Preparation and application of bone removal and nerve protection guide for sagittal mandibular splitting

Abstract

The present invention discloses a method for making and applying a bone removal and nerve protection guide for mandibular sagittal splitting surgery, and belongs to the field of medical devices in surgical operations. The making method comprises the following steps: S01: acquiring CT data of the patient's mandible; S02: importing the CT data of the patient's mandible into a three-dimensional software to segment and reconstruct a model of the patient's mandible and inferior alveolar nerve; S03: simulating mandibular sagittal splitting surgery on the segmented and reconstructed mandibular model; S04: designing a bone removal and nerve protection guide that matches the mandibular model according to the simulated osteotomy line; S05: 3D printing to make a bone removal and nerve protection guide. Compared with the prior art, the present invention uses CT image digital design and 3D printing technology to personalize and customize a bone removal and nerve protection guide that matches the patient's mandible, and accurately locates the patient's bone removal position; at the same time, it can also help the surgeon control the position of the inferior alveolar nerve to avoid damaging the inferior alveolar nerve during bone removal.

Description

Technical Field

[0001] The invention belongs to the field of surgical medical instruments, and particularly relates to a method for making and applying a guide plate for bone removal and nerve protection in mandibular sagittal splitting. Background Art

[0002] Mandibular sagittal splitting is a commonly used surgical procedure in clinical practice. It is used to correct jaw deformities such as the relative position of the maxillary and mandibular bones, morphological abnormalities, facial appearance abnormalities, and occlusal disorders between the upper and lower jaws. It is widely used in clinical practice and has become the preferred method for most orthognathic surgeons to treat jaw deformities.

[0003] At present, due to the inferior alveolar nerve wrapped in the mandible, the cortical bone density and morphology of each patient are different. When performing sagittal mandibular splitting, oral and maxillofacial surgeons cannot determine the position and direction of the inferior alveolar nerve by visual inspection alone. In addition, due to the lack of suitable positioning tools, doctors can only rely on their own clinical experience to perform osteotomy. During bone removal, the amount of bone removed will be different from the preoperative surgical plan, and it is impossible to achieve accurate bone removal. At the same time, due to the inability to control the position of the inferior alveolar nerve, the inferior alveolar nerve is often damaged during bone removal. After the operation, symptoms such as numbness or paresthesia of the lower lip and chin, and weak bite will appear, which are not easy to recover. Summary of the invention

[0004] In order to solve the above problems, the primary purpose of the present invention is to provide a method for manufacturing a mandibular sagittal splitting bone removal and nerve protection guide, which can manufacture a protection guide that matches the mandible of the patient and can effectively protect the inferior alveolar nerve during surgery;

[0005] Another object of the present invention is to provide an application method of a mandibular sagittal splitting bone removal and nerve protection guide plate, which can achieve precise osteotomy during surgery and avoid damage to the inferior alveolar nerve during the osteotomy process.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] The present invention provides a method for manufacturing a mandibular sagittal splitting bone removal and nerve protection guide plate, comprising the steps of:

[0008] S01: Acquire CT data of the patient's mandible;

[0009] S02: Importing the CT data of the patient's mandible into the 3D software to segment and reconstruct the model of the patient's mandible and inferior alveolar nerve;

[0010] S03: Simulate sagittal mandibular splitting on the segmented and reconstructed mandibular model;

[0011] S04: According to the simulated osteotomy line, design a bone removal and nerve protection guide that matches the mandibular model;

[0012] S05: 3D printing to make bone removal and nerve protection guide.

[0013] Furthermore, in step S04, the bone removal and nerve protection guide plate includes: a fixing portion for fixing to the mandible and a positioning portion for positioning the bone removal position, the fixing portion and the positioning portion are integrally formed; a positioning hole is provided on the positioning portion, and the side wall of the positioning hole is provided with an osteotomy guide surface and a nerve protection guide surface, and the osteotomy guide surface is connected to the nerve protection guide surface by the same edge. In the present application, after the positioning hole locates the bone removal position, the knife can be cut downward from the osteotomy guide surface, and when the nerve protection guide surface is cut, the downward cutting is stopped; and the horizontal cutting is turned along the nerve protection guide surface to perform bone removal and trimming on the upper side of the ascending ramus and the lower edge of the mandible until the bone removal is completed, thereby avoiding damage to the inferior alveolar nerve.

[0014] Further, the osteotomy guide surface is a longitudinal surface for controlling the mandibular osteotomy depth, and the nerve protection guide surface is a transverse surface intersecting the osteotomy guide surface. In the present application, the nerve protection guide surface can guide the cutting depth of the osteotomy guide surface to avoid excessive downward cutting and damage to the inferior alveolar nerve.

[0015] Furthermore, a fitting surface that can fit the mandible is provided at the bottom of the positioning portion, and the upper edges of the osteotomy guide surface and the nerve protection guide surface are coterminous with the upper surface of the positioning portion, and the lower edges are coterminous with the fitting surface; and the side edges of the osteotomy guide surface and the nerve protection guide surface are coterminous with each other.

[0016] Furthermore, the nerve protection guide surface includes a first guide surface and a second guide surface, and the osteotomy guide surface includes a third guide surface and a fourth guide surface, and the third guide surface and the fourth guide surface are arranged opposite to each other; the two side edges of the third guide surface and the fourth guide surface are respectively connected by the first guide surface and the second guide surface.

[0017] Furthermore, the positioning portion is an arc-shaped structure that fits with the mandible, the upper surface and the lower surface of the positioning portion are both arc-shaped surfaces, and the upper surface of the positioning portion forms the fitting surface.

[0018] Furthermore, the upper surface of the positioning portion is also provided with an indication path for indicating the direction and position of the intraosseous nerve, and the indication path is a projection of the inferior alveolar nerve on the upper surface of the positioning portion. When cutting to the indication path, the staff can be reminded to control the cutting depth to avoid damaging the inferior alveolar nerve.

[0019] Furthermore, the fixing portion is provided with fixing holes for placing screws, which can indicate the screw placement position and facilitate the fixing of the protective guide plate by screws on the mandible.

[0020] Furthermore, the fixing portion is an arc-shaped strip structure, which can be adapted to the shape of the mandibular angle of the human body, thereby improving the stability of the fixing of the protection guide plate.

[0021] The present invention also provides a method for applying a mandibular sagittal splitting bone removal and nerve protection guide plate, comprising the following steps:

[0022] S11: The surgeon places the bone removal and nerve protection guide plate on the patient's mandible according to the mandibular angle;

[0023] S12: The surgeon places nails in the fixation holes to fix the bone removal and nerve protection guide plate to the patient's mandible;

[0024] S13: The surgeon uses tools to perform osteotomy cutting along the osteotomy guide surface and stops osteotomy when the cutting reaches the nerve protection guide surface;

[0025] S14: The surgeon uses surgical tools to perform bone removal and trimming on the upper side of the ascending ramus and the lower edge of the mandible from the nerve protection guide surface.

[0026] Compared with the existing technology, the present invention can customize the bone removal and nerve protection guide that matches the patient's mandible through CT image digital design and 3D printing technology, and can accurately locate the patient's bone removal position, reduce the difficulty of the operation, and achieve precise bone removal; at the same time, the bone removal and nerve protection guide can also use the nerve protection guide surface to help the surgeon control the position of the inferior alveolar nerve, avoid damage to the inferior alveolar nerve during bone removal, and improve the safety of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the manufacturing method of this embodiment.

[0028] Figure 2 This is a 3D model diagram of the mandibular bone and inferior alveolar nerve reconstructed in step S02 of this embodiment.

[0029] Figure 3 This is a 3D model diagram after simulating sagittal mandibular splitting surgery in step S03 of this embodiment.

[0030] Figure 4 It is the 3D model of the bone removal and nerve protection guide designed in step S04 of this embodiment. Figure 1 .

[0031] Figure 5 It is the 3D model of the bone removal and nerve protection guide designed in step S04 of this embodiment. Figure 2 .

[0032] Figure 6It is the 3D model of the bone removal and nerve protection guide designed in step S04 of this embodiment. Figure 3 .

[0033] Figure 7 It is a schematic diagram of the structure of the bone removal and nerve protection guide plate fitting the mandible.

[0034] Figure 8 It is a schematic diagram of the front structure of the bone removal and nerve protection guide.

[0035] Fig. 9 It is a schematic diagram of the structure of the back side of the bone removal and nerve protection guide.

[0036] Fig.10 is a flow chart of the application method of this embodiment.

[0037] In the figure, 1. bone removal and nerve protection guide; 11. fixing part; 111. fixing hole; 12. positioning part; 121. positioning hole; 122. osteotomy guide surface; 1221. third guide surface; 1222. fourth guide surface; 123. nerve protection guide surface; 1231. first guide surface; 1232. second guide surface; 124. fitting surface; 125. indication path; 2. mandible. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] To achieve the above object, the technical solution of the present invention is as follows:

[0040] See also Figure 1-6 As shown, this embodiment provides a method for making a mandibular sagittal splitting bone removal and nerve protection guide plate, comprising the steps of:

[0041] S01: Take spiral CT data of the patient's mandible and export it in dicom format;

[0042] S02: Import the spiral CT data of the patient's mandible into the 3D software mimic to segment and reconstruct the model of the patient's mandible and inferior alveolar nerve;

[0043] S03: Simulate sagittal mandibular splitting on the segmented and reconstructed mandibular model;

[0044] S04: According to the simulated osteotomy line, design a bone removal and nerve protection guide that matches the mandibular model;

[0045] S05: 3D printing of metal bone removal and nerve protection guide.

[0046] For details, see Figure 3-5 The 3D model of the mandible is reconstructed from the spiral CT data of the patient's mandible, and has a very high similarity with the patient's mandible. The gray part is the 3D model of the entire mandible. In the 3D model of the mandible, the lines inside the model are the inferior alveolar nerve, the yellow is the ascending ramus of the mandible, the red is the position where bone removal is required, and the blue is the bone removal and nerve protection guide 1. By simulating the sagittal splitting of the mandible on the model, the osteotomy line can be accurately determined in advance, so that the bone removal and nerve protection guide 1 that matches the patient's mandible can be personalized and made using 3D printing. During the operation, the patient's bone removal position can be accurately located to reduce the difficulty of the operation and achieve precise bone removal; at the same time, the bone removal and nerve protection guide 1 can also use the nerve protection guide surface to help the surgeon control the position of the inferior alveolar nerve, avoid damage to the inferior alveolar nerve during bone removal, and improve the safety of the operation.

[0047] pass Figure 6 It can be seen from the bottom of the 3D model that there is a certain safety distance between the inferior alveolar nerve and the osteotomy line. During the operation, positioning by bone removal and nerve protection guide 1 can achieve precise bone removal, protect the inferior alveolar nerve, and avoid nerve damage during the operation.

[0048] Furthermore, in step S05, the bone removal and nerve protection guide plate 1 is made of titanium alloy material, which has higher hardness and is not easy to deform compared with conventional materials.

[0049] For details, see Figure 7-9 The bone removal and nerve protection guide plate 1 includes: a fixing portion 11 for fixing to the mandibular bone 2 and a positioning portion 12 for positioning the bone removal position, the fixing portion 11 and the positioning portion 12 are integrally formed; a positioning hole 121 is provided on the positioning portion 12, and a bone cutting guide surface 122 and a nerve protection guide surface 123 are provided on the side wall of the positioning hole 121, and the bone cutting guide surface 122 and the nerve protection guide surface 123 are connected by the same edge. In this operation, after the positioning hole 121 locates the bone removal position, the knife can be cut downward from the bone cutting guide surface 122, and when the nerve protection guide surface 123 is cut, the downward cutting is stopped; and the horizontal cutting is turned along the nerve protection guide surface 123 to remove the bone on the upper side of the ascending ramus and the lower edge of the mandible until the bone removal is completed, thereby avoiding damage to the inferior alveolar nerve.

[0050] Furthermore, the osteotomy guide surface 122 is a longitudinal surface for controlling the osteotomy depth of the mandibular bone 2, and the nerve protection guide surface 123 is a transverse surface intersecting the osteotomy guide surface 122. During the operation, the osteotomy guide surface 122 is cut downward along the longitudinal surface, and the nerve protection guide surface 123 can guide the cutting depth of the osteotomy guide surface 122, and stop when the cutting reaches the transverse surface to avoid excessive downward cutting and damage to the inferior alveolar nerve.

[0051] Furthermore, the bottom of the positioning portion 12 is provided with a fitting surface 124 that can fit the mandible 2, and the upper edges of the osteotomy guide surface 122 and the nerve protection guide surface 123 are co-edge with the upper surface of the positioning portion 12, and the lower edges are co-edge with the fitting surface 124; and the side edges of the osteotomy guide surface 122 and the nerve protection guide surface 123 are co-edge with each other. The fitting surface 124 can fit the outer side of the mandible 2, which facilitates the positioning of the bone removal position.

[0052] Furthermore, the nerve protection guide surface 123 includes a first guide surface 1231 and a second guide surface 1232, and the first guide surface 1231 and the second guide surface 1232 are in the same horizontal plane; the osteotomy guide surface 122 includes a third guide surface 1221 and a fourth guide surface 1222, and the third guide surface 1221 and the fourth guide surface 1222 are relatively arranged longitudinal cutting surfaces; the two side edges of the third guide surface 1221 and the fourth guide surface 1222 are connected by the first guide surface 1231 and the second guide surface 1232 respectively.

[0053] Furthermore, the positioning portion 12 is an arc-shaped structure that fits with the mandible 2 , the upper surface and the lower surface of the positioning portion 12 are both arc-shaped surfaces, and the upper surface of the positioning portion 12 forms a fitting surface 124 .

[0054] Furthermore, the upper surface of the positioning portion 12 is also provided with an indication path 125 for indicating the direction and position of the intraosseous nerve. The indication path 125 is a projection of the inferior alveolar nerve on the upper surface of the positioning portion 12, and is a groove-shaped structure penetrating the positioning hole 121 in the positioning portion 12. When the indication path 125 is cut, the staff can be reminded to control the cutting depth to avoid damaging the inferior alveolar nerve.

[0055] Furthermore, the fixing portion 11 is provided with a fixing hole 111 for placing a screw, which can indicate the position of placing the screw, making it convenient to place the screw on the mandible 2 to fix the protective guide plate.

[0056] Furthermore, the fixing portion 11 is an arc-shaped strip structure, which can be adapted to the shape of the mandibular angle of the human body, thereby improving the stability of the fixing of the protection guide plate.

[0057] See also Fig.10 This embodiment also provides a method for applying a mandibular sagittal splitting bone removal and nerve protection guide plate, comprising the following steps:

[0058] S11: The bone removal and nerve protection guide is positioned on the patient's mandible according to the mandibular angle;

[0059] S12: Place nails in the fixation holes to fix the bone removal and nerve protection guide to the patient's mandible;

[0060] S13: Use a saw to perform osteotomy along the osteotomy guide surface, and stop osteotomy when the cut reaches the nerve protection guide surface;

[0061] S14: Use surgical tools such as chisels to perform bone removal and trimming on the upper side of the ascending ramus and the lower edge of the mandible from the nerve protection guide surface.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for making a mandibular sagittal splitting bone removal and nerve protection guide, characterized in that: Includes steps: S01: Acquire CT data of the patient's mandible; S02: Import the CT data of the patient's mandible into the 3D software to segment and reconstruct the model of the patient's mandible and inferior alveolar nerve; S03: Simulate sagittal mandibular splitting on the segmented and reconstructed mandibular model; S04: According to the simulated osteotomy line, design a bone removal and nerve protection guide that matches the mandibular model; S05: 3D printing to make bone removal and nerve protection guide; In step S04, the bone removal and nerve protection guide plate includes: a fixing portion for fixing to the mandibular bone and a positioning portion for positioning the bone removal position, wherein the fixing portion and the positioning portion are integrally formed; a positioning hole is provided on the positioning portion, and a side wall of the positioning hole is provided with an osteotomy guide surface and a nerve protection guide surface, wherein the osteotomy guide surface and the nerve protection guide surface are connected to each other on the same side; The osteotomy guide surface is a longitudinal surface for controlling the mandibular osteotomy depth, and the nerve protection guide surface is a transverse surface intersecting the osteotomy guide surface; The bottom of the positioning part is provided with a fitting surface that can fit the mandible, the upper edges of the osteotomy guide surface and the nerve protection guide surface are coterminous with the upper surface of the positioning part, and the lower edges are coterminous with the fitting surface; and the side edges of the osteotomy guide surface and the nerve protection guide surface are coterminous with each other.

2. The method for making a mandibular sagittal splitting bone removal and nerve protection guide as claimed in claim 1, characterized in that: The nerve protection guide surface includes a first guide surface and a second guide surface, and the osteotomy guide surface includes a third guide surface and a fourth guide surface. The third guide surface and the fourth guide surface are arranged opposite to each other; the two side edges of the third guide surface and the fourth guide surface are connected by the first guide surface and the second guide surface respectively.

3. The method for making a mandibular sagittal splitting bone removal and nerve protection guide as claimed in claim 1, characterized in that: The positioning portion is an arc-shaped structure that fits the mandible, the upper surface and the lower surface of the positioning portion are both arc-shaped surfaces, and the upper surface of the positioning portion forms the fitting surface.

4. The method for making a mandibular sagittal splitting bone removal and nerve protection guide as claimed in claim 1, characterized in that: The upper surface of the positioning portion is also provided with an indication path for indicating the direction and position of the intraosseous nerve.

5. The method for making a mandibular sagittal splitting bone removal and nerve protection guide as claimed in claim 1, characterized in that: The fixing part is provided with a fixing hole for placing a nail.

6. The method for making a mandibular sagittal splitting bone removal and nerve protection guide as claimed in claim 1, characterized in that: The fixing portion is an arc-shaped strip structure, which is adapted to the shape of the mandibular angle of the human body.

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