Mouth gag special for temporomandibular joint magnetic resonance imaging

Abstract

The utility model relates to a mouth gag special for temporomandibular joint magnetic resonance imaging. An existing mouth gag needs tooth clamping and positioning, and the use experience is affected. The clamping device comprises a body with a main supporting piece and a sliding block with an auxiliary supporting piece, the sliding block moves along the surface of the body and adjusts the distance between the auxiliary supporting piece and the main supporting piece, a movable clamping piece is arranged on the sliding block, and the clamping piece and the auxiliary supporting piece are matched to form a clamping opening. The body is clamped and positioned on a clamped object through the clamping opening so that the main supporting piece and the auxiliary supporting piece can be positioned at a preset supporting station. The clamping piece is arranged to be matched with the auxiliary supporting piece to form the clamping opening capable of clamping the lower jaw of a user, so that the body is conveniently clamped and fixed to the jaw through the clamping opening, it is guaranteed that the main supporting piece and the auxiliary supporting piece are always located at the supporting station, abutting and locating of teeth of the user are facilitated, and the duration for maintaining the oral cavity contour of the user unchanged is effectively prolonged; the detection accuracy is effectively improved, a user does not need to bite the mouth gag forcibly for a long time, and the use comfort is improved.

Description

Technical Field

[0001] The utility model relates to the field of medical instruments, in particular to a special mouth opener for magnetic resonance imaging of the temporomandibular joint. Background Art

[0002] During an MRI examination of the temporomandibular joint (TMJ), the patient's mouth is scanned in both open and closed positions. To maximize the effect of the open-mouth scan, the patient's mouth must remain open for an extended period. Typically, patients use a mouth opener to help locate the mouth contours and prevent changes in the mouth contour from affecting the accuracy of the examination.

[0003] The existing special mouth opener for MRI of the temporomandibular joint includes a main body with a main support and a slider with a secondary support. The slider moves along the surface of the main body and adjusts the distance between the secondary support and the main support. When in use, the distance between the main support and the secondary support is adjusted by moving the slider. The user fixes the shape of the mouth by biting the main support and the secondary support, thereby ensuring that the user's oral contour remains unchanged during the MRI examination. Since the mouth opener requires the user to continuously apply biting force to achieve fixation, when the examination time is long, the user's oral muscles will become numb and sore due to long-term exertion, causing the mouth opener to shift due to loose teeth occlusion, thereby causing the user's oral contour to deform, which not only affects the accuracy of the test, but also causes discomfort to the user's mouth, affecting the user experience. Utility Model Content

[0004] In order to address the shortcomings of the existing technology, the utility model provides a special mouth opener for magnetic resonance imaging of the temporomandibular joint. A clamping piece is provided to form a clamping opening, which facilitates the positioning of the main body by clamping. It does not require the user to bite hard for a long time to position the mouth, thereby improving the comfort of use. It can also effectively extend the time for the user to maintain the unchanged oral contour, effectively improve the detection accuracy, and enhance the user experience.

[0005] The present invention is realized in the following manner: a special mouth opener for magnetic resonance imaging of the temporomandibular joint, comprising a main body with a main support member and a slider with a secondary support member, the slider moving along the surface of the main body and adjusting the distance between the secondary support member and the main support member, the slider being provided with a movable clamping member, the clamping member cooperating with the secondary support member to form a clamping opening, the main body being clamped and positioned on the clamping object by the clamping opening, so that the main support member and the secondary support member are positioned at a preset support position. By providing a clamping member to cooperate with the secondary support member to form a clamping opening that can clamp the user's jaw, the main body is conveniently clamped and fixed on the chin by the clamping opening, ensuring that the main support member and the secondary support member are always positioned at the support position, facilitating the positioning of the user's teeth, effectively extending the time for the user to maintain the unchanged oral contour, effectively improving the detection accuracy, and also eliminating the need for the user to bite the mouth opener with force for a long time, thereby improving the comfort of use.

[0006] Preferably, the main support, secondary support, and clamp are located on the same straight line, and the main support and clamp are located on either side of the secondary support so that the secondary support cooperates with the main support and clamp, respectively. The main support and secondary support are used to provide a occlusal contact for the user's lower and upper teeth, ensuring that the oral contour remains unchanged. The secondary support and clamp cooperate to form a clamp, which secures the main body by clamping the lower jaw, thereby ensuring that the main support and secondary support are always in their supporting position within the user's oral cavity.

[0007] Preferably, the body is provided with a main groove, the slider being reciprocally slidably embedded in the main groove, the main support being disposed at the notch end of the main groove, and the slider sliding along the main groove to adjust the distance between the secondary support and the main support. The main groove is used to guide the slider's movement, thereby adjusting the degree of oral opening and closing by adjusting the distance between the main support and the secondary support.

[0008] Preferably, the bottom of the slider is provided with a force-bearing thread along its length, and the body is provided with a first screw, the first screw being provided with a driving portion exposed to the bottom wall of the main groove and meshing with the force-bearing thread, and a pushing force portion exposed to the body. The first screw is rotated by the pushing force portion and driven to slide back and forth along the main groove by the driving portion in cooperation with the force-bearing thread, so that the distance between the main support and the secondary support can be adjusted. The cross-sectional profile of the main groove matches the cross-sectional profile of the slider, ensuring that the slider slides within the main groove, effectively preventing the slider from rotating with the first screw, and ensuring that the slider can convert the rotational force from the first screw into a linear force for forward and backward sliding, thereby ensuring that the slider can slide accurately under the drive of the first screw and effectively improving the forward and backward positioning performance of the slider, preventing the slider from deviating along the main groove due to the forward and backward force applied to the secondary support, and ensuring that the user's oral contour remains stable for a long time. The pushing force portion is exposed to the body, and the user can contact the pushing force portion with a finger and turn the first screw to rotate, so that the first screw obtains the rotational force for driving the slider to slide.

[0009] Preferably, the body is provided with a mounting cavity in an area below the main guide groove. The mounting cavity includes a first cavity opening communicating with the bottom wall of the main guide groove and a second cavity opening formed in the side wall of the body. The first screw is inserted into the mounting cavity through the second cavity opening, such that the side of the first screw is exposed at the second cavity opening and forms the pushing force portion. The first screw is concealed within the mounting cavity, which not only protects the first screw but also ensures that the first screw can reliably engage with the force-bearing thread provided at the bottom of the slider through the first cavity opening, thereby ensuring precise adjustment of the slider. The second cavity opening not only exposes the pushing force portion for ease of operation but also forms a disassembly and assembly channel for the first screw, facilitating disassembly and maintenance.

[0010] Preferably, a third cavity opening communicating with the outside is provided in the middle of the end wall of the mounting cavity, and an axial hole is provided in the middle of the first screw along its axis for the passage of a rotating shaft. When the first screw is inserted into the mounting cavity, the rotating shaft sequentially passes through the third cavity opening and the axial hole and is fixedly connected to the end wall of the mounting cavity, so that the first screw can rotate about the rotating shaft. The first screw is rotatably mounted within the mounting cavity via the rotating shaft, which prevents the first screw from escaping from the mounting cavity, ensures that the first screw is always reliably engaged with the force-bearing thread, and ensures that the first screw rotates about the rotating shaft, effectively transmitting the rotational force and ensuring that the slider accurately performs reciprocating movement.

[0011] Preferably, the slider is elongated, with the secondary support member disposed on the top surface of the slider near the front end of the main support member. A secondary guide groove is disposed at the rear end of the slider's top surface, and the bottom of the clamping member is slidably inserted into the secondary guide groove to control the opening and closing of the clamp. The elongated slider can slide along the main guide groove, improving the smoothness of the slider's sliding by increasing the contact area. The secondary support member is disposed at the front end of the slider to facilitate cooperation with the main support member, and a secondary guide groove is disposed at the rear end of the slider to guide the clamping member's sliding and securely clamp the user's jaw.

[0012] Preferably, a through-hole communicating with the secondary guide groove is provided on the rear end wall of the slider, and a force-bearing screw hole is provided at the bottom of the clamping member along the length of the secondary guide groove. A second screw is threadedly mounted in the force-bearing screw hole, and the rear end of the second screw extends rearward and is exposed after passing through the through-hole to form a rotational force-bearing portion. The second screw is rotated by the force-bearing screw hole and drives the clamping member to slide back and forth along the secondary guide groove through the force-bearing screw hole, so that the opening and closing of the clamp can be controlled. The second screw receives the rotational force provided by the user through the rotational force-bearing portion and transmits it to the clamping member through the force-bearing screw hole, so that the clamping member can slide back and forth along the secondary guide groove and clamp the user's lower jaw, ensuring that the relative position between the main body and the lower jaw remains fixed.

[0013] Preferably, a pin hole is provided in the area between the rear edge of the secondary guide groove notch and the rear edge of the top surface of the slider, and the second screw rod is provided with a reduced diameter section. When the second screw rod is inserted into the secondary guide groove through the through hole, the reduced diameter section is locked and positioned by a pin passing through the pin hole, thereby limiting the axial displacement of the second screw hole along the through hole. After the second screw rod passes through the through hole and the force-bearing screw hole in sequence, it abuts against the front end wall of the secondary guide groove, so that the reduced diameter section is aligned with the pin hole. The pin rod passes through the pin hole and is locked at the reduced diameter section, which plays an axial positioning role for the second screw rod, preventing the second screw rod from being separated from the through hole and the screw hole, thereby ensuring that the bottom of the clamping member is always locked in the secondary guide groove, ensuring that the clamping member can only move linearly along the secondary guide groove and cooperate with the secondary support member to clamp the user's jaw.

[0014] Preferably, the back sides of the main support member and the auxiliary support member are provided with limiting grooves, and the user's teeth are stuck in the corresponding grooves to prevent the main support member and the auxiliary support member from being separated from the support position due to excessive bite force of the user.

[0015] Preferably, the side wall of the main body is provided with a scale ruler, and the scale ruler is arranged along the movable direction of the secondary support to measure the distance between the main support and the secondary support. The 0 scale end of the scale ruler is arranged close to the main support, and the secondary support can move back and forth along the direction of the scale ruler, so that the distance between the main support and the secondary support can be pre-adjusted by the scale ruler.

[0016] The beneficial effects of the present invention are as follows: by arranging a clamping piece to cooperate with the auxiliary support piece to form a clamp that can clamp the user's lower jaw, it is convenient for the main body to be clamped and fixed on the chin through the clamping piece, ensuring that the main support piece and the auxiliary support piece are always positioned at the support position, facilitating the positioning of the user's teeth, effectively extending the time for the user to maintain the unchanged oral contour, effectively improving the detection accuracy, and eliminating the need for the user to bite the opener with force for a long time, thereby improving the comfort of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the mouth opener;

[0018] Figure 2 is a schematic cross-sectional structural diagram of the mouth opener;

[0019] Figure 3 This is a schematic diagram of the disassembled structure of the mouth opener;

[0020] Figure 4 is a structural schematic diagram of the slider;

[0021] In the figure: 1. Main body, 2. Main support member, 3. Auxiliary support member, 4. Slider, 5. Clamping member, 6. Clamping jaw, 7. Main guide groove, 8. Force-bearing thread, 9. First screw, 10. Mounting cavity, 11. Shaft hole, 12. Rotating shaft, 13. Auxiliary guide groove, 14. Through hole, 15. Force-bearing screw hole, 16. Second screw, 17. Rotation force part, 18. Pin hole, 19. Pin, 20. Scale, 21. Reduced diameter section, 22. Tooth socket. DETAILED DESCRIPTION

[0022] The essential features of the present invention will be further described below with reference to the accompanying drawings and specific implementation methods.

[0023] like Figure 1 and 2The illustrated embodiment of a special mouth opener for magnetic resonance imaging of the temporomandibular joint comprises a main body 1 with a main support 2 and a slider 4 with a secondary support 3. The slider 4 moves along the surface of the main body 1 and adjusts the distance between the secondary support 3 and the main support 2. The slider 4 is provided with a movable clamping member 5. The clamping member 5 cooperates with the secondary support 3 to form a clamping opening 6. The main body 1 is clamped and positioned on the clamping object by the clamping opening 6, so that the main support 2 and the secondary support 3 are positioned at a preset support position. By providing the clamping member 5 to cooperate with the secondary support 3 to form a clamping opening 6 that can clamp the user's jaw, it is convenient for the main body 1 to be clamped and fixed on the chin by the clamping opening 6, ensuring that the main support 2 and the secondary support 3 are always positioned at the support position, facilitating the positioning of the user's teeth, effectively extending the time for the user to maintain the oral contour unchanged, effectively improving the detection accuracy, and also eliminating the need for the user to bite the mouth opener with force for a long time, thereby improving the comfort of use.

[0024] In actual operation, the main support 2, the secondary support 3 and the clamp 5 are located on the same straight line, and the main support 2 and the clamp 5 are placed on both sides of the secondary support 3, so that the secondary support 3 can be used in conjunction with the main support 2 and the clamp 5 respectively. The main support 2, the secondary support 3 and the clamp 5 are located on the same straight line, ensuring that the secondary support 3 can be used in conjunction with the main support 2 and the clamp 5 respectively at the same time. The clamp 5 and the secondary support 3 are enclosed to form a clamp 6 for clamping the user's jaw. The clamp 5 is below the jaw, and the secondary support 3 is inserted into the oral cavity. The clamp 5 moves closer to the secondary support 3 and contracts the clamp 6 so that the clamp 6 is firmly clamped on the jaw, ensuring that the main body 1 is fixed to the jaw, and further ensuring that the main support 2 and the secondary support 3 are stably positioned at the support station located in the oral cavity; the secondary support 3 and the main support 2 cooperate to shape the oral contour and adjust the gap between the main support 2 and the secondary support 3. The upper teeth in the user's mouth contact the top surface of the main support 2, and the lower teeth contact the bottom surface of the auxiliary support 3. The main support 2 and the auxiliary support 3 are used to limit the degree of opening of the mouth. The user only needs to contact the main support 2 and the auxiliary support 3 with the teeth to effectively maintain the oral contour. There is no need to clamp the fixed body 1 by biting hard, which effectively reduces the burden on the user's mouth and ensures that the mouth can maintain a fixed contour for a long time, thereby ensuring the smooth progress of the magnetic resonance examination and improving the reliability of the examination results.

[0025] In actual operation, the slider 4 and the body 1 as well as the clamping member 5 and the slider 4 are driven by a screw structure (eg Figure 3As shown), the screw structure has the characteristics of high control accuracy and effective positioning, which makes it easy to adjust the distance between the main support member 2 and the support member, and between the auxiliary support member 3 and the clamping member 5, thereby improving the operation accuracy. It can also achieve positioning after the slider 4 and the clamping member 5 are adjusted into place, effectively preventing the slider 4 or the clamping member 5 from being offset due to external force, thereby improving the positioning reliability.

[0026] In actual operation, the main body 1 is provided with a main groove 7, and the slider 4 can be reciprocatingly slidably embedded in the main groove 7. The main support member 2 is provided at the notch end of the main groove 7, and the slider 4 slides along the main groove 7 and adjusts the distance between the secondary support member 3 and the main support member 2. The opening direction of the main groove 7 is consistent with the straight line direction of the main support member 2, the secondary support member 3 and the clamping member 5, ensuring that the secondary support member 3 is always located between the main support member 2 and the clamping member 5 when moving along the main groove 7, ensuring that the opener can always have both the support and shaping performance of the oral cavity and the reliability of clamping with the lower jaw. Specifically, the bottom of the slider 4 is provided with a force-bearing thread 8 (such as Figure 4 As shown, the main body 1 is provided with a first screw 9, which is provided with a driving portion exposed to the bottom wall of the main guide groove 7 and meshing with the force-bearing thread 8, and a pushing force portion exposed to the outside of the main body 1. The first screw 9 is rotated by the pushing force portion, and the driving portion cooperates with the force-bearing thread 8 to drive the slider 4 to slide back and forth along the main guide groove 7, thereby adjusting the distance between the main support member 2 and the secondary support member 3. During use, the user's fingers contact the pushing force portion and push the first screw 9 to rotate. The rotating first screw 9 meshes with the force-bearing thread 8 and converts the rotational force into a linear force, which is used to drive the slider 4 to slide back and forth along the main guide groove 7, thereby adjusting the distance between the main support member 2 and the secondary support member 3 to meet the requirements of oral contour shaping.

[0027] In actual operation, the main body 1 is provided with a mounting cavity 10 in the area below the main groove 7. The mounting cavity 10 includes a first cavity opening communicating with the bottom wall of the main groove 7 and a second cavity opening formed on the side wall of the main body 1. The first screw 9 is inserted into the mounting cavity 10 through the second cavity opening, so that the side of the first screw 9 is exposed to the second cavity opening and forms the pushing force portion. A third cavity opening communicating with the outside is provided in the middle of the end wall of the mounting cavity 10. The first screw 9 is provided with an axial hole 11 formed along its axis in the middle and for the rotation shaft 12 to pass through. When the first screw 9 is inserted into the mounting cavity 10, the rotation shaft 12 passes through the through hole 14 and the axial hole 11 in sequence and is fixedly connected to the end wall of the mounting cavity 10, so that the first screw 9 can rotate around the rotation shaft 12. During installation, first, the first screw 9 is inserted into the installation cavity 10 through the second cavity opening, so that the axial hole 11 is aligned with the third cavity opening. After that, the rotating shaft 12 passes through the third cavity opening and the axial hole 11 and is screwed and locked with the rear end wall of the installation cavity 10, so that the rotating shaft 12 is fixed in the installation cavity 10, which plays a radial limiting role on the first screw 9, prevents the first screw 9 from radially offset, and ensures that the first screw 9 is always effectively engaged with the force-bearing thread 8.

[0028] In this embodiment, the slider 4 is in the shape of an elongated strip, and the bottom of the slider 4 is covered with force threads 8 from front to back, which not only facilitates its sliding along the main groove 7 and effectively increases the sliding range of the slider 4, but also ensures that it can always match and engage with the first screw 9 through the force threads 8 provided at its bottom during the sliding process, thereby increasing the distance adjustment range between the main support member 2 and the auxiliary support member 3 to meet actual usage needs.

[0029] In actual operation, the secondary support member 3 is disposed on the top surface of the slider 4 near the front end of the main support member 2. A secondary guide groove 13 is provided at the rear end of the top surface of the slider 4. The bottom of the clamping member 5 is slidably inserted into the secondary guide groove 13 to control the opening and closing of the clamping jaw 6. The front edge of the top surface of the slider 4 extends upward to form the secondary support member 3. The secondary guide groove 13 is provided at the rear end of the top surface of the slider 4. The secondary guide groove 13 is arranged in the same direction as the main guide groove 7, ensuring that the clamping member 5 can slide along the secondary guide groove 13 toward the secondary support member 3 and be firmly clamped on the lower jaw.

[0030] In actual operation, a through hole 14 connected to the secondary guide groove 13 is provided on the rear end wall of the slider 4, and a force-bearing screw hole 15 is provided at the bottom of the clamping member 5 along the length direction of the secondary guide groove 13. A second screw 16 is screwed in the force-bearing screw hole 15, and the rear end of the second screw 16 extends backward and is exposed after passing through the through hole 14 to form a rotating force part 17. The second screw 16 is rotated by the rotation force part 17 and drives the clamping member 5 to slide back and forth along the secondary guide groove 13 through the force-bearing screw hole 15, so that the opening and closing of the clamp 6 can be controlled. One end of the second screw 16 is exposed from the main body 1 and forms a rotation force portion 17, and the other end is inserted into the secondary guide groove 13 and cooperates with the screw hole to play a screw driving role on the clamping member 5, ensuring that the clamping member 5 can reciprocate along the length direction of the secondary guide groove 13 in a fixed posture. The groove walls on both sides of the secondary guide groove 13 contact the bottom side walls of the clamping member 5, effectively preventing the clamping member 5 from deflecting, thereby ensuring that the rotational force from the second screw 16 can be effectively converted into a linear force that drives the clamping member 5 to slide along the secondary guide groove 13.

[0031] In actual operation, a pin hole 18 is set in the area between the rear edge of the slot of the secondary guide groove 13 and the rear edge of the top surface of the slider 4, and a reduced diameter section 21 is provided on the second screw rod 16. When the second screw rod 16 is inserted into the secondary guide groove 13 through the through hole 14, the reduced diameter section 21 is clamped and positioned by the pin 19 passing through the pin hole 18 to limit the axial displacement of the second screw hole along the through hole 14. During installation, first, the bottom of the clamping member 5 is inserted into the auxiliary guide groove, and the force-bearing screw hole 15 and the through-hole 14 are coaxially arranged. After that, the second screw rod 16 passes through the through-hole 14 and the force-bearing screw hole 15 and is rotatably inserted into the front end wall of the auxiliary guide groove 13. The reduced diameter section 21 of the second screw rod 16 is located at the lower end of the pin hole 18. Finally, the pin 19 is inserted into the pin hole 18 from top to bottom and is clamped in the reduced diameter section 21. This ensures that the second screw rod 16 can rotate freely and achieve the purpose of driving the clamping member 5 to move by cooperating with the force-bearing screw hole 15. It also plays an axial limiting role for the second screw rod 16, preventing the second screw rod 16 from axial deviation, and ensuring the driving control accuracy of the clamping member 5. The front end wall of the auxiliary guide groove 13 facing away from the through-hole 14 is provided with a transfer hole, and the end of the second screw rod 16 is rotatably inserted into the transfer hole, which plays a radial limiting role for the second screw rod 16.

[0032] In actual operation, the dorsal sides of the main support member 2 and the auxiliary support member 3 are provided with limiting grooves 22, and the user's teeth are vertically engaged in the pressure groove 19, which effectively prevents the main support member 2 and the auxiliary support member 3 from being separated from the mouth due to excessive or insufficient bite force, ensuring that the oral contour remains fixed for a long time.

[0033] In actual operation, a scale 20 is provided on the side wall of the main body 1, and is arranged along the movable direction of the secondary support 3 to measure the distance between the main support 2 and the secondary support 3. During use, the distance between the main support 2 and the secondary support 3 can be adjusted to an appropriate size before being placed in the support station, or the distance between the main support 2 and the secondary support 3 can be adjusted after being placed in the support station, both of which should be considered as specific embodiments of the present invention.

Claims

1. A mouth gag for magnetic resonance imaging of the temporomandibular joint, comprising a body (1) with a main support (2) and a slider (4) with a secondary support (3), wherein the slider (4) moves along the surface of the body (1) and adjusts the distance between the secondary support (3) and the main support (2), characterized in that: The slider (4) is provided with a movable clamping member (5), and the clamping member (5) cooperates with the auxiliary support member (3) to form a clamping opening (6). The body (1) is clamped and positioned on the clamping object through the clamping opening (6), so that the main support member (2) and the auxiliary support member (3) are positioned at a preset support position.

2. The special mouth opener for MRI of temporomandibular joint according to claim 1, characterized in that: The main support member (2), the auxiliary support member (3) and the clamping member (5) are located on the same straight line, and the main support member (2) and the clamping member (5) are respectively arranged on both sides of the auxiliary support member (3), so that the auxiliary support member (3) can be used in conjunction with the main support member (2) and the clamping member (5).

3. The special mouth opener for MRI of temporomandibular joint according to claim 2, characterized in that: The main body (1) is provided with a main groove (7), the slider (4) is embedded in the main groove (7) in a reciprocating sliding manner, the main support member (2) is arranged at the notch end of the main groove (7), and the slider (4) slides along the main groove (7) and adjusts the distance between the secondary support member (3) and the main support member (2).

4. The special mouth opener for MRI of the temporomandibular joint according to claim 3, characterized in that: The bottom of the slider (4) is provided with a force-bearing thread (8) along its length direction, and the body (1) is provided with a first screw (9), the first screw (9) is provided with a driving portion exposed to the bottom wall of the main groove (7) and engaged with the force-bearing thread (8) and a pushing force portion exposed to the body (1), the first screw (9) is rotated by the force of the pushing force portion and drives the slider (4) to slide back and forth along the main groove (7) through the driving portion and the force-bearing thread (8), so that the distance between the main support member (2) and the auxiliary support member (3) can be adjusted.

5. The special mouth opener for MRI of temporomandibular joint according to claim 4, characterized in that: The main body (1) is provided with an installation cavity (10) in an area below the main groove (7). The installation cavity (10) includes a first cavity opening connected to the bottom wall of the main groove (7) and a second cavity opening opened on the side wall of the main body (1). The first screw (9) is inserted into the installation cavity (10) through the second cavity opening so that the side of the first screw (9) is exposed at the second cavity opening and forms the pushing force portion.

6. The special mouth opener for MRI of temporomandibular joint according to claim 5, characterized in that: A third cavity opening communicating with the outside is provided in the middle of the end wall of the installation cavity (10), and an axial hole (11) is provided in the middle of the first screw rod (9) along its axis and for the rotation shaft (12) to pass through. When the first screw rod (9) is inserted into the installation cavity (10), the rotation shaft (12) passes through the through hole (14) and the axial hole (11) in sequence and is fixedly connected to the end wall of the installation cavity (10), so that the first screw rod (9) can rotate around the rotation shaft (12).

7. A mouth gag for MRI of the temporomandibular joint according to any one of claims 1 to 6, characterized in that: The slider (4) is in the shape of an elongated strip. The auxiliary support member (3) is provided on the top surface of the slider (4) near the front end of the main support member (2). A secondary guide groove (13) is provided at the rear end of the top surface of the slider (4). The bottom of the clamping member (5) is slidably inserted into the secondary guide groove (13) so that the opening and closing of the clamping jaw (6) can be controlled.

8. The special mouth opener for MRI of temporomandibular joint according to claim 7, characterized in that: A through hole (14) communicating with the auxiliary guide groove (13) is provided on the rear end wall of the slider (4); a force-bearing screw hole (15) is provided on the bottom of the clamping member (5) along the length direction of the auxiliary guide groove (13); a second screw rod (16) is screwed in the force-bearing screw hole (15); the rear end of the second screw rod (16) extends backward and is exposed after passing through the through hole (14) to form a rotation force portion (17); the second screw rod (16) is rotated by the force of the rotation force portion (17) and drives the clamping member (5) to slide back and forth along the auxiliary guide groove (13) through the force-bearing screw hole (15), so that the opening and closing of the clamping mouth (6) can be controlled.

9. The special mouth opener for MRI of temporomandibular joint according to claim 8, characterized in that: A pin hole (18) is provided in an area between the rear edge of the slot of the secondary guide groove (13) and the rear edge of the top surface of the slider (4); a reduced diameter section (21) is provided on the second screw rod (16); when the second screw rod (16) is inserted into the secondary guide groove (13) through the through hole (14), the reduced diameter section (21) is positioned by a pin (19) passing through the pin hole (18), so as to limit the axial displacement of the second screw hole along the through hole (14).

10. The special mouth opener for magnetic resonance imaging of the temporomandibular joint according to any one of claims 1 to 6, characterized in that: The back sides of the main support member (2) and the secondary support member (3) are both provided with a limiting tooth groove (22); or, the side wall of the body (1) is provided with a scale ruler (20), and the scale ruler (20) is arranged along the movable direction of the secondary support member (3) to measure the distance between the main support member (2) and the secondary support member (3).

Images