JPH0621445Y2 - Dental panoramic X-ray equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a dental panoramic X-ray imaging apparatus, and more specifically, it allows the dental arch of a patient and the X-ray tomographic region to be matched accurately and promptly and to the jaw. The present invention relates to a new dental panoramic X-ray imaging apparatus capable of appropriately switching to joint imaging.

(Prior Art) In a dental panoramic X-ray imaging apparatus, it is highly accurate to match a tomographic region (namely, dental arch) of a patient with a tomographic region (hereinafter simply referred to as a tomographic region) of the device. It is extremely important for performing panoramic X-ray photography. Therefore, preparatory work is required to place the patient in the proper position before imaging. Conventionally, the positioning to the proper position is performed by manually or electrically moving the patient holding device or the tomographic forming mechanism using an indicating means such as a gauge, a bite block, or a light beam. The judgment was made by the operator's vision.

For the purpose of diversifying recent diagnostic information, a panoramic radiographing device having a temporomandibular joint division (hereinafter abbreviated as TMJ) radiographing function has been developed and put into practical use.

(Problems to be solved by the device) However, in the positioning of the dental arch and the fault area by the operator's vision as described above, an error due to the operator's parallax or the like is likely to occur, and particularly such positioning is performed in the front tooth portion. Generally, the width of the fault area with the anterior tooth as the dental arch is several mm.
Due to the degree, it is very difficult to match the front tooth portion with this width, and considerable skill and experience are required. Moreover,
If such positioning is incomplete, the accuracy on the film on which the image is taken deteriorates, and in the worst case, re-imaging is necessary and the patient is forced to be exposed to unnecessary X-rays. Therefore, development of a simple and rational method for this positioning has been strongly desired.

The above T. M. In a device that also has a J shooting function, M. When performing J. J. imaging, the relative positional relationship between the horizontal swivel arm of the tomographic forming mechanism and the patient's dental arch is determined by T.J. M. It is necessary to set each time so that it is appropriate for J imaging, but in such a conventional device, the operator himself moves to a predetermined position manually (including a case where an electric mechanism is included). However, there was still room for improvement in terms of operability and accuracy. Furthermore, the incident angle of X-rays on the temporomandibular joint is only one type, and it is undeniable that there is insufficient in obtaining accurate diagnostic information such as temporomandibular joint disease.

The present invention has been made in view of the above, and enables accurate and quick positioning of the patient's dental arch and the X-ray tomographic region in panoramic radiography, and at the same time, T.S. M. A new dental panorama X that enables easy and accurate switching of J radiographs and systematically integrates these to obtain various diagnostic information related to dental treatment quickly and with high accuracy.
The purpose is to provide a radiographic device.

(Means for Solving the Problems) The structure of the present invention for achieving the above object will be described with reference to the accompanying drawings.

The dental panoramic X-ray imaging apparatus of the present invention comprises a panoramic X-ray imaging apparatus main body 1, a horizontal swing arm 21 supported by the main body 1 so as to be horizontally rotatable, and an X-axis supported at opposite ends of the arm 21. Line generator 22 and film cassette 23
In a dental panoramic X-ray imaging apparatus including a tomographic forming mechanism 2 including a tomography apparatus and a patient holding apparatus 3 arranged between the X-ray generator 22 and the film cassette 23, the panoramic X-ray imaging apparatus is A position detection sensor 4 for detecting the relative position of the patient's dental arch T held by the patient holding device 3 with respect to the device body 1, and a front-back position detection for moving the tomographic forming mechanism 2 and / or the patient holding device 3 back and forth. Means 4 '
A moving mechanism 50 including a moving mechanism 50, and a temporomandibular joint imaging selecting means 6 for outputting a radiographic position data signal for moving the tomographic forming mechanism 2 and / or the patient holding device 3 to a position suitable for temporomandibular joint imaging by a selection operation. (Hereinafter, referred to as TMJ photographing selection means 6), comparison data of the detection position data by the sensor 4 and relative position data of the tomographic region P with respect to the apparatus main body 1, and the actual position by the front and rear position detection means 4 '. Data and T. M. A drive circuit 5 for operating the moving mechanism 50 based on the selected data from the comparison data with the photographing position data from the J photographing selection means 6;
The above T. M. The X-ray generator 22 is driven by the T.J. M. The X-ray irradiation control means 7 is turned on and off so as to match a predetermined mode suitable for J imaging.

The dental panoramic X-ray imaging apparatus which is the subject of the present invention includes a pillar 11, a panoramic X-ray imaging apparatus main body 1 mounted on the pillar 11 so that the vertical position of the panoramic X-ray imaging apparatus can be freely adjusted, and the panoramic X-ray imaging apparatus can be horizontally swung by the main body 1. And a patient holding device 3 arranged in the turning trajectory of the tomographic forming mechanism 2.

The fault forming mechanism 2 includes the horizontal swing arm 21 as described above,
The arm 21 includes an X-ray generator 22 and a film cassette 23 provided at opposite ends of the arm 21 in a facing relationship, and a swivel drive mechanism 24 for swiveling the arm 21 into a shape along the patient's dental arch T. The X-ray generator 22 and the film cassette 23 are rotated along a dental arch T of the patient placed on the patient holding device 3 so as to draw a substantially elliptical locus, thereby performing curved surface tomography of the dental arch on the film. It is something to do. The turning drive mechanism 24 is configured to cause the horizontal turning arm 21 to draw such a substantially elliptical locus, and various conventionally known mechanisms are adopted.

The sensor 4 detects the position of the patient's head held by the patient holding device 3 and outputs relative position data of the patient's dental arch T with respect to a virtual reference position O in the panoramic X-ray imaging apparatus. . The sensor 4 is installed at an appropriate position on the patient midline outside the turning trajectory of the apparatus body 1, the tomographic forming mechanism 2 itself or the tomographic forming mechanism 2. The sensor 4 is an optical sensor that detects reflected light such as visible light, laser light, and infrared light emitted to the patient's dentition (anterior teeth or canines), lips or cheeks, etc. Distance sensors, ultrasonic distance sensors, or optical phase difference detection sensors are used. The reference position O can be provided at any fixed part of the device, but the position that intersects with the patient midline of the device body 1 is most appropriate.

The tomographic region P is a region where X-ray tomography is performed along the patient's dental arch T by the tomographic forming mechanism 2. As the fault area P, in addition to the one fixedly set in the apparatus, many morphologies of dental arches are statistically aggregated, some typical models are created from the aggregated data, and these are described below. A circuit is used which is input in advance to the comparison operation circuit 8 and selectively outputs it to compare it with the detection data from the sensor 4.
That is, in the former case, the difference value between the detection position data of the sensor 4 and the position data of the tomographic region P is directly input to the drive circuit 5, whereby the tomographic formation mechanism 2 and / or the patient holding device 3 moves to an appropriate position. To be done. In the latter case, the operator looks at the morphology of the patient's dentition and selects an appropriate model from the above models (selection of the keyboard of the microprocessor 82 described below), and the selected tomographic region P and the sensor 1 are used. The patient is positioned by comparing and calculating the detected data.

The drive circuit 5 receives a command from the sensor 4 or the comparison calculation circuit 8 and moves the tomographic formation mechanism 2 and / or the patient holding device 3 to an appropriate position to substantially align the tomographic region P with the dental arch T. Emits a signal for That is, the drive circuit 5
Is connected to a moving mechanism 50 including a driving means (an example of a driving mechanism by a motor is shown in the figure) 500 such as a motor (including a linear motor) or a solenoid. And / or patient support device 3
Will be the main body to move the. In this case, it is most desirable to introduce the command from the drive circuit 5 directly into the moving mechanism 50 to automatically operate the moving mechanism 50, but to operate manually by way of a manual ON / OFF circuit or the like. It is also possible to do it.

The relative position data is compared by the comparison operation circuit 8, and the output data from the comparison operation circuit 8 is input to the drive circuit 5 to input the tomographic formation mechanism 2 and / or the patient support device 3.
It is desirable to move back and forth. The comparison operation circuit 8 is arranged to detect the electric signal from the sensor 4 and the tomographic region P.
Of the relative position data with respect to the reference position O, the deviation between the dental arch T and the tomographic region P should be calculated, and the patient holding device 3 or the tomographic forming mechanism 2 should be moved in which direction and to what extent. To judge. Yi, T. M. By the J photographing selection means 6, the T. M. When the J shooting mode is selected, the T.S. M. The position data appropriate for the J imaging mode is compared with the actual position data of the anterior-posterior position detecting means 4'provided in the tomographic forming mechanism 2 and / or the patient holding device 3 to calculate the deviation, and the patient holding device is the same as above. 3 or to which direction and to what extent the tomographic forming mechanism 2 should be moved, and the comparison data is output and input to the drive circuit 5. As the comparison operation circuit 8 as described above,
As shown in the figure, A / D conversion stage 81 and microprocessor 8
In addition to the combination of 2 and, an analog calculation type, or a type that controls by phase detection is adopted.
It is also possible to preliminarily input the position data of the tomographic region P to the comparison calculation circuit 8 in performing the comparison calculation in the comparison calculation circuit 8, but it is possible to perform the comparison calculation from the reference distance data generation circuit 80 described later. It is also possible to receive the command and input the above-mentioned data to the comparison operation circuit 8 each time.

The reference distance data generation circuit 80 mainly functions as a central command circuit for issuing the operation command of the comparison calculation circuit 8 and the drive circuit 5 in addition to inputting the position data of the tomographic region P to the comparison calculation circuit 8 as described above. Further, the shape, size and other shape characteristics (individual difference) of the patient's dental arch are detected and the detection position of the sensor 4 is adjusted in advance based on this detection information, or the comparison operation circuit 8 compares the detected position. It also has a function of inputting reference data for calculation / judgment to the comparison calculation circuit 8 and inputting reference data of an appropriate movement amount of the moving mechanism 50 by the drive circuit 5 to the drive circuit 5. Further, it is possible to incorporate a circuit capable of inputting data for adjusting the shape of the tomographic region P drawn by the tomographic forming mechanism 2 in advance so as to match the shape of the dental arch T or the like. Furthermore, reference data (for example, the front-back position coefficient of the patient holding device 3 and the tomographic forming mechanism 2) is previously input to the reference distance data generation circuit 80, and the reference distance data generation circuit is started before the positioning operation is started. Based on the information output from 80, tomography is performed in any of the dental region, the otolaryngology region, and the oral surgery region, and the patient dentition has a standard dentition or an anterior projecting dentition (the anterior teeth projecting). It is also possible that the circuit can be set in advance to a condition according to the imaging mode of those circuits.
The various functions of the reference distance data generating circuit 80 are, specifically, a position where the reference position of the tomographic region P substantially coincides with the position of the patient's dental arch T according to each condition and / or a little before and after. It means that the position is set to have a shift of. Further, as the reference distance data generation circuit 80,
The analog type is such that the variable resistance taps are switched, and the digital type is such that the data stored in the memory is selectively called.

Further, if the position detection sensor 4 is provided with the sensing position changing means 40, the positioning can be performed with higher accuracy. The sensing position changing means 40 is configured so that even if there is an individual difference in the patient's head held by the patient holding device 3 (for example, an adult and a child, or a person with a large jaw and a person with a small jaw).
The detection by the sensor 4 is performed accurately. That is, as the sensing position varying means 40, the vertical position of the sensor 4 is adjusted (see FIGS. 16 to 19) or the orientation angle of the sensor 4 is variably adjusted (see FIGS. 20 to 21). (See) is mainly adopted. However, the present invention is not limited to this. For example, in an optical sensor, a plurality of pairs of a light emitting unit and a light receiving unit are vertically arranged, and one of these pairs is selected by dial operation (a pair that matches the detection target site). The variable means 40 is also included in the concept of the variable means 40.

The above T. M. The J-imaging selection unit 6 causes the tomographic forming mechanism 2 and / or the patient holding device 3 to perform a T.S.
M. Although it is intended to automatically move to an appropriate position for J imaging, it is also possible to provide a selection mode of various X-ray incident angles with respect to the temporomandibular joint. This is because, as will be described in detail below, the diseased site of the temporomandibular joint varies depending on the patient, and if the X-ray incidence angle is variable, more accurate diagnostic information on this diseased site can be obtained.

The X-ray irradiation control means 7 is the same as the T. M. The X-ray generator 22 is driven by the T.J. M. It is turned on and off so as to match a predetermined mode suitable for J shooting. More specifically, this is described in T.W. M.
In the J-imaging, only the left and right temporomandibular joint parts are imaged on the film cassette 23 as the swivel arm 21 swivels. However, X-ray irradiation is performed while the X-ray irradiation axis passes through parts other than the left and right temporomandibular joint parts. Irradiation is unnecessary. Therefore, it is necessary to turn off the X-ray generator 22 during this period, and the timing of starting irradiation is different from that in panoramic imaging. M.
By programming in advance the X-ray irradiation pattern unique to J. M. The X-ray generator 22 is switched to the T.J. M. It is turned on / off to match the predetermined mode suitable for J shooting. If the feed start / stop timing and the feed speed of the film cassette 23 are controlled in synchronization with the X-ray irradiation control means 7, the left and right temporomandibular joints can be formed on a single film as shown in an embodiment described later. It is possible to project a plurality of images such as the closed / opened state or the same mode state at different incident angles, which makes it easy and convenient to compare the diagnostic information.

The above T. M. A microprocessor 61 is interposed between the J imaging selection means 6 and the X-ray irradiation control means 7, and various imaging modes (including a panoramic imaging mode) are programmed in the microprocessor 61. M. J
A selection operation signal of the photographing selection means 6 is input to the microprocessor 61 to perform the proper photographing mode, and at the same time, the microprocessor 61 issues an interlocking signal to the positioning microprocessor 82 to form a tomographic image. The mechanism 2 and / or the patient support device 3 are connected to the T. M.
It is designed to move to a proper position for J shooting.

Incidentally, in the analog arithmetic type positioning device, it is possible to perform the same operation by switching and using a voltage signal or the like relating to a preset position instead of the sensor input value.

(Operation) Next, a schematic function of the apparatus having the above configuration will be described with reference to the drawings. 2 to 14 show the positioning capacity during panoramic photography. In the figure, when the patient's head is held by the patient holding device 3, the sensor 4 reads the relative position of the dental arch T with respect to the reference position O of the device and converts it into an electric signal. In the case of the example shown in the figure, this electric signal is input to the comparison calculation circuit 8, and the difference between the relative position of the tomographic region P and the reference position O is compared and calculated, and the tomographic formation mechanism 2
And / or the movement direction and the appropriate movement amount of the patient holding device 3 are determined. The information on the moving direction and the moving amount set by the comparison operation circuit 8 is inputted to the drive circuit 5, and the moving mechanism 50 operates as it is in the case of automatic operation by this input signal, and in the case of the manual operation, the manual ON / OFF circuit described above. The moving mechanism 50 is similarly operated by the operation of. As a result, the tomographic formation mechanism 2 and / or the patient holding device 3 move with an appropriate direction and movement amount, and the third, fifth, seventh, ninth and first
As shown in FIG. 1, the dental arch T and the tomographic region P substantially coincide with each other. When the reference distance data generation circuit 80 is provided, the reference distance data generation circuit 80 is artificially turned on before the above operation, and the sensor 4, the comparison operation circuit 8 or the drive circuit 5 is turned on. An operation command is issued, or the reference data is input to them, thereby performing quick and accurate positioning. After positioning, the X-ray irradiation switch (not shown) is turned on to emit X-rays from the X-ray generator 22, and the horizontal swivel arm 21 swivels around the patient's head. The tomographic images of the patient's dental arch T are successively projected on the film cassette 23.

Fig. 15 shows T. M. It shows a positioning procedure in the case of J photographing. In the figure, T. M. By the J photographing selection means 6, the T. M. When an appropriate shooting mode for J shooting is selected (command input keyboard operation), the T.S. M. J shooting mode detection circuit and T.J. M. A command signal is input to the microprocessor 61 from the J photographing position data generation circuit, and the microprocessor 61 selects various pre-programmed photographing modes. The position data in this selection mode is further input to the comparison operation circuit 8, and in the comparison operation circuit 8, the tomographic formation mechanism 2
And / or the position information of the patient support device 3 is compared with the actual position information data, and a command signal of an appropriate movement amount of the tomographic formation mechanism 2 and / or the patient support device 3 is input to the drive circuit 5. Thus, an output signal is issued from the drive circuit 5 to the moving mechanism 50, the tomographic forming mechanism 2 and / or the patient holding device 3 moves back and forth, and the T.I. M. It is set to the proper position for J shooting. Thus, T. M. When the X-ray irradiation switch is turned on after the position for J imaging is set, a tomographic image of the temporomandibular joint is projected on the film cassette 23 according to the imaging mode that is extended next.

As described above, T. M. When the selection operation of the J photographing selection means 6 is performed, the corresponding photographing mode is selected by the microprocessor 61. This imaging mode is for X-ray generator 2
2 including pattern elements such as on / off timing, feed start / stop timing of the film cassette 23, and feed speed. When the X-ray irradiation switch is turned on after that, the X-ray generator 22 is turned on according to the selected photographing mode.・
The turning off and the feeding of the film cassette 23 are performed, and a tomographic image of the temporomandibular joint is displayed on the film cassette 23.

Here, T. M. Specific examples of various shooting modes of J shooting and operation of each mechanism will be described. FIG. 25 shows an example in which four types of photographed images of the left and right temporomandibular joints are closed and opened on one film. When such an imaging mode is selected, the horizontal swing arm 21 of the tomographic forming mechanism 2 is installed at the imaging start position of the left (right) temporomandibular joint. This is set as the photographing start position in the closed state. After that, when the X-ray irradiation switch is turned on, the revolving arm 21 starts revolving, and the X-ray generator 22 is turned on at almost the same time or with a slight time difference, and the feeding of the film cassette 23 is started, so that the film cassette 23 is placed on the film cassette 23. Tomography of the left (right) temporomandibular joint is performed. When the tomography of the left (right) temporomandibular joint is completed, the X-ray generator 22 is turned off, and during that time, the film cassette 23 is speed-adjusted so as to be fed by 1/4 of that time, and the tomography of the left (right) temporomandibular joint is performed. The image is projected in the area of 0 to 1/4 of the film cassette 23. After that, the swivel arm 21 is swung and the film cassette 2 is moved.
When the feeding of 3 is continued and the image capturing start position of the right (left) temporomandibular joint is reached, the X-ray generator 22 is turned on and tomography of the right (left) temporomandibular joint is performed. During this time, the right (left) temporomandibular joint is imaged in the 4/4 to 3/4 section of the film cassette 23, and when the radiography of the right (left) temporomandibular joint is completed, the X-ray generator 22 is turned off and the swing arm 21 is turned on.
And the feeding of the film cassette 23 are stopped.
Next, the revolving arm 21 starts reversing, and the film cassette 23 is fed backward. The revolving arm 21 returns to the left (right) temporomandibular joint imaging start position again, at which time the film cassette 23 stops at the 1/4 position. Here, when the patient's jaw is opened and the X-ray irradiation switch is turned on,
The horizontal swivel arm 21 swivels, the X-ray generator 22 is turned on almost at the same time or with a slight time difference, and the feeding of the film cassette 23 is started, so that the film cassette 23 is divided into 1/4 to 2/4. A tomographic image of the left (right) temporomandibular joint in the open state is displayed. After this imaging is completed and the X-ray generator 22 is turned off, the horizontal swing arm 2
When 1 continues to turn and reaches the right (left) temporomandibular joint imaging start position, the X-ray generator 22 turns on and the right (left)
A tomographic image of the temporomandibular joint is taken. During this time, the film cassette 23 is fed from the 2/4 position, and the film cassette 2
Right side (left side) of the open state in the 2/4 to 3/4 section of 3
A tomographic image of the temporomandibular joint is displayed. In this way, the left and right temporomandibular joint tomography images in the open state are projected on both sides of the film, and the left and right temporomandibular joint tomography images in the open state are projected in the central portion in a uniformly divided state. The above-described series of operations are performed by the microprocessor 61, in which the swivel pattern of the swivel arm 21, the on / off timing pattern of the X-ray generator 22, and the feeding start of the film cassette 23 are started.
It is automatically and smoothly performed according to the photographing mode such as the stop timing pattern and the feed speed pattern thereof.

In FIG. 28, the film is divided into eight parts in the vertical and horizontal directions, and another photographing mode is added to the above, and these are collectively displayed on one film. An example of such an imaging mode is a case where the temporomandibular joint imaging in a closed / opened state is performed for two types of X-ray incident angles. In this case, the vertically long slit for panoramic imaging (not shown) arranged in the front part of the X-ray generator 21 can be switched to the upper half, and the slit can be switched to the upper half. In the same manner as above, T.
M. When J imaging is performed, a tomographic image of the left and right temporomandibular joints in the closed / open state at one incident angle selected is projected on the upper half of the film cassette 23.
After that, the X-ray incident angle is switched to another angle, and the film cassette 23 is turned upside down. M. When J imaging is performed, a tomographic image of the left and right temporomandibular joints in the closed / opened state at another incident angle is projected on the remaining portion of the film cassette 23.

The X-ray incident angle is changed by changing the front-rear relative positional relationship between the dental arch T and the tomographic region P. FIG. 26 shows the relative positional relationship between the dental arch T and the fault region P at three types of incident angles. FIG. 26 (a) shows a state in which the dental arch T and the fault region P substantially match with each other, and FIG. 26 (b) shows a state in which the dental arch T protrudes slightly forward from the fault region P. On the contrary, FIG. 26 (c) shows a state in which the fault region P projects from the dental arch T to the front. Further, A, B, and C in each drawing show the X-ray irradiation axis with respect to the central portion of the articular process T ₁ , and a, b, and c show the X-ray irradiation imaging range, respectively. The images of the temporomandibular joint photographed at such three types of incident angles have different forms even if the temporomandibular joint is the same as shown in FIG. This means that the joint projections T ₁ etc. were seen through at different angles,
As a result, more diagnostic information of morphological abnormalities such as articular process T ₁ in temporomandibular disorders can be easily obtained. Such a combination of photographing in several directions and a combination of closing and opening the temporomandibular joint are arbitrary, and the number of divided images on the film can be appropriately changed by changing the size of the film or the feeding speed of the film cassette 23. It

(Example) Next, an example will be described. FIG. 1 is a schematic explanatory view showing an example of a dental panoramic radiography apparatus of the present invention. In the figure, a panoramic X-ray imaging apparatus main body 1 is supported by a column 11 so as to be adjustable in vertical position, and a horizontal swing arm 21 of a tomographic formation mechanism 2 is suspended from the apparatus main body 1 via a swing drive mechanism 24. Has been done. The horizontal swivel arm 21 is swivelable along the shape of the patient's dental arch T by a swivel drive mechanism 24, and a moving mechanism 50 mounted in the apparatus main body 2 is provided.
It is possible to move back and forth. Two types of patient holding devices 3 and 3'are attached to the lower part of the device body 1. One of the patient holding devices 3 supports the jaw of the patient from below and is used during panoramic imaging. To be done. The other patient holding device 3'is designed to lightly support the nostril of the patient from below. M. Used when shooting J. These can be retracted from a predetermined position, and are selectively used according to their respective photographing modes. The reason why the two types of patient holding devices 3 and 3'are provided so as to be retractable is as follows. That is, in the human jaw, the lower jaw moves up and down with the temporomandibular joint as a fulcrum. Thus, with the lower jaw fixed so as to support it from below, the T.O. M. When the J radiography is performed, the temporomandibular joint moves up and down, and the diagnostic value is lowered in view of the purpose of comparative diagnosis of the state of the relative position of the temporomandibular joint when the mouth is opened and closed. Therefore, if the patient is held by the nostril, only the lower jaw can be moved up and down with the head fixed, and the temporomandibular joint is held at a fixed position accordingly. If panoramic radiography is to be performed while being held by the nostril, the patient holding device 3'exists in front of the anterior tooth. M. This is because it does not hinder panoramic shooting even if it does not hinder J shooting. However, it goes without saying that when the patient holding device 3'is made of an X-ray transparent material, panoramic radiography can be performed by using this.

2 to 11 show a mode of positioning means for panoramic photography, which will be sequentially described below.

In FIGS. 2 and 3, the tomographic formation mechanism 2 is suspended from the apparatus main body 1 via the movement mechanism 50 so as to be movable back and forth along the midline of the patient. Further, the sensor 4 is arranged integrally with the tomographic forming mechanism 2 on the midline between the turning trajectory of the tomographic forming mechanism 2 and the apparatus body 1. The patient holding device 3 is fixed to the device body 1, and the distance d between the front tooth of the patient's dental arch T placed on the holding device 3 and the sensor 4 is detected by the sensor 4. The distance d is summed with a preset distance d ₁ between the sensor 4 and the reference position O, and relative position data d _{0 with} respect to the reference position O of the dental arch T.
Is input to the comparison operation circuit 8. Thus, the relative position data D with respect to the reference position O of the preset fault area P
And the input data d _{0 from the} sensor 4 are compared and calculated by the comparison calculation circuit 8 as described above. Based on this information, the fault forming mechanism 2 moves by the shift width (D-d ₀ ), and the fault region P and the dental arch T substantially match as shown in FIG. In the case of the drawing, the tomographic formation mechanism 2 is moved back and forth by the drive circuit 5, and this back and forth movement is performed by the moving mechanism 50.
The moving mechanism 50 is a driving means including a motor 51 and a rack and pinion 52 arranged in the upper portion of the apparatus body 1.
Including 500. The moving mechanism 50 has a potentiometer 5
3 is attached, and the result of the above movement is the potentiometer 5.
The position is detected by 3, and the tomographic formation mechanism 2 can be finely moved and corrected.

4 and 5, the fault forming mechanism 2 is fixed to the standing body 1, while the patient holding device 3 is movable back and forth along the midline with respect to the device body 1 via the moving mechanism 50. Equipped. The sensor 4 is arranged integrally with the tomographic formation mechanism 2 as described above, and the relative position data d ₀ of the dental arch T detected by the sensor 4 and the previously input relative position data D of the tomographic region P are compared. The calculation circuit 8 performs comparison calculation. Based on this information, the moving mechanism 50 operates to move the patient holding device 3, and the tomographic region P and the dental arch T are substantially aligned with each other as shown in FIG. Also in this case, a potentiometer 53 is attached to the moving mechanism 50, and the position of the result of the movement is detected and the patient holding device 3 is moved again so that the minute movement can be corrected.

In FIGS. 6 and 7, the tomographic forming mechanism 2 is movably suspended back and forth on the apparatus main body 1 via a moving mechanism 50 'including a driving means 500', while the patient holding device 3 is moved. The apparatus main body 1 is equipped with a device 50 via a 50 so as to be movable back and forth. The patient support device 3 is provided with a truncated articulation device 33,
A sensor 4 such as a potentiometer, a differential transformer or a digital linear scale is connected to the engaging device 33. When the front teeth of the patient's dental arch T occlude the incisor 33, the occlusal pressure is transmitted to the sensor 4, whereby the sensor 4 detects the position of the front tooth and substantially functions as a contact sensor. This position detection data is output as relative position data d ₀ of the dental arch T with respect to the reference position O of the device body 1. Further, the moving mechanism 50 'of the tomographic forming mechanism 2 is provided with a position detecting means for the tomographic forming mechanism (potentiometer or differential transformer 4'). The relative position data D of the tomographic region P and the relative position data d ₀ of the dental arch T by the position detecting means 4 ′ are input to the comparison calculation circuit 8, and both data D and d ₀ are compared and calculated to move. Either or both mechanisms 50, 50 'are activated. As a result, the tomographic region P and the dental arch T substantially match as shown in FIG. FIG. 7 shows the result of movement of both moving mechanisms 50, 50 '. The position detecting means 4 ′ for the tomographic formation mechanism is
When only the patient holding device 3 is moved to perform positioning, it is possible to function to check whether or not the movement is correctly performed. In this case, the fault forming mechanism 2 is corrected and moved based on the check result.

8 and 9, as in the case of FIGS. 2 and 3, the tomographic forming mechanism 2 is provided in the apparatus main body 1 via the moving mechanism 50 so as to be movable back and forth, while the patient holding apparatus is provided. 3 is fixed to the apparatus main body 1. Further, the sensor 4 is attached to the vertical portion of the apparatus main body 1 on the midline of the patient and coincides with the reference position O. By mounting the sensor 4 on the apparatus main body 1 in this manner, the distance between the tomographic formation mechanism 2 and the vertical portion of the apparatus main body 1 can be made small, and the overall size can be made compact. In this case, the distance d between the front teeth of the dental arch T detected by the sensor 4 coincides with the relative position data d _0, and this data d ₀ and the relative position data D of the tomographic region P are the same as the comparison operation circuit 8 described above. Is compared and calculated. Based on these calculated data, the moving mechanism 50 is used to move the patient holding device 3 in the proper direction and by the proper amount for positioning. As a result, the dental arch T and the tomographic region P substantially coincide with each other as shown in FIG. Other configurations are the same as those in FIGS. 2 and 3.

FIG. 10 and FIG. 11 show an example in which the vertical position of the sensor 4 can be adjusted by the sensing position changing means 40. That is, the sensing position changing means 40
Is for adjusting the vertical position of the sensor 4 so that the light from a light emitting element (described later) 41 of the sensor 4 is irradiated horizontally to the front teeth of the patient's dental arch T. The variable means 40 has a first
As shown in FIG. 6, the pinion gear 401 disposed in the lower portion of the device body 1 and the device body 1 that meshes with the pinion gear 401.
Pinion gear 401 associated with the operation of an external operation knob (not shown)
The rack gear 402 moves up and down by the rotation of the. The sensor 4 is fixed to the upper end of the rack gear 402,
The operator adjusts the upper and lower positions of the patient's front teeth with the operation knob so that the light from the light emitting element 41 is horizontally irradiated. The patient holding device 3 is a chin rest 3 that supports the patient's jaw.
1 and a regulation frame 32 that is hung from the upper portion of the apparatus main body 1 and regulates the direction and the like at the patient's ear. Although the regulation frame 32 is provided so as to hang from the upper portion in the illustrated example, it may be provided so as to stand from the chin rest 31 side.
Further, in the case of FIGS. 1, 2, 4, 6 and 8, provision of such a regulation frame is not excluded. The patient holding device 3 is in a fixed relationship with the device body 1, and the holding device 3
Then, the head of the patient is placed, and the position of the sensor 4 is detected and the tomographic formation mechanism 2 is moved back and forth. In the case of this figure, the drive circuit 5 causes the tomographic formation mechanism 2 to move back and forth. This movement back and forth is performed by the moving mechanism 50.
The moving mechanism 50 includes a driving means 500 including a motor 51 and a rack and pinion mechanism 52 installed in the lower portion of the apparatus main body 1, and a wire 54 connecting the driving means 500 and the fault forming mechanism 2. Further, a tomographic pointing beam projector 55 is fixedly mounted on the driving means 500, and a tomographic position detecting potentiometer 53 is associated therewith. When the above-mentioned movement signal is issued, the motor 51 of the driving means 500 is driven, and the rack and pinion mechanism 52 causes the tomographic pointing beam projector 55 and the tomographic forming mechanism 2 to simultaneously move back and forth via the wire 54. The reference position of the tomographic region P by the tomographic forming mechanism 2 and the irradiation beam by the tomographic pointing beam projector 55 are bound by the wire 54 so as to always match, and the operator visually observes the spot irradiated on the face of the patient. Therefore, the approximate position of the fault area P can be estimated. Further, the potentiometer 53 constantly monitors the position of the tomographic region P, the information is input to the A / D converter 81 of the comparison operation circuit 8 and A / D converted, and the microprocessor 82 again performs comparison operation. Then, a drive signal is issued to the drive circuit 5 (see FIG. 12).
In the case of the illustrated example, the tomographic formation mechanism 2 and the tomographic pointing beam projector 55 are connected by the wire 54 so that both can be moved at the same time, but the invention is not limited to this, and the two may be electrically synchronized. Does not exclude that they are driven by asynchronous independent motors. Further, the tomographic pointing beam projector 55 is provided only as an auxiliary consideration to the operator, and it can be omitted from the meaning of automatic positioning. When positioning the patient in the apparatus of this embodiment, first, the lower jaw is raised on the patient holding apparatus 3, and the vertical position of the sensor 4 is adjusted by the sensing position changing means 40. Next, the distance d between the anterior tooth of the patient's dental arch T and the sensor 4 is detected as described above, and the preset distance d ₁ between the sensor 4 and the reference position O is summed to obtain the dental arch T. The relative position data d _{0 with} respect to the reference position O is input to the comparison calculation circuit 8.
Then, the relative position data D with respect to the reference position O of the preset tomographic area P and the input data d by the sensor 4 are set.
As described above, ₀ is compared and calculated by the comparison calculation circuit 8.
The tomographic formation mechanism 2 is based on the information from the comparison calculation circuit 8.
Shifts by a deviation width (D-d ₀ ), and the tomographic region P and the dental arch T substantially coincide with each other as shown in FIG. 11. As a result of this move,
The potentiometer 53 is used if necessary, and the fault formation mechanism 2
It is also possible to detect the position of, and operate in the same manner as above to correct the minute movement.

17 to 21 show another embodiment of the sensing position changing means 40. 17 and 1
FIG. 8 shows a portion of the apparatus body 1 different from the above, that is, the first portion.
In FIG. 7, a pinion gear 401 similar to that in FIG. 16 and a rack gear 402 that moves up and down by meshing with the pinion gear 401 are arranged in the vertical portion of the apparatus body 1 in FIG. 18, and in the upper portion of the apparatus body 1 in FIG.
This shows that the vertical position of the sensor 4 is adjusted by operating an operation knob (not shown).

FIG. 19 shows a pinion gear 401 similar to that shown in FIG. 16 and a rack gear 402 that moves up and down by meshing the sensor 4 arranged in the film cassette 23 in the tomographic forming mechanism 2.
It is to adjust the vertical position.

In the embodiment shown in FIGS. 17 to 19,
The sensor 4 described later (FIGS. 23 and 24) is adopted. That is, in order to horizontally irradiate the irradiation beam emitted from the light emitting element 41 to the front teeth of the dental arch T, the vertical position of the sensor 4 itself is adjusted by the sensing position changing means 40.

20 and 21 show that the orientation angle of the sensor 4 is adjusted by the sensing position changing means 40. That is, the sensor 4 is pivotally attached to the apparatus main body 1 in FIG. 20 and to the revolving arm 21 in FIG. The orientation angle is adjusted by an operation knob (not shown), and the operator applies the irradiation beam to the front teeth of the dental arch T. The distance r detected by the sensor 4 is input to the comparison calculation circuit 8 together with the orientation angle θr, and the horizontal distance d is calculated here. Based on this calculation result, a drive signal is issued to the drive circuit 5 via the comparison calculation circuit 8 as in the above.

In these embodiments, the vertical position or orientation angle of the sensor 4 is adjusted by the sensing position changing means 40. After that, the horizontal distance d between the sensor 4 and the target portion of the dental arch T (front tooth in the illustrated example) is measured, and the moving mechanism 50 operates based on the measurement result, and the dental arch T and the tomographic region P coincide with each other. . Therefore, these embodiments are preferably adopted, but it goes without saying that other suitable means can be adopted without being limited thereto.

Next, the sensor 4 preferably used in the present invention will be described. That is, the sensor 4 includes a light emitting element 41 and a semiconductor position detecting element (hereinafter referred to as a PSD element) 4 as shown in FIG.
It consists of two. The sensor 4 irradiates light from the light emitting element 41 to, for example, the front teeth of the patient's dental arch T to diffusely reflect it, and the reflected light is received by the PSD element 42 to calculate the distance d.

The principle of calculating the distance d will be described. In FIG. 23,
The light from the light emitting element 41 is condensed by the light projecting lens 43 and strikes the front tooth (patient dental arch) T as an object. The light diffusely reflected on the surface of the front tooth T is condensed by the light receiving lens 44, and P
Focus on the surface of the SD element 42. Now, the distance from the lens 43 to the front tooth T is d, the focal length of the lens 44 is f, the distance between the centers of the light projecting lens 43 and the light receiving lens 44 is X, and the light receiving surface of the PSD element 42 from the light receiving lens central axis. If the distance to the reflected light condensing point is e, Therefore, Since the values of X and f are known, the distance d to T can be calculated by detecting the value of e.

Next, e is detected and d is calculated according to the principle of the PSD element 42. In FIG. 24, (However, x is the distance from the center of the PSD element 42 to the light receiving point, L is the distance from the center of the PSD element 42 to both electrodes, and I ₁ and I ₂ are photocurrents at both ends of the PSD element 42.) Now L Is a constant, (I ₂ −I ₁ ) / (I ₁ +
It can be seen that I ₂ ) is proportional to the distance x. On the other hand, e = x + s (where s is the central axis of the light receiving lens 44 and the PSD element 42)
Distance from the center axis of Therefore, when substituting these into the formula, (I ₂ −I ₁ ) / (I ₁ + I ₂ ) = δ Then, d becomes a function of δ, that is, (I ₂ −I ₁ ) / (I ₁ + I ₂ ), and if δ is output as a DC voltage value, d is calculated from this δ.

FIG. 22 shows another arrangement example of the sensor 4, in which the two sensors 4 and 4 are oriented, for example, to the left and right canines of the dental arch T, and the same as above based on the position detection data of these two types. It is intended to position the. In this case, since the two-dimensional position data of the dental arch T is obtained by the sensors 4 and 4, the shape characteristics of each patient are also input to the comparison calculation circuit 8 and more accurate by comparison with the shape model input in advance. It is possible to position it high. In this sense, if more sensors 4 are arranged and a plurality of positions of the dental arch T are detected, the positioning accuracy is further improved.

FIGS. 12, 13, and 14 are block diagrams showing various aspects of the circuit configuration of the panoramic imaging positioning adopted in the device of the present invention.

FIG. 12 is a block diagram of a circuit configuration which is preferably applied to all of the positioning examples in the above panoramic photography.
Position detection data of the dental arch T by the sensor 4 and the fault area P
The position data of is compared and calculated by the comparison calculation circuit 8 as described above. The arithmetic circuit 8 compares an A / D converter 81 for A / D converting the detection data of the sensor 4 with the arithmetic data of the A / D converter 81 and the position data of the tomographic region P input in advance. And a microprocessor 82 which outputs a signal to the drive circuit 5. A sensor signal processing circuit 9 is interposed between the arithmetic circuit 8 and the sensor 4, and a position detection signal from the sensor 4 is processed by the processing circuit 9 and then digitally converted by an A / D converter 81. Input to the processor 82. The microprocessor 82 stores some of the above models in advance, and the operator determines the morphology of the patient's dentition, that is, the shape, size, and other shape characteristics of the dentition and responds to the appropriate model. Select the keyboard to use. Then, the microprocessor 82 calculates the relative positional relationship between the processed data by the processing circuit 9 and the tomographic region P corresponding to the selected model, and issues a movement signal to the drive circuit 5 based on the calculation result.

FIG. 13 is a block diagram applied to FIGS. 2 to 5. In this case, conditions are set by the reference distance generation circuit 80, and the relative position data of the tomographic region P is input to the comparison calculation circuit 8, and then the position detection information from the sensor 4 is input to the comparison calculation circuit 8. . The comparison calculation circuit 8 compares and calculates the relative position deviation between the tomographic region P and the dental arch T, and determines the moving direction and amount of movement of the tomographic region P or the dental arch T. Further, the drive circuit 5 operates based on the data from the comparison operation circuit 8 and the moving mechanism 50 operates. The result of the movement by the movement mechanism 50 is
It is detected again by the sensor 4 and its movement can be corrected.

FIG. 14 is a block diagram applied to FIGS. 6 to 11. In this case, the detection information from the sensor 4 and the position detecting means 4 '(53) for the tomographic formation mechanism is input to the comparison calculation circuit 8, where the detection information and the relative position data of the tomographic region P input in advance. A comparison operation is performed. Then, based on the result of the comparison calculation, the dental arch T or the tomographic region P is moved back and forth similarly to the above. Further, the result of movement by the moving mechanism 50 is fed back to the tomographic formation mechanism position detecting means 4 '(53), and the movement of the tomographic region P is corrected again.

FIG. M. It is a block diagram of positioning at the time of J photographing. In this case, T. M. J shooting mode detection circuit and T.J. M. The J.J. shooting position data generating circuit, that is, the T.J. M. The shooting mode information selected by the selection operation by the J shooting selection means 6 is input to the comparison calculation circuit 8 and is compared with the actual position data.
This comparison calculation result is input to the drive circuit 5, and the drive means 50
A movement signal is sent to 0, the movement mechanism 50 operates, and the tomographic formation mechanism 2 and / or the head fixing device 3 move to the T.O. M. J
Move back and forth to a position suitable for shooting. And the moving mechanism 5
The movement result by 0 is the position detection means 4'for the fault forming mechanism.
It is fed back to (53), and the movement of the fault area P is corrected again.

FIG. 29 shows a panoramic shot and a T.S. M. It is a comprehensive block diagram of positioning and X-ray irradiation mode in J imaging. T. M. The panorama shooting and the T.J. M. Selection command keyboard for J shooting, T.K. M. A keyboard for selecting various shooting modes for J shooting is included. When the panoramic shooting mode is selected using the shooting mode selection command keyboard and the automatic positioning command keyboard is operated, the automatic positioning microprocessor 8
By the action of 2, the movement signal of the fault formation mechanism 2 is emitted,
This movement is performed by the drive circuit 5 so that the dental arch T and the tomographic mechanism P are matched. Whether or not this movement is proper is checked by the arm position detection circuit, that is, the tomographic formation mechanism position detection means 4 '(53) and the comparison operation circuit 81, and the movement is corrected. After that, when the X-ray irradiation switch is turned on, the main unit side microprocessor 61
In accordance with the panoramic photographing mode programmed in the above, the swiveling arm 21 is swung, the X-ray generator 22 is turned on, and the film cassette 23 is fed to perform panoramic photographing. Also, the T.S.
M. When any one of the various shooting modes of the J shooting is selected, the T.C. M. Position data relating to J imaging is transmitted to the automatic positioning microprocessor 82 as an interlocking signal, and the tomographic formation mechanism 2 is operated according to the various imaging modes described above.
Is set. After that, when the X-ray irradiation switch is turned on, the X-ray irradiation control means 7 and the microprocessor 61
By the action of the T.S.T., according to various aspects of the turning pattern of the turning arm 21, the on / off timing pattern of the X-ray generator 22, the feed start / stop timing pattern of the film cassette 23, and the speed pattern. M. J shooting is done.

FIG. 30 shows a general flow chart of positioning in the various shooting modes. This is outlined below. First, press the start button to select the shooting mode. T. M. When the J shooting mode is selected, M. J shooting position data R
₁ is compared with the actual position data P of the swing arm, and R
_{When 1} = P, T.I. M. Positioning for J shooting ends.
When R ₁ and P are not equal to each other, a movement signal is sent to the front or rear of the arm to compare the two again, or after this is repeated, the positioning is completed. On the other hand, T. M. When a mode other than the J shooting mode is selected, it is necessary to determine whether or not to select the special mode in this embodiment. This special mode means, for example, panoramic radiography of the maxillary sinus, and when the special mode is not selected, the original full-jaw panoramic radiography is used. When this full-jaw panoramic imaging mode is selected, the sensor value is input and the position data R ₂ of the patient's dental arch is calculated. The position data R ₂ is the same as the actual position data P of the swing arm as described above.
After that, the movement is corrected in the same manner as described above, and then the positioning of the turning arm in panoramic photography is completed. Also, when the special mode is selected, the special position correction data is set before the sensor value is input. In the case of the maxillary sinus panoramic radiographing described above, this special position has a constant deviation statistically calculated from the full-jaw panoramic radiographing position, and the position correction data set is designed to correct this deviation difference. . After that, the same operation as described above is performed and the turning arm is positioned at a position suitable for special mode shooting.

In the above description of the embodiment, the sensor 4 directly detects the relative position of the dental arch. However, the position of another part of the patient's head is detected, and the relative position of the dental arch is detected from the detected data. It is also possible to calculate. In the above description, the sensor 4 is the T.O. M. Although not directly involved in the positioning of the J image, the position information is input to the microprocessor 82, and the T. M. It is also possible to perform the positioning of J photographing in a composite manner. Furthermore, the thirteenth, fourteenth, fifteenth, twoth
In the description of FIGS. 9 and 30, various positioning is performed by moving the tomographic forming mechanism 2, but it is also possible to achieve the same purpose by moving the patient holding device 3 or both. . In addition, it is not excluded to add the head standard radiography (cephalometer) function to the device of the present invention, whereby more various diagnostic information can be obtained.

(Effects of the Invention) As described above, in the dental panoramic X-ray imaging apparatus of the present invention, the relative position of the patient's dental arch is detected by the sensor,
This detection result is compared with the relative position data of the fault area,
Based on the comparison result, the tomographic region and / or the dental arch are moved so that the both agree with each other. Therefore, even a beginner can perform accurate and quick positioning. As a result, the film quality of panoramic shooting is improved and the frequency of shooting failure and re-shooting due to positioning error is drastically reduced.
Unnecessary X-ray exposure to the patient is significantly reduced.

Further, when the comparison operation circuit is incorporated, the positioning operation is simplified and its accuracy is further improved. Further, when the vertical position or orientation angle of the sensor can be adjusted by the sensing position changing means, the relative position can be accurately detected even if there is individual difference in the form of the patient subject.

Furthermore, in addition to the high-precision and simple positioning function at the time of panoramic photography, the device of the present invention has a function of T.S. M. It has a simple and appropriate function for switching to J imaging, and by organically combining these functions, various diagnostic information regarding dental treatment can be quickly and accurately obtained.

The present invention having such remarkable advantages has a great practical value.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of a dental panoramic X-ray imaging apparatus of the present invention, and FIGS. 2, 4, 6 and 8 are various views of other embodiments. Similar to Figure 3, Figure 3,
5, FIG. 7 and FIG. 9 are explanatory views of the adjusting mechanism corresponding to the embodiment, FIG. 10 is a schematic side view showing an example of the device to which the sensing position changing means is added, and FIG. 11 is the same. Explanatory views of the adjusting mechanism in the embodiment, FIGS. 12 to 1
FIG. 5 is a block diagram showing an example of the circuit configuration of the device of the present invention, FIG. 16 is an enlarged view of the XVI line part of the tenth, and FIGS.
FIG. 22 is a view similar to FIG. 16 of another embodiment, FIG. 22 is an explanatory view showing another arrangement example of the sensor, FIGS. 23 and 24 are principle diagrams of the sensor adopted in the present invention, and FIG. The figure shows T.
M. FIG. 26 is a diagram showing an example of a film image in J shooting.
FIG. 27 is an explanatory view showing various patterns of X-ray irradiation angles, 27th
The figure is an enlarged view of the imaging of the temporomandibular joint corresponding to the figure, FIG. 28 is a view similar to FIG. 25 showing an example of another film image, and FIG. 29 is a panorama-T. M. Integrated block diagram of J shooting, 30th
The figure shows Panorama-T. M. FIG. 7 is a general positioning chart of J imaging. (Explanation of symbols) 1 ... Main body of panoramic X-ray imaging apparatus, 2 ... Tomography forming mechanism, 21 ... Horizontal swiveling arm, 22 ... X-ray generator, 2
3 ... film cassette, 24 ... turning drive mechanism, 3 ...
... Patient holding device, 4 ... Position detection sensor, 40 ... Sensing position changing means, 5 ... Drive circuit, 50 ...
... moving mechanism, 500 ... driving means, 6 ... temporomandibular joint imaging selecting means, 7 ... X-ray irradiation control means, 8 ... comparison arithmetic circuit, 80 ... reference distance data generating circuit, P ... tomographic region,
T: dental arch.

Claims (12)

[Scope of utility model registration request] 1. A panoramic X-ray imaging apparatus main body (1) and the main body
A horizontal swivel arm (21) supported so that it can swivel horizontally (1),
Between the X-ray generator (22) and the film cassette (23) including the X-ray generator (22) and the film cassette (23) supported at both ends of the arm (21), and between the X-ray generator (22) and the film cassette (23) A dental panoramic X-ray imaging apparatus comprising a patient holding device (3) arranged in the patient's dental arch (T) held by the patient holding device (3). Position detection sensor that detects the relative position of the device to the device body (1)
(4), a tomographic forming mechanism (2) and / or a moving mechanism (50) having a front-back position detecting means (4 ') for moving the patient holding device (3) back and forth, and the tomographic formation by the selection operation A temporomandibular joint radiography selecting means for outputting a radiographic position data signal for moving the mechanism (2) and / or the patient holding device (3) to an appropriate position for temporomandibular joint radiography
(6), the comparison data between the position data detected by the sensor (4) and the relative position data of the fault area (P) with respect to the device body (1), and the front-back position data by the front-back position detection means (4 ′) A drive circuit (5) for operating the moving mechanism (50) based on any selected data of the comparison data with the imaging position data from the temporomandibular joint imaging selecting means (6), and the temporomandibular joint imaging selecting means X-ray irradiation control means (7) for turning on / off the X-ray generator (22) according to the selected radiographing mode signal of (6) so as to match a predetermined mode suitable for temporomandibular joint radiography.
And a dental X-ray panoramic radiographing apparatus. 2. The relative position data is compared by a comparison calculation circuit (8), and the output data from the comparison calculation circuit (8) is input to a drive circuit (5) to form a tomographic formation mechanism (2) and / or Device according to claim 1, characterized in that the patient support device (3) is moved back and forth. 3. The apparatus according to claim 1, wherein the position detection sensor (4) comprises a sensing position changing means (40). 4. The apparatus according to claim 2, wherein the position data of the tomographic region (P) is input to the comparison operation circuit (8) by the reference distance data generation circuit (80). 5. The tomography mechanism (2) includes a swivel drive mechanism (24) for swiveling the horizontal swivel arm (21) into a shape along a patient's dental arch (T). The device according to 3. 6. The sensor (4) is a non-contact type or a contact type sensor, and the apparatus main body (1), a tomographic formation mechanism.
At least a dental arch on either (2) or the patient support device (3)
The front tooth portion of (T) is arranged to face the front tooth portion,
The device according to 2 or 3. 7. The drive circuit (5) is connected to a moving mechanism (50) including a drive means (500) such as a motor or a solenoid,
4. The device according to claim 1, 2 or 3, wherein the patient holding device (3) or the tomographic forming mechanism (2) is moved back and forth by the moving mechanism (50) which has an output from the comparison operation circuit (8). 8. The reference distance data generating circuit (80) sets the reference position of the tomographic region (P) to a position substantially coincident with the position of the dental arch (T) and / or a position slightly shifted back and forth. 5. The apparatus according to claim 4, which is for instructing to: 9. The sensing position changing means (40)
4. The device according to claim 3, wherein is for adjusting the vertical position of the sensor (4). 10. The sensing position changing means (40)
The device according to claim 3, wherein the means for adjusting the orientation angle of the sensor (4). 11. The apparatus according to claim 1, wherein said temporomandibular joint imaging selection means (6) has various modes for selecting various X-ray incident angles with respect to the temporomandibular joint. 12. The X-ray irradiation control means (7) turns on / off the X-ray generator (22) in accordance with the selection mode and sets the feed start / stop timing and the feed speed of the film cassette (23). The device according to claim 1 or 11, which is controlled.