Zygomatic implant and corresponding kit

Description

[0001] The invention relates to the technical field of dental implantology and more particularly that of zygomatic dental implants, these implants being intended to support a dental prosthesis.

[0002] These implants are used in patients with severe bone loss in the upper jaw, whether this results from long-standing total toothlessness of the jaws accompanied by the disappearance of the alveolar bone that supports the teeth, or from malformation, trauma or tumor excision.

[0003] Indeed, the loss of maxillary teeth in a young patient leads to a progressive resorption of the alveolar bone, which disappears almost entirely. Thus, the height of the maxillae decreases and the maxillary sinuses, which they limit, are no longer separated from the oral cavity by alveolar bone but by a thin layer of cortical bone which is fragile and poorly vascularized.

[0004] When the alveolar bone has resorbed, it is no longer possible to place traditional maxillary dental implants in this thin bone wall to which a prosthesis would be attached. Indeed, the bone present would not ensure their fixation and, in any case, these implants would penetrate the overlying maxillary sinus and would be the cause of infections.

[0005] It should also be noted that total alveolar reconstruction using large bone grafts (cranial or iliac) is complex and its results are, moreover, uncertain. It is therefore reserved for rare patients treated by highly experienced craniofacial surgery teams.

[0006] Conversely, the use of a complete resin appliance also becomes difficult, even impossible, due to a lack of retention.

[0007] An example of a maxillary implant is offered by the company Spider, under the name MiniZygo.

[0008] This implant consists of two parts, a relatively short conventional implant and an osteosynthesis plate fixed by osteosynthesis screws on the maxillary bone near or at the level of its curved part underlying the zygomatic bone. They are always at a distance from the zygomatico-maxillary suture and, therefore, from the zygomatic bone.

[0009] Its fixation always requires a significant quantity of residual maxillary bone at the level of its anchorage.

[0010] In addition, the plate fixation screws penetrate the maxillary sinus and with risks of definitive chronic sinusitis.

[0011] This is why implants were designed to be placed in solid bone, away from the residual jawbone.

[0012] Now, the bones closest to the jaws are the right and left zygomatic bones, located on either side of the jaws and forming the cheekbone relief on each side. Such implants, extending from the lower edge of a jaw to a zygomatic bone, are called zygomatic implants.

[0013] These are cylindrical and straight implants which correspond to a simple extrapolation of the classic implants usually placed in the alveolar position.

[0014] A well-known zygomatic implant consists of a straight cylindrical rod with two parts of different diameters, both threaded.

[0015] It is inserted from the resorbed alveolar region (or often from the lateropalatine region) towards the body of the zygomatic bone, following a straight trajectory. A cavity is thus drilled through the maxilla, the drilling continuing so as to drill a cavity in the zygomatic bone. This trajectory thus crosses the maxillary sinus in whole or in part or at least opens it in a punctate manner.

[0016] One end of the implant is intended to be screwed into one of the two zygomatic bones at the level of its two cortices (internal or external), while the other end is intended to be positioned in the palatal region of the maxilla.

[0017] An implant of this type is marketed by Straumann and Nobel under the name Branemark System Zygoma.

[0018] It is anchored in both the zygomatic bone and the jawbone and is therefore much longer than a traditional implant positioned only in the jawbone. Its length is typically between 35 and 57 mm.

[0019] With this technique, patients avoid bone grafts and sinus lift procedures.

[0020] These implants have been widely used for over 10 years and work has been carried out to assess their effectiveness and possible complications.

[0021] In fact, these implants are long and, moreover, they are inserted in risk areas because they are close to the orbit and the maxillary sinus.

[0022] Thus, the major accident during surgery is the perforation of the floor of the orbit during drilling of the cavity intended for the implant or subsequently, through the upper part of the implant, during its insertion.

[0023] This creates an intraorbital hematoma which causes compression of the optic nerve which can lead to blindness.

[0024] Furthermore, the most common post-operative complication is sinusitis.

[0025] Indeed, even if there are anatomical differences between patients, the implant necessarily passes at least partly through the sinus. The sinus may present an inflammatory reaction linked to the insertion of the implant, a foreign body, at its level.

[0026] In addition, a bucco-sinusal communication between the sinus and the oral cavity may then appear.

[0027] This leads to permanent chronic sinusitis which is a source of significant discomfort for patients and will need to be treated with antibiotics.

[0028] It should be noted that these sinusitis are very difficult to cure, even after removal of the implant.

[0029] It can also be noted that the implant frequently has, at the level of the maxilla, an emergence on the palatal side which hinders the realization of the maxillary prosthesis whose transverse diameter must be enlarged so as not to be too small compared to that of the antagonistic mandibular arch whether natural or prosthetic. Sometimes, the implant even comes out in the middle of the palate, which is very inconvenient for the patient.

[0030] Other implants have been proposed to try to overcome these drawbacks.

[0031] We can notably cite the implant described in patent US9125708.

[0032] This implant still comes in the form of a straight rod but it has a single threaded part extending from its end intended to be inserted into the zygomatic bone.

[0033] The rest of the implant is therefore threadless.

[0034] The implant is placed as follows.

[0035] A recess or groove is dug on the cheek surface of the jawbone. A fixation hole is then made at a distance from this recess in the thickness of the body of the zygomatic bone. The implant is then fixed by its threaded end in this fixation hole, while the non-threaded part extends into the recess present on the cheek surface of the jawbone.

[0036] Throughout the description, the cheek surface is understood to mean the surface of the bone (maxillary or zygomatic) which is in contact with the cheek, that is to say the external surface of the bone, facing the outside of the patient's face.

[0037] Thus, this implant has only one anchor point at the level of the zygomatic bone and it is designed not to extend into the maxillary sinus cavity.

[0038] However, the inventors found that there is still a risk of opening the sinus, particularly at the zygomato-maxillary suture.

[0039] In fact, the implant penetrates the thickness of the body of the zygomatic bone at this suture, that is, through the maxillary process of the zygomatic bone. Contrary to what is indicated in implantology diagrams, the inventors have noted that the sinus very often extends into the zygomatic process of the maxillary bone. The risk of opening the sinus is therefore not ruled out. However, an opening, even a small one, will cause a sinus infection.

[0040] Furthermore, the creation of the recess in the jugal surface of the maxillary bone very often leads to perforating it because this bone is very thin, even if the recess is designed not to extend into the maxillary sinus cavity.

[0041] Thus, the risks of sinus infection complications are not eliminated with implants of the type described in patent US9125708. These complications are extremely difficult to treat, and their cure most often requires the removal of all implant material.

[0042] Since the zygomatic bone is curved while the implant is straight, there is also a risk that the tip of the implant will penetrate the bone and thus sink into the temporal region, which has further harmful consequences for the patient.

[0043] Finally, it should also be noted that, to ensure good stability of the prosthesis, it is necessary to provide on each side, not only an implant of the type described in patent US9125708, but also a traditional implant positioned towards the front of the jaw. This constraint limits the use of this implant because it is very often impossible to provide these traditional implants due to bone loss.

[0044] Thus, known zygomatic implants allow for prosthetic rehabilitation. However, in approximately 20% of cases, infectious complications occur and they therefore do not constitute a lasting rehabilitation.

[0045] Dismantling all known zygomatic implants is difficult, although it may be necessary, particularly in cases of chronic sinusitis caused by implant infection or in the event of implant fracture.

[0046] Indeed, when one end of the implant has successfully osseointegrated into the zygomatic bone, the surrounding bone must be resected to be able to move the implant and remove it. This causes significant bone damage, putting the patient's integrity at risk.

[0047] It should also be noted that with known implants, the intrazygomatic distal end of the implant can accidentally fracture when excessive force is exerted on the implant during its screwing. This requires the removal of the implant fragment that remains in the bone, which again requires releasing it by drilling the surrounding bone, with the same harmful consequences for the patient.

[0048] The prior art documents US 10 792 126 B2 and US 2016 / 120582 A1 are also cited.

[0049] Document US 2011 / 269100 A1 discloses an implant intended for orthognathic surgery of the jaw.

[0050] The invention therefore aims to propose a zygomatic dental implant which avoids these drawbacks.

[0051] The inventors' approach goes against all the solutions proposed in the state of the art by proposing a dental implant which is intended to be fixed only by and on the cheek surface of one of the two zygomatic bones, without penetrating this bone, which therefore avoids any risk of intra-sinus penetration of the implant or sinus breach and therefore sinusitis, and allows easy disassembly of the implant in the event of problems. In other words, this implant is positioned on the cheek surface of one of the two zygomatic bones (and not both) and it is fixed by this cheek surface using fixing means which can penetrate this bone. It is preferable that these fixing means do not pass through the zygomatic bone.

[0052] Thus, the invention relates to a zygomatic implant, intended to support a dental prosthesis and to be fixed solely by the cheek face of a zygomatic bone of a patient, this implant comprising: A zygomatic attachment portion arranged to be attached to the cheek face of a patient's zygomatic bone, forming a plate, in which at least one attachment opening is defined which passes through the plate and which is configured to receive a attachment element so as to attach the plate to the cheek face of a patient's zygomatic bone, A maxillary portion comprising at least one elongate element arranged to extend opposite the cheek face of the patient's maxillary bone and one end of which is connected to the zygomatic portion and the other end of which is free and intended to be connected to a connection interface with a dental prosthesis.

[0053] In advantageous embodiments, one and / or the other of the following arrangements is further used: the zygomatic portion is made in one piece with the maxillary portion. the implant is made in at least two independent pieces, wherein the zygomatic portion defines at least one means for fixing an elongated element. said plate comprises a single fixing opening and, optionally, in this case, on its convex internal face intended to be in contact with the cheek face of the zygomatic bone, at least one relief projecting relative to said internal face. said plate comprises at least two fixing openings. the maxillary portion comprises at least two elongated elements, said elongated elements forming an acute angle between them. said zygomatic portion is pre-operatively pre-formed to correspond to the external shape of the patient's zygomatic bone. said at least one elongated element is pre-operatively pre-formed to correspond to the shape and dimensions of the cheek face of the patient's maxillary bone.

[0054] The invention also relates to a kit for producing a zygomatic implant, intended to receive a dental prosthesis and to be fixed only on the cheek surface of the zygomatic bone of a patient, comprising: A zygomatic fixing portion arranged to be fixed on the cheek face of the zygomatic bone of a patient, forming a plate, in which is defined at least one fixing opening which passes through the plate and which is configured to receive a fixing element so as to fix the plate on the cheek face of the zygomatic bone of a patient, the zygomatic portion defining at least one means for fixing an elongate element, in which said elongate element can be fixed in a removably manner and At least one elongate element arranged to extend opposite the cheek face of the maxillary bone of the patient and one end of which is intended to be fixed in a means for fixing the zygomatic portion and the other end of which is free and intended to be connected to a connection interface with a dental prosthesis.

[0055] In advantageous embodiments, one and / or the other of the following arrangements is further used: said zygomatic portion is preoperatively preformed to match the external shape of the patient's zygomatic bone. said zygomatic portion is standard. said at least one elongated element is preoperatively preformed to match the shape and dimensions of the cheek surface of the patient's jawbone. said at least one elongated element is standard.

[0056] The invention finally relates to a surgical method for placing an implant comprising the following steps: Incision of the upper vestibular mucosa, at the level of the alveolar region devoid of residual teeth Subperiosteal detachment exposing the cheek surface of the maxillary bones and the cheek surface of the zygomatic bone Drilling in the zygomatic bone, from its cheek surface, of the holes for fixing the implant fixation elements Placement of the zygomatic part of the implant on the cheek surface of the zygomatic bone and fixation in the latter by means of fixation screws. Closure of the approach.

[0057] The maxillary part of the implant can be placed during the initial intervention (corresponding to the placement of the zygomatic part) or later, during a second intervention.

[0058] The invention will be better understood and other aims, advantages and characteristics thereof will appear more clearly on reading the description which follows and which is made with reference to the appended drawings in which: [Fig. 1 ] is a plan view of an example of a zygomatic implant according to the invention. [ Fig. 2 ] is a perspective view of a variant of the implant of the figure 1 . [ Fig. 3 ] is an anterior three-quarter perspective view illustrating the implant of the figure 1 in position on a facial mass. [ Fig. 4 ] is a partial frontal sectional view illustrating the implant of the figure 1 in position on a facial mass. [ Fig. 5 ] is a plan view of another example of a zygomatic implant according to the invention. [ Fig. 6 ] is a three-quarter anterior view illustrating the implant of the type of that of the figure 5 in position on the right part of a facial mass. Fig. 7 ] is a perspective side view illustrating the implant of the type of that of the figure 5 in position on the right part of a facial mass. Fig. 8 ] is a plan view of another example of a zygomatic implant according to the invention made in three independent parts. [ Fig. 8a ] illustrates a variant of the figure 8 . [ Fig. 9 ] is a perspective view of the drill guide. [ Fig. 10 ], [ Fig. 11] et [Fig. 12 ] illustrate three steps of the surgical method of placing an implant according to the invention.

[0059] Elements common to the different figures will be designated by the same references.

[0060] THE figures 1 à 4 illustrate an example of an implant intended to be placed on the right side of a patient's facial mass.

[0061] We recall here that the skeleton of the head includes the skull and the facial mass.

[0062] They show that this implant 1, made in one piece, comprises a zygomatic part 10 and a maxillary part 11.

[0063] The zygomatic part 10 has the shape of a plate. In this example, seen from above, the plate has a general Y shape but the invention is not limited to this example. The plate can have any shape, for example a disc, a triangle, a square or even an X, Z or W.

[0064] In this plate, three fixation openings 100, 101 and 102 are defined. Each of them passes through the plate and is configured to receive a fixation element, such as an implant screw, so as to fix the plate by and on the cheek surface of the zygomatic bone of a patient.

[0065] However, the invention is not limited to this example. Thus, the plate may have only one fixing opening for a fixing element. In this case, to ensure the stability of the implant, another anchoring means may be provided, for example in the form of a relief. This may in particular be a lug provided on the zygomatic part of the implant, on the surface of this zygomatic part intended to be opposite the cheek face of the zygomatic bone when the implant is placed on a patient (i.e. the internal face of the zygomatic part), and projecting relative to this internal face. This lug is intended to be inserted into a corresponding hole, made by the surgeon at the level of the cheek face of the patient's zygomatic bone. It is also possible to provide a right-angled extension of the zygomatic plate, located at one end of the plate and also projecting from the internal face of the plate.This extension is intended to insert under the antero-inferior edge of the zygomatic bone.

[0066] The plate may also have two fixing openings for a fixing element.

[0067] Generally, it is preferable that the plate has at least two anchoring means to ensure stable positioning relative to the zygomatic bone.

[0068] Furthermore, this plate is preferably curved so as to adapt to the rounded shape of the zygomatic bone.

[0069] The maxillary portion 11 extends the zygomatic portion 10 and forms an elongated element which will extend from the zygomatic portion opposite the maxillary bone to the dental prosthesis, when the implant is positioned on the facial mass. An elongated element is understood to mean an element stretched in length or even longer than it is wide, the latter extending in this case from the zygomatic portion of the implant to the connection interface to the dental prosthesis.

[0070] The length of this maxillary part corresponds approximately to the residual height of the maxillary bone located under the zygomatic bone.

[0071] The free end 110 of the maxillary part is intended to be connected to a connection interface with a dental prosthesis (not shown).

[0072] This elongated element is not designed to be fixed to the maxillary bone and therefore it does not have any opening passing through it which is intended to receive a fixing element such as a screw.

[0073] As will be illustrated in the figure 5 , the invention is not limited to this type of maxillary part and the latter may comprise several elongated elements.

[0074] The shape of implant 1 is illustrated more precisely in the figure 2 which illustrates in perspective an implant 1a which is a variant of implant 1 illustrated in figure 1 .

[0075] Indeed, this implant 1a still comprises a zygomatic part 10a and a maxillary part 11a but only two fixing openings 100a and 101a for a fixing element are provided in the zygomatic part 10a. Here again, the elongated element 11a does not comprise any through opening for a fixing element.

[0076] There figure 2 shows that the zygomatic part 10a is curved, while the maxillary part 11a is substantially straight.

[0077] Reference is now made to the figures 3 et 4 which show implant 1 fixed on a facial mass 2.

[0078] On the figures 3 et 4 , the bone orbit 20, the zygomatic bone 21, the maxillary bone 22 and the maxillary sinus 23 are identified, the latter being shown in dotted lines (on the right side of the skull). These figures show that the zygomatic part 10 is fixed to the cheek face 210 of the zygomatic bone by means of fixing elements 103, 104 and 105, each of them passing through a fixing opening 100, 101, 102 and being inserted into the thickness of the zygomatic bone 21 while being positioned substantially orthogonal to the cheek face 210 of the bone. These fixing elements may in particular be implant screws made of an osteointegrable material such as titanium or zircon.

[0079] As more precisely shown in the figure 4 , the concave face 106 of the plate 10 (internal face of the plate) is opposite the cheek face 210 of the zygomatic bone so as to come into contact with it and to match its general rounded shape, while its convex face 107 (external face of the plate) is free. In practice, it will be in contact with the soft tissues of the cheek.

[0080] The maxillary portion 11 of the implant extends opposite the jugal face of the maxillary bone 22. In other words, the maxillary portion 11 is not fixed in the maxillary bone.

[0081] It is extended, on the side opposite the zygomatic part 10, by a connection interface 12 to a prosthesis.

[0082] Thus, no part of the implant 1 passes through the maxillary bone 22 (except possibly at the level of a notch made in the bony crest of the maxillary bone) or the cavity of the maxillary sinus 23. Furthermore, the fixing elements 103, 104, 105 penetrate only into the zygomatic bone and this, from its jugal face and are therefore completely at a distance from the sinus.

[0083] There figure 5 illustrates another example of an implant 3 according to the invention, intended to be fixed on the right side of the facial mass.

[0084] This implant 3 always comprises a zygomatic part 30 having the shape of a plate, preferably curved so that its concave internal face intended to come into contact with the zygomatic bone matches the shape of the latter. Three fixing openings 300, 301, 302 pass through the part 30.

[0085] Its maxillary part 31 extends the zygomatic part 30 but comprises two elongated elements 310, 311 extending from the zygomatic part and not a single elongated element as for the implant of the figure 1 .

[0086] There figure 5 shows that these two elongated elements form an acute angle between them. This angle is generally between 15° and 45°.

[0087] THE figures 6 And 7 illustrate implant 3 fixed on facial mass 2, on the right side.

[0088] As for the implant 1, the zygomatic part 30 is fixed on the jugal face of the zygomatic bone 21 by means of fixing elements (not illustrated), each of them passing through a fixing opening 300, 301, 302 and being inserted into the thickness of the zygomatic bone while being positioned substantially orthogonally to the jugal face 210 of the bone.

[0089] The maxillary portion 31 extends opposite the jugal face 220 of the maxillary bone. In other words, the maxillary portion 11 is not fixed in the maxillary bone.

[0090] There figure 6 shows that, thanks to the angle between the two elongated elements, the posterior element 310 can be directed towards the position of the missing first molar while the anterior element 311 extends towards the position of the canine also extracted.

[0091] In practice, the rear element 310 extends substantially vertically.

[0092] Thus, the length of each elongated element corresponds approximately to the distance between the lower part of the patient's zygomatic bone and the area of the lower part of the maxillary bone (i.e., the alveolar bone or the bony crest) towards which the elongated element is directed.

[0093] The free end 312,313 of each elongated element is intended to be connected to a connection interface with a dental prosthesis.

[0094] By providing an implant 3 with two elongated elements on each side of the facial mass, it is possible to stabilize a prosthesis thanks to these two fixation points, one posterior, one anterior, on each side, without other means being necessary.

[0095] There figure 7 shows the curvature of the zygomatic part of implant 3, which allows it to adapt to the curved shape of the zygomatic bone.

[0096] An implant according to the invention could comprise more than two elongated elements, particularly in cancerology, after the removal of an extended part of the maxillary bones.

[0097] A third elongated element can then be considered, directed towards the resected palatal region, so as to be able to stabilize an extended maxillary prosthetic reconstruction.

[0098] In the embodiments just described, the implants are designed in one piece. However, the invention is not limited to these examples and the implant can be designed such that its zygomatic part and its maxillary part are independent of each other.

[0099] Reference is now made to the figure 8 which illustrates an example of a kit for making an implant of the type illustrated in figures 5 à 7 , that is, comprising two elongated elements. This implant is made in several parts and is therefore illustrated here in its disassembled state.

[0100] This implant 4 thus comprises a zygomatic part 40 forming a preferably curved plate in which two fixing openings 400, 401 are defined which pass through the plate and which are intended to receive fixing elements.

[0101] This part 40 comprises two fixing means 406, 407 for two elongated elements 410, 411 which form the maxillary part 41 of the implant 4.

[0102] In the example shown in figure 8 , the two fixing means form two branches, separated from each other. However, the invention is not limited to this embodiment. As illustrated in the figure 8a , these two means can also be combined over all or part of their length.

[0103] These fixing means are intended to receive one end of an elongated element and to secure it with the zygomatic part 40, so as to achieve the assembly between the elongated elements 410, 411 and the zygomatic part 40. The elongated elements can be fixed in a removably manner in the fixing means.

[0104] The fixing means 406,407 may thus have, in a non-limiting manner, a substantially cylindrical threaded recess 4060,4070, while one end of each elongated element 410,411 has a thread 4100,4110 so that it can be screwed into this recess.

[0105] The other end 412,413 of each elongated element 410,411 is intended to be connected to a prosthesis.

[0106] The end of the elongated element may also include a ball joint (not shown). The corresponding fixing means then has a complementary recess into which the ball joint is inserted. This embodiment ensures a degree of freedom between the zygomatic part and the maxillary part. This allows the surgeon to adjust, during the operation, the position of each elongated element 410, 411 relative to the zygomatic part 40, to find an optimized position for the patient.

[0107] In practice, this kit may include a zygomatic plate and a set of elongated elements which are delivered simultaneously to the practitioner. The practitioner may also prefer a two-stage delivery, particularly when he chooses, as will be explained later, to install the elongated elements several months after fixing the zygomatic part of the implant. He may also choose to hold a large quantity of standard elongated elements in stock and order a specific zygomatic part from the manufacturer for each patient. In all cases, the practitioner is ultimately provided with a kit or a set which includes a zygomatic part and at least one elongated element intended to be fixed in the zygomatic part.

[0108] Other means of attachment could be provided without departing from the scope of the invention as defined by the following claims.

[0109] The two elongated elements are presented here in the form of cylindrical rods.

[0110] The invention is however not limited to this embodiment and they could also be partly flattened or have an elliptical section for example.

[0111] In reference to the figures 10 à 12 The steps of the surgical method for placing an implant according to the invention, made in several parts, such as the implant 4 illustrated in the figure will now be described. figure 8 , with an illustrated operating guide at the figure 9 .

[0112] There figure 10 illustrates the lower part of the maxilla with the residual alveolar region 50 devoid of teeth.

[0113] Line 51 in a continuous line represents the outline of the incision in the upper mucosa that the surgeon will make, here on the right side.

[0114] This incision can be extended, at each of its ends, by a small posterior vertical discharge incision 510, 511.

[0115] Its topography is adapted to the extent of bone resorption (crestal or vestibular).

[0116] There figure 11 illustrates, once the mucosa 52 has been incised, the subperiosteal detachment of the soft parts covering the jugal surface of the maxilla.

[0117] Retractors 53 are then placed to expose the extended operating area to the jugal surface of the maxilla 54, to the inferior orbital rim above (after exposure of the infraorbital nerve 55 at its emergence), to the zygomato-maxillary suture 56 laterally, to the jugal surface of the zygomatic bone 57, up to the zygomatic process of the frontal bone 58 above and to that of the temporal bone 59 behind.

[0118] The surgeon can then use a drill guide 6 which is described with reference to the figure 9 .

[0119] This guide is custom-made for each patient, preoperatively. Its design will be described later, along with that of an implant also custom-designed preoperatively.

[0120] It includes a gutter 60 which fits into the alveolar region 50 and extends onto the palate.

[0121] This gutter is connected by means of two rods 61, 62 to two plates 63, 64. The guide 6 is here designed for two implants (one implant on the right side and one implant on the left side) and it therefore comprises two rods and two plates. Each plate corresponds to the position of the zygomatic part of the implant to be placed and has openings corresponding to the fixing openings of the implant.

[0122] This guide is temporarily fixed to the palate by screws inserted into openings 65,66.

[0123] The surgeon can then drill holes into the zygomatic bone through the openings in the guide and, once drilling is complete, remove the guide.

[0124] The zygomatic portion of the implant is then placed on the cheek surface of the zygomatic bone and fixed in the bone by fixation screws or implant screws passing through the fixation openings of the implant and screwed into the holes drilled in the bone.

[0125] The surgeon may plan to place small bone grafts at appropriate points, particularly at the future contact zones between the elongated elements of the maxillary part and the lower edge of the maxilla.

[0126] The surgeon closes the incision if the rest of the implant is planned to be placed at a later stage.

[0127] This type of placement is preferred for some patients. It also allows the dimensions of the elongated elements of the maxillary part to be checked.

[0128] A few months later, the surgeon makes a repeat incision 51, as illustrated in the figure 10 .

[0129] The detachment of the mucosa is then carried out in a similar way but less extensively, and only up to the zygomatic part of the implant of which only the lower part is exposed.

[0130] The surgeon then places each elongated element of the maxillary part along the jugal surface of the maxillary bone and inserts one of its ends into a corresponding fixation means of the zygomatic part, then locks the connection between them, for example by screwing.

[0131] The surgeon finally closes the incision.

[0132] Of course, the steps just described are carried out in a similar manner for the placement of an implant on the patient's left side.

[0133] As long as the free end of each elongated element is connected to a connection interface with a dental prosthesis, the latter can be put in place.

[0134] Of course, the implant can also be inserted in one step, especially when the implant is made from a single piece.

[0135] The various steps which have just been described confirm that with the implant according to the invention, all risks of opening of the sinus are eliminated, since the zygomatic part of the implant is fixed on the jugal face of the zygomatic bone and its maxillary part extends opposite the jugal face of the maxillary bone, without penetrating it.

[0136] Furthermore, taking into account the design of the implant according to the invention and the placement technique, operational errors occurring during its placement, such as accidental penetration into a neighboring region, are eliminated.

[0137] The implants according to the invention may be standard implants offered in several different dimensions so that the surgeon can choose the one that is most appropriate for his patient.

[0138] Given the bone loss suffered by the patient, the height of the maxillary bone is reduced and generally between 1.5 and 2 cm.

[0139] Therefore, the length of each elongated element will generally be between 10 and 20 mm.

[0140] In the case of standard implants, each elongated element may be in the form of a cylindrical rod with a diameter of less than 4.5 mm and a length that will vary greatly, from less than 8 mm to more than 25 mm. These standard implants may be offered in several lengths, for example 10 mm, 12 mm, 14 mm, 16 mm, 18 mm or 20 mm.

[0141] Furthermore, the zygomatic part can also be available in several different sizes and shapes.

[0142] For example, implants will be available in two or three sizes and for each side, right and left.

[0143] The implants according to the invention can also be made to measure and preoperatively, according to a computer protocol based on the scanographic data of each patient and on those of the library of characteristics of the zygomatic and maxillary parts.

[0144] To do this, an imaging of the patient's skull, and in particular of the lower area of the skull, is carried out, for example using a CT Scan (scanner) or a CBCT (Cone Beam Computed Tomography or Cone Beam).

[0145] The images from the scanner or cone beam are then loaded into a computer. Image processing software creates a virtual model of the skull that can be manipulated by a user and used to design personalized equipment.

[0146] This image processing and manipulation can be performed using standard software, such as Mimics software marketed by Materialise. Such software allows the user, particularly a surgeon, to analyze the patient's characteristics and virtually design both an implant and a custom guide.

[0147] Based on the virtual skull model, the surgeon first designs a drilling guide, such as the one shown in the figure 9 .

[0148] This guide is specific to each patient and is therefore produced based on data from computer files established from the patient's scanner (or cone beam) and a prosthetic assembly of the teeth appearing on the definitive prosthesis produced from the patient's own occlusal plane.

[0149] To do this, on the virtual model of the skull, the surgeon determines the locations of the fixation holes of the zygomatic part of the implant in the zygomatic bone.

[0150] He then determines the size of the constituent elements of the guide as well as their shape.

[0151] A digital file corresponding to the virtual model of the surgical guide can then be stored in a computer memory.

[0152] In a variant, after designing a prosthesis, a scan image is produced which is superimposed with those from the bone structure scan to create a surgical guide allowing the implant to be placed.

[0153] The user or surgeon then designs a virtual implant model, again using the virtual skull model.

[0154] Thus, the zygomatic part of the implant will have a generally curved shape which will be adapted to that of the patient's zygomatic bone and, in particular, the surface of the face (internal and convex) of this zygomatic part, intended to come into contact with the jugal face of the bone, will be chosen to adapt to it.

[0155] The orientation of the elongated elements will also be adapted to the patient's skull and the means of fixation provided on the zygomatic part of the implant will be designed accordingly.

[0156] Similarly, the length and shape of each elongated element will be chosen to fit the dimensions and shape of the jawbone. These elongated elements may therefore be slightly curved. However, it should be noted that, given the short length of the elongated elements, their curvature is relatively slight.

[0157] A digital file corresponding to the virtual model of the implant can then be stored in the computer's memory.

[0158] These two digital files can then be transferred from the computer to a 3D printer or a conventional CAD / CAM manufacturing machine in order to manufacture the surgical guide and the implant.

[0159] It is understood that a design of the implant in several independent parts makes it possible to combine all the possibilities that have been described: use two standard parts of the implant or on the contrary make the two parts individually, make the zygomatic part of the implant individually or even custom-made and also use standard elongated elements or finally, use a standard zygomatic part and make the elongated elements custom-made.

[0160] Finally, an implant made from several standard pieces makes it easier to adapt to a patient's morphology, using a limited number of different pieces.

[0161] Such an implant also has the advantage of simplifying interventions when the implant must be removed, particularly when an inflammatory phenomenon such as peri-implantitis is observed. In this case, as soon as the diagnosis is made, one or more elongated elements are removed by separating them from the zygomatic part. Once this peri-implantitis has healed, elongated elements are put back in place, without it being necessary to remove the zygomatic part.

[0162] Regardless of the type of implant, whether it is multi-part or a single piece, removing the zygomatic part, if necessary, does not cause bone damage because the screws are removed from outside the bone. Thus, even if the screws are osseointegrated, they are easily accessible and it is not necessary to make a cut in the bone to reach them, as with conventional zygomatic implants.

[0163] The invention is not limited to the embodiments more particularly described. On the contrary, it encompasses all variants thereof, in particular those where the shape of the zygomatic part or of the elongated elements is different from that described and those where, for an implant made of several pieces, the attachment between them is achieved by means different from those described and / or illustrated.

Claims

1. Zygomatic dental implant (1, 3, 4) for supporting a dental prosthesis and for being fixed only to the jugal surface of the zygomatic bone (21) of a patient, this implant comprising: - A zygomatic fixation part (10, 30, 40) arranged to be fixed to the jugal surface (210) of the zygomatic bone of a patient, forming a plate, in which there is defined at least one fixation opening (100, 101, 102; 300, 301, 302; 400, 401, 402) which extends through the plate and which is configured to receive a fixation element (103, 104, 105; 303, 304, 305) so as to fix the plate to the jugal surface of the zygomatic bone of a patient; - A maxillary part (11, 31, 41) comprising at least one elongate element (11; 310, 311; 410, 411) arranged to extend facing the jugal surface of the maxillary bone of the patient, and one end of which is connected to the zygomatic part, and the other end of which is free and is connected to an interface for connection with a dental prosthesis.

2. Implant according to Claim 1, wherein the zygomatic part (10; 30) is formed integrally with the maxillary part (11; 31).

3. Implant according to Claim 1, made in at least two independent parts, wherein the zygomatic part (40) defines at least one fixation means (406, 407) for an elongate element (410, 411).

4. Implant according to one of Claims 1 to 3, wherein said plate comprises a single fixation opening.

5. Implant according to Claim 4, comprising, on its convex internal face intended to be in contact with the jugal surface of the zygomatic bone, at least one relief projecting with respect to said internal face.

6. Implant according to one of Claims 1 to 3, wherein said plate (11, 31, 41) comprises at least two fixation openings.

7. Implant according to one of Claims 1 to 6, wherein the maxillary part (31, 41) comprises at least two elongate elements (310, 311; 410, 411), said elongate elements forming an acute angle between them.

8. Implant according to one of Claims 1 to 7, wherein said zygomatic part is pre-formed pre-operatively in order to match the external shape of the zygomatic bone of the patient.

9. Implant according to one of Claims 1 to 8, wherein said at least one elongate element is pre-formed pre-operatively in order to match the shape and dimensions of the jugal surface of the maxillary bone of the patient.

10. Kit for producing a zygomatic dental implant (4) intended to receive a dental prosthesis and to be fixed only to the jugal surface of the zygomatic bone (21) of a patient, comprising: - A zygomatic fixation part (40) arranged to be fixed to the jugal surface of the zygomatic bone of a patient, forming a plate in which there is defined at least one fixation opening (400, 401, 402) which extends through the plate and which is configured to receive a fixation element so as to fix the plate to the jugal surface of the zygomatic bone of a patient, the zygomatic part defining at least one fixation means (406, 407) for an elongate element, in which said elongate element can be fixed removably, and - At least one elongate element (410, 411) arranged to extend facing the jugal surface of the maxillary bone of the patient, and one end of which is intended to be fixed in a fixation means of the zygomatic part, and the other end of which is free and is connected to an interface for connection with a dental prosthesis.

11. Kit according to Claim 10, wherein said zygomatic part is pre-formed pre-operatively in order to match the external shape of the zygomatic bone of the patient.

12. Kit according to Claim 10, wherein said zygomatic part is standard.

13. Kit according to one of Claims 10 to 12, wherein said at least one elongate element is pre-formed pre-operatively in order to match the shape and dimensions of the jugal surface of the maxillary bone of the patient.

14. Kit according to one of Claims 10 to 12, wherein said at least one elongate element is standard.