A type of mandibular prosthesis

Abstract

This utility model discloses a molded mandibular prosthesis, belonging to the field of medical devices, aiming to solve the problems of insufficient fit between existing mandibular prostheses and the human mandible, and the tendency for postoperative bone resorption. The prosthesis is a one-piece molded structure, symmetrical on both sides, with a decompression groove on the side closest to the mandible. The decompression groove is symmetrical about the center line and transitions smoothly and continuously from both ends to the center along its length, with the middle section being deeper than the two ends. The prosthesis surface is smooth and has a microporous structure with pore diameters greater than 15μm, which can induce cell ingrowth and fixation, resulting in a natural postoperative effect and effectively reducing the degree of bone resorption.

Description

Technical Field

[0001] This utility model relates to the field of medical devices, specifically to a mandibular prosthesis used for facial soft tissue filling. Background Technology

[0002] In facial reconstruction surgery, particularly chin augmentation, the structural design of the implant is crucial to the surgical outcome and postoperative recovery. Currently used chin implants typically have a smooth surface on the side closest to the patient's natural mandible. However, the area where the mandible contacts the implant is not flat, preventing complete fit between the implant and the mandible. Postoperatively, the persistent tension can lead to bone resorption, affecting the stability of the surgical results.

[0003] To address the aforementioned issues, this invention provides a novel molded mandibular prosthesis that improves its fit with the mandible through optimized structural design, thereby reducing the risk of bone resorption. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing mandibular prostheses, such as insufficient fit between the prosthesis and the mandible and easy bone resorption after surgery. It provides a molded mandibular prosthesis that achieves tension dispersion by optimizing the decompression groove structure, thereby improving the stability of surgical results.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] like Figure 1-5 As shown, a mandibular prosthesis is a one-piece molded structure with overall left-right symmetry; a decompression groove is provided on the side near the mandible, the decompression groove is symmetrical about the center line, and transitions smoothly and continuously from both ends to the center along the length direction, and the depth of the middle section is greater than the depth of the two ends; the surface of the prosthesis is smooth and has a microporous structure with a micropore diameter greater than 15μm.

[0007] Furthermore, the middle section is the area within 1 / 4 of the total length of the pressure relief groove on both sides of the center line along the length direction, and the two end sections are the areas within 1 / 4 of the total length of the pressure relief groove from both ends to the endpoints along the length direction. This division method is based on the stress distribution characteristics of the inner side of the human mandible. The middle section corresponds to the area of ​​the mandible that bears the main tension, and targeted pressure relief is achieved by increasing the depth.

[0008] Furthermore, the pressure relief groove is rectangular or elliptical in shape, and its outline is adapted to the anatomical shape of the inner side of the human mandible. The four corners of the rectangular pressure relief groove are rounded to avoid local stress concentration; the long axis of the elliptical pressure relief groove is consistent with the length direction of the prosthesis, which better fits the natural curvature of the mandible.

[0009] Furthermore, the length of the prosthesis is 45-70mm, the width is 25-55mm, the thickness of the middle section of the prosthesis is 7-12mm, the width of both ends of the prosthesis is 20-25mm, the length of the pressure relief groove is 16-20mm, and the width of the pressure relief groove is 5-9mm.

[0010] Furthermore, the transition area of ​​the pressure-reducing groove is free of sharp edges and has a smooth arc-shaped connection, making the depth change more in line with the principle of mechanical dispersion and avoiding local pressure increase caused by abrupt transition.

[0011] Furthermore, the pore size of the micropores ranges from 15μm to 50μm. This pore size range can ensure that cells can grow in smoothly to achieve biological fixation, while maintaining the structural strength of the prosthesis and preventing insufficient support due to excessively large micropores.

[0012] Furthermore, the edges of the prosthesis are all rounded with a radius of not less than 0.5 mm, which reduces friction and stimulation to surrounding tissues and lowers the risk of postoperative inflammatory response.

[0013] Furthermore, the overall thickness of the prosthesis gradually changes from the center to the edge, with a gradient slope of 5°-15°, which conforms to the natural shape of the human mandible and improves its compatibility with surrounding tissues.

[0014] This utility model has the following beneficial effects:

[0015] 1. The prosthesis adopts a one-piece molded symmetrical structure that conforms to the physiological and anatomical characteristics of the human mandible. The decompression groove is designed with "deep in the middle section and shallow at both ends" to match the thickness after the change of the inner curvature of the mandible, increasing the contact area between the prosthesis and the bone surface and improving the fit.

[0016] 2. The continuous and smooth transition design of the decompression groove along its length can evenly distribute postoperative tissue tension throughout the contact area, reduce local pressure peaks, and effectively reduce the risk of bone resorption.

[0017] 3. The smooth surface design and rounded edges avoid mechanical stimulation of surrounding nerves and blood vessels; the microporous structure provides channels for cell ingrowth, achieving biological fixation of the prosthesis to surrounding tissues and reducing displacement rate.

[0018] 4. The depth difference of the decompression groove is controlled within a reasonable range. Combined with the overall structural design, integrated manufacturing processes ensure structural stability and avoid gaps or loosening problems that may occur with split structures. While ensuring the decompression effect, the structural strength of the prosthesis is maintained, and its resistance to deformation is improved.

[0019] 5. The overall thickness gradually changes from the center to the edge, conforming to the natural shape of the human jaw, resulting in a more natural appearance after surgery and reducing the feeling of a foreign body. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Figure 2 This is the front view of the present invention.

[0022] Figure 3 This is a top view of the present invention.

[0023] Figure 4 This is a rear view of the present invention.

[0024] Figure 5 This is a side view of the present invention. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1-5 As shown, the mandibular prosthesis 1 provided by this utility model is an integrally molded structure, which is symmetrically distributed on both sides, and its axis of symmetry coincides with the midline of the human mandible.

[0027] The decompression groove 2 is located on the side of the prosthesis 1 near the mandible, and is rectangular or elliptical in shape. Along the length of the decompression groove 2, it transitions continuously from both ends towards the center in an arc, with a radius of 10-20 mm (i.e., ...). Figure 3 Mark a) to ensure smooth depth changes.

[0028] All exposed surfaces of prosthesis 1 are polished to a roughness Ra≤0.8μm, with even lower roughness on the outer surface in contact with soft tissue to reduce frictional irritation. A microporous structure (not shown in the figure) is uniformly distributed throughout prosthesis 1, with pore sizes ranging from 15-50μm and porosity of 50%-70%, ensuring efficient cell ingrowth and structural strength of prosthesis 1. All edges of prosthesis 1 are rounded with a radius of at least 0.5mm.

[0029] Implant 1 has a length of 45-70mm (measured in a bent state, i.e.) Figure 3 (marked at point A in the middle), suitable for patients of different body types; width is 25-55mm (i.e., Figure 3 , 5 (Point B in the middle) corresponds to the transverse dimension of the mandibular body; the middle segment (i.e. Figure 2 The area marked E (18-26mm in length, preferably 20mm) provides sufficient support for the prosthesis 1 within one-quarter of its total length on either side of the centerline along its length direction; the two end sections (i.e. Figure 2 The area marked H (20-25mm in length, preferably 20mm) is the region along the length of prosthesis 1 located within 1 / 4 of the total length from both ends to the middle section endpoint. The thickness of the middle section (i.e. Figure 4 , 5 The dimension at point D (7-12mm) is greater than the thickness of the two end sections (i.e., Figure 4 , 5 The dimension at point G is 7-10mm.

[0030] The length of pressure-reducing tank 2 is 16-20mm, and the width of pressure-reducing tank 2 is 5-9mm (i.e. Figure 2 (marked at F in the middle), preferably 8mm, matching the lateral range of the mandibular stress concentration zone, the depth of decompression groove 2 is 3-6mm (i.e. Figure 3 (Category C) The thickness is preferably 5mm, covering the main stress area on the inner side of the mandible. The overall thickness gradually changes from the center to the edge, with a gradient slope of 5°-15°, conforming to the natural shape of the human mandible. The transition area of ​​the decompression groove 2 is smooth and rounded without any sharp edges.

[0031] Furthermore, the prosthesis in this embodiment is made using 3D printing technology.

[0032] The method of using the prosthesis provided in this embodiment is as follows: First, detailed anatomical data of the patient's mandible are obtained through three-dimensional CT scanning and three-dimensional reconstruction technology, including the length, width, curvature and concavity and convexity features of the mandible, to determine the specific area of ​​the patient's mandible that needs to be filled and repaired, and to assess whether the patient is suitable for implantation of the mandibular prosthesis 1.

[0033] Next, based on the patient's mandibular bone data, the prosthesis 1 that best matches the patient's needs is selected from the available prostheses of different sizes and specifications. If there are slight differences in the matching degree between the selected prosthesis 1 and the patient's mandibular bone, the prosthesis 1 is locally adjusted using a special medical sculpting tool.

[0034] According to the surgical plan, a suitable incision location is selected in the patient's mandible, usually in the mandibular vestibule inside the mouth. A scalpel is used to cut along the designed incision line through the mucosa and subcutaneous tissue until the mandibular bone surface is exposed. The incision length is determined based on the size of the prosthesis 1 and the implantation method.

[0035] After sterilization, implant 1 is inserted into the prepared cavity in the correct orientation, ensuring that the decompression groove 2 of implant 1 faces the mandibular bone surface and that the middle section is aligned with the area of ​​the mandible that bears the main tension. After implantation, gently press implant 1 with your fingers to adjust its position, ensuring that implant 1 fits tightly against the mandibular bone surface and that the decompression groove 2 can fully exert its decompression effect. Because the microporous structure on the surface of implant 1 can induce cell ingrowth and achieve biological fixation after surgery, screws or other auxiliary fixation instruments are generally not required.

[0036] The principle behind this embodiment is to reduce the risk of bone resorption:

[0037] Bone resorption is essentially the adaptive atrophy of bone tissue under abnormal mechanical stress or inflammatory stimulation. The key inducing factor is the pressure concentration and relative movement at the interface between the prosthesis and the bone surface. Human bone tissue has a definite tolerance range for pressure. When a traditional smooth-surface prosthesis comes into contact with the mandible, due to the concave and convex structures on the bone surface such as the chin protuberance and the curvature of the mandibular base, the prosthesis and the bone surface can only form a few discrete contact points, causing the pressure at these points to increase sharply, far exceeding the tolerance threshold.

[0038] Furthermore, the human mandible is not a standard symmetrical structure, and individual differences lead to significant variations in the curvature of the bone surface and the position of protrusions. Traditional prostheses, lacking grooves, require sculpting to compromise their integrity or forcibly compressing the bone surface to achieve a proper fit, resulting in continuous elastic return tension—the prosthesis attempts to restore its original shape, while the bone surface hinders its deformation, creating a vicious cycle of stress.

[0039] This invention achieves bone resorption prevention by opening a decompression groove 2. The core lies in the optimization of the groove structure in terms of "pressure distribution" and "spatial adaptation": the groove design of the decompression groove 2 accommodates the protruding parts of the bone surface through "recessed space", transforming the original point contact into surface contact: the edges of the prosthesis 1 on both sides of the groove fit into the flat area of ​​the bone surface, increasing the contact area and dispersing the pressure to the entire contact surface, which is within the physiologically safe range.

[0040] The groove depth of the decompression groove 2 provides a safe tolerance for irregular areas of the bone surface: it can achieve a fit without excessive carving, avoiding the return tension caused by the forced deformation of the prosthesis 1. At the same time, a gap is formed between the groove and the bone surface, which can be filled by the postoperative proliferating fibrous tissue. These tissues act as a "buffer pad," further absorbing the relative motion stress between the prosthesis 1 and the bone surface, thus reducing dynamic tension.

[0041] In summary, by optimizing the depth distribution, transition method, and overall thickness design of the decompression groove 2, this utility model significantly improves the adaptability, stability, and naturalness of the mandibular prosthesis 1 to the human body, effectively solving the bone resorption problem of traditional prostheses 1, and has important clinical application value.

Claims

1. A shaped mandibular prosthesis, characterized in that, The prosthesis (1) is a one-piece molded structure with overall left and right symmetry; a decompression groove (2) is provided on the side near the mandible. The decompression groove (2) is symmetrical about the center line and transitions smoothly from both ends to the center along the length direction, and the depth of the middle section is greater than the depth of the two ends; the surface of the prosthesis (1) is smooth and has a microporous structure with a micropore diameter greater than 15μm.

2. The shaped mandibular prosthesis of claim 1, wherein, The middle section is the area within 1 / 4 of the total length of the pressure relief groove (2) on both sides of the center line along the length direction, and the two end sections are the areas within 1 / 4 of the total length of the pressure relief groove (2) from both ends to the endpoints along the length direction.

3. The shaped mandibular prosthesis of claim 1, wherein, The pressure relief groove (2) is rectangular or elliptical in shape.

4. The shaped mandibular prosthesis of claim 1, wherein, The length of the prosthesis (1) is 45-70mm, the width is 25-55mm, the thickness of the middle section of the prosthesis (1) is 7-12mm, the width of both ends of the prosthesis (1) is 20-25mm, the length of the pressure relief groove (2) is 16-20mm, and the width of the pressure relief groove (2) is 5-9mm.

5. The shaped mandibular prosthesis of claim 1, wherein, The transition area of ​​the pressure relief groove (2) has no sharp edges and is smoothly connected in an arc shape.

6. The shaped mandibular prosthesis of claim 1, wherein, The pore size of the micropores ranges from 15μm to 50μm.

7. The shaped mandibular prosthesis of claim 6, wherein, The edges of the prosthesis (1) are all rounded, with a radius of not less than 0.5 mm.

8. The shaped mandibular prosthesis of claim 7, wherein, The overall thickness of the prosthesis (1) gradually changes from the center to the edge, with a gradient slope of 5°-15°.

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