JP6357014B2 - Measurement jig - Google Patents

Description

  The present invention relates to a measuring jig for measuring a bone width from a lingual side surface of an alveolar bone to an implant embedding fossa during treatment of an implant (artificial tooth root).

  In implant treatment, the position of the implant embedding cavity with respect to the alveolar bone is important. For example, the section of the lower jaw after tooth extraction has a complicated shape, and in particular, the lingual cortical bone that forms the side surface of the alveolar bone may be greatly undercut (recessed) on the buccal side. If the implant embedding cavity is formed without confirming the amount of undercut (the amount of depression), the lingual cortical bone may be perforated and the surrounding site may be damaged. Conventionally, a measuring jig for measuring the bone width from the bone surface of the lingual cortical bone to the implant embedding space has been devised in consideration of the undercut amount of the lingual cortical bone of the alveolar bone at the time of implant treatment (for example, , See Patent Document 1).

  In the measurement jig of Patent Document 1, a pair of rotating pieces are cross-connected through a support shaft so as to be openable and closable like a spear, the tip of one rotating piece is formed in a pole shape, and the other rotating piece is The tip of the moving piece is formed in a needle shape bent to one side. Moreover, the gauge for measuring the relative rotation amount of a pair of rotation piece is attached to the measurement jig. The measuring jig is inserted into an implant embedding cavity in which the pole-shaped tip of one rotating piece is drilled in the alveolar bone, and the needle-like tip of the other rotating piece is inserted into the gingiva and lingual cortex Pressed against the bone. By reading the amount of rotation of the pair of rotating pieces at this time from the gauge, the bone width from the implant embedding cavity to the side surface of the alveolar bone is measured.

International Publication No. 2011-018851

  By the way, the appropriate bone width at the time of implant placement varies greatly depending on the position and direction of implantation of the implant and the diameter and major axis (length) of the implant. Since the undercut of the alveolar bone is present in the lingual cortical bone, the longer the implant is placed, the longer the implant can be placed. On the other hand, the closer the implant placement position is to the lingual side, the greater the risk of perforating the lingual cortical bone even with a short implant. In addition, when the upper end of the implant is tilted to the lingual side and the implantation direction is inclined to the lingual side, the risk of piercing the lingual cortical bone is reduced, and conversely, when the implantation direction is inclined to the buccal side, The risk of perforating the lingual cortical bone is increased.

  As the diameter of the implant increases, the outer peripheral surface of the tip of the implant approaches the lingual cortical bone, increasing the risk of perforating the lingual cortical bone. Moreover, since the undercut of the alveolar bone exists in the apical direction of the alveolar bone apex, the risk of perforating the lingual cortical bone decreases as the length of the implant decreases. Conversely, the longer the major axis of the implant, the greater the risk of perforating the lingual cortical bone. The implantation position and orientation of these implants, as well as the diameter and major axis of the implant are determined within many constraints such as the shape of the alveolar bone and the pair of teeth, and are determined according to the size of the undercut amount of the alveolar bone. It is not something.

  Therefore, by measuring the bone width from the lingual cortical bone (side surface) of the alveolar bone to the center of the tip of the implant embedding cavity, it can be confirmed whether or not the implant fits in the mandible. However, in the measurement jig of Patent Document 1, the bone width is measured by rotating the needle-like tip of the other rotating piece while inserting the pole-like tip of one turning piece into the implant embedding cavity. Therefore, an implant embedding cavity must be formed in advance for the alveolar bone. Therefore, when the measurement jig of Patent Document 1 is used, there is a risk of puncturing the lingual cortical bone depending on the position and direction of formation of the implant embedding pit when forming the implant embedding pit.

  This invention is made | formed in view of this point, and it aims at providing the measurement jig | tool which can measure the bone width required for an implant treatment before forming an implant embedding fossa.

  The measuring jig of the present invention is a measuring jig capable of measuring the bone width of the alveolar bone from the planned implantation position of the implant, and has a long scale portion, a stator fixed to the scale portion, , A movable part slidably attached to the scale part, and either one of the stator and the movable part is provided with a pole part to support the scale part, and the stator and the movable part The other end of the child is provided with a bending portion with a tip directed toward the pole portion, and the tip of the bending portion is the tip of the pole portion in a direction perpendicular to the extending direction of the scale portion. It is further away from the scale part.

  According to this structure, the curved portion of the measuring jig is brought into contact with the side surface of the alveolar bone, and the pole portion is projected to the alveolar bone crest (upper part). And while checking the occlusal relationship with the counter teeth, rotate the measuring jig around the pole part and move it to an appropriate position and direction, depending on the distance between the tip of the curved part and the tip of the pole part The mover is slid on the scale. By reading the distance between the stator and the mover at this time on the scale part, the bone width of the alveolar bone from the contact position of the pole part to the contact position of the bending part can be measured. In this way, the bone width required for implant placement can be measured before the implant placement cavity is formed in the alveolar bone. Therefore, it is possible to confirm before operation whether or not an implant with a desired diameter and a long diameter can be placed in a desired planned placement position and a planned placement direction.

  Further, in the measurement jig of the present invention, when the distance between the stator and the mover is 0 in the scale portion, the extension direction of the scale portion is on the extension line of the center position of the tip of the pole portion. The tips of the curved portions are coincident. According to this configuration, the distance from the center position of the tip of the pole portion to the tip of the bending portion can be matched with the distance from the stator to the mover.

  In the measurement jig of the present invention, the bending portion is provided on the stator, and the pole portion is provided on the mover. According to this configuration, the bone width of the alveolar bone from the contact position of the pole portion is measured by bringing the tip of the bending portion into contact with the side surface of the alveolar bone and sliding the pole portion with respect to the bending portion. Can do.

  In the measuring jig of the present invention, the tip of the pole portion is formed in a spherical shape. According to this configuration, the embedding direction can be easily confirmed by swinging the measuring jig with the spherical tip of the pole portion as a fulcrum.

  In the measurement jig of the present invention, the distance from the tip of the pole part to the tip of the curved part in the direction orthogonal to the extending direction of the scale part matches the major axis of the implant. According to this configuration, the bone width of the alveolar bone can be appropriately measured according to the major axis of the implant.

  According to the measuring jig of the present invention, since the bone width of the alveolar bone can be measured without forming an implant embedding fovea in the alveolar bone, the cortical bone of the alveolar bone is perforated when measuring the bone width of the alveolar bone. Is prevented. In addition, it is possible to confirm before operation whether or not an implant having a desired diameter and a long diameter can be placed in a desired placement position and a planned placement direction.

It is an external appearance perspective view of the measuring jig concerning this embodiment. It is a side view of the measuring jig concerning this embodiment. It is explanatory drawing of the measuring method by the measuring jig concerning this Embodiment. It is explanatory drawing of the measuring method by the measuring jig concerning this Embodiment.

  Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a measuring jig according to the present embodiment. FIG. 2 is a side view of the measurement jig according to the present embodiment. 1A and 2A show a state in which the distal end of the bending pin and the extension line of the pole portion coincide with each other, and FIGS. 1B and 2B show a state in which the bending pin and the pole portion are separated from each other. In FIG. 2B, the implant is indicated by a two-dot chain line for convenience of explanation.

  The measuring jig 1 shown in FIG. 1 is configured such that the distal end side of the long handle portion 2 is inserted into the patient's oral cavity and the bone width of the alveolar bone from the planned implantation position can be measured before the implant operation. Has been. The handle portion 2 is formed in a columnar shape, and a scale portion 21 having a smaller diameter than the proximal end side of the handle portion 2 is provided on the distal end side of the handle portion 2. A stator 3 provided with a bending pin (curving portion) 35 is fixed to the tip portion of the scale portion 21, and a mover 4 provided with pole portions 44 and 45 is slidably attached to an intermediate portion of the scale portion 21. ing. A scale 22 indicating the distance between the stator 3 and the mover 4 is attached to the outer peripheral surface on the tip side of the scale portion 21.

  The stator 3 is formed in a cylindrical shape so as to be fitted to the tip portion of the scale portion 21, and an attachment hole 31 for fixing the bending pin 35 is provided on the outer peripheral surface of the stator 3. One end face 32 of the stator 3 facing the mover 4 is aligned with the 0 position of the scale 22 of the scale portion 21 and serves as a reference position when measuring the bone width. The other end surface 33 of the stator 3 is formed with a screw hole (not shown) for screwing the bending pin 35 inserted into the attachment hole 31 from the side with a screw 34. The stator 3 can be replaced with another bending pin 35 having a different size (10 mm in the present embodiment) by loosening the screw 34 and removing the bending pin 35.

  The bending pin 35 is curved so that the proximal end 36 side is linear and the distal end 37 side faces the pole portion 45 side. That is, the distal end 37 of the bending pin 35 is bent so as to contact the side surface of the alveolar bone from the side. The distal end 37 of the bending pin 35 is farther from the scale portion 21 than the distal end 47 of the pole portion 45 in a direction (vertical direction in the drawing) orthogonal to the extending direction of the scale portion 21. The distal end 37 of the bending pin 35 is directed to the buccal side with the bending pin 35 inserted on the lingual cortical bone 61 side of the alveolar bone 6 in the oral cavity (see FIG. 3). For this reason, the tip 37 of the bending pin 35 is easily brought into contact with the lingual cortical bone 61 of the alveolar bone 6 (see FIG. 3).

  The mover 4 is formed in a cylindrical shape that is slidable on the scale portion 21, and columnar pole portions 44 and 45 project from the mover 4 in the vertical direction. One end face 41 of the movable element 4 facing the stator 3 serves as a pointer for reading the scale 22 of the scale portion 21, and the bone width of the alveolar bone is measured by the position of the one end face 41. The measurement principle of the measurement jig 1 will be described later. On the upper surface of the movable element 4, a finger hooking portion 42 is provided for fixing the position of the pole portion 45 to a predetermined position of the alveolar bone during the operation. The upper pole portion 44 functions as a mark for the operator to confirm the planned implantation position and the planned implantation direction before surgery.

  The lower pole portion 45 is configured to be in contact with the alveolar bone and support the distal end side of the measuring jig 1. The tip 47 of the pole portion 45 is formed in a spherical shape, and the spherical tip 47 is formed in a hemispherical depression 64 (see FIG. 3) that serves as a mark of a planned site of the implant embedding cavity formed on the alveolar bone crest. Abutted. Thereby, the front end side of the measuring jig 1 is supported to be tiltable and rotatable with the front end 47 as a fulcrum. It is possible to appropriately measure the bone width of the alveolar bone necessary for implant placement by moving the lower pole portion 45 so as to match the planned placement position and the intended placement direction of the implant. . At this time, since the lower pole portion 45 and the upper pole portion 44 are coaxial, the upper pole portion 44 is visually checked to confirm the position of the lower pole portion 45 and the biting with the counter teeth. It is possible to do.

  Next, the measurement principle of the measurement jig 1 will be described. As shown in FIG. 2A, when the distance between the stator 3 and the mover 4 is 0, the distal end 37 of the bending pin 35 is the center of the distal end 47 of the pole portion 45 in the extending direction of the scale portion 21. It coincides with the extension of the position. That is, when the distance between the stator 3 and the mover 4 is 0, the distance in the lateral direction (extending direction of the scale portion 21) between the distal end 37 of the bending pin 35 and the distal end 47 of the pole portion 45 is also 0. . Further, in the longitudinal direction orthogonal to the extending direction of the scale portion 21, the distance from the center of the spherical tip 47 of the pole portion 45 to the tip 37 of the bending pin 35 is the major axis of the implant (in this embodiment, 10 mm). Match.

  As shown in FIG. 2B, the mover 4 is moved relative to the stator 3 on the scale portion 21 by the distance that the tip 47 of the pole portion 45 is separated from the tip 37 of the bending pin 35. Since the one end surface 32 of the stator 3 is aligned with the 0 position of the scale 22, the position of the one end surface 41 of the mover 4 that is separated from the one end surface 32 of the stator 3 is read from the scale 22. The distance between the tip 37 and the tip 47 of the pole portion 45 is measured. At this time, since the distal end 37 of the bending pin 35 is positioned deeper than the distal end 47 of the pole portion 45, the lateral direction from the distal end 37 of the bending pin 35 to the extended line of the distal end 47 of the pole portion 45 at this deep position. The distance in the direction is measured.

  Specifically, the intersection point between the straight line L extending in the extending direction of the scale portion 21 from the tip 37 of the bending pin 35 and the center line C of the pole portion 45 is P, and the distance from the tip 37 of the bending pin 35 to the intersection P Is measured. In the vertical direction, since the tip 47 of the pole portion 45 and the tip 37 of the bending pin 35 are separated by the major axis (length) of the implant 5, the tip of the bending pin 35 is located at a position corresponding to the lower end of the implant 5. The distance from 37 to the center position of the implant 5 is measured. Thus, assuming that the implant 5 is actually embedded in the alveolar bone before the operation, the bone width necessary for the implantation of the implant 5 can be measured, and the desired implant 5 can be safely used. It is possible to confirm before implantation whether or not it is possible to implant.

  In the measuring jig 1 configured as described above, the tip 47 of the pole portion 45 protrudes from the alveolar bone crest, and the tip 37 of the bending pin 35 is fixed to the alveolar bone with the contact position of the pole portion 45 fixed to the alveolar bone crest. Moved to contact the side of the. By moving the handle portion 2 while confirming the occlusal relationship with the opposing teeth while the distal end side of the measuring jig 1 is supported in the oral cavity by the pole portion 45, the pole portion 45 is placed in the planned implantation position of the implant 5. And can be adjusted according to the direction of embedding. By reading the distance between the stator 3 and the mover 4 at this time, from the planned implantation position of the implant 5 where the tip 47 of the pole portion 45 abuts to the side surface of the alveolar bone where the tip 37 of the bending pin 35 contacts The bone width is measured appropriately.

  In addition, the measuring jig 1 can measure the bone width necessary for implanting the implant 5 before forming the implant embedding cavity. Since it is possible to confirm whether or not an implant embedding cavity can be formed in the alveolar bone before surgery, it is prevented that the cortical bone of the alveolar bone is perforated during the formation of the implant embedding cavity. Therefore, even in the case where there is an undercut like the lingual cortical bone of the alveolar bone, the implant 5 having the desired diameter and the long diameter is appropriately applied to the alveolar bone at the appropriate planned implantation position and the planned implantation direction. It is possible to embed.

  With reference to FIG.3 and FIG.4, the measuring method by a measuring jig is demonstrated. 3 and 4 are explanatory diagrams of a measurement method using the measurement jig according to the present embodiment. 3 and 4, an example of measuring the bone width from the implant placement planned position to the bone surface of the lingual cortical bone in the alveolar bone of the mandible will be described. The measurement can be performed in the same manner using a measurement jig. Here, description will be made assuming that an implant having a diameter of 3 mm and a major axis of 10 mm is embedded in the alveolar bone.

  As shown in FIG. 3A, the gingiva is peeled from the alveolar bone 6, and a hemispherical depression 64 having a diameter of about 2 mm and a depth of about 1 mm is provided by a round bar (not shown) at a position where the implant is to be placed on the alveolar bone 6. Is formed. Thereby, the planned implantation position of the implant 5 (see FIG. 3C) is determined on the alveolar bone 6. Since the actual surface of the alveolar bone 6 is not flat and often bleeds, the surgeon can check the planned implantation position of the implant 5 using the depression 64 as a clue. Further, a bending pin 35 for a major axis 10 mm of the implant 5 is attached to the stator 3 of the measuring jig 1.

  Next, the distal end side of the measuring jig 1 is inserted into the oral cavity of the patient, and the distal end 37 of the bending pin 35 is brought into contact with the lingual cortical bone 61 of the alveolar bone 6. At this time, the measuring jig 1 is inserted into the oral cavity while being tilted so that the tip end side thereof is raised. Further, since the distal end 37 of the bending pin 35 is curved toward the pole portion 45 (buccal side), it can be easily brought into contact with the lingual cortical bone 61 even when the measuring jig 1 is tilted. Then, the tip 37 of the bending pin 35 is slid in the apical direction without floating from the bone surface of the lingual cortical bone 61, and the spherical tip 47 of the pole portion 45 is changed to a hemispherical depression 64 on the alveolar bone 6. Press. As a result, the pole portion 45 is positioned at the planned implantation position of the implant. At this time, the position of the pole part 45 is fixed with respect to the alveolar bone 6 by supporting the finger-hanging part 42 with an operator's finger.

  Next, as shown in FIG. 3B, the base end of the measuring jig 1 (handle portion 2) is centered on the spherical tip 47 of the pole portion 45 with the tip 47 of the pole portion 45 fixed to the alveolar bone 6. The side is lifted. As a result, the distal end 37 of the bending pin 35 is further slid along the bone surface of the lingual cortical bone 61 in the apical direction, and the distal end 37 of the bending pin 35 begins to move away from the extension line of the distal end 47 of the pole portion 45. At this time, since the pole portion 45 is fixed to the alveolar bone 6, the stator 3 connected to the bending pin 35 is slid with respect to the mover 4 connected to the pole portion 45, and the distance between the stator 3 and the mover 4 increases. start. At this time, the measuring jig 1 is lifted while confirming the insertion direction of the implant 5 by the upper pole portion 44.

  Next, as shown in FIG. 3C, when the pole portion 45 is brought perpendicular to the occlusal plane and the orientation of the pole portion 45 becomes the target occlusal relationship, the lifting of the measuring jig 1 is stopped. By reading the scale 22 of the scale portion 21 where the one end surface 41 of the mover 4 is positioned at this time, the lingual cortical bone is determined from the center position (the contact position of the pole portion 45) of the lower end of the implant 5 to be implanted. The bone width to the side of 61 is measured. In the case of FIG. 3C, the distal end 37 of the bending pin 35 is positioned at the undercut 63 and is 10 mm deep from the alveolar crest 62 and the lingual cortical bone 61 from the center position (planned implantation position) of the implant 5. There is a bone width of 4 mm to the side.

  In this case, even if an implant embedding cavity is formed in the alveolar bone 6 with a 3 mm diameter cutting bar, there is a bone width of 2.5 mm between the implant embedding cavity and the side surface of the lingual cortical bone 61. There is no possibility of the side cortical bone 61 perforating. Therefore, it is determined that the implant 5 having a diameter of 3 mm and a major axis of 10 mm can be safely embedded in the alveolar bone 6 in the planned implantation position and the planned implantation direction. Thus, before forming the implant embedding cavity in the alveolar bone 6, it is determined in advance whether or not the implant 5 can be implanted.

  On the other hand, as shown in FIG. 4, when the amount of undercut of the alveolar bone 6 is large, the side surface of the lingual cortical bone 61 from the center position (planned implantation position) of the implant 5 at a position 10 mm deep from the alveolar bone crest 62. There is only a bone width of 1.5 mm by the time. For this reason, if an implant embedding cavity is formed in the alveolar bone 6 with a cutting bar having a diameter of 3 mm, the lingual cortical bone 61 may be perforated without sufficient bone width, and it is determined that the implant 5 cannot be implanted. The Since it is determined that the implant 5 cannot be placed in advance, other measures such as the use of the implant 5 having a small one-step diameter, the use of the implant 5 having a short one-step long diameter, and the adjustment of the placement direction of the implant 5 are taken. be able to.

  As described above, according to the present embodiment, the bending pin 35 of the measuring jig 1 is brought into contact with the side surface of the alveolar bone 6, and the pole portion 45 is projected to the alveolar bone top 62. When the measuring jig 1 is moved and moved in an appropriate position and direction while confirming the occlusal relationship with the mating teeth, the movable element 4 is moved to the scale portion 21 according to the distance between the bending pin 35 and the pole portion 45. Slide up. By reading the distance between the stator 3 and the mover 4 at this time by the scale portion 21, the bone width of the alveolar bone 6 from the contact position of the pole portion 45 to the contact position of the bending pin 35 can be measured. Thus, before forming the implant embedding fovea in the alveolar bone, the bone width necessary for the implantation of the implant 5 can be measured. Therefore, it is possible to confirm before the operation whether or not the implant 5 having the desired diameter and the long diameter can be placed in the desired planned implantation position and the planned implantation direction.

  The present invention is not limited to the above embodiments, and can be implemented with various modifications. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, in the present embodiment, the configuration is such that the bending pin 35 is provided on the stator 3 and the pole portion 45 is provided on the movable element 4, but the configuration is not limited thereto. A pole portion 45 may be provided on the stator 3, and a bending pin 35 may be provided on the mover 4. Even in such a configuration, it is possible to measure the bone width necessary for the implantation of the implant 5 by moving the bending pin 35 in a state where the pole portion 45 is protruded from the alveolar crest 62.

  Further, in the present embodiment, when the distance between the stator 3 and the mover 4 is 0, the tip 47 of the pole portion 45 and the tip 37 of the bending pin 35 coincide with each other in the extending direction of the scale portion 21. Although the configuration has been described, it is not limited to this configuration. When the distance between the stator 3 and the mover 4 is 0, the tip 47 of the pole portion 45 and the tip 37 of the bending pin 35 do not have to coincide with each other. In this case, the method of attaching the scale 22 of the scale portion 21 is changed so that the distance between the tip 47 of the pole portion 45 and the tip 37 of the bending pin 35 can be measured.

  In the present embodiment, a configuration in which the distance from the tip 47 of the pole portion 45 to the tip 37 of the bending pin 35 matches the major axis of the implant 5 in a direction orthogonal to the extending direction of the scale portion 21 will be described. However, it is not limited to this configuration. Even if the distance from the tip 47 of the pole portion 45 to the tip 37 of the bending pin 35 does not match the major axis of the implant 5, it is possible to roughly grasp the bone width necessary for the implantation of the implant 5. .

  Moreover, in this Embodiment, although the pole part 45 was formed in the column shape, it is not limited to this shape. The pole portion 45 may have any shape as long as it can support the tip side of the measuring jig 1. Moreover, in this Embodiment, although the front-end | tip 47 of the pole part 45 was made into the structure formed in a spherical form, it is not limited to this structure. The tip 47 of the pole portion 45 may be formed in any shape as long as it can be abutted against the alveolar bone 6 so as to support the scale portion 21.

  Moreover, in this Embodiment, although the bending part was formed in the shape which curved the cylindrical pin as the bending pin 35, it is not limited to this shape. The curved portion has a tip 37 that is curved so that the tip 37 is directed toward the pole portion 45, and is formed in any shape as long as it is farther from the scale portion 21 than the tip 47 of the pole portion 45. Also good.

  Moreover, in this Embodiment, although it was set as the structure which measures the distance of the stator 3 and the needle | mover 4 with the scale 22 attached | subjected to the scale part 21, it is not limited to this structure. The scale unit 21 only needs to be able to measure the distance between the stator 3 and the mover 4. For example, the scale unit 21 may be configured to be able to electrically measure the distance.

  Moreover, in this Embodiment, although the structure which measures the bone width at the time of embedding the implant 5 in the alveolar bone 6 of a mandible was demonstrated, it is not limited to this structure. The measuring jig according to the present embodiment can also be used when measuring the bone width when the implant 5 is embedded in the alveolar bone 6 of the maxilla.

  As described above, the present invention has an effect that the bone width necessary for implant treatment can be measured before forming the implant embedding fossa, and in particular, the implant from the side of the alveolar bone of the mandible This is useful for measuring jigs that measure the bone width to the embedding fossa.

DESCRIPTION OF SYMBOLS 1 Measuring jig 2 Handle part 21 Scale part 3 Stator 35 Curved pin (curved part)
37 Tip of the curved pin 4 Movable element 45 Pole part 47 Tip of the pole part 5 Implant 6 Alveolar bone 62 Alveolar crest 63 Undercut

Claims (5)

A measurement jig capable of measuring the bone width of the alveolar bone from the planned implantation position of the implant,
A long scale section;
A stator fixed to the scale portion;
A mover slidably attached to the scale portion;
Either one of the stator and the mover is provided with a pole portion so as to support the scale portion, and the other end of the stator and the mover has a tip directed toward the pole portion. A curved portion is provided,
The measuring jig according to claim 1, wherein a tip of the bending portion is further away from the scale portion than a tip of the pole portion in a direction orthogonal to the extending direction of the scale portion.   When the distance between the stator and the mover is 0 in the scale portion, the distal end of the bending portion coincides with the extension line of the center position of the distal end of the pole portion in the extending direction of the scale portion. The measuring jig according to claim 1.   The measuring jig according to claim 1, wherein the bending portion is provided in the stator, and the pole portion is provided in the movable element.   The measuring jig according to any one of claims 1 to 3, wherein a tip of the pole portion is formed in a spherical shape.   The distance from the tip of the pole part to the tip of the curved part in a direction orthogonal to the extending direction of the scale part is equal to the major axis of the implant. A measuring jig according to any one of the above.

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