Dental mirror

Abstract

To provide a dental mirror for treatment using the dental mirror in microscopic dentistry, capable of facilitating treatment of all teeth in a lower jaw and preventing damage to a mirror for extending a service life.SOLUTION: A dental mirror 10 comprises: a first mirror 12; a second mirror 14; and a shaft member 16, and a mirror surface of the second mirror 14 is arranged to cross at a prescribed angle θ, for example, 45° with respect to a mirror surface of the first mirror 12. When the first mirror 12 and second mirror 14 supported and fixed to a tip of the shaft member 16 are inserted into the oral cavity of a patient, the first mirror 12 is arranged at a position of looking down on a mandibular tooth row from an upper side, and an image of teeth on the first mirror 12 which is reflected on the second mirror 14 is enter in a field of view by a visual line 25 from an external view point 20. In a microscope field of view 28 of viewing the second mirror 14 from an external part, a positional relationship of the mandibular tooth row becomes a positional relationship in front / rear sides equal to that when the mandibular tooth row is directly viewed from directly above, therefore a treatment tool 34 can be easily operated.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a dental mirror used for performing treatment while viewing the image of the teeth reflected in the mirror under a magnified microscope. [Background technology]

[0002] Conventionally, in microscopic dentistry, as shown in FIG. 10, a dental treatment observation system is used in which a surgical microscope 100 and a display unit (stereoscope) 102 are supported so that they can be moved freely in three dimensions. When treating a patient 106 lying on a treatment table, an operator 104 moves the surgical microscope 100 to a position where the operator can observe the inside of the patient's mouth and proceeds with the dental treatment while checking the microscopic image on the display unit 102 in stereoscopic vision (Patent Document 1).

[0003] In this type of microdental treatment, as in general dental treatment, for parts of the teeth that are difficult for the surgeon 104 to see directly, a technique known as the mirror technique is used, in which the dentist treats the teeth while looking through a dental mirror (Patent Documents 2 and 3). In the mirror technique of microdental dentistry, a dental mirror is inserted into the patient's oral cavity, and the image reflected in the mirror is magnified and viewed through a surgical microscope 100 while treatment is performed.

[0004] The mirror technique in conventional microscopic dentistry is particularly useful in the treatment of the maxillary dentition. The mirror image of the maxillary dentition reflected in the dental mirror, which is magnified by the microscope, is the same as when viewed directly from left to right and front to back, and the operation of positioning the treatment tool on the part of the tooth to be treated appears as a front to back movement in the mirror image in contrast to the actual front to back movement, so the surgeon does not need special training. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-069276 A [Patent Document 2] JP 2015-216944 A [Patent Document 3] Patent Publication No. 2021-108984 [Patent Document 4] Patent No. 3498092 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the mirror technique of microdontology in the mandibular dentition is rarely used because it is technically very difficult.

[0007] 11(A) shows an example of a conventional microdentition mirror technique for the mandibular dentition. As is well known, a dental mirror 110 has a mirror 114 supported and fixed to the tip of a shaft member 112.

[0008] In the description of Fig. 11, the X, Y and Z directions are mutually orthogonal directions, and specifically, the left-right direction when the dental mirror is viewed from the viewpoint direction of the microscope field of view (microscope observation field of view) as the front is defined as the X direction, the front-back direction is defined as the Y direction, and the up-down direction is defined as the Z direction. In addition, the +X side in the X direction is defined as the right side, the -X side is defined as the left side, the +Y side in the Y direction is defined as the front side (depth side), the -Y side is defined as the rear side (near side), the +Z side in the Z direction is defined as the upper side, and the -Z side is defined as the lower side. In this respect, the X, Y and Z directions are the same in Figs. 1 to 9 which are the embodiment of the present invention and Figs. 13 to 15 which are the conventional example.

[0009] In the mirror technique of microscopic dentistry for the mandibular dentition, the surgeon inserts the mirror 114 of the dental mirror 110 into the patient's oral cavity so that the mandibular teeth are reflected, and the image of the teeth reflected on the mirror surface is observed through a microscope from a front viewpoint 116, and is enlarged and displayed, for example, as in the microscope field of view 118 shown in Fig. 11(B). Here, the microscope field of view 118 in Fig. 11(B) is an example in which part A (first molar) on the left side shown in the mandibular model 120 in Fig. 12 is reflected on the mirror 114 and enlarged and displayed. Note that the arrow 122 is placed diagrammatically to indicate the direction of the image reflected on the mirror.

[0010] As shown in Fig. 11(B), the image reflected on the dental mirror 110 in the mirror technique for the mandibular dentition is the same as when viewed directly, but the front and back (back and front) are reversed. For example, as shown in Fig. 13(B), when a treatment instrument 124 is positioned on a tooth to be treated in a mirror image of teeth in which the front and back are reversed, the operation appears to move from back to front, as opposed to the actual movement from front to back, as shown in the microscope field of view 118 in Fig. 13(B), and the surgeon 104 is required to make corrections to visually recognize the image in the same way as when viewed directly, which requires considerable training.

[0011] Furthermore, in microscopic dental treatment, the treatment area on the dental mirror 110 is enlarged and displayed in the field of view of the microscope, and the anatomical morphology around the mirror cannot be seen in the microscope field of view 118. For this reason, it is necessary to move the treatment instrument 124 in any direction while viewing only the enlarged portion of the microscope field of view 118 reflected and inverted on the dental mirror 110, making treatment of the mandible more difficult.

[0012] In addition, the dental mirror 110 used in microscopic dentistry has another problem in that the reflective surface is likely to come into contact with the treatment instrument 124 during the mirror technique, as shown in FIG. 13(A), and the reflective surface is easily scratched.

[0013] In addition, since conventional dental mirrors are single-sided, it is difficult to see the fine details and backsides of teeth, so a dental mirror 130 has been proposed in which a circular mirror is divided by a straight line into two semicircular mirrors 134, 138 and connected by a hinge 136, as shown in Figure 14 (Patent Document 4).

[0014] However, when a dental mirror 130 having split semicircular mirrors 134, 138 connected by a hinge 136 is used in microscopic dentistry, the surgeon must move the mirror surface of the split mirrors 134, 138, which have different inclinations, to align the viewpoint 116 corresponding to the microscope field of view 118.In this case, the movement from back to front is seen in reverse to the actual movement from front to back, and as with the single mirror shown in Figures 11 and 13, the surgeon must make corrections to visually recognize the image in the same way as when looking directly, which requires considerable training.

[0015] Also, as shown in Fig. 15, dental mirror 130 is arranged so that front split mirror 134 overlooks the teeth of the mandibular dentition, and rear split mirror 138 is arranged at an angle so that the image of front split mirror 134 is viewed from outside, so that when one tries to view the image of split mirror 138 in the same way as when looking directly at it, there is a problem that shaft member (holder) 132 is located between external viewpoint 116 and rear split mirror 138, blocking the view, making it impossible to see the image of the rear split mirror from outside. In other words, dental mirror 130 is not intended to be used in such a way that the image of front split mirror 134 is reflected on rear split mirror 138 and viewed from outside, as shown in Fig. 15.

[0016] To provide a dental mirror which, in treatment using a dental mirror in microdental dentistry, facilitates treatment of all teeth in the lower jaw, prevents the mirror surface from being scratched, and extends the life of the mirror. [Means for solving the problem]

[0017] (dental mirror) The present invention is a dental mirror for use in microdental treatment, A first mirror having a mirror surface formed on one side; A second mirror having a mirror surface formed on one side thereof and disposed so that the mirror surface intersects with the mirror surface of the first mirror at a predetermined acute angle; a shaft member that supports and fixes the first mirror and the second mirror at one end on the oral cavity side via a predetermined support structure so that, when the first mirror and the second mirror are inserted into the oral cavity, the mirror surface of the first mirror faces the row of teeth of the mandible at a predetermined angle and the mirror surface of the second mirror can be observed from outside the oral cavity; The present invention is characterized by comprising:

[0018] (mirror intersection angle) The first mirror and the second mirror are arranged so that the mirror surface crossing angle between the first mirror and the second mirror is a predetermined angle in the range of 40° to 50°, and preferably approximately 45°.

[0019] (Shaft component arrangement) The shaft member and the first mirror are arranged so that an extension line of the mirror surface of the first mirror forms a predetermined angle in the range of 27.5° to 37.5° with respect to the axial center line of the shaft member.

[0020] (Mirror support structure for shaft member) The shaft member has an end on the oral cavity side, and the rear side of the first mirror or the second mirror is supported and fixed via a support structure. The support structure disposes the first mirror and the second mirror on the right side of the shaft member when viewed from the back surface direction of the first mirror.

[0021] (Movement structure of the second mirror) The second mirror is provided with a moving structure that enables the second mirror to move relative to the first mirror while maintaining the mirror surface crossing angle.

[0022] (Example of a moving structure) The moving structure is A guide shaft fixed in a direction perpendicular to the mirror surface of the first mirror; a slider portion that supports the second mirror relative to the first mirror so as to be movable along a guide shaft while maintaining a mirror surface crossing angle; a fixing member for fixing or releasing the slider portion to or from the guide shaft; Equipped with. Effect of the Invention

[0023] (Dental mirror effect) The present invention is a dental mirror used in microscopic dental treatment, comprising a first mirror having a mirror surface formed on one side; a second mirror having a mirror surface formed on one side and positioned so that the mirror surface intersects with the mirror surface of the first mirror at a predetermined acute angle; and a shaft member that supports and fixes the first and second mirrors via a predetermined support structure at one end facing the oral cavity so that when the first and second mirrors are inserted into the oral cavity, the mirror surface of the first mirror faces the lower jaw dentition at a predetermined angle and the mirror surface of the second mirror can be observed from outside the oral cavity.Therefore, when the surgeon inserts the first mirror and the second mirror held at the tip of the shaft member into a patient's oral cavity and positions the mirror surface of the first mirror in a position that overlooks the lower jaw teeth to be treated from above, an image of the teeth reflected by the mirror surface of the first mirror will be projected onto the mirror surface of the second mirror, which is positioned at a crossing angle of, for example, 45°, and when the mirror surface of the second mirror is viewed from outside the oral cavity, it will have the same front-to-back relationship as if it were viewed directly. Therefore, when the surgeon uses an instrument to perform treatment while observing the image of the teeth reflected on the surface of the second mirror with a treatment microscope, moving the instrument back and forth will also move back and forth in the same way in the microscope's field of view, and the movement of the instrument in the microscope's field of view will be the same as when viewed directly, making it possible for the surgeon to easily treat all of the teeth in the lower jaw in treatment using a dental mirror in microscopic dentistry without the need for special training.

[0024] In addition, because the movement of the instruments observed through the microscope field of view is the same as when viewed directly, the surgeon will not accidentally hit the instruments he is using for treatment against the mirror surface, preventing scratches on the mirror surface and making it possible to sufficiently extend the life of the dental mirror.

[0025] (Effect of mirror crossing angle) The first mirror and the second mirror are arranged so that the crossing angle between the mirror surfaces of the first mirror and the second mirror is a predetermined angle in the range of 40° to 50°, preferably approximately 45°. Therefore, when the surgeon arranges the first mirror in a position to look down on the patient's lower jaw teeth from above, the image reflected on the mirror surface of the first mirror can be reflected on the mirror surface of the second mirror and observed from a line of sight from outside the oral cavity.

[0026] Here, when the mirror crossing angle between the mirror surface of the first mirror and the mirror surface of the second mirror is larger than 50°, the degree to which the first mirror blocks the line of sight to the second mirror increases, so the upper limit of the mirror crossing angle is approximately 50°. When the mirror crossing angle between the mirror surface of the first mirror and the mirror surface of the second mirror is smaller than 30°, the first mirror and the second mirror interfere with each other, narrowing the line of sight to the second mirror, so the lower limit is approximately 40°. When the mirror crossing angle between the mirror surface of the first mirror and the mirror surface of the second mirror is 45°, the line of sight to the second mirror is maximized, so the surgeon can easily proceed with treatment by operating the treatment instrument in the same way as when looking directly at the teeth while looking at the teeth magnified in the microscope field of view.

[0027] (Effect of shaft material) Furthermore, the shaft member and the first mirror are positioned so that the extension line of the mirror surface of the first mirror forms a specified angle in the range of 27.5° or more and 37.5° or less with respect to the axial line of the shaft member.Therefore, when the surgeon inserts the first mirror and the second mirror at the tip of the shaft member into the patient's oral cavity, the surgeon can appropriately and easily hold the first mirror in a position looking down on the lower jaw teeth from above, ensuring a sufficient field of view when the second mirror is looked at from outside, and making it possible to easily perform microscopic dental treatment of all of the lower jaw teeth while viewing the reflected image of the teeth in the second mirror.

[0028] (Effect of the mirror support structure of the shaft member) In addition, the shaft member supports and fixes the back side of the first mirror or second mirror via a support structure at one end facing the oral cavity, and the support structure positions the first mirror and the second mirror on the right side of the shaft member when viewed from the rear direction of the first mirror.Therefore, by holding the first mirror in a position where it looks down on the patient's lower jaw teeth from above, a sufficient field of view can be secured when the second mirror is directed from outside, and therefore the first mirror and second mirror held at the tip of the shaft member can be appropriately inserted and positioned in the oral cavity so that the surgeon can perform microscopic dental treatment of all of the lower jaw teeth while viewing the reflected image of the teeth in the second mirror.

[0029] (Effect of the moving structure of the second mirror) The device also has a moving structure that allows the second mirror to move relative to the first mirror while maintaining the mirror crossing angle.This moving structure includes, for example, a guide axis fixed in a direction perpendicular to the mirror surface of the first mirror, a slider section that supports the second mirror so that it can move freely along the guide axis while maintaining the mirror crossing angle relative to the first mirror, and a fixing member that fixes and releases the slider section to the guide axis.Since the space in the oral cavity is larger on the front side of the mandibular dentition and the space becomes narrower toward the back, the surgeon can adjust the position of the second mirror relative to the first mirror so that it is appropriately positioned depending on the position of the tooth to be treated, that is, the distance between the second mirror and the first mirror is larger on the front tooth side, while the distance between the second mirror and the first mirror is smaller on the back tooth side. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is an explanatory diagram showing a first embodiment of a dental mirror. [Diagram 2] 2 is an explanatory diagram showing an optical system for observing the lower jaw dentition using a first mirror and a second mirror. FIG. [Diagram 3] 1 is an explanatory diagram showing an example of use of the dental mirror of the first embodiment on the mandibular dentition and a microscope field of view. FIG. [Figure 4] 1A to 1C are explanatory diagrams showing an example of use of the dental mirror and treatment instrument of the first embodiment on the mandibular dentition and a microscope field of view. [Diagram 5] FIG. 11 is an explanatory diagram showing a second embodiment of a dental mirror. [Figure 6] FIG. 11 is an explanatory diagram showing an example of using the dental mirror of the second embodiment on the mandibular dentition. [Figure 7] FIG. 11 is an explanatory diagram showing a third embodiment of a dental mirror. [Figure 8] FIG. 13 is an explanatory diagram showing an example of using the dental mirror of the third embodiment on the molar side of the mandibular dentition. [Figure 9]FIG. 11 is an explanatory diagram showing an example of using the dental mirror of the third embodiment on the anterior teeth side of the mandibular dentition. [Figure 10] FIG. 1 is an explanatory diagram showing a dental treatment system used in conventional microdental dentistry. [Figure 11] FIG. 1 is an explanatory diagram showing an example of using a conventional dental mirror on the mandibular dentition. [Figure 12] FIG. 2 is an explanatory diagram showing the dentition of a lower jaw model. [Figure 13] 1 is an explanatory diagram showing an example of the use of a conventional dental mirror and tools on the mandibular dentition and a microscope field of view. [Figure 14] FIG. 1 is an illustration showing the use of a conventional dental mirror having hinged split mirrors. [Figure 15] 15 is an explanatory diagram showing an unintended use of the split mirror of FIG. 14. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a dental mirror according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following preferred embodiments.

[0032] [Basic Concept of the Embodiment] The embodiments relate generally to dental mirrors used in microdental procedures.

[0033] Here, "microscope dentistry" refers to a dental treatment in which a surgical microscope is moved to a position where the inside of the patient's oral cavity can be observed, and the surgeon performs dental treatment while checking the microscope image in stereoscopic vision. Also, a "dental mirror" generally refers to a mirror dedicated to dentistry, in which a circular mirror is attached to the tip of a shaft member, and the surgeon performs dental treatment while viewing the part of the tooth that is difficult for the surgeon to see directly on the mirror, and includes the concept of a dental mirror. The "shaft member" of a dental mirror is a rod-shaped member that supports and fixes the circular mirror to one end on the oral cavity side, and is a concept that includes a holder part, a handle part, a stick part, and a pattern.

[0034] In addition, "microscopic dental treatment using a dental mirror" refers to dental treatment in which the surgeon projects parts of the teeth that are difficult to see directly onto a dental mirror and then magnifies the image reflected in the dental mirror using a surgical microscope.

[0035] The "dental mirror used in microscopic dental treatment" of the embodiment is composed of a first mirror having a mirror surface formed on one side, a second mirror having a mirror surface formed on one side and positioned so that the mirror surface intersects with the mirror surface of the first mirror at a predetermined acute angle, and a shaft member at one end facing the oral cavity that supports and fixes the first mirror and second mirror via a predetermined support structure.

[0036] In addition, the "shaft member" is positioned so that when the surgeon inserts the first mirror and second mirror, which are supported and fixed at one end facing the oral cavity, into the patient's oral cavity, the mirror surface of the first mirror faces the row of teeth on the mandible at a specified angle and the mirror surface of the second mirror can be observed from a direction outside the oral cavity.

[0037] With this embodiment of the dental mirror, when the first mirror and the second mirror supported and fixed to the tip of the shaft member are inserted into the patient's oral cavity and the mirror surface of the first mirror is positioned so as to look down on the lower jaw tooth to be treated, the image of the tooth reflected in the first mirror is reflected in the second mirror, resulting in the same front-to-back relationship when the surgeon views the second mirror from outside the oral cavity as when looking directly at it.When an instrument is used to perform treatment while observing the image of the tooth on the second mirror with a treatment microscope, moving the instrument back and forth will also move back and forth in the same way in the microscope field of view, and the movement of the instrument in the microscope field of view will be the same as when viewed directly, making it possible for the surgeon to easily treat all of the teeth in the lower jaw in treatment using a dental mirror in microscopic dentistry without requiring any special training.

[0038] In addition, because the movement of the treatment instrument viewed by the surgeon through the microscope field is the same as when viewed directly, the treatment instrument will not hit the mirror surface of the dental mirror, preventing scratches on the mirror surface and sufficiently extending the life of the dental mirror.

[0039] The first mirror and the second mirror are arranged so that the mirror surface crossing angle between the first mirror and the second mirror is a predetermined angle in the range of 40° to 50°, preferably about 45°. By setting the mirror surface crossing angle between the first mirror and the second mirror to a predetermined angle in the range of 40° to 50° in this manner, when the surgeon places the first mirror in a position to look down on the lower jaw teeth from above, the image reflected on the first mirror can be reflected on the mirror surface of the second mirror and observed from a line of sight from outside the oral cavity.

[0040] Here, when the mirror surface crossing angle between the first mirror and the second mirror is larger than 50°, the degree to which the first mirror blocks the line of sight to the second mirror increases, so the upper limit is approximately 50°. Also, when the mirror surface crossing angle between the first mirror and the second mirror is smaller than 30°, the first mirror and the second mirror interfere with each other, narrowing the line of sight to the second mirror, so the lower limit is approximately 40°. And, when the mirror surface crossing angle between the first mirror and the second mirror is 45°, the line of sight to the second mirror is maximized, so the surgeon can easily proceed with treatment by operating the treatment instruments in the same way as when looking directly at the teeth while looking at the teeth magnified in the microscope field of view.

[0041] Furthermore, the shape and size of the first mirror and the second mirror are arbitrary; for example, the first mirror and the second mirror may be circular mirrors of approximately the same size, or elliptical mirrors of approximately the same size, or rectangular mirrors with chamfered corners.

[0042] Furthermore, the first mirror is disposed on the "shaft member" so that the extension line of the mirror surface of the first mirror forms a predetermined angle in the range of 27.5° to 37.5° with respect to the axial center line. Therefore, when the surgeon inserts the first mirror and the second mirror supported and fixed to the tip of the shaft member into the oral cavity of a patient, the surgeon can appropriately and easily hold the first mirror in a position that overlooks the teeth of the lower jaw from above, ensure a sufficient field of view when the second mirror is directed from the outside, and easily perform microdental treatment of all the teeth of the lower jaw while viewing the reflected image of the teeth on the second mirror.

[0043] Here, if the angle between the axis line of the shaft member and the extension line of the mirror surface of the first mirror is greater than 37.5°, when the surgeon inserts the first mirror and the second mirror into the oral cavity of the patient, the shaft member interferes with the front teeth side of the upper jaw, restricting the insertion into the oral cavity, so the upper limit of the angle between the axis line of the shaft member and the extension line of the mirror surface of the first mirror is approximately 37.5°. Also, if the angle between the axis line of the shaft member and the extension line of the mirror surface of the first mirror is less than 5°, the shaft member interferes with the first mirror and the second mirror side, narrowing the line of sight to the second mirror, so the lower limit is approximately 27.5°. Therefore, an angle of approximately 32.5° is optimal as an angle that does not restrict the insertion of the first mirror and the second mirror into the oral cavity and does not obstruct the line of sight to the second mirror.

[0044] In addition, the "mirror support structure of the shaft member" refers to one end of the shaft member that faces the oral cavity supporting and fixing the back side of the first mirror or the second mirror. Therefore, by holding the first mirror in a position where the surgeon can look down on the patient's lower jaw teeth from above, the surgeon can ensure a sufficient field of view when looking from outside at the second mirror, and therefore the surgeon can properly insert and position the first mirror and the second mirror held at the tip of the shaft member into the oral cavity so that he or she can perform microdental treatment of all the teeth in the lower jaw while looking at the reflected image of the teeth in the second mirror.

[0045] Moreover, the embodiment includes a moving structure that allows the second mirror to move relative to the first mirror while maintaining the mirror surface crossing angle. Here, the "moving structure" is arbitrary, but may include, for example, a guide shaft fixed in a direction perpendicular to the mirror surface of the first mirror, a slider unit that supports the second mirror so that it can move freely along the guide shaft while maintaining the mirror surface crossing angle, and a fixing member that fixes or releases the slider unit relative to the guide shaft.

[0046] Since the oral cavity space is larger on the front side of the mandibular dentition and becomes narrower toward the back, this "moving structure of the second mirror" is used by the surgeon to adjust the second mirror to an appropriate position relative to the first mirror according to the position of the tooth to be treated. In other words, the distance between the second mirror and the first mirror is made larger on the front teeth side, while the distance between the second mirror and the first mirror is made smaller on the back teeth side, making it possible to adjust the position of the second mirror to an appropriate position for use.

[0047] Specific embodiments will be described below. In the specific embodiments shown below, a dental mirror in which the tip of the shaft member is supported and fixed to the left side of the back surface of the first mirror when viewed from the back surface direction of the first mirror will be referred to as a "first dental mirror embodiment," a dental mirror in which the tip of the shaft member is supported and fixed to the left side of the back surface of the second mirror will be referred to as a "second dental mirror embodiment," and a dental mirror in which the second mirror is provided with a moving structure will be referred to as a "third dental mirror embodiment."

[0048] [Specific details of the embodiment] The embodiment of the dental mirror for use in microdental dentistry will now be described in more detail, with the contents being divided into the following parts: a. First embodiment of dental mirror a1.Structure a2.Optical system a3. Example of microscope dentistry using a dental mirror b. Second embodiment of dental mirror c. Third embodiment of dental mirror d. Modifications of the present invention

[0049] [a. First embodiment of dental mirror] First, a first embodiment of the dental mirror will be described. In this description, reference will be made to Fig. 1 showing the first embodiment of the dental mirror. Fig. 1(A) shows a side view of the dental mirror, and Fig. 1(B) shows a plan view of the dental mirror.

[0050] (a1. structure) 1(A), in the dental mirror 10 of this embodiment, a first mirror 12 and a second mirror 14 are supported and fixed to the tip of a shaft member 16 via a support arm 1610. The first mirror 12 and the second mirror 14 may have any shape, for example, a circular mirror. The mirror structures of the first mirror 12 and the second mirror 14 are also known, for example, a mirror structure in which a reflective layer is formed on the back surface of a circular glass plate having a predetermined thickness.

[0051] Furthermore, the support structure for the first mirror 12 and the second mirror 14 is also arbitrary, but for example, the first mirror 12 and the second mirror 14 are fitted and fixed in mirror covers 1210, 1410, respectively, which have a storage section for a circular mirror.

[0052] The first mirror 12 and the second mirror 14 are fitted and fixed into the mirror covers 1210, 1410, and are connected to the mirror covers 1210 and 1410 by a mirror connecting part 15 so that the mirror extension 18 of the first mirror 12 and the mirror extension 19 of the second mirror 14 intersect at point P at a mirror crossing angle θ, which is a predetermined acute angle, and the first mirror 12 and the second mirror 14 connected by the mirror connecting part 15 are arranged at the tip of the shaft member 16 via a support arm 1610.

[0053] Here, the mirror crossing angle θ between the mirror surface of the first mirror 12 and the mirror surface of the second mirror 14 is arbitrary, but is, for example, a predetermined angle within a range of 40° to 50°, and in Fig. 1, the mirror crossing angle θ is 45°, which is the optimal value. When the surgeon treats the lower jaw dentition of a patient, the first mirror 12 is positioned so that it looks down on the teeth to be treated when inserted into the patient's oral cavity. The second mirror 14 reflects the image of the teeth reflected on the first mirror 12, and the image on the mirror surface is enlarged and displayed by an external surgical microscope, making it possible to observe it.

[0054] Also, the mirror surface extension line 18 of the first mirror 12 is disposed at a predetermined inclination angle α with respect to the axial center line 1620 of the shaft member 16. The inclination angle α is arbitrary, but is, for example, a predetermined angle within a range of 27.5° to 37.5°, and Fig. 1 shows a case where the inclination angle α is 32.5°, which is the optimal value.

[0055] Also, as shown in FIG. 1(B), the tip of the support arm 1610 at the tip side facing the oral cavity of the shaft member 16 is bent to the right at approximately a right angle when viewed from the rear surface of the first mirror 12 (in the illustrated state with the mirror surface facing downwards) to support and fix a mirror support portion 1220 provided on the mirror cover 1210 on the rear surface of the first mirror 12.

[0056] In this way, the dental mirror 10 in which the shaft member 16 is disposed on the left side of the first mirror 12 as viewed from the back of the first mirror 12 is intended for use by a right-handed surgeon. The surgeon, holding the shaft member 16 of the dental mirror 10 in the left hand and the treatment instrument in the right hand, inserts the dental mirror 10 into the oral cavity of the patient, positions the first mirror 12 in a position that overlooks the teeth to be treated in the mandibular dentition from above, and projects the image of the patient's teeth reflected on the first mirror 12 (by the first mirror 12) onto the second mirror 14, enabling treatment to be performed while viewing the image on the second mirror 14 from the outside (outside the oral cavity) with a surgical microscope. Note that, if the surgeon is left-handed, the dental mirror 10 may be configured so that the shaft member 16 is disposed on the right side of the first mirror 12 as viewed from the back of the first mirror 12.

[0057] (a2.optical system) Next, the optical system of the dental mirror will be described with reference to Fig. 2, which shows an optical system for observing the lower jaw dentition using a first mirror and a second mirror.

[0058] The dental mirror of the embodiment is intended to observe the mandibular dentition in the oral cavity, and in Fig. 2, the mandibular dentition is shown as a virtual observation surface 22. The first mirror 12 is disposed at a position facing the observation surface 22 at an inclination angle of 22.5° and looking down on it from above, and the second mirror 14 is disposed at an inclined position with respect to the first mirror 12 at a mirror surface crossing angle θ of 45°, so that it can be observed by a line of sight 25 from an external viewpoint 20, which is the microscope field of view. That is, the dental mirror of the embodiment makes it possible to view the image of the observation surface 22 reflected on the first mirror 12 on the second mirror 14 by the line of sight 25 from the viewpoint 20.

[0059] Furthermore, if the image on observation surface 22 is represented by an arrow pointing from the front to the back (an arrow going from -Y to +Y), the image of first mirror 12 is an arrow with an inclination angle of 22.5° from observation surface 22, and the image of second mirror 14 is an arrow pointing diagonally upward at an inclination angle of 67.5° from observation surface 22, and when second mirror 14 is viewed from viewpoint 20, it appears as an arrow pointing up and down perpendicular to observation surface 22.

[0060] Therefore, when the treatment instrument is moved from the front to the depth along the observation surface 22, the image of the treatment instrument reflected on the second mirror 14 seen from the viewpoint 20 moves from bottom to top, and since both movements are from a close position to a far position, it can be perceived as the same movement as when viewed directly.

[0061] Here, the vertical distance H between the upper end of the first mirror 12 and the lower end of the second mirror 14 is an arbitrary distance that allows the innermost tooth (second molar) of the lower dentition in the oral cavity to be observed. In order to reduce this distance H, the first mirror 12 and the second mirror 14 are moved closer to the intersection point P while maintaining the mirror crossing angle θ of 45°, resulting in an arrangement structure in which the distance H is set to a predetermined value that allows the innermost tooth (second molar) of the lower dentition to be observed.

[0062] (a3. Example of microscope dentistry using a dental mirror) Next, an example of use of microscopic dentistry using the dental mirror of this embodiment will be described. In this description, reference will be made to Fig. 3, which shows an example of use of the dental mirror of the first embodiment on the mandibular dentition and the microscope field of view, and Fig. 4, which shows an example of use of the dental mirror and treatment instrument of the first embodiment on the mandibular dentition and the microscope field of view. Fig. 3(A) and Fig. 4(A) show the use state when the dentition is viewed from the side, and Fig. 3(B) and Fig. 4(B) show the microscope field of view.

[0063] 3, when the tooth 30 (second premolar on the right side) of the mandibular dentition 26 is to be treated, for example, the surgeon holds the shaft member 16 of the dental mirror 10 with his left hand, inserts the first mirror 12 and the second mirror 14 supported and fixed to the tip of the shaft member 16 into the patient's oral cavity, and positions the first mirror 12 above looking down on the tooth 30 to be treated. In this case, the second mirror 14 is positioned diagonally upward relative to the first mirror 12 and behind the tooth 30.

[0064] In this state, the surgeon, while looking at the second mirror 14 as shown in the line of sight 25 from an external viewpoint 20, adjusts the orientation of the first mirror 12 relative to the tooth 30 using the shaft member 16 so that the image of the tooth 30 on the first mirror 12 reflected on the second mirror 14 is visible.

[0065] Therefore, as shown in the microscope field of view 28 in Fig. 3(B), an image of the tooth 30 viewed from above is displayed enlarged as an image of the second mirror 14 viewed from the viewpoint 20. Note that the arrow 32 indicates the direction when the tooth 30 is viewed from the front to the depth direction, and as shown in Fig. 10, when the surgeon 104 views the display unit 102, the direction is from bottom to top.

[0066] Next, as shown in Fig. 4(A), the surgeon inserts the necessary treatment instrument 34 into the oral cavity and performs an operation to position the instrument tip 3410 at the treatment site of the tooth 30. In this case, as shown in Fig. 4(B), the surgeon performs an operation to move the treatment instrument 34 so as to position the instrument tip 3410 at the treatment site while observing the tooth 30 in the microscope field of view 28, but when the treatment instrument 34 is moved from the front (-Y side) to the back (+Y side), the instrument tip 3410 viewed in the microscope field of view 28 also moves from the front (-Y side) to the back (+Y side), and the movement when actually viewed becomes the same as the movement when the second mirror 14 is viewed through a surgical microscope, and the surgeon can easily treat all the teeth of the mandibular dentition 26 by the mirror technique using the dental mirror 10 of this embodiment without requiring special training.

[0067] Furthermore, as shown in FIG. 4(A), the first mirror 12 is positioned above the tooth 30 to be treated, and the second mirror is positioned behind the tooth 30 to be treated, so that even when the tip 3410 of the treatment instrument 34 is moved to the tooth 30, there is almost no risk of the mirror surface of the first mirror 14 or the second mirror 14 being hit and damaged. This reliably prevents the mirror surfaces of the first mirror 12 and the second mirror 14 from being scratched, and improves the durability of the dental mirror 10 of the embodiment.

[0068] Here, the mirror crossing angle θ between the first mirror 12 and the second mirror 14 is set to an optimal angle of 45°, but the mirror crossing angle θ can be any angle within a range of 40° to 50°. In this case, if the mirror crossing angle θ is greater than 50°, the degree to which the first mirror 12 blocks the field of view indicated by the line of sight 25 from the viewpoint 20 toward the second mirror 14 increases, so the upper limit of the mirror crossing is approximately 50°.

[0069] Furthermore, if the mirror surface intersection angle θ between the first mirror 12 and the second mirror 14 is smaller than 40°, the first mirror 12 and the second mirror 14 will interfere with each other, narrowing the field of view of the line of sight 25 toward the second mirror 14, so the mirror surface intersection has a lower limit of approximately 40°.

[0070] 1, the mirror surface extension line 18 of the first mirror 12 is disposed to have a predetermined inclination angle α in the range of 27.5° to 37.5° with respect to the shaft member 16. Here, if the inclination angle α of the shaft member 16 becomes larger than 37.5°, the shaft member 16 will interfere with the front teeth side of the maxillary dentition 24, restricting its insertion into the oral cavity, and in order to prevent this, the inclination angle α is set at an upper limit of approximately 37.5°.

[0071] Furthermore, if the inclination angle α of the shaft member 16 is smaller than 27.5°, the shaft member 16 will interfere with the first mirror 12 and the second mirror 14, narrowing the field of view of the line of sight 25 to the second mirror 14, and in order to prevent this, the lower limit of the inclination angle α is approximately 5°. The optimal inclination angle α of the shaft member 16 is approximately 32.5°, which is an angle that does not restrict the insertion of the first mirror 12 and the second mirror 14 into the oral cavity and does not obstruct the field of view of the line of sight to the second mirror 14.

[0072] [b. Second embodiment of dental mirror] Next, a second embodiment of the dental mirror will be described. In this description, reference will be made to Fig. 5 showing the second embodiment of the dental mirror and Fig. 6 showing an example of using the dental mirror of the second embodiment on the mandibular dentition. Fig. 5(A) shows a side view, and Fig. 5(B) shows a plan view.

[0073] As shown in Figure 5(A), the first mirror 12 and the second mirror 14 are supported and fixed to the tip of the shaft member 16 with the mirror surface crossing angle θ being 45°, and the second embodiment is characterized in that the second mirror 14 is supported and fixed via a support arm 1610 provided at the tip of the shaft member 16, as shown in Figure 5(B).

[0074] That is, the tip of the support arm 1610 is bent approximately 90° from the left side to the right of the second mirror 14 when viewed from the rear direction of the first mirror 12 and is fixed to a mirror cover 1410 on the rear of the second mirror 14, and further, the mirror cover 1210 on the rear of the first mirror 12 is supported by the mirror cover 1410 on the rear of the second mirror 14 via the mirror connection part 15.

[0075] In this manner, in the dental mirror 10 in which the tip of the shaft member 16 supports and fixes the second mirror 14 from the left side as viewed from the rear direction of the first mirror 12, when treating, for example, tooth 30 of the mandibular dentition 26, as shown in Fig. 6, the surgeon inserts the first mirror 12 and the second mirror 14 into the oral cavity of the patient using the shaft member 16 and positions the first mirror 12 at a position that overlooks the tooth 30 from above, but at this time, since the second mirror 14 is supported and fixed to the tip of the shaft member 16, the shaft member 16 is positioned approximately in the center of the oral cavity compared to the first embodiment in Fig. 3(A). This allows the surgeon to have some leeway in the movement of the shaft member 16 in order to determine the positions of the first mirror 12 and the second mirror 14 in the oral cavity of the patient, making it easier to perform the mirror technique for treating any tooth of the mandibular dentition 26 using a microdentistry.

[0076] In the second embodiment of the dental mirror 10, the shaft member 16 is arranged to the left of the second mirror 12 when viewed from the rear of the first mirror 12 for right-handed use (holding a treatment instrument in the right hand and a dental mirror in the left hand). However, if the shaft member 16 is arranged on the right side of the mirror connection part 15 connecting the first mirror 12 and the second mirror 14 when viewed from the rear of the first mirror 12, it can be used for left-handed use (holding a treatment instrument in the left hand and a dental mirror in the right hand).

[0077] [c. Third embodiment of dental mirror] Next, a third embodiment of the dental mirror will be described. In this description, reference is made to Fig. 7 showing the third embodiment of the dental mirror, Fig. 8 showing an example of using the dental mirror of the third embodiment on the back teeth side of the mandibular dentition, and Fig. 9 showing an example of using the dental mirror of the third embodiment on the front teeth side of the mandibular dentition. Fig. 7(A) shows a side view, and Fig. 7(B) shows a plan view.

[0078] 7, the dental mirror 10 of this embodiment is characterized in that it includes a moving structure 36 that moves the second mirror 14 while maintaining the mirror surface crossing angle θ relative to the first mirror 14. The structure and function of the moving structure 36 are arbitrary, but it may include, for example, an axis holder 38, a guide axis 40, a slide portion 42, a locking screw 44, and a stopper portion 46.

[0079] The guide shaft 40 has one end fixed to the shaft holder 38 fixed to the mirror cover 1210 on the back of the first mirror 12, and is held parallel to the line L connecting the center of the first mirror 12 and the center of the second mirror 14. The slide part 42 is fixed to the mirror cover 1410 on the back of the second mirror 14, and is slidably fitted into the guide shaft 40, allowing the second mirror 14 to move while maintaining a mirror crossing angle θ with the first mirror 12, for example, a mirror crossing angle θ of 45°. The set screw 44 functions as a fixing member that fixes or releases the slide part 42 to the guide shaft 40. The stopper part 46 is a flange part formed at the tip of the guide shaft 40, and prevents the slide part 42 from falling off the guide shaft 40.

[0080] With this type of moving structure 36, since the space in the oral cavity is larger at the front side of the mandibular dentition and becomes narrower toward the back, the second mirror 14 can be moved to any position until it is restricted by a stopper 46 shown by an imaginary line while maintaining the mirror surface intersection angle θ relative to the first mirror 12 according to the position of the tooth to be treated in the mandibular dentition.

[0081] Figure 8 shows a case where the surgeon is treating the back teeth side of the patient's mandibular dentition 26. Since the vertical distance within the oral cavity is small on the back teeth side, the moving structure 36 is used to adjust the second mirror 14 to a position that reduces the distance relative to the first mirror 12.

[0082] Figure 9 shows a case where the surgeon is treating the front teeth side of the patient's mandibular dentition 26. Since the vertical distance in the oral cavity is large on the front teeth side, the moving structure 36 is used to adjust the second mirror 14 to a position that increases the distance from the first mirror 12.

[0083] In this way, the moving structure 36 makes it possible to appropriately adjust the position of the second mirror 14 relative to the first mirror 12 according to the position of the tooth to be treated in the mandibular dentition 26 .

[0084] [d. Modifications of the present invention] Modifications of the dental mirror according to the present invention will now be described. In addition to the above-described embodiment, the dental mirror according to the present invention includes the following modifications.

[0085] (Shape and size of the first and second mirrors) In the above embodiment, the first mirror 12 and the second mirror 14 are the same circular mirror, but the present invention is not limited to this and may be of any suitable shape that does not have any corners that would be a hindrance when inserted into the patient's oral cavity, such as an oval mirror or an elliptical mirror with a major axis in any direction, a rectangular mirror with rounded corners, etc. Also, the first mirror and the second mirror are the same size, but the second mirror may be smaller than the first mirror, for example, as long as it does not restrict the field of view.

[0086] (Microscopic dentistry) The above embodiment has been described with reference to an example in which the dental mirror is used in microdental treatment, but the present invention is not limited to this and does not preclude use in normal dental care other than microdental treatment.

[0087] (others) Furthermore, the present invention includes appropriate modifications that do not impair the objects and advantages of the present invention, and is not limited to the numerical values ​​shown in the above embodiment. [Explanation of symbols]

[0088] 10: Dental mirror 12: 1st mirror 1210,1410:Mirror cover 14: 2nd mirror 15: Mirror connection part 16: Shaft material 1610: Support arm 18,19: Mirror extension line 20: Point of View 22: Observation surface 24: Upper dentition 25: Gaze 26: Mandibular dentition 28: Microscope field of view 30: Teeth 34: Treatment equipment 3410: Instrument tip 36: Moving structure 38: Shaft holding part 40: Guide shaft 42: Slide section 44: Set screw 46: Stopper part 100:Surgical microscope 102: Display unit 104: Surgeon

Claims

1. A dental mirror for use in microdental treatment, A first mirror having a mirror surface formed on one surface; a second mirror having a mirror surface formed on one surface thereof and disposed so that the mirror surface intersects with the mirror surface of the first mirror at a predetermined acute angle; a shaft member that supports and fixes the first mirror and the second mirror at one end on the oral cavity side via a predetermined support structure so that, when the first mirror and the second mirror are inserted into the oral cavity, a mirror surface of the first mirror faces the row of teeth of the mandible at a predetermined angle and a mirror surface of the second mirror can be observed from a direction outside the oral cavity; A dental mirror comprising:

2. 2. The dental mirror of claim 1, A dental mirror, characterized in that the first mirror and the second mirror are arranged so that a mirror surface crossing angle between the first mirror and the second mirror is a predetermined angle in a range of 40° or more and 50° or less.

3. 2. The dental mirror of claim 1, A dental mirror, wherein the first mirror and the second mirror are arranged so that a mirror surface crossing angle between the first mirror and the second mirror is approximately 45°.

4. 2. The dental mirror of claim 1, A dental mirror characterized in that the shaft member and the first mirror are arranged so that the extension line of the mirror surface of the first mirror forms a predetermined angle in the range of 27.5° or more and 37.5° or less with respect to the axial line of the shaft member.

5. 2. The dental mirror of claim 1, The shaft member supports and fixes the back side of the first mirror or the second mirror to one end of the shaft member that is on the oral cavity side via the support structure, A dental mirror, wherein the support structure disposes the first mirror and the second mirror on the right side of the shaft member when viewed from the rear surface direction of the first mirror.

6. 2. The dental mirror of claim 1, A dental mirror comprising a moving structure that enables the second mirror to move relative to the first mirror while maintaining a mirror surface crossing angle.

7. 7. The dental mirror of claim 6, The moving structure includes: A guide shaft fixed in a direction perpendicular to the mirror surface of the first mirror; a slider portion that supports the second mirror relative to the first mirror so as to be movable along the guide shaft while maintaining the mirror surface crossing angle; a fixing member that fixes or releases the slider portion to or from the guide shaft; A dental mirror comprising:

Images