Surgical guide for orthognatic surgery

Abstract

The present invention provides a surgical guide for achieving a set position of a mandibular ramus with respect to the position of the maxilla before and after surgery, when performing orthognatic surgery using a mandibular ramus sagittal splitting method.　Provided is a surgical guide that makes it possible to fix a mandibular ramus during orthognatic surgery using a mandibular ramus sagittal splitting method, said surgical guide comprising: a body that has a first main surface which has an upper tooth shape and a second main surface which has a lower tooth shape; and a pair of attachment parts that are respectively disposed at the two ends of the body and that have a connection holes for connection to the pair of mandibular rami of the lower jaw via attachment members.

Description

Surgical guide for orthognathic surgery

[0001] The present invention relates to a surgical guide used in orthognathic surgery using the sagittal split ramus approach.

[0002] In a person's face, when the lower jaw is positioned forward relative to the upper jaw, orthognathic surgery may be performed to move the lower jaw backward. Similarly, in a person's face, when the lower jaw is positioned backward relative to the upper jaw, orthognathic surgery may be performed to move the lower jaw forward. Orthognathic surgery can position the lower jaw appropriately relative to the position of the upper jaw. Orthognathic surgery can achieve functional and cosmetic improvements to the person's face.

[0003] The sagittal split ramus osteotomy is one of the methods used for orthognathic surgery. Non-Patent Document 1 provides a literature review of the use of condylar positioning devices (CPDs) in orthognathic surgery since 1990, with regard to sagittal split ramus osteotomy.

[0004] Furthermore, Patent Document 1 describes a positioning device for a proximal mandibular fragment in sagittal split ramus osteotomy.

[0005] Fabio Costa, Massimo Robiony, Corrado Toro, Salvatore Sembronio, Francesco Polini, Massimo Politi, “Condylar positioning devices for orthognathic surgery: a literature review”, Oral Surg Oral Med Oral Pathol Oral Radiol Endod, Volume 106, Issue 2, August 2008, Pages 179-190 (DOI: 10.1016 / j.tripleo.2007.11.027)

[0006] JP 2014-155634 A

[0007] When a person's face has a lower jaw that is positioned forward or backward relative to the upper jaw, orthognathic surgery is performed to move the lower jaw backward or forward. Orthognathic surgery may be performed as a cosmetic procedure.

[0008] In orthognathic surgery to set back the mandible using the sagittal split ramus method, the mandible is divided into three parts: the bone containing the lower teeth (mandibular body), the part connecting to the temporomandibular joint on the left side, and the part connecting to the temporomandibular joint on the right side (left ramus and right ramus). After division, portions of the left and right mandibular ramus are resected. Next, the mandibular body is moved back a predetermined distance and connected to the left and right ramus. This type of surgery can set back the mandible. Even if the mandibular position is posterior relative to the maxilla, surgery can be performed in a similar manner to the above case. That is, first, the mandibular body and the left and right ramus are divided. Next, the mandibular body is moved forward and connected to the ramus. This type of surgery can advance the position of the mandible relative to the maxilla.

[0009] During surgery using the sagittal split ramus technique, the mandibular corpus, which contains the mandibular dentition, can be positioned in a predetermined position relative to the maxillary dentition (upper teeth) using a surgical guide. The surgical guide has upper and lower dental impressions. By fitting the upper maxillary teeth and the lower mandibular corpus's teeth into the upper and lower dental impressions on the surgical guide, the mandibular corpus can be positioned in a predetermined position relative to the maxillary dentition (upper teeth). Meanwhile, the left and right ramus of the mandible are connected to the temporomandibular joint (TMJ). The left and right ramus can move freely within the range of motion of the temporomandibular joint (TMJ). Therefore, during surgery using the sagittal split ramus technique, the ramus is fixed so that it is positioned relative to the maxilla in the same way as it was before resection. With the ramus fixed, it is necessary to connect the mandibular corpus, containing the dentition, to the ramus.

[0010] Generally, in surgery using the sagittal split ramus approach, the following procedure is performed to fix the mandibular ramus in the same position relative to the maxilla as it was before resection. First, before resectioning the mandible, a predetermined position (position A) is marked on the part corresponding to the left ramus. The distances (distances A-B and A-C) from position A to two predetermined positions (positions B and C) on the maxillary dentition are measured. Next, the mandible is cut into three parts: the mandibular body, the left ramus, and the right ramus, and the predetermined portions are resected. Next, the maxillary dentition and the left ramus are fixed using a metal rod or similar tool so that the distances A-B from position A to position B and A-C from position A to position C are the same as the distances before surgery. For the right mandibular ramus, as with the left mandibular ramus, measure the distances (distance A'-B' and distance A'-C' before amputation) from a predetermined position A' on the part corresponding to the right mandibular ramus to two predetermined positions (positions B' and C') on the maxillary dentition. Next, fix the maxillary dentition and the right mandibular ramus using a metal rod or the like so that the distance is the same as the distance before amputation of the mandibular ramus.

[0011] As described above, when the mandibular ramus is fixed at the same position relative to the maxilla as before amputation, errors may occur when measuring the distances A-B and A-C of the left mandibular ramus. Furthermore, even when the mandibular ramus is fixed with a metal wire or other device so that the distances A-B and A-C are the same as before amputation, errors may occur in the actual distances A-B and A-C after fixation. If errors occur in the distances A-B and A-C, the position of the mandibular ramus relative to the maxilla will differ from the originally planned position. The same is true for the distances A'-B' and A'-C' of the right mandibular ramus. As a result, the positions of the mandibular body and ramus after connection often differ from the originally planned positions, resulting in a misalignment of the maxilla and, ultimately, the position of the mandibular ramus condyle within the temporomandibular joint of the skull. Therefore, current orthognathic surgery can sometimes cause problems with the occlusion of the mandibular dentition and the maxillary dentition.

[0012] Furthermore, compared to other joints, the temporomandibular joint (TMJ) has a unique structure, allowing it to perform not only hinge movement but also gliding movement. In other words, the TMJ can move relatively freely compared to other joints. When the mandible is resected during orthognathic surgery using the sagittal split ramus method, the ramus connects to the skull via muscles. This makes the position of the ramus unstable. Therefore, in order to position the ramus in a predetermined (appropriate) position relative to the position of the maxilla, it is necessary to position the ramus condyle in a predetermined position within the temporomandibular joint of the skull, and further to ensure that the position (angle, etc.) of the ramus relative to the ramus condyle is in a predetermined position.

[0013] Thus, when the mandible is resected, the ramus becomes very unstable, and it is therefore not easy to position the ramus in a fixed position relative to the position of the maxilla, even if the above-mentioned method of maintaining the same distance before and after orthognathic surgery is used.

[0014] Therefore, an object of the present invention is to provide a surgical guide for maintaining a constant position of the mandibular ramus relative to the position of the maxilla before and after surgery in orthognathic surgery using the sagittal split ramus method.Another object of the present invention is to provide a surgical guide for maintaining a constant position of the mandibular ramus relative to the position of the condyle of the ramus within the temporomandibular joint of the skull before and after surgery in orthognathic surgery using the sagittal split ramus method.

[0015] In order to solve the above problems, the present invention has the following configuration.

[0016] (Configuration 1) Configuration 1 is a surgical guide capable of fixing the mandibular ramus during orthognathic surgery using the sagittal split ramus method, the surgical guide comprising: a main body having a first main surface with an upper tooth impression and a second main surface with a lower tooth impression; and a pair of attachment portions arranged at both ends of the main body and having connection holes for connecting to a pair of mandibular ramus of the mandible with attachment members.

[0017] (Configuration 2) Configuration 2 is the surgical guide of configuration 1, wherein the second main surface of the body has a first lower dental impression before movement of the mandible and a second lower dental impression after movement of the mandible.

[0018] (Configuration 3) Configuration 3 is the surgical guide of Configuration 1 or 2, wherein the pair of attachment portions have a mandibular contact portion having a recess for fitting onto the mandibular jaw, and an attachment member attachment portion that is arranged on the surface of the mandibular contact portion opposite to the surface on which the recess is formed, and the connection hole is arranged to pass through the mandibular contact portion and the attachment member attachment portion.

[0019] (Configuration 4) Configuration 4 is the surgical guide of any one of configurations 1 to 3, wherein each of the pair of attachment portions has one or more of the connection holes.

[0020] (Configuration 5) Configuration 5 is the surgical guide of any one of Configurations 1 to 4, wherein the attachment members are screws, the diameters of the connection holes of the pair of attachment portions are equal to or slightly larger than the diameter of the screws, and the diameter of the connection holes is 0.5 to 4 mm.

[0021] (Configuration 6) Configuration 6 is the surgical guide of any one of configurations 1 to 5, wherein the pair of attachment portions are disposed on both ends of the body so as to protrude in the direction of the first main surface.

[0022] (Configuration 7) Configuration 7 is the surgical guide of any one of configurations 1 to 6, wherein the main body is flat and has the first main surface and the second main surface, and the main body has a thickness of 2 to 8 mm.

[0023] (Configuration 8) Configuration 8 is the surgical guide of any one of configurations 1 to 7, wherein the material of the surgical guide is a thermoplastic resin, a thermosetting resin, a photocurable resin, or a metal.

[0024] According to the present invention, a surgical guide can be provided for maintaining a constant position of the mandibular ramus relative to the position of the maxilla before and after surgery in orthognathic surgery using the sagittal split ramus method.Furthermore, according to the present invention, a surgical guide can be provided for maintaining a constant position of the mandibular ramus relative to the position of the condyle of the ramus within the temporomandibular joint of the skull before and after surgery in orthognathic surgery using the sagittal split ramus method.

[0025] FIG. 1 is a schematic bottom view showing an example of a surgical guide of this embodiment; FIG. 2 is a schematic bottom view showing an example of a surgical guide of this embodiment; FIG. 3 is a schematic back view showing an example of a surgical guide of this embodiment; FIG. 4 is a schematic view showing an example of an attachment portion of the surgical guide of this embodiment; FIG. 5 is a schematic view showing an example of an attachment member attachment portion of the attachment portion of the surgical guide of this embodiment; FIG. 6 is a schematic view showing an example of a surgical guide of this embodiment attached between upper and lower teeth, as viewed from diagonally front; FIG. 7 is a schematic view showing an example of a surgical guide of this embodiment attached between upper and lower teeth, as viewed from the front.

[0026]

[0023] The following description will discuss in detail embodiments of the present invention with reference to the accompanying drawings. Note that the following embodiments are merely examples of how the present invention can be embodied, and are not intended to limit the scope of the present invention.

[0027] 1 to 3 show schematic diagrams of an example of a surgical guide 10 according to this embodiment. This embodiment is a surgical guide 10 capable of fixing the mandibular ramus 52 during orthognathic surgery using the sagittal split ramus method. The surgical guide 10 according to this embodiment includes a predetermined main body 20 and a predetermined attachment portion 30.

[0028] 6 and 7 show an example of a portion of the mandibular 50 where bone is resected (bone resection portion 56) during orthognathic surgery. The shape of the bone resection portion 56 is actually complex, but for the sake of explanation, it is illustrated in a simplified form in FIGS. 6 and 7 . In orthognathic surgery using the sagittal split ramus method, the mandibular 50 is divided into three portions: the bone (mandibular body 54) containing the row of lower teeth 70, the left mandibular ramus 52, and the right mandibular ramus 52. After the division, portions of the left and right mandibular ramus 52 are resected or cut, and the mandibular body 54 is moved backward or forward a predetermined distance to connect to the left and right mandibular ramus 52, thereby moving the mandibular ramus 54 backward or forward. By using the surgical guide 10 of this embodiment, which includes a predetermined main body 20 and a predetermined attachment portion 30, the position of the mandibular ramus 52 relative to the position of the maxilla (upper teeth 60) can be kept constant before and after or after orthognathic surgery using the sagittal split ramus method. Furthermore, by using the surgical guide 10 of this embodiment, it is possible to fix the position of the mandibular ramus 52 relative to the position of the maxilla (upper teeth 60). Furthermore, by using the surgical guide 10 of this embodiment, it is possible to keep the position of the mandibular ramus relative to the position of the ramus condyle within the temporomandibular joint of the skull constant before and after surgery in orthognathic surgery using the sagittal split ramus method.

[0029] <<Main Body 20 of Surgical Guide 10 >> First, the main body 20 of the surgical guide 10 of this embodiment will be described.

[0030] As shown in Figures 1 and 2, the surgical guide 10 of this embodiment includes a body 20 having a tooth impression.

[0031] When performing orthognathic surgery using the sagittal split ramus approach, it is necessary to consider the occlusion between the upper teeth 60 and the lower teeth 70. This is because performing surgery to simply move the bone of the mandible 50 backward or forward without considering the occlusion would result in problems with the occlusion between the upper teeth 60 and the lower teeth 70. To avoid this problem, first, the distance d to which the bone of the mandible 50 will be moved during the surgery is determined before performing the orthognathic surgery. Next, the positions of one or both of the upper teeth 60 and the lower teeth 70 are corrected before performing the orthognathic surgery so that problems with the occlusion between the upper teeth 60 and the lower teeth 70 do not occur after the surgery, taking into account the distance d of the bone of the mandible 50. For example, if the position of the lower teeth 70 is corrected before the orthognathic surgery, problems with the occlusion between the upper teeth 60 and the lower teeth 70 immediately before the orthognathic surgery will occur, but the occlusion will be correct after the orthognathic surgery. During the orthognathic surgery, a dental impression of the surgical guide 10 can be used for alignment to move the bone of the mandible 50 by the distance d. In this specification, the part of the surgical guide 10 of this embodiment that has the tooth impressions is referred to as the "main body 20."

[0032] The main body 20 of the surgical guide 10 of this embodiment has a first main surface 21 having an upper tooth pattern and a second main surface 22 having a lower tooth pattern. Figures 1 and 2 show schematic views of the bottom of an example of the surgical guide 10 of this embodiment. Therefore, Figures 1 and 2 show the second main surface 22 of the main body 20.

[0033] The main body 20 of the surgical guide 10 of this embodiment is generally substantially flat and has two main surfaces. One of the two main surfaces (first main surface 21) has an upper tooth impression, and the other main surface (second main surface 22) has a lower tooth impression. The upper tooth impression and the lower tooth impression of the main body 20 of the surgical guide 10 can be the tooth impressions when the upper teeth 60 and the lower teeth 70 are engaged. By having the upper tooth impression and the lower tooth impression on the main body 20 of the surgical guide 10, the relative positional relationship between the upper jaw having the upper teeth 60 and the lower jaw 50 (particularly the mandibular body 54) having the lower teeth 70 can be adjusted to a predetermined position using the surgical guide 10 of this embodiment.

[0034] In the surgical guide 10 of this embodiment, the second main surface 22 of the main body 20 has a first lower tooth impression 23 before movement of the mandible 50 and a second lower tooth impression 24 after movement of the mandible 50. Two different surgical guides 10 can be manufactured. In this case, one surgical guide 10 may be manufactured having the first lower tooth impression 23 before movement of the mandible 50 on the second main surface 22, and the other surgical guide 10 may be manufactured having the second lower tooth impression 24 after movement of the mandible 50 on the second main surface 22. In this case, the first main surfaces 21 of the two surgical guides 10 have the same upper tooth impression.

[0035] FIG. 1 illustrates the entire dental molds (the entire first lower dental mold 23 and the entire second lower dental mold 24). To avoid complexity, FIG. 2 illustrates only the dental molds of the lower front teeth. The surgical guide 10 shown in FIG. 2 illustrates the lower dental mold (first lower dental mold 23) before jaw retraction and the lower dental mold (second lower dental mold 24) after the lower jaw 50 has been retracted, in orthognathic surgery to retract the lower jaw 50. Note that in orthognathic surgery to advance the lower jaw 50, the positional relationship between the first lower dental mold 23 and the second lower dental mold 24 is reversed.

[0036] Generally, the lower dental impression on the second main surface 22 of the surgical guide 10 of this embodiment includes a first lower dental impression 23 before the mandible 50 is moved by surgery, and a second lower dental impression 24 after the mandible 50 is moved by surgery. The relative positional relationship between the upper and lower dental impressions (first lower dental impression 23) before surgery can be obtained by taking impressions of the patient's upper teeth 60 and lower teeth 70. The shapes of the impressions of the upper teeth 60 and lower teeth 70 can be obtained as three-dimensional data that can be processed by an information processing device such as a computer. The relative positional relationship between the upper and lower dental impressions (second lower dental impression 24) after surgery can be obtained by moving the coordinates of the first lower dental impression 23 by a movement distance d. Using the three-dimensional data of the upper dental impression, the first lower dental impression 23, and the second lower dental impression 24, the main body 20 of the surgical guide 10 can be manufactured using, for example, a 3D printer. During orthognathic surgery using the sagittal split ramus method, the mandibular body 54 is positioned so that the lower teeth 70 of the mandible 50 are located at the position of the second lower tooth mold 24, and the mandibular body 54 is fixed to the mandibular ramus 52, thereby allowing the upper teeth 60 and lower teeth 70 to be properly aligned.

[0037] The main body 20 of the surgical guide 10 of this embodiment is preferably in the form of a flat plate having a first main surface 21 and a second main surface 22 .

[0038] When the main body 20 of the surgical guide 10 has a flat plate shape, the thickness of the main body 20 is preferably 0.5 to 8 mm, more preferably 1 to 6 mm, and even more preferably 2 to 4 mm. By having the thickness of the main body 20 within the above-mentioned predetermined range, deformation of the surgical guide 10 is prevented, and by forming an appropriate range of tooth impressions of the tip portions of the upper teeth 60 and lower teeth 70 on the surgical guide 10, it is possible to properly align the mandible 50 and the maxilla.

[0039] <<Attachment portion 30 of surgical guide 10>> Next, the attachment portion 30 (attachment) of the surgical guide 10 of this embodiment will be described. The surgical guide 10 of this embodiment includes the attachment portion 30 for connecting and attaching the surgical guide 10 to the mandibular ramus 52.

[0040] The left and right mandibular ramus 52 are connected to the skull by the temporomandibular joint (TMJ), allowing them to move freely within the range of motion of the temporomandibular joint. In orthognathic surgery using the sagittal split ramus approach, the mandibular body 54 must be fixed to the ramus 52 after movement so that the ramus 52 is positioned correctly when fixed to the ramus 52. The "correct position" of the ramus 52 refers to a position where the relative positional relationship between the upper teeth 60 and the ramus 52 is the same as that between the upper teeth 60 and the lower teeth 70 before orthognathic surgery, or a healthy and stable position of the ramus condyle of the ramus 52 within the glenoid cavity. If the ramus 52 is in a different position from before orthognathic surgery or in a pathological position when the upper teeth 60 and the lower teeth 70 are occluded after orthognathic surgery, the patient may experience discomfort and problems with their bite. In orthognathic surgery, the mandibular body 54 is moved by a distance d and then fixed to the ramus 52. The surgical guide 10 of this embodiment includes a predetermined attachment portion 30. Therefore, by using the surgical guide 10 of this embodiment, the mandibular body 54 can be fixed to the ramus 52 so that the ramus 52 is in the correct position during orthognathic surgery.

[0041] 1 to 3, the attachment portions 30 of the surgical guide 10 of this embodiment are disposed on both ends of the main body 20. Fig. 4 is a schematic diagram of an example of the attachment portion 30. As shown in Fig. 4, the attachment portion 30 has connection holes 36 for connecting to a pair of mandibular ramus 52 of the mandible 50 with attachment members.

[0042] The pair of attachment portions 30 are arranged on both ends of the main body 20 so as to be able to contact the left and right mandibular ramus 52 when the patient's upper teeth 60 and lower teeth 70 engage with the dental impressions on the main body 20 of the surgical guide 10. The attachment portions 30 are preferably made of the same material as the main body 20. The attachment portions 30 are preferably manufactured to be integral with the main body 20. The 3D shape of the patient's mandible 50 can be converted into 3D data by CT scanning. The 3D data of the mandible 50 can be combined with 3D data of the patient's upper teeth 60 and lower teeth 70. By using the combined 3D data of the mandible 50, upper teeth 60, and lower teeth 70, the shape of the pair of attachment portions 30 can be designed so that the attachment portions 30 contact the mandibular ramus 52 when the patient's upper teeth 60 and lower teeth 70 engage with the dental impressions on the main body 20.

[0043] The attachment portion 30 has a connection hole 36 that penetrates the attachment portion 30. By passing an attachment member through the connection hole 36 of the attachment portion 30 and fastening the attachment member to the mandibular ramus 52, the surgical guide 10 of this embodiment can be fixed to the mandibular ramus 52.

[0044] As shown in FIG. 4 , the pair of attachment portions 30 of the surgical guide 10 of this embodiment preferably have a mandibular contact portion 32 and an attachment member mounting portion 34 .

[0045] 4, the mandibular contact portion 32 preferably has a recess 33 for fitting onto the mandibular 50. By having the mandibular contact portion 32 have the recess 33, the surgical guide 10 can be more appropriately fixed to the mandibular 50.

[0046] As shown in Fig. 4, the attachment member attachment portion 34 is preferably disposed on the surface opposite to the surface on which the recess 33 of the mandibular contact portion 32 is formed. By including the attachment member attachment portion 34 in the attachment portion 30, it is possible to easily attach the attachment member to the mandibular jaw 50. Fig. 5 shows an example of the attachment member attachment portion 34. The attachment member attachment portion 34 has a connection hole 36 for guiding the attachment member.

[0047] When the pair of attachment portions 30 have the mandibular contact portion 32 and the attachment member attachment portion 34, the connection holes 36 of the pair of attachment portions 30 are preferably arranged to penetrate the mandibular contact portion 32 and the attachment member attachment portion 34. By having the connection holes 36 with a predetermined structure, the surgical guide 10 of this embodiment can be more reliably attached to the mandibular jaw 50.

[0048] In the surgical guide 10 of this embodiment, each of the pair of mounting portions 30 preferably has one or more connection holes 36, more preferably one to two connection holes 36, and even more preferably two connection holes 36. By having one mounting portion 30 have one or more connection holes 36, the surgical guide 10 can be fixed to the mandible 50 so that it does not rotate. Note that each of the pair of mounting portions 30 can have three or more connection holes 36. However, considering the effort required to attach three mounting members, it is more preferable that the number of connection holes 36 be one to two.

[0049] The attachment member for fixing the surgical guide 10 of this embodiment to the mandible 50 is preferably a screw. By using a screw as the attachment member, the screw can be passed through the connection hole 36 of the attachment portion 30 and screwed into the mandible 50. Therefore, by using a screw as the attachment member, the surgical guide 10 can be easily fixed to the mandible 50.

[0050] The diameter of the connection holes 36 of the pair of mounting portions 30 of the surgical guide 10 of this embodiment is preferably 0.5 to 4 mm, more preferably 1 to 3 mm, and even more preferably 1.5 to 2.5 mm. By using mounting members of a size that corresponds to a predetermined range of the diameter of the connection holes 36, the mounting members can be fixed to the mandible 50 with an appropriate force.

[0051] In order to accurately attach the surgical guide 10 of this embodiment to the mandible 50, the diameter of the connection holes of the pair of attachment portions is preferably equal to or slightly larger than the diameter of the screw. Furthermore, the diameter of the screw is preferably equal to or slightly smaller than the diameter of the connection hole 36 of the attachment portion 30. If there is a gap between the screw and the connection hole 36 of the attachment portion 30 when the surgical guide 10 is attached to the mandible 50, it becomes difficult to attach the surgical guide 10 to the mandible 50 accurately and in the same position. In this specification, a diameter that is "slightly larger" than a predetermined diameter means a diameter that is 0.1 to 10% larger, preferably 0.5 to 5% larger, and more preferably 1 to 2% larger than the predetermined diameter. In this specification, a diameter that is "slightly smaller" than a predetermined diameter means a diameter that is 0.1 to 10% smaller, preferably 0.5 to 5% smaller, and more preferably 1 to 2% smaller than the predetermined diameter.

[0052] Furthermore, the length of the connection hole 36 of the attachment portion 30 is preferably 0.5 to 10 mm, more preferably 1 to 5 mm, and even more preferably 2 to 4 mm. If the length of the connection hole 36 of the attachment portion 30 is short, the attachment portion 30 may wobble relative to the attachment member. If the length of the connection hole 36 of the attachment portion 30 is long, inconveniences may occur, such as the driver for screw installation not being able to be inserted, or the screw being insufficient in length to provide sufficient fixation of the mandibular ramus.

[0053] As shown in Figure 3, the pair of attachment portions 30 of the surgical guide 10 of this embodiment are preferably arranged on both ends of the main body 20 so as to protrude in the direction of the first main surface 21 of the main body 20. As shown in Figures 6 and 7, the positions at which the pair of attachment portions 30 connect to the mandible 50 need to be above the bite position (the position at which the main body 20 is located) of the upper teeth 60 and lower teeth 70 in order to avoid the mandibular resection line. Therefore, the pair of attachment portions 30 are preferably arranged on both ends of the main body 20 so as to protrude in the direction of the first main surface 21 of the main body 20. Note that, in the surgical guide 10 of this embodiment, the positions and angles at which the attachment portions 30 are arranged on the main body 20 can be adjusted as appropriate depending on the positional relationship between the patient's upper teeth 60, lower teeth 70, and maxillary bone.

[0054] 6 and 7 show that the connection holes 36 of the attachment portion 30 of the surgical guide 10 are generally open in the anterior-posterior direction of the patient's face. That is, the examples of Figures 6 and 7 show a case in which the surgical guide 10 is fixed from the front of the patient's face using an attachment member at a position corresponding to the ramus 52 of the mandible 50. However, the position of the ramus 52 for fixing the surgical guide 10 using the attachment member is not limited to this. For example, it is also possible to position the attachment portion 30 of the surgical guide 10 so that it is laterally aligned with the patient's face, and then fix the surgical guide 10 to the ramus 52 from the lateral direction of the patient's face using the attachment member.

[0055] As shown in Figure 1, the main body 20 of the surgical guide 10 of this embodiment may have a notch 28. When attempting to fit the surgical guide 10 to a patient with a small mouth, the surgical guide 10 may not fit into the patient's mouth. In this case, during orthognathic surgery, the surgical guide 10 can be divided into two pieces using the notch 28, and the two pieces can be fitted into the patient's mouth.

[0056] 1 , the main body 20 of the surgical guide 10 of this embodiment can have a ring-shaped portion 26. During orthognathic surgery, the surgical guide 10 needs to be fixed to the patient's upper teeth 60 and lower teeth 70. In this case, the ring-shaped portion 26 of the surgical guide 10 can be connected to the orthodontic appliances for the patient's upper and lower teeth with ligatures such as thin wires, thereby fixing the surgical guide 10 to the patient's upper and lower teeth.

[0057] <<Material of Surgical Guide 10>> In the surgical guide 10 of this embodiment, the material of the surgical guide 10 is preferably a thermoplastic resin, a thermosetting resin, a photocurable resin, or a metal. By using a thermoplastic resin, a thermosetting resin, a photocurable resin, or a metal as the material of the surgical guide 10, a surgical guide 10 having appropriate rigidity and high dimensional accuracy can be easily manufactured. Furthermore, by using the above-mentioned material, the surgical guide 10 can be manufactured using a 3D printer.

[0058] As the thermoplastic resin, for example, a resin selected from ABS resin, ASA resin, polylactic acid (PLA) resin, polypropylene resin, polyethylene terephthalate (PET) resin, acrylic resin, polycarbonate resin, polyamide resin (nylon), and thermoplastic polyurethane can be used.

[0059] As the thermosetting resin, for example, a resin selected from phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, silicone resin, and the like can be used.

[0060] As the photocurable resin, for example, an acrylic resin and a photocurable epoxy resin composition can be used.

[0061] Examples of metals that can be used include gold alloys, titanium, and titanium alloys.

[0062] The material of the surgical guide 10 is preferably a material that can be used to manufacture the surgical guide 10 using a 3D printer. By using a 3D printer, the surgical guide 10 designed using 3D data of the patient's upper teeth 60, lower teeth 70, and mandible 50 can be manufactured easily and with high accuracy.

[0063] <Method of Manufacturing Surgical Guide 10 of This Embodiment> Next, an example of a method of manufacturing the surgical guide 10 of this embodiment will be described.

[0064] First, 3D data of the patient's lower jaw 50, upper teeth 60 and lower teeth 70 is obtained using a CT scan (Computed Tomography).

[0065] Next, upper and lower dental impressions are obtained. 3D data of the upper teeth 60 and lower teeth 70 obtained by CT scanning may not be as accurate as 3D data of bones such as the upper jaw and lower jaw 50. Therefore, it is preferable to obtain the 3D data of the upper and lower dental impressions separately. To obtain the upper and lower dental impressions, for example, an oral scanner can be used.

[0066] Next, the 3D data of the CT scan and the 3D data of the upper and lower dental impressions are superimposed to create 3D data of the patient's upper jaw, lower jaw 50, upper teeth 60, and lower teeth 70 on the same data.

[0067] Next, 3D data of the lower teeth 70 after the lower jaw 50 has been moved by the movement distance d by orthognathic surgery is created.

[0068] Next, based on the 3D data of the upper teeth 60, the lower teeth 70 before movement, and the lower teeth 70 after movement, 3D data of the shapes of the upper tooth mold, the lower tooth mold before movement (first lower tooth mold 23), and the lower tooth mold after movement (second lower tooth mold 24) of the main body 20 of the surgical guide 10 is created.

[0069] Next, the main body 20 of the surgical guide 10 is designed to have an upper tooth mold on the first main surface 21 and a first lower tooth mold 23 and a second lower tooth mold 24 on the second main surface 22, and 3D data of the shape of the main body 20 is created.

[0070] Next, based on the 3D data of the upper tooth mold and the shape of the lower jaw 50, the shape and dimensions of the attachment part 30 (mandibular contact part 32 and attachment member attachment part 34) having the connection hole 36 are designed so that the mandibular contact part 32 of the attachment part 30 of the surgical guide 10 can come into contact with the mandibular ramus 52 of the lower jaw 50 when the upper teeth 60 are fitted into the upper tooth mold of the main body 20. Based on the design of the attachment part 30, 3D data of the shape of the attachment part 30 is created. The 3D data of the shape of the main body 20 and the 3D data of the shape of the attachment part 30 are combined to create 3D data of the shape of the surgical guide 10.

[0071] Based on 3D data of the shape of the surgical guide 10 including the main body 20 and the attachment portion 30, the surgical guide 10 is manufactured using a 3D printer using a predetermined material (resin, metal, etc.).

[0072] In this manner, the surgical guide 10 of this embodiment can be manufactured.

[0073] <Method of Using the Surgical Guide 10 of This Embodiment> Next, an example of how to use the surgical guide 10 of this embodiment will be described. The surgical guide 10 of this embodiment can be used to fix the mandibular ramus 52 during surgery on the mandible 50 using the sagittal split ramus approach. The following explanation will be given taking as an example a case where two connection holes 36 are formed in each of the left and right mounting portions 30.

[0074] First, the distance d by which the lower jaw 50 is moved relative to the upper jaw during orthognathic surgery is determined. After the orthognathic surgery, the positions of the patient's upper teeth 60 and / or lower teeth 70 are corrected to achieve correct occlusion. The surgical guide 10 of this embodiment is manufactured as described above based on the 3D data of the shapes of the upper jaw, lower jaw 50, upper teeth 60, and lower teeth 70 of a specific patient, and the distance d by which the lower jaw 50 is moved.

[0075] 6 and 7, in orthognathic surgery, the patient's upper teeth 60 and lower teeth 70 are fitted and bitten into the upper tooth mold and the first lower tooth mold 23 of the main body 20 of the surgical guide 10 of this embodiment. In this state, the mandibular contact portion 32 of the attachment portion 30 of the surgical guide 10 of this embodiment comes into contact with the portion of the mandibular ramus 52 of the mandible 50.

[0076] Next, screws are inserted into the connection holes 36 (two locations) of the left and right mounting portions 30 of the surgical guide 10 of this embodiment, and the surgical guide 10 is attached to the mandible 50 with the screws. At this time, screw holes can be formed in the mandible 50 by threading the screws into the mandible 50.

[0077] Next, the surgical guide 10 of this embodiment is removed from the mandible 50, and a portion of the mandible 50 is resected. This resection divides the mandible 50 into three parts: the mandibular body 54 and the left and right ramus 52. Figures 6 and 7 show an example of a bone resection portion 56 of the mandible 50.

[0078] Next, the surgical guide 10 of this embodiment is positioned so that the upper tooth mold of the main body 20 of the surgical guide 10 fits over the patient's upper teeth 60. Screws are inserted into the connecting holes 36 (two locations) of the left and right mounting parts 30, and the surgical guide 10 is attached with screws into the screw holes of the left and right mandibular ramus 52. As a result, the positional relationship between the maxilla, which has the upper teeth 60, and the mandibular ramus 52 becomes the same as the positional relationship before the mandible 50 was divided.

[0079] Next, the mandibular body 54 is positioned so that the second lower tooth impression 24 (a lower tooth impression corresponding to the lower teeth 70 after being moved by the distance d in the orthognathic surgery) of the main body 20 of the surgical guide 10 of this embodiment fits into the lower teeth 70 of the mandibular body 54. In this state, the mandibular body 54 is connected to the left and right mandibular ramus 52 using a connecting jig or the like.

[0080] As described above, orthognathic surgery using the sagittal split ramus method can be performed using the surgical guide 10 of this embodiment.

[0081] By using the surgical guide 10 of this embodiment, in orthognathic surgery using the sagittal split ramus method, it is possible to fix the mandibular ramus 52 so that the position of the mandibular ramus 52 relative to the position of the maxilla is constant before and after surgery. Furthermore, by using the surgical guide 10 of this embodiment, it is possible to keep the position of the mandibular ramus relative to the position of the ramus condyle within the temporomandibular joint of the skull constant before and after surgery in orthognathic surgery using the sagittal split ramus method.

[0082] REFERENCE SIGNS LIST 10 surgical guide 20 main body 21 first main surface 22 second main surface 23 first lower tooth impression 24 second lower tooth impression 26 ring-shaped portion 28 cutout portion 30 attachment portion 32 mandibular contact portion 33 recessed portion 34 attachment member mounting portion 36 connection hole 50 mandible 52 mandibular ramus 54 mandibular body 56 bone resection portion 60 upper tooth 70 lower tooth

Claims

1. A surgical guide capable of fixing the mandibular ramus during orthognathic surgery using the sagittal split ramus method, said surgical guide comprising: a main body having a first main surface with an upper tooth impression and a second main surface with a lower tooth impression; and a pair of attachment portions disposed on both ends of said main body and having connection holes for connecting to a pair of mandibular ramus of said mandible with attachment members.

2. The surgical guide of claim 1, wherein the second major surface of the body has a first lower dental impression before movement of the mandible and a second lower dental impression after movement of the mandible.

3. A surgical guide as described in claim 1 or 2, wherein the pair of attachment portions have a mandibular contact portion having a recess for fitting onto the mandibular jaw, and an attachment member attachment portion arranged on the surface opposite to the surface on which the recess is formed of the mandibular contact portion, and the connection hole is arranged to pass through the mandibular contact portion and the attachment member attachment portion.

4. The surgical guide according to claim 1 or 2, wherein each of the pair of mounting portions has one or more of the connection holes.

5. A surgical guide according to claim 1 or 2, wherein the attachment members are screws, the diameter of the connection holes of the pair of attachment portions is equal to or slightly larger than the diameter of the screws, and the diameter of the connection holes is 0.5 to 4 mm.

6. A surgical guide according to claim 1 or 2, wherein the pair of mounting portions are disposed at both ends of the body so as to protrude in the direction of the first main surface.

7. A surgical guide according to claim 1 or 2, wherein the main body is flat and has the first main surface and the second main surface, and the thickness of the main body is 2 to 8 mm.

8. The surgical guide according to claim 1 or 2, wherein the material of the surgical guide is a thermoplastic resin, a thermosetting resin, a photocurable resin, or a metal.

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