Implant for supporting an upper-jaw dental prosthesis on the cranial bone

Abstract

An implant (X) for supporting an upper-jaw dental prosthesis (Z) on the cranial bone (S), wherein the implant (X) has a receiving portion (ZA) for receiving the upper-jaw dental prosthesis (Z), and also a plurality of fastening portions (B1, B2, B3, B4), wherein the fastening portions (B1, B2, B3, B4) are connected to the receiving portion (ZA) and have at least one through-hole (DL) for receiving a fastening screw (BT), wherein the fastening portions (B1, B2, B3, B4) are formed at least by a first fastening portion (B1), a second fastening portion (B2) and a third fastening portion (B3), wherein the first fastening portion (B1) is designed to anchor the implant (X) on the lateral cranial base (S1), and wherein the second and third fastening portions (B2, B3) are designed to anchor the implant (X) on one of the following three cranial bone portions (S2, S3, S4): the pterygoid process (S2), the zygomatic bone (S3), and the maxilla (S4).

Description

[0001] IMPLANT FOR SUPPORTING AN UPPER DENTURE ON THE SKULL BONE

[0002] The invention relates to an implant for supporting an upper jaw dental prosthesis on the skull bone, particularly in the case of loss or pre-existing damage to parts of the upper jaw and / or midface.

[0003] Several factors can lead to the partial or complete loss of upper jaw and / or midface bone. For example, the bone structure in this area can be severely damaged by trauma. In the case of a tumor in this area, removal or radiation therapy of the local bone structure is often necessary. Radiation therapy can damage the bone structure, making the anchoring of an upper jaw denture to the remaining bone unreliable. Systemic factors such as chemotherapy, immunotherapy, or the use of medications that affect bone metabolism can also damage this area.

[0004] To treat patients with this diagnosis, it is known to place an implant in the skull bone to restore the missing or damaged structure. Preferably, such an implant already incorporates a support for an upper jaw denture. Alternatively, it is possible to first reconstruct the missing and / or damaged parts of the upper jaw and / or midface, and only after a healing period for this reconstruction, to place an upper jaw denture. However, this prolongs the patient's healing process.

[0005] WO 2016 / 198935 A1 describes a jaw implant for oral, subperiosteal placement above the alveolar ridge of the maxilla. The jaw implant has a J-, L-, or U-shaped body with multiple support areas that extend through the gingiva. The body features several extensions with attachment holes for securing the implant to the jawbone, for example, at the piriform aperture, the zygomatic column, or the zygomatic arch. This solution involves the introduction of a significant amount of foreign material near the reconstruction site, thus carrying the risk of postoperative inflammation and / or unreliable implant retention. This is undesirable for the patient.

[0006] German patent DE 102018 102 568 A1 describes an implant with a support structure designed for bone-contour-following anchorage to a jawbone and / or skull. At least one post projects from the support structure, designed to anchor a final dental prosthesis. Bridge components may project from the support structure, designed for remote attachment of the implant. However, a specific design for such remote attachment is not described.

[0007] It is therefore an object of the invention to provide an implant for supporting an upper jaw dental prosthesis on the skull bone, which is particularly suitable in the case of loss or pre-damage of upper jaw and / or midface parts and does not require prior reconstruction of these structural parts.

[0008] The problem is solved by the features of claim 1. Advantageous embodiments result from the dependent claims, the description and the figures.

[0009] To solve the problem, an implant is proposed for supporting an upper jaw denture on the skull bone. The implant has a receiving section for the upper jaw denture and several attachment sections connected to this receiving section. By aligning the attachment sections with the bony anatomy of the skull, the implant can be positioned on the skull. Each attachment section has at least one through-hole for receiving a fixing screw, allowing the implant to be anchored in the correct position to the skull bone using multiple fixing screws.

[0010] According to the invention, the attachment sections are formed by at least a first, second, and third attachment section. The first attachment section is designed to anchor the implant to the lateral base of the skull. The second and third attachment sections are designed to anchor the implant to further defined skull bone segments, namely the pterygoid process, the zygomatic bone, or the maxilla. Of these three defined skull bone segments, at least two are used for anchoring the implant. For example, the second attachment section can be designed for anchoring to the pterygoid process, and the third attachment section for anchoring to the zygomatic bone. Alternatively, the second attachment section can be designed for anchoring to the pterygoid process, and the third attachment section for anchoring to the maxilla.According to another alternative, the second attachment section can be designed for anchorage to the zygomatic bone, and the third attachment section for anchorage to the maxilla. The proposed arrangement and design of the first attachment section is based on the understanding that anchoring the implant away from the affected and potentially damaged structures of the maxilla and / or midface significantly improves the chances of successful implant integration. Furthermore, the geometrically wide support base considerably improves the precise positioning of the implant on the anatomy of the skull. By utilizing the lateral skull base as an anchoring support, the implant can be positioned much more accurately on the skull than with a conventional, localized support.

[0011] However, the proposed arrangement and design of the first attachment section leads to a high mechanical load on the implant, since the distance between the force applied to the maxillary denture, which is later supported by the implant, and the support at the lateral skull base is relatively large. According to the invention, this is solved by the proposed arrangement and design of the second and third attachment sections, which provide additional support for the forces at the skull bone. This effectively prevents overloading of the anchorage at the first attachment section.

[0012] The implant proposed according to the invention is further characterized by the fact that it can be administered to the patient with relatively little invasiveness. The preparation for performing the first attachment section can, for example, be carried out transorally with subperiosteal dissection along the lateral midface to the preauricular region. The necessary preparation at the pterygoid process can also be performed transorally.

[0013] Preferably, the implant has a fourth attachment point designed to anchor it to the remaining of the three skull bone segments. In other words, according to this design, the implant is anchored to the lateral skull base, the pterygoid process, the zygomatic bone, and the maxilla. This design achieves a particularly stable anchorage with high positional accuracy.

[0014] Preferably, at least one of the attachment sections is designed in pairs. "In pairs" here means that a single attachment section and another single attachment section, which are intended for attachment to the same anatomical structure on different sides of the skull bone, are conceptually grouped together. Therefore, if the implant has two individual attachment sections, both of which serve to anchor the implant to, for example, the lateral base of the skull, these two individual attachment sections form a pair. This design allows for uniformly stable anchoring of the implant on both sides. Two, three, or, if present, all four attachment sections can be designed in pairs.

[0015] Preferably, the implant has a total of four or five attachment posts extending from the receiving section. In this design, the attachment sections are formed on these four or five posts. The design with exactly four or five attachment posts allows the implant to be positioned with exceptional precision against the anatomy of the skull bone.

[0016] Preferably, the attachment section used to anchor the implant to the zygomatic bone is designed such that anchorage occurs at the root of the zygomatic arch. This design effectively relieves stress on the first attachment section, allowing it to be designed with a smaller cross-section. This results in less foreign material being introduced into the patient.

[0017] According to one possible embodiment, at least one of the attachment sections is designed such that a portion of the implant rests directly against the zygomatic bone. The shape of the zygomatic bone aids in positioning the implant on the skull bone, allowing for particularly precise alignment with the anatomy. In this embodiment, the portion of the implant that rests directly against the zygomatic bone is preferably designed to at least partially encircle it. This ensures not only precise positioning but also efficient force transmission from the implant to the skull bone.

[0018] Preferably, the attachment section used to fix the implant to the pterygoid process is designed such that one attachment direction has an angle between 30 and 60 degrees to the vertical, preferably an angle between 40 and 50 degrees, and most preferably an angle of 45 degrees. "Vertical" here refers to the longitudinal axis of the anatomy. This geometry facilitates implant anchorage with the mandible open during surgery, as the necessary drilling and screwing directions are more easily accessible.

[0019] According to a preferred embodiment, the attachment section used to anchor the implant to the pterygoid process has exactly one or two through-holes for receiving one fixing screw each. This design easily avoids geometric overdetermination of the implant position. If the attachment section for anchoring the implant to the pterygoid process is designed in pairs, so that the implant can be attached to the right and left pterygoid processes, each half of the attachment section has one or two through-holes – one for attachment to the right pterygoid process and one for attachment to the left pterygoid process.

[0020] Preferably, the first attachment section extends essentially horizontally along the lateral base of the skull. This design simplifies transoral insertion and subperiosteal preparation.

[0021] Preferably, the first attachment section has several through-holes for receiving fastening screws, particularly preferably more than five through-holes. The number "five" refers to a single attachment section, so that in a pair of first attachment sections, at least ten through-holes are provided. The high number of through-holes allows the first attachment section to be anchored particularly securely to the lateral skull base. It is not necessary for all through-holes to actually be used for anchoring the implant.

[0022] Preferably, the first attachment section is designed such that at least one of the through-holes for anchoring the implant is located in close proximity to the temporomandibular joint. This enables particularly good support of the biting forces between the upper and lower jaw, which can even surpass the support provided by a complete and unimpaired dentition.

[0023] Preferably, at least one of the attachment sections has a projection that points away from the direction of extension of the attachment section and is curved. This design improves and further defines the positioning of the implant in relation to the anatomy.

[0024] Preferably, the implant is manufactured in one piece. For example, the implant can be produced by 3D printing or milling from a single blank, such as titanium or steel. This design eliminates the need for a joint that could compromise the implant's stability. Preferably, at least one of the attachment points has a marker to indicate the position of a sensitive tissue segment, such as nerves, brain tissue, cerebrospinal fluid fistulas, or blood vessels. Such a marker assists the surgeon in securing the implant by directly indicating the location of sensitive tissue at the implant site.

[0025] Preferably, the implant is designed such that it can only be positioned on the skull bone in a single location, thus preventing incorrect alignment due to the implant's geometry. However, embodiments are also conceivable in which the implant geometry deliberately allows some flexibility in its placement on the skull bone.

[0026] Exemplary embodiments of the invention are described in detail with reference to the figures. The figures show:

[0027] Fig. 1-2 different views of an implant according to a first embodiment;

[0028] Figs. 3-4 show different views of an implant according to a second embodiment;

[0029] Fig. 5 shows a detailed view of the implant according to the second embodiment;

[0030] Fig. 6 shows a detailed view of the implant being placed on the zygomatic bone;

[0031] Fig. 7 shows a detailed view of a fastening section; and Figs. 8-9 show further views of the implant according to the first embodiment.

[0032] Figures 1 and 2 each show a view of an implant X according to a first embodiment. In the illustrations of Figures 1 and 2, the implant X is positioned relative to a skull bone S, specifically in the position in which the implant X is to be anchored to the skull bone S during surgery. The implant X serves to support an upper jaw denture Z on the skull bone S. For this purpose, the implant X has a receiving section ZA to which the upper jaw denture Z can be attached. First, second, third, and fourth attachment sections B1, B2, B3, and B4 are connected to the receiving section ZA, allowing the implant X to be attached to various locations on the skull bone S. Each of the attachment sections B1, B2, B3, and B4 has at least one through-hole designed to receive a fixing screw.Thus, the implant X can be firmly connected to the skull bone S by means of several fixing screws. The fixing screws are not shown in Fig. 1 and Fig. 2. Instead, the screw vectors are shown to clarify the subsequent orientation of the fixing screws.

[0033] Depending on the available bony anatomy, the implant X can be attached to the same location on both sides of the skull bone S. In the embodiment shown in Figs. 1 and 2, for example, it is attached unilaterally to the pterygoid process S2 and bilaterally to the zygomatic bone S3 and the maxilla S4. Attachment to the lateral skull base is only performed on the right lateral skull base S1 (from the patient's perspective), but not on the left lateral skull base.

[0034] In the embodiment shown in Figures 1 and 2, the implant X has a total of five attachment posts F1, F2, F3, F4, and F5 extending from the receiving section ZA. Attachment sections B1, B2, B3, and B4 are formed on the attachment posts F1, F2, F3, F4, and F5. Thus, attachment post F1 extends from the receiving section ZA to the right lateral skull base S1 (from the patient's perspective). The first attachment section B1 is formed on attachment post F1 to allow the implant X to be fixed to the right lateral skull base S1 using several fixing screws. The right half of the third attachment section B3 is also formed on attachment post F1. The second attachment section B2 is formed on attachment post F5. The implant X can be attached to the right pterygoid process S2 via the second attachment section B2.The implant X can be attached to the zygomatic bone S3 via the right half of the third attachment section B3, in the embodiment according to Fig. 1 and Fig. 2 at the root of the zygomatic arch S3x.

[0035] Starting from the receiving section ZA, the fixation posts F2 and F3 extend towards the maxilla S4. The right half of the fourth fixation section B4 is formed on fixation post F2. The left half of the fourth fixation section B4 is formed on fixation post F3. The two individual halves of the fourth fixation section B4 together form a pair of fixation sections to secure the implant X bilaterally to the maxilla S4. Also extending from receiving section ZA is fixation post F4, on which the left half of the third fixation section B3 is formed. The implant X can be attached to the root of the left zygomatic arch S3x via the left half of the third fixation section B3.

[0036] Figures 3 and 4 each show a view of an implant X according to a second embodiment, which differs significantly in its structure from the first embodiment shown in Figures 1 and 2. This illustrates that the specific geometric structure of the implant X depends on the individual patient's situation and must therefore be adapted accordingly. The second embodiment shown in Figures 3 and 4 is intended for reconstruction after a gunshot wound. The embodiment of the implant X according to Figures 3 and 4 has exactly four attachment posts F1, F2, F3, and F4, which extend from the receiving section ZA. The right half of the first attachment section B1 is arranged on the attachment post F1 to enable the implant X to be fixed to the right lateral skull base S1.Furthermore, the right half of the third attachment section B3 is arranged on the attachment post F1 to allow the implant to be fixed to the left zygomatic bone S3. The right half of the second attachment section B2 is assigned to a separate attachment post F2 to fix the implant X to the right pterygoid process S2. The left half of the second attachment section B2 is likewise assigned to a separate attachment post F3 to fix the implant X to the left pterygoid process S2. The left half of the first attachment section B1 is formed on the attachment post F4 to allow the implant X to be fixed to the left lateral skull base S1. Furthermore, the left half of the third attachment section B3 is arranged on the attachment post F4 to allow the implant X to be fixed to the left zygomatic bone S3.

[0037] The implant X according to the second embodiment shown in Figs. 3 and 4 is thus attached bilaterally to three skull bone sections: to the lateral skull base S1, to the pterygoid process S2, and to the zygomatic bone S3. The individual halves of the attachment sections B1, B2, B3 each form a pair of attachment sections.

[0038] Figures 3 and 4 clearly show that the left and right halves of the attachment section B2 each have exactly one through-hole for receiving exactly one fastening screw to secure the implant X to the left and right pterygoid processes S2. Figure 5 shows a detailed view of the implant X according to the second embodiment. Two markings Z are arranged on the left half of the first attachment section B1 of the implant X. The markings Z could, for example, be indentations, a roughened surface, or colored anodizing. The markings Z indicate the position of sensitive tissue sections in this area, such as nerves, brain tissue, cerebrospinal fluid fistulas, or blood vessels. This provides the surgeon with appropriate support during preparation and subsequent fixation of the implant X. This embodiment is only an example.The markings Z could be located at any other relevant point on the implant X.

[0039] Fig. 5 further shows the right half of the second attachment section B2 in detail, which allows the implant X to be attached to the right pterygoid process S2. This illustration clearly shows that the second attachment section B2 is designed such that an attachment direction B2R for securing the implant X to the pterygoid process S2 is oriented at an angle W1 of approximately 45 degrees to the vertical V. Naturally, the specific attachment direction B2R depends on the individual case, so the angle W1 is usually in a range between 30 and 60 degrees to the vertical V.

[0040] In Fig. 5 it can be clearly seen that the first fastening section B1 is designed in such a way that the implant X can be anchored in the immediate vicinity of the position of the temporomandibular joint KG on the lateral skull base S1.

[0041] Fig. 6 shows a detailed view of the placement of implant X on the zygomatic bone S3. The implant X rests directly against the zygomatic bone S3 at a section X1. This section X1 at least partially surrounds the zygomatic bone S3. This ensures good force transmission from implant X to the skull bone S.

[0042] Fig. 7 shows a detailed view of the fourth attachment section B4 of the first embodiment of the implant X shown in Fig. 1. A projection H is arranged on the right half of the fourth attachment section B4, which points away from the direction of extension of the fourth attachment section B4 and is curved. This design improves the positioning of the implant X on the anatomy of the maxilla S4. Fig. 8 shows a view of the implant X according to the first embodiment shown in Figs. 1 and 2. In this view, the implant X is shown without the skull bone S and without the maxillary denture ZA. Instead of the screw vectors shown in Figs. 1 and 2, the attachment screws BT are shown in Fig. 8. The length of the attachment screws BS shown in Fig. 8 is for illustrative purposes only.

[0043] Depending on the individual attachment situation on the skull bone S, the surgeon would select different screw lengths.

[0044] Fig. 9 shows another view of the implant X according to the first embodiment shown in Figs. 1 and 2. In this view, the implant X is shown without the skull bone S and without the fixing screws BS, so that the fixing holes DL are visible, highlighted by way of example in Fig. 9 at the fixing post F2. Furthermore, it is clearly visible in Fig. 9 that the implant X is formed in one piece.

[0045] Reference symbol list

[0046] X Implant

[0047] Section XI of the implant

[0048] S skull bones

[0049] 51 lateral skull base

[0050] 52 pterygoid process

[0051] 53 Cheekbone

[0052] S3x root of the zygomatic arch

[0053] 54 Maxilla

[0054] Z upper jaw denture

[0055] ZA Admission Section

[0056] F1 mounting post

[0057] F2 Mounting post

[0058] F3 mounting post

[0059] F4 mounting post

[0060] F5 Mounting post

[0061] B1 First fastening section

[0062] B2 Second fastening section

[0063] B3 Third fastening section

[0064] B4 Fourth fastening section

[0065] BT mounting screw

[0066] DL through hole

[0067] W1 Angle

[0068] V Vertical

[0069] H extension

[0070] Z marking

[0071] KG Position of the temporomandibular joint

Claims

Patent claims 1. Implant (X) for supporting an upper jaw denture (Z) on the skull bone (S), wherein the implant (X) has a receiving section (ZA) for receiving the upper jaw denture (Z) and several attachment sections (B1, B2, B3, B4), wherein the attachment sections (B1, B2, B3, B4) are connected to the receiving section (ZA) and have at least one through-hole (DL) for receiving a fixing screw (BT), wherein the attachment sections (B1, B2, B3, B4) are formed by at least a first attachment section (B1), a second attachment section (B2), and a third attachment section (B3), characterized in that the first attachment section (B1) is configured to anchor the implant (X) to the lateral skull base (S1), and wherein the second and third attachment sections (B2, B3) are configured to anchor the implant (X) to each of the following three skull bone sections (S2, S3, S4) is trained: - at the pterygoid process (S2), - at the cheekbone (S3), - at the Maxilla (S4).

2. Implant (X) according to claim 1, characterized in that the implant (X) has a fourth attachment section (B4) which is configured to anchor the implant (X) to the remaining of the three skull bone sections (S2, S3, S4).

3. Implant (X) according to claim 1 or claim 2, characterized in that at least one of the attachment sections (B1 , B2, B3, B4) is formed in pairs.

4. Implant (X) according to one of claims 1 to 3, characterized in that the implant (X) has a total of four or five attachment posts (F1, F2, F3, F4, F5) extending from the receiving section (ZA), wherein the attachment sections (B1 , B2, B3, B4) are formed on the four or five attachment posts (F1, F2, F3, F4, F5).

5. Implant (X) according to one of claims 1 to 4, characterized in that the fastening section (B3) which serves to anchor the implant (X) to the zygomatic bone (S3) is designed such that the anchoring takes place at the root of the zygomatic arch (S3x).

6. Implant (X) according to one of claims 1 to 5, characterized in that at least one of the attachment sections (B1 , B2, B3, B4) is designed such that a section (X1) of the implant (X) lies directly against the zygomatic bone (S3).

7. Implant (X) according to claim 6, characterized in that the section (X1) of the implant (X) which lies directly against the zygomatic bone (S3) is designed such that the section (X1) at least partially surrounds the zygomatic bone (S3).

8. Implant (X) according to one of claims 1 to 7, characterized in that the attachment section (B2) which serves to attach the implant (X) to the pterygoid process (S2) is designed such that an attachment direction (B2R) has an angle (W1) between 30 and 60 degrees to the vertical (V), preferably an angle (W1) between 40 and 50 degrees, particularly preferably an angle (W1) of 45 degrees.

9. Implant (X) according to one of claims 1 to 8, characterized in that the fastening section (B2) which serves to anchor the implant (X) to the pterygoid process (S2) has exactly one or two through holes (DL) for receiving one fastening screw (BT) each.

10. Implant (X) according to one of claims 1 to 9, characterized in that the first attachment section (B1) extends substantially horizontally along the lateral skull base (S1).

11. Implant (X) according to one of claims 1 to 10, characterized in that the first fastening section (B1) has several through holes (DL) for receiving fastening screws (BT).

12. Implant (X) according to claim 11, characterized in that the first fastening section (B1) is designed such that at least one of the through holes (DL) for anchoring the implant (X) is arranged in the immediate vicinity of the position of the temporomandibular joint (TMJ).

13. Implant (X) according to one of claims 1 to 12, characterized in that a projection (H) is arranged on at least one of the fastening sections (B4), which points away from the extension direction of the fastening section (B4) and is bent.

14. Implant (X) according to one of claims 1 to 13, characterized in that the implant (X) is formed in one piece.

15. Implant (X) according to one of claims 1 to 14, characterized in that at least one of the attachment sections (B1) has a marking (Z) to indicate the position of a sensitive tissue section such as nerves, brain, cerebrospinal fluid fistulas or vessels.

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