arm 14 with the second indicating portion 15b thereof positioned on the upper side. Where the indicating member 15 is mounted in this manner, the second indicating portion 15b thereof opposes the film package 6 and has a certain inclination with respect to the film package 6. It is to be noted that the reason of such selection of the mounting face of the mounting member 16 will become apparent from the following description. In this condition, the film package 6 is inserted into an oral cavity of a patient together with the supporting member 11. Here, in case the tooth for an object of photographing is a tooth 1a, the film package 6 is positioned inside the tooth 1a (on the side adjacent the tongue) such that a substantially central portion thereof may coincide with the tooth 1a as seen in FIGS. 5(a) and 5(b). Subsequently, the bite portions 13a and 13b of the supporting member 11 are bitten by the teeth 1a and 1b, respectively, so that the film package 6 may be held at the location. In this instance, due to presence of the gums 2, the film package 6 is held with a certain inclination with respect to a line interconnecting the teeth 1a and 1b, that is, to a vertical line D shown in a long and short dash line in FIG. 5(b) (perpendicular line to the bite portions 13a and 13b). The inclination is substantially fixed for each of a tooth for an object of photographing. It is to be noted that, though not specifically shown, the bitten portions 13a and 13b of the supporting member 11 are actually distorted a little because the supporting member 11 is made of a comparatively soft material. In the condition in which the film package 6 is held in such a manner as described above, the portion 14a of the arm 14 extends forwardly outwardly of the oral cavity and then laterally sidewardly farther than the thickness of the cheek 4. The second indicating portion 15b of the indicating member 15 is thus positioned in an opposing relationship to a substantially central portion of the film package 6 with a predetermined inclination α (about one half to the inclination of the film package 6). The arm 14 has such a configuration as to attain such positioning of the second indicating portion 15b of the indicating member 15. Subsequently, an X-ray irradiating device not shown is positioned such that an irradiating end face thereof may coincide with the plane defined by the second indicating portion 15b of the indicating member 15, and then an X-ray is emitted from the X-ray irradiating device. Thereupon, the X-ray is irradiated perpendicularly to the plane of the second indicating member 15b as indicated by a long and short dash line X in FIG. 5(b). Accordingly, an X-ray image (latent image) of the tooth 1a is produced with the substantially same size as the exact size on the X-ray film 7. The reason will be hereinafter described. After completion of X-ray irradiation, the film package 6 is taken out of the oral cavity together with the dental X-ray irradiation indicating device 10, and then the indicating member 15 is removed from the arm 14. Then, either after removal of or without removing the film package 6 from the supporting member 11, the X-ray film 7 is taken out of the film package 6, and predetermined developing and fixing operations are made for the X-ray film 7. Here, the inclination of the second indicating portion 15b of the indicating member 15 and the reason why an X-ray image of the tooth 1a is obtained with the exact size will be described with reference to diagrammatic representations of FIGS. 6(a) and 6(b). It is assumed here that the film package 6 is held with an inclination of an angle ϑ with respect to the vertical line D and the tooth 1a has a length L (length between points P₂ and P₃) in the direction of the vertical line D. If an X-ray is thus irradiated in a direction perpendicular to the vertical line D, then the points P₂ and P₃ are projected at points P₂' and P₃', respectively, on the X-ray film as shown in FIG. 6(a). The distance between the points P₂' and P₃' is given by L/cosϑ, and the dimension L/cosϑ is greater than the dimension L because cosϑ is smaller than 1. To the contrary, if an X-ray is irradiated in a direction perpendicular to the plane of the X-ray film, the points P₂ and P₃ are projected at points P₂'' and P₃'', respectively, on the X-ray film. The distance between the points P₂'' and P₃'' is given by L·cosϑ, and the dimension L·cosϑ is smaller than the dimension L because cosϑ is smaller than 1. In this manner, where the film package 6 is held in an inclined position, if an X-ray is irradiated in a direction perpendicular to the vertical line D or to the plane of the X-ray film, an X-ray image of the exact size of a tooth cannot be obtained. Here, means will be examined for obtaining an X-ray image of the exact size of a tooth. To this end, a line E is considered which has an inclination angle equal to one half of the inclination angle ϑ of the film package 6 as shown in FIG. 6(b). An X-ray is thus irradiated in a direction perpendicular to the line E. Consequently, the points P₂ and P₃ are projected at points P₂''' and P₃''' on the X-ray film. In this condition, the triangle P₁, P₃, P₃''' defined by a point of intersection between the vertical line D and an extension line of the film package 6 and the points P₃ and P₃''' is an isosceles triangle. Accordingly, the dimension between the points P₂''' and P₃''' is equal to the dimension L between the points P₂ and P₃. After all, where the film package 6 is held in an inclined position, if an X-ray is irradiated in a direction perpendicular to a line or plane having an inclination angle equal to one half of the inclination angle of the film package 6, then an X-ray image of a tooth can be obtained with the exact size. The one half inclination angle corresponds to the angle α shown in FIG. 3(c). The film package 6 is described held in an inclined position in the foregoing description. Actually, however, the dimensions of various portions of an oral cavity and configurations of rows of teeth and gums are different to some degree among individuals so that the film package 6 may not be inclined but remain in a vertical position. In this instance, if the mounting member 16 is selectively mounted at the mounting portion 14c of the arm 14 such that the first indicating portion 15a may oppose the film package 6, then the plane thereof is parallel to the plane of the film package 6. Accordingly, if X-ray photographing is conducted with the irradiating end face of the X-ray irradiating device held in the plane of the first indicating portion 15a of the indicating member 15, then an X-ray image of a tooth is obtained with the exact size on the X-ray film 7. Generally, the inclination of the film package 6 substantially depends upon a location of a tooth for an object of photographing in a pair of rows of teeth. Description is given here of mounting of the film package 6 at the mounting portion 14c of the arm 14 when X-ray photographing of teeth at various locations in the rows of the teeth is to be effected. Selections of the mounting faces 16a to 16d of the mounting members 16 and the first and second indicating portions 15a and 15b are given below. i. Left upper jaw ..... select mounting face 16b with indicating portion 15b positioned upwardly (inclined); select mounting face 16d with indicating portion 15a positioned upwardly (not inclined). ii. Left lower jaw ..... select mounting face 16d with indicating portion 15b positioned downwardly (inclined); select mounting face 16b with indicating portion 15a positioned downwardly (not inclined). iii. Right upper jaw ..... select mounting face 16d with indicating portion 15b positioned upwardly (inclined); select mounting face 16b with indicating portion 15a positioned upwardly (not inclined). iv. Left lower jaw ..... select mounting face 16b with indicating portion 15b positioned downwardly (inclined); select mounting face 16d with indicating portion 15a positioned downwardly (not inclined). v. Front upper jaw ..... select mounting face 16b or 16d with indicating portion 15b positioned upwardly (inclined); select mounting face 16b or 16d with indicating portion 15a positioned upwardly (not inclined). vi. Front lower jaw ..... select mounting face 16b or 16d with indicating portion 15b positioned downwardly (inclined); select mounting face 16b or 16d with indicating portion 15a positioned downwardly (not inclined). In this manner, X-ray photographing of all teeth is covered by combinations of the first and second indicating portions 15a and 15b and the four mounting faces 16a to 16d of the mounting members 16. As can be seen from the foregoing description, according to the present embodiment, the indicating member is mounted at the end of the arm extending from the supporting member in an opposing relationship to a film package by way of a selected one of combinations of the first and second indicating portions and the four mounting faces of the two mounting members. In this instance, when the film package is in a vertical plane, the indicating member is disposed in parallel to the vertical plane of the film package, but when the film package is in an inclined plane, the indicating member is disposed with an inclination equal to one half of the inclination of the plane of the film package. Accordingly, irradiation of an X-ray can be made readily and accurately and an X-ray image of a tooth can be obtained with the exact size, which will assure an accurate diagnosis and treatment. Referring now to FIGS. 7(a) and 7(b), there are shown an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device according to a second embodiment of the present invention. It is to be noted that like parts or elements are denoted by like reference symbols to those of the first embodiment shown in FIGS. 2 to 4, and overlapping description thereof is omitted herein to avoid redundancy (this also applies to the following description of various embodiments and modifications of the present invention). The indicating member denoted at 15 of the dental X-ray irradiation indicating device shown has a pair of projections 20 mounted thereon at or near connecting portions between a first indicating portion 15a and a pair of connecting members 15c thereof. A guide plate 21 in the form of a flat plate is secured to an end of each of the projections 20 and extends with substantially equal spans in the opposite directions from the end of the projection 20. Meanwhile, each of a pair of mounting members 16 has a pair of L-shaped holding pieces 22 formed at a pair of upper and lower ends of a side face thereof, and a slot 23 is thus defined by the side face and the holding pieces 22 of the mounting member 16. The mounting plate 16 can thus be mounted readily on the indicating member 15 by fitting one of the guide plates 21 into the slot 23 thereof and can be adjusted relative to the indicating member 15 by slidably moving the guide plate 21 in the slot 23 thereof. The conditions of the gums, rows of teeth, lips, cheeks and so on are different to some degree among individuals as described hereinabove. Due to such differences, the position of the mounting portion 14c of the arm 14 (refer to FIGS. 2 to 4) when the supporting member 11 is held in a bitten condition in an oral cavity in order to effect X-ray photographing is different more or less among individuals. Further, even with a same person, the position of the mounting portion 14c of the arm 14 may be different more or less depending upon a tooth for an object of photographing. There is the possibility, therefore, that, when a mounting member 16 is mounted on the mounting portion 14c of the arm 14, the indicating member 15 may be contacted with and distorted by an outer face of a cheek. Such distortion will cause failure in accurate photographing. According to the present embodiment, however, since the mounting member 16 can be slidably moved back and forth on the guide plate 21 relative to the indicating member 15, where there is the possibility that the indicating member 15 may be contacted with a cheek, the indicating member 15 can be positioned in a spaced relationship from the cheek by slidably displacing the mounting member 16 toward the cheek and mounting the thus adjusted mounting member 16 at the mounting portion 14c of the arm 14. The distance between the indicating member 15 and the cheek can also be adjusted suitably by such sliding displacement of the mounting member 16 on the guide plate 21. It is to be noted that, while in the present embodiment the guide plates 21 are mounted on the indicating member 15 side and the slots for receiving the guide plates 21 therein are formed in the mounting bodies 16, the mounting members 16 may be secured reversely to ends of guide plates while guide slots or guide holes for receiving the guide plates therein are formed in the indicating member 15. In this manner, according to the present embodiment, since the mounting members can be displaced in the forward and backward directions with respect to the indicating member, not only similar effects to those of the preceding first embodiment can be anticipated, but also the indicating member can be held in a suitably spaced relationship from an outer face of a cheek. Referring now to FIGS. 8(a) to 8(d), there are shown an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device according to a third embodiment of the present invention. The indicating member 15 of the dental X-ray irradiation indicating device shown has a pair of mounting plates 25 mounted thereon at or near connecting portions between a first indicating portion 15a and a pair of connecting portions 15c thereof. A pin 26 is implanted on each of the mounting plates 25, and a pivotal member 27 is mounted for pivotal motion on the pin 27. The pivotal member 26 has a mounting member 16 secured to an end thereof. In FIG. 8(a), the left-hand side pivotal member 27 is shown in its horizontal position while the right-hand side pivotal member 27 is shown in its upwardly pivoted position. Each of the mounting plates 25 has, as particularly seen in FIGS. 8(c) and 8(d), up to four grooves 29a, 29b, 29c and 29d formed in vertical and horizontal directions in an angularly spaced relationship by 90 degrees in a wall thereof. The pin 26 is provided at a crossing location of the grooves 29a to 29d on the mounting plate 25 and has an enlarged head portion 26a formed at an end thereof and a diametrical slit 26b formed therein. Meanwhile, each of the pivotal plates 27 has a projection 28 provided at a location thereon near a hole in which the pin 26 is fitted. In order to fit a pivotal member 27 onto a pin 26, the pivotal member 27 is pressed at the hole thereof strongly against the pin 26. Consequently, the pin 26 is distorted to reduce the slit 26b thereof so that the diameter of the enlarged head portion 26a is reduced to allow the pin 26 to be fitted into the hole of the pivotal member 27. After the pivotal member 27 is fitted onto the pin 26, the pin 26 is restored to its original shape expanding the slit 26b to expand the enlarged head portion 26a. Consequently, the pivotal member 27 is thereafter prevented from coming off from the pin 26. If the pivotal member 27 is pivoted in this condition, the projection 28 thereon will slidably move on a surface of the mounting plate 25 until it is fitted into one of the grooves 29a to 29d in the mounting plate 25, but if the pivotal member 27 is pivoted further, the projection 28 thereon will be removed from the one groove and then fitted into an adjacent next one of the grooves 29a to 29d. With the projection 28 thus fitted in one of the grooves 29a to 29d, the pivotal member 27 is retained at the position. The dental X-ray irradiation indicating device of the present embodiment can prevent possible contact of the indicating member 15 with a cheek similarly as in the preceding embodiment. In particular, when X-ray photographing is to be effected, one of the pivotal members 27 to which the mounting member 16 to be mounted at the mounting portion 14c of the arm 14 is secured is pivoted until the projection 28 thereon is fitted into the groove 29a or 29d of the mounting plate 25 to retain the pivotal member 27 at its horizontal position. The mounting member 16 is then mounted onto the mounting portion 14c of the arm 14. As a result, the indicating member 15 can be held at a position spaced from an outer face of a cheek. In this manner, according to the present embodiment, since the pivotal members are mounted for pivotal motion on the indicating member and the mounting members are secured to ends of the pivotal members, not only similar effects to those of the second embodiment can be attained, but also the pivotal members and the mounting members can be prevented from interfering with some other elements upon photographing or upon storage of the indicating member if an unnecessary one of the pivotal members is retained at the upwardly pivoted position. Referring to FIGS. 9(a) to 9(d), there are shown an indicating member and a mounting structure for the same of a dental X-ray irradiation indicating device according to a fourth embodiment of the present invention. The indicating member denoted at 15' of the dental X-ray irradiation indicating device shown corresponds to the indicating member 15 of the first to third embodiments described hereinabove. The indicating member 15' of the present embodiment is different from the indicating member 15 of the preceding embodiments in that a first indicating portion 15a and a pair of connecting members 15c thereof are coupled to each other by a pair of pivotally connecting means 31 and 32. The pivotally connecting means 31 includes, as shown in FIG. 9(b), a plate-formed member 31c secured to or molded in an integral relationship with one of the connecting members 15c, another plate-formed member 31a secured to or molded in an integral relationship with one end of the first indicating portion 15a, and a pin 31p for connecting the plate-formed members 31c and 31a for pivotal motion relative to to each other. Meanwhile, the other pivotally connecting means 32 includes, as shown in FIG. 9(c), a plate-formed member 32c secured to or molded in an integral relationship on the other connecting member 15c, another plate-formed member 32a secured to or molded in an integral relationship on the other end of the first indicating portion 15a, and a screw 32b for securing the plate-formed members 32c and 32a to each other. A nut 32n is secured to the end of the screw 32b. The plate-formed member 32c has a mark 33a applied at an end portion thereof while several graduations 33b are applied to the other plate-formed member 32a of the pivotally connecting means 32 in an opposing relationship to the mark 33a as shown in FIG. 9(d). Since the conditions of the oral cavity are different to some degree among individuals as described hereinabove, when the supporting member 11 is bitten and held in the oral cavity and the indicating member 15 is mounted on one of the mounting members 16 at the mounting portion 14c of the arm 14 thereof, the plane defined by the first and second indicating portions 15a and 15b may not always be inclined by an angle equal to one half of such an inclination angle ϑ of the film package 6 as shown in FIG. 6(b). In such an instance, there is the possibility that a desired degree of accuracy may not always be attained in X-ray photographing. In the present embodiment, however, the inclination of the indicating member 15 can be adjusted readily in such an instance. In particular, if the screw 32b of the pivotally connecting portion 32 is loosened, then a pivotal motion of the plate-formed members 32c and 32a relative to each other (a pivotal motion between the first indicating member 15a and the connecting member 15c) is permitted. Meanwhile, the pivotally connecting means 31 always permits a pivotal motion between the plate-formed members 31c and 31a. Accordingly, the angle between the first and second indicating portions 15a and 15b can now be changed freely. A change of the angle can be discriminated from the mark 33a and the graduations 33b of the pivotally connecting means 32. After a desired plane is obtained by such pivotal motion between the first and second indicating portions 15a and 15b, the screw 32b is tightened to fix the plate-formed members 32c and 32a relative to each other, and in this condition, X-ray photographing is conducted. In this manner, according to the present embodiment, since the pivotal means are interposed between the first indicating portion and the connecting portions, an effect can be exhibited, in addition to the effects of the first embodiment described hereinabove, that the inclination of the plane of the indicating member can be adjusted. Referring now to FIGS. 10(a) and 10(b), there is shown a example of coupling structure between a supporting member and an arm. The coupling structure shown includes a supporting member 131 composed of a single member 132. The member 132 has a pair of bitten portions or faces 132a and 132b, and an adhering face 132c for a film package 6. The member 132 further has a bonding agent layer 132d applied to a face thereof opposite the adhering face 132c. The coupling structure further includes an arm 134 formed as a unitary member composed of a portion 134a extending from the supporting member 131, another portion 134b contiguous to the portion 134a and extending substantially in a direction perpendicular to the portion 134a, and a plate-formed portion 134d adhered to the bonding agent layer 132d of the member 132 of the supporting member 131. It is to be noted that a portion of the arm 134 at which an indicating member is to be mounted on the arm 134 is omitted in FIGS. 10(a) and 10(b) (this also applies to the following examples of coupling structure). With the present coupling structure, since the plate-formed portion of the arm is adhered to the side face of the supporting member, such an effect can be attained that a pair of bitten faces or portions can be assured at upper and lower portions of the supporting member. FIG. 11 shows an example of coupling structure between a supporting member and an arm. Referring to FIG. 11, the coupling structure shown includes a supporting member 141 composed of a single member 142. The member 142 has a bitten portion or face 142a and another bitten portion or face not shown, and an adhering face 142c for a film package 6. The member 142 further has a bonding agent layer 142d applied to a face thereof perpendicular to the adhering face 142c. The coupling structure further includes an arm 144 formed as a unitary member composed of a portion 144a extending from the supporting member 141, another portion 144b contiguous to the portion 144a and extending substantially in a direction perpendicular to the portion 144a, and a plate-formed portion 144d adhered to the bonding agent layer 142d of the member 142 of the supporting member 141. Comparing with the coupling structure shown in FIGS. 10(a) and 10(b), the present coupling structure is different in location of the face of the member 142 of the supporting member 141 to which the plate-formed portion 144d of the arm 144 is adhered. The present coupling structure thus presents similar effects to those of the seventh coupling structure. Referring now to FIG. 12, there is shown a example of coupling structure between a supporting member and an arm. The coupling structure shown includes a supporting member 151 composed of a single member 152. The member 152 has a bitten portion or face 152a and another bitten portion or face not shown, and an adhering face 152c for a film package 6. The member 152 further has a bonding agent layer 152d applied to a face thereof perpendicular to the adhering face 152c. The coupling structure further includes an arm 154 formed as a unitary member composed of a portion 154a extending from the supporting member 151, another portion 154b contiguous to the portion 154a and extending substantially in a direction perpendicular to the portion 154a, and a plate-formed portion 154d adhered to the bonding agent layer 152d of the member 152 of the supporting member 151. Comparing with the coupling structure shown in FIG. 11, the present coupling structure is different in that the face of the member 152 of the supporting member 151 to which the plate-formed portion 154d of the arm 154 is secured is located at the opposite position to that in the coupling structure of Fig. 11 and the portion 154a of the arm 154 extends on and across a face of the member 152 of the supporting member 151 opposite the adhering face 152c. The present coupling structure thus presents similar effects to those of the eighth coupling structure. Referring now to FIG. 13, there is shown a example of coupling structure between a supporting member and an arm. The coupling structure shown includes a supporting member 151' composed of a single member 152. The supporting member 151' is different from the supporting member 151 of the coupling structure shown in FIG. 12 in that it has an additional second bonding agent layer 152d' applied to a face thereof opposing an adhering face 152c thereof. An arm 154' of the present coupling structure is also different from the arm 154 of the coupling structure shown in FIG. 12 in that it has a second plate-formed portion 154d' contiguous to a first plate-formed portion 154d thereof and extending substantially in a direction perpendicular to the first plate-formed portion 154d. The second plate-formed portion 154d' of the arm 154' is adhered to the bonding agent layer 152d of the member 152 of the supporting member 151'. With the present coupling structure, since the second plate-formed portion is adhered to the second bonding agent layer, similar effects to those of the coupling structure of Fig. 12 can be attained, and besides such an effect can be anticipated that fixation between the supporting member and the arm is further assured. Referring now to FIG. 14, there is shown an example of coupling structure between a supporting member and an arm. The coupling structure shown includes a supporting member 161 composed of a single member 162 having a bitten portion or face 162a. The member 162 further has a bonding agent layer 162d applied to a side face thereof. An arm 164 of the coupling structure is composed of a portion 164a extending from the supporting member 161, another portion 164b contiguous to the portion 164a and extending substantially in a direction perpendicular to the portion 164a, a plate-formed portion 164d adhered to the bonding agent layer 162d of the supporting member 161, and a bonding agent layer 164e applied to the plate-formed portion 164d. A film package 6 is adapted to be applied to the bonding agent layer 164e of the arm 164. The present coupling structure also presents similar effects to those of the coupling structure shown in FIGS. 10(a) and 10(b). It is to be noted that, while in any of the coupling structures two portions interconnecting the opposite end portions of the arm are described each in the form of a bar-like member having a rectangular cross section, they need not have such a specific cross section and may have some other cross section such as, for example, an X-shaped cross section so that they may have an increased strength. Further, the material of the arm is not limited to a synthetic resin and may otherwise be a metal or some other suitable material. In the following, an example of structure for supporting a film package on a supporting member will be described with reference to FIGS. 15(a) and 15(b). A film package 6 is enclosed in an envelope 6'. The envelope 6' is made of a softer material than that of an outer package member or cover of the film package 6. Such an outer package member of the film package 6 is limited in flexibility due to the necessity for interruption of light and also for protection of an X-ray film. Therefore, when the film package 6 is inserted into an oral cavity, it will in most cases give a disagreeable feeling to the patient due to lack in flexibility. Besides, upon X-ray photographing, saliva will always apply to the film package 6. Upon processing after such photographing, the saliva on the film package 6 may apply to the dentist, which will give a disagreeable feeling to the dentist and besides is not preferable for sanitation. From those reasons, in most cases a film package 6 is enclosed in an envelope 6' made of a very flexible material and inserted in this condition into an oral cavity of a patient. A bonding agent layer 170 is applied to an adhering portion or face 12 of a supporting member 11. A supporting element 171 for supporting an envelope 6' and a film package 6 in the envelope 6' thereon is formed separately from the supporting member 11 and applied to the bonding agent layer 170 of the supporting member 11. The supporting element 171 is composed of a U-shaped member 171a made of a synthetic resin having a suitable elasticity. The U-shaped member 171a has a wall 171b adapted to be applied to the bonding agent layer 170 of the supporting member 11, and a supporting portion 171c for cooperating with the wall 171b to hold therebetween an envelope 6' and a film package 6 in the envelope 6'. When X-ray photographing is to be conducted using a film package 6 enclosed in an envelope 6', the wall 171b of the supporting element 171 is applied to the adhering portion 12 of the arm 11 to which the film package 6 is to be primarily adhered. Consequently, the supporting element 171 is secured to the supporting member 11. The envelope 6' in which the film package 6 is enclosed is subsequently inserted into the supporting portion 171c of the supporting element 171. Since the U-shaped member 171a of the supporting element 171 has a suitable elasticity, the envelope 6' inserted in this manner is held firmly by the supporting portion 171c of the supporting element 171 so that the film package 6 is supported with certainty on the supporting element 171. If such a flexible envelope 6' is otherwise applied directly to the adhering portion 12 of the supporting member 11, it is impossible to support the film package 6 in the flexible envelope 6' at a fixed location. To the contrary, in the case of the present structure in which the supporting element 171 is used, while the film package 6 is enclosed in the envelope 6', it is supported fixedly on the supporting member 11 in a similar condition as it is applied directly to the adhering portion 12 of the supporting member 11. Accordingly, X-ray photographing can be conducted without any trouble. It is to be noted that while in the supporting structure the supporting element is described composed of a U-shaped member, it may have any other configuration only if a film package or an envelope enclosed in an envelope can be fixed firmly thereto. Further, while the supporting member and the arm are shown formed as a unitary member, they may otherwise be formed as separate members. Meanwhile, naturally a film package 6 may otherwise be adhered directly to the supporting element 171. Various embodiments of the present invention have been described so far. While in any of the embodiments coupling between an end portion of an arm and a mounting member is described provided by a projection and a hole for receiving the projection therein, it may be provided by any other means. Further, while an indicating member is described formed either as a ring or as a substantially circular plate member, it is not limited to the specific members and may be a member of any other configuration only if it is made of a material which transmits an X-ray therethrough. For example, plate members of various configurations, plate members in which openings of various shapes are formed and cross-shaped bar members may be used for the indicating member. As apparent from the foregoing description, according to the present invention, a dental X-ray irradiation indicating device comprises a supporting member, an arm means extending from the supporting member, and an indicating member mounted on the arm means by way of a mounting member, whereby the indicating member is positioned in an opposing relationship to an intra-oral X-ray film package which is held in a predetermined angular position in an oral cavity of a patient. Therefore, it is only necessary to irradiate an X-ray with reference to the indicating member. Accordingly, irradiation of an X-ray can be effected readily and accurately with a simple construction. Besides, an X-ray image of an object of photographing can be obtained with a substantially same size on an X-ray film.

Claims: A device (10) for holding an intra-oral X-ray film package in an oral cavity of a patient, comprising: a supporting member (11, 161, 171) having a film fixing portion (12) to which an intra-oral X-ray film package (6) is to be fixed and a bite portion means (13, 162) for being held by the teeth of the patient; a substantially L-shaped arm means (14, 164) extending from said supporting member (11, 161, 171) and oriented outwards of the oral cavity when said bite portion means (13, 162) is held by the teeth; an indicating member (15) including a first indicating portion (15a) defining a first plane, normal to which irradiating X-rays are to be directed, a connecting portion (15c) and two mounting structures (16) fixed at or near the connecting portion (15c) and at or near said indicating portion (15a), said mounting structures (16) being adapted to removably mount said indicating member (15) on said arm means (14) selectively in a predetermined first orientation or in a second orientation corresponding to a mirror image with respect to the first orientation, whereby said first plane extends in parallel with the plane of the film package (6) to be mounted in the film fixing portion (12) of the supporting member (11) when said indicating member (15) has been mounted on said arm means (14, 164) in the predetermined first orientation or in said second orientation by said mounting structures (16), characterized in that said indicating member (15) further includes a second indicating portion (15b) defining a second plane, the normal of which represents an alternative direction for applying said X-rays, which second plane extends at a predetermined angle (α) with respect to said first plane wherein the film package (6) is tiltable with respect to the supporting member (11) so as to be substantially parallel to said second plane for allowing an X-ray image to be taken also in those portions of the oral cavity where the gums interfere with an non-tilted position of the film package (6). Device according to claim 1, wherein the arm means (14) is formed integrally with the supporting member (11). Device according to claim 1, wherein the arm means (164) has a first face (164d) for being fixed to a fixing portion (162d) of the supporting member (161), a second face (164e) to which an intra-oral X-ray film package (6) is to be fixed, and an arm portion (164b) which extends outwardly of an oral cavity when the first face of the arm means is fixed to the fixing portion (162d) of the supporting member and the bite portion (162a) of the supporting member is held by the teeth of the patient. Device according to claim 1 or 2, wherein the supporting member (11) has an adhering portion (12) to which a layer of a bonding agent (170) is applied and a support element (171) is provided having an adhering face (171b) for being adhered to the adhering portion (12) of the supporting member (11) and a supporting portion (171c) for supporting the intra-oral X-ray film package (6) thereon. Device according to claim 4, wherein the support element (171) is a holding member (171a) having a U-shaped cross section.

Inventors: TANAKA HIROYUKI, TANAKA, HIROYUKI
Applicants: NIX CO LTD, NIX COMPANY LTD.
Application year: 1988
Main classification: A61B6
IPC codes: G03B42