Guide for zygomatic implant surgery

Abstract

Guide (1) for zygomatic implant surgery comprising: a pair of guiding bodies (2, 3) defining a seat (4) adapted to house a working tool (5, 6, 7), of which: a first guiding body (2); a second guiding body (3) comprising an half-bushing (8) having a section which is conformed to a semi-circumference; a connecting body (9); wherein: the first guiding body (2) comprises a slotted portion (10) comprising a first extremal stretch (10a), a second extremal stretch (10b) and a joint stretch (10c); the first extremal stretch (10a) has a substantially semi-circumference conformation with concavity opposite that of the half-bushing (8); the extremal stretches (10a, 10b) and the joint stretch (10c) bound an elongated slot (10a, 10b, 10c) adapted to guide the working tool (5, 6, 7).

Description

[0001] GUIDE FOR ZYGOMATIC IMPLANT SURGERY

[0002] Technical Field

[0003] The present invention relates to a guide for zygomatic implant surgery.

[0004] Background Art

[0005] As is well known, a dental implant substantially consists of a screw which is placed within the alveolar bone to replace a tooth that is extracted or is missing.

[0006] This allows an abutment to be attached thereto, protruding externally from the cavity and serving a structural function, onto which the dental crown is affixed, replacing the missing tooth in its appearance and function.

[0007] In this regard, one of the most cutting-edge solutions for patients with severe maxillary atrophy is rehabilitative surgery using zygomatic implants.

[0008] Specifically, this approach involves the use of endosseous dental implants having significantly greater length than traditional implants and are designed, instead of inserting into the maxillary bone alone as the latter do, to anchor into the zygomatic bone.

[0009] This technique is, however, marked by considerable practical difficulties and, as it requires highly specialized anatomical and surgical skills, is particularly complex to perform freehand in a precise and repeatable manner.

[0010] In this regard, bone-supported / fixed guides are known to date specially designed to stabilize the movements of the burr when making osteotomies and, at the same time, to guide the subsequent insertion of the dental implant within the zygomatic bone.

[0011] A first example of such guides is provided by patent document IT102018000006998.

[0012] Specifically, this document describes a guide comprising a first half-bushing and a second half-bushing, connected to each other and defining a common longitudinal median axis, having a semi-circular cross-section with opposite concavities.

[0013] Specifically, half-bushings define a seat into which a working element, e.g. of the type of a dentist’ s burr, can be inserted, movable along the median axis and rotatable around that axis.

[0014] In more detail, the first half-bushing is arranged in a maxillary crestal position with vestibular concavity and determines the working depth of the working element (i.e., the vestibular-palatal sinking), while the second half-bushing is arranged at the zygomatic region.

[0015] The special construction of the aforementioned guide and, in particular, the fact that the half-bushings have opposite concavities, makes it possible to stabilize the burr by applying thereon a momentum of forces directed to push it towards the concavity of the first half-bushing and, at the same time, towards the concavity of the second halfbushing.

[0016] At the same time, the fact that the half-bushings have a semicircular conformation and are, therefore, open allows minimizing the overall dimensions of the guide within the oral cavity, leaving much of the latter accessible for performing the surgical operation and allowing the dentist to move the burr with greater freedom of movement.

[0017] Despite this, the guide described in IT102018000006998 is not without drawbacks.

[0018] In fact, while, on the one hand, the fact of providing open semi-bushings makes it possible to achieve the aforementioned advantages, this same fact implies, on the other hand, that moving of the burr in the vestibular-palatal and palatal-vestibular directions is completely free and, therefore, solely entrusted to the manual skills of the dentist.

[0019] It is straightforward to appreciate how this fact can result, under certain circumstances, in excessive burr strokes which, leading to the risk of contact between the burr and the adjacent tissues, compromise the overall safety of the procedure.

[0020] Not only that, but such strokes can also undermine the correct directionality of the osteotomy made on the maxillary bone and on the zygomatic bone, consequently leading to a high probability that the implant will be placed incorrectly.

[0021] That said, a second type of guides for zygomatic implant surgery disclosed by patent document EP3843655 is known in the state of the art.

[0022] In the present case, within this document, an apparatus for the insertion of zygomatic implants is described comprising: a guide fixable to the maxillary bone in a removable manner and provided with an anterior and posterior hollow template, spaced apart from each other and aligned along one direction of insertion of a zygomatic implant; and a working tool (e.g., of the type of a dental burr) insertable into the guide and provided with a spherical head that serves as a fulcrum and with an abrasive surface which, as a result of the rotation around the spherical head, can be displaced from a first position to a second position wherein it is placed within the front template along the direction of insertion.

[0023] By rotating the working tool around the spherical head, therefore, the abrasive surface can perform the osteotomy on the maxillary bone, allowing the subsequent insertion of the implant into the seat thus created.

[0024] It should be noted, however, that the apparatus of EP3843655 suffers from limitations quite similar to those complained about in the guide of IT102018000006998 and is, therefore, also susceptible to various and substantial improvements.

[0025] Again, in fact, the stroke of the working tool in the vestibular-palatal and palatal- vestibular directions is completely left to the practicality and experience of the dentist, thus leading to the risk of incorrect osteotomies and undermining the safety of the surgical operation.

[0026] In light of what has been said so far, it is evident to appreciate how, to date, there is a particular need to create a guide which allows fixing the aforementioned drawbacks of the prior art and, in particular, to facilitate the performance of zygomatic implant surgery.

[0027] Description of the Invention

[0028] The main aim of the present invention is to devise a guide for zygomatic implant surgery which makes the procedure of osteotomy of the maxillary and zygomatic bone and the subsequent placement of the zygomatic implant within the cavity thus created safe and controlled.

[0029] Within that main aim, one object of the present invention is to devise a guide for zygomatic implant surgery which allows guiding the movement of the burr in the vestibular-palatal and palatal- vestibular directions in a precise manner.

[0030] Another object of the present invention is to devise a guide for zygomatic implant surgery which eliminates the risk of contact between the burr and the adjacent tissues to the area to be operated on.

[0031] Another object of the present invention is to devise a guide for zygomatic implant surgery which allows the aforementioned drawbacks of the prior art to be overcome within the framework of a simple, rational, easy and efficient to use as well as cost- effective solution.

[0032] The aforementioned objects are achieved by this guide for zygomatic implant surgery having the characteristics of claim 1.

[0033] The aforementioned objects are achieved by this kit for zygomatic implant surgery having the characteristics of claim 10.

[0034] Brief Description of the Drawings

[0035] Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a guide for zygomatic implant surgery, illustrated by way of an indicative, yet non-limiting example in the attached tables of drawings in which: Figures 1 and 2 are axonometric views of the guide according to the invention from two different angles;

[0036] Figure 3 is a front view of the guide according to the invention;

[0037] Figure 4 is an axonometric, overall view of the kit according to the invention;

[0038] Figures 5 to 9 show, in a sequence of detailed views, the operation of the kit according to the invention.

[0039] Embodiments of the Invention

[0040] With particular reference to these figures, reference numeral 1 globally denotes a guide for zygomatic implant surgery.

[0041] The guide 1 for zygomatic implant surgery comprises at least one pair of guiding bodies 2, 3 defining at least one longitudinal seat 4 adapted to house at least one working tool 5, 6, 7 (Figure 3).

[0042] For example, the working tool 5, 6, 7 may be of the type of a dental burr or of a zygomatic implant to be fixed in an adequate osteotomy carved out on a maxillary bone M and on a zygomatic bone Z of a patient.

[0043] In terms of its use, the guide 1 can be used profitably simply by leaning it by “interlocking” on the maxillary bone M, that is, without necessarily having to attach it to the latter.

[0044] Alternatively, the guide 1 can be installed on the maxillary bone M by means of fasteners, e.g. of the threaded type (e.g., screws).

[0045] In this sense, the guide 1 can be provided with special seats (not shown in the figures) into which the fasteners can be inserted and which allow the latter to be grafted into the patient’s maxillary bone M, enabling a firm and secure fixation of the guide 1 on the latter.

[0046] That said, the guide 1 comprises: at least a first guiding body 2 arranged, in use, in the proximity of the residual bone crest of the maxillary bone M of the patient; and at least a second guiding body 3 arranged, in use, in the proximity of the base of a zygomatic bone Z of the patient and comprising at least one half-bushing 8 having a section which is substantially conformed to a semi-circumference and defining a respective first median axis Al.

[0047] Preferably, at least one of the guiding bodies 2, 3 is made at least partly of at least one metallic material.

[0048] More specifically, at least one of the guiding bodies 2, 3 is made of titanium. Preferably, the first guiding body 2 and the second guiding body 3 are made of titanium. This makes it possible to obtain strong, easily fabricated and biocompatible guiding bodies 2, 3.

[0049] In addition, the guide 1 comprises at least one connecting body 9 positioned between the guiding bodies 2, 3 and visible in Figures 1-3.

[0050] Preferably, the connecting body 9 is obtained starting from a digital reconstruction of at least part of the oral cavity of the patient.

[0051] For example, digital reconstruction can be obtained from radiological investigations conducted on the patient.

[0052] In other words, the particular conformation of the connecting body 9 is dictated according to the anatomical characteristics of the patient to be operated on and is, therefore, individually customized to the patient’s specifications.

[0053] In this regard, the connecting body 9 is preferably made, at least partly, of resin. Advantageously, the connecting body 9 is made of composite resin and / or acrylic resin. The choice of resin as the constituent material of the connecting body 9 proves to be particularly advantageous because it allows the latter to be molded easily, adapting it to the anatomical specifications of the patient on whom the guide 1 is to be applied, as well as to obtain a strong and perfectly biocompatible connecting body 9.

[0054] In addition, such a material is easily and quickly manufactured by means of technological processes such as additive manufacturing, thus allowing the connecting body 9 and, therefore, the guide 1 to be manufactured in a practical and quick manner.

[0055] In this case, therefore, it is possible to manufacture the guiding bodies 2, 3 and the connecting body 9 as separate components from each other and then couple these together to define the guide 1.

[0056] Alternatively, the connecting body 9 can be made of titanium.

[0057] Thus, in this case, the entire guide 1 can be made of titanium.

[0058] Specifically, the titanium guide 1 is made by means of one or more additive manufacturing technology processes.

[0059] Preferably, the titanium guide 1 is made by means of a unique additive manufacturing technology process.

[0060] Specifically, the titanium guide 1 is made by SLM (Selective Laser Melting).

[0061] Importantly, the technical expedient of manufacturing the guiding bodies 2, 3 and the connecting body 9 in a single body piece and, therefore, of being able to obtain the guide 1 by means of a single technological process makes it possible to drastically reduce the production time and related costs of the guide 1, proving particularly advantageous.

[0062] As can be appreciated by observing Figures 1 and 2, the connecting body 9 is provided with at least one passage opening 9a of elongated conformation developing substantially parallel to the first median axis Al.

[0063] Specifically, the passage opening 9a is shaped as a slot.

[0064] In this sense, the passage opening 9a is provided with two substantially curved portions and with a connecting portion positioned between the previous portions.

[0065] Specifically, the passage opening 9a is sized so as to allow the free movement of the working tool 5, 6, 7 in the palatal-vestibular and vestibular-palatal direction, i.e., transverse to the first median axis Al.

[0066] As will become clearer in the remainder of the disclosure, this expedient allows the bone crest of the maxillary bone M to be worked properly and therein to prepare, in this way, an adequate osteotomy.

[0067] According to the invention, the first guiding body 2 comprises at least one slotted portion 10 comprising, in turn, at least a first extremal stretch 10a, at least a second extremal stretch 10b and at least a joint stretch 10c positioned between the extremal stretches 10a, 10b.

[0068] In particular, the first extremal stretch 10a has a substantially semi-circumference conformation with concavity opposite that of the half-bushing 8 and defines a respective second median axis A2 substantially coincident with the first median axis Al.

[0069] In actual facts, if you look at the guide 1 by aligning with the first median axis Al (as shown in Figure 3), the first extremal stretch 10a and the half-bushing 8 together define a full-circumference profile.

[0070] In addition, the extremal stretches 10a, 10b and the joint stretch 10c bound an elongated slot 10a, 10b, 10c along a direction transverse to the median axes Al, A2, A3 and adapted to guide the working tool 5, 6, 7.

[0071] This makes it possible for the operator to insert the working tool 5, 6, 7 into the seat 4 and, if necessary, to move it in the direction transverse to the first median axis Al, that is, making it slide in one way or the other within the elongated slot 10a, 10b, 10c.

[0072] This means that, after being inserted into the seat 4, the working tool 5, 6, 7 is inserted into the elongated slot 10a, 10b, 10c and, at the same time, resting on the half-bushing 8.

[0073] In this way, the operator is guided during the movement of the working tool 5, 6, 7 and can, thus, obtain precise and accurate osteotomies in a systematic manner. Conveniently, the second extremal stretch 10b has a substantially semi-circumference conformation with concavity opposite that of the first extremal stretch 10a (see Figures 1-3).

[0074] In particular, the second extremal stretch 10b defines a respective third median axis A3 that is substantially parallel to the first median axis Al and to the second median axis A2.

[0075] Conveniently, the joint stretch 10c has a substantially straight conformation.

[0076] In other words, as inferred from the aforementioned figures, the thickness of the elongated slot 10a, 10b, 10c is substantially constant.

[0077] Usefully, the slotted portion 10 and the half-bushing 8 define a working volume V within which the working tool 5, 6, 7, shown in Figure 1, is movable.

[0078] The working volume V substantially consists of the maximum space that can be occupied by the working tool 5, 6, 7 during the sliding of the latter along the elongated slot 10a, 10b, 10c, that is, along the palatal-vestibular and vestibular-palatal directions. Specifically, the sliding of the working tool 5, 6, 7 along the elongated slot 10a, 10b, 10c takes place thanks to the fact that the latter, once inserted, rests on the half-bushing 8 which, therefore, serves as a rotational pin for the working tool 5, 6, 7.

[0079] In this regard, the connecting body 9 is arranged externally to the working volume V.

[0080] Due to this expedient and to the fact of having the passage opening 9a, the connecting body 9 allows the free movement of the working tool 5, 6, 7 along the elongated slot 10a, 10b, 10c, thus enabling the operator to perform the osteotomy accurately and effectively.

[0081] All this being said, it is important to specify how the peculiar conformation of the first guiding body 2 and, specifically, of the slotted portion 10 proves to be particularly advantageous and allows, in particular, to overcome the drawbacks of the prior art complained of earlier.

[0082] In fact, as already mentioned, the fact of providing a slotted portion 10 in the proximity of the crest of the maxillary bone M allows guiding the working tool 5, 6, 7 in the vestibular-palatal direction and vice versa in a very precise manner.

[0083] This makes the procedure safer and more controlled since, in case the working tool 5, 6, 7 is of the type of a dental burr, it limits the strokes of the latter to only those strictly necessary to perform the osteotomy, thus avoiding the risk of contact of the burr with the adjacent tissues and ensuring, thus, the proper directionality of the osteotomy on the maxillary bone M and on the zygomatic bone Z for proper placement within it of the zygomatic implant.

[0084] Advantageously, at least one of either the first guiding body 2 or the second guiding body 3 comprises, respectively: at least a first anchoring portion 11 associated with the slotted portion 10 and adapted to anchor to the connecting body 9; and at least a second anchoring portion 12 associated with the half-bushing 8 and adapted to anchor to the connecting body 9.

[0085] Preferably, the first guiding body 2 and the second guiding body 3 comprise the first anchoring portion 11 and the second anchoring portion 12, respectively.

[0086] As visible in Figures 1 and 2, at least one of the anchoring portions 11, 12 is at least partly threaded.

[0087] Preferably, both anchoring portions 11, 12 are threaded.

[0088] In this regard, it is specified that the connecting body 9 can be shaped so as to only partly “embrace” the anchoring portions 11, 12, as shown by way of example in Figures 1-3.

[0089] It is easy to appreciate, however, how it is possible to provide for a connecting body 9 of a different conformation from that illustrated in the above figures and, e.g., more complex, so as to enable the latter to “embrace” more of the anchoring portions 11, 12. In accordance with a further aspect of the invention, the present invention also relates to a kit 13 for zygomatic implant surgery illustrated by way of example in Figure 4.

[0090] Specifically, the kit 13 comprises at least one guide 1 and a plurality of working tools 5, 6, 7 each insertable within the seat 4.

[0091] Specifically, the working tools 5, 6, 7 comprise, first of all, at least a first dental burr 5, visible in detail in Figures 5 and 6, comprising: at least a first proximal portion 5a connectable to a device D, e.g. the type of a dental burr, for setting in rotation; at least a first median working portion 5b insertable within the slotted portion 10 and adapted to remove part of the maxillary bone M to obtain at least one substantially cylindrical housing H having a predefined diameter; and at least a first smooth distal portion 5c which can be coupled to the half-bushing 8 and adapted to be placed in support on a corresponding apical portion of the zygomatic bone Z without removal of the zygomatic bone Z.

[0092] In this regard, it should be specified that, in the context of this disclosure, the terms “proximal” and “distal” are used with reference to the position of the various components in relation to the device D; therefore, the first proximal portion 5a represents a segment of the first dental burr 5 which, in use, is intended to be placed closer to the device D, while the first distal portion 5c represents a segment of the first dental burr 5 which, in use, is intended to remain further away from the device D.

[0093] Advantageously, the first proximal portion 5a, the first median portion 5b and the first distal portion 5c are aligned along a geometric axis (longitudinal axis of the first dental burr 5) which coincides with the axis of rotation of the first dental burr 5.

[0094] The first proximal portion 5a preferably consists of a stem provided with one end shaped to be coupled to the device D and with one end, opposite the previous one, connected to the first median portion 5b.

[0095] As for, however, the first median portion 5b, it preferably comprises a plurality of diamond- shaped cutting elements.

[0096] Specifically, the cutting elements are arranged to peripherally cover the entire surface of the first median portion 5b.

[0097] Different embodiments cannot, however, be ruled out wherein, instead of diamondshaped cutting elements, helical blades or straight cutters are provided.

[0098] Conveniently, the first distal portion 5c has a substantially truncated cone shape and has a decreasing cross-section in the way of departure from the first median portion 5b.

[0099] In other words, the diameter of the truncated cone of the first distal portion 5c is maximum in the proximity of the first median portion 5b and gradually decreases as one moves away from the latter along the first distal portion itself.

[0100] Different embodiments are, however, possible wherein, e.g., the first distal portion 5c is substantially shaped like a straight cylinder.

[0101] The first distal portion 5c comprises at least one smooth lateral surface adapted to be placed in sliding contact with the zygomatic bone Z.

[0102] In other words, the smooth lateral surface is devoid of cutting elements and thus slides over the zygomatic bone Z without leading to the removal thereof.

[0103] The working tools 5, 6, 7 then comprise at least a second dental burr 6, visible in detail in Figures 7 and 8, comprising: at least a second proximal portion 6a connectable to the device D; at least a second median non-working portion 6b insertable within the housing H without removal of the maxillary bone M; at least a second distal working portion 6c adapted to pierce the zygomatic bone Z so that on the latter at least one apical hole F is obtained.

[0104] Advantageously, the second proximal portion 6a, the second median portion 6b and the second distal portion 6c are aligned along a geometric axis (longitudinal axis of the second dental burr 6) which coincides with the axis of rotation of the second dental burr 6.

[0105] Similarly to the above, the second proximal portion 6a preferably consists of a stem provided with one end shaped to be coupled to the device D and of one end, opposite the previous one, connected with the second median portion 6b.

[0106] In this regard, it is specified that the use of the term “non-working” is intended to encompass both the case in which the second median portion 6b is smooth and the case in which the latter has a smaller diameter than that of the housing H.

[0107] In the first case, therefore, the second median portion 6b is devoid of cutting elements and has a smaller diameter than or substantially coincident with that of the housing H. In actual facts, in this case, the second median portion 6b is definable as “non-working” since, although it may have a diameter coincident with that of the housing H, it is devoid of cutting elements that would allow it to remove the maxillary bone M during the contact with the same.

[0108] In the second case, however, the second median portion 6b may or may not have cutting elements and has a strictly smaller diameter than that of the housing H.

[0109] In actual facts, in this case, the second median portion 6b is definable as “non-working” since, although it can be provided with cutting elements, it has a smaller diameter than that of the housing H and, therefore, is not capable of removing the maxillary bone M. As for the second distal portion 6c, it is, as mentioned, adapted to carve out at least one apical hole F on the zygomatic bone.

[0110] For this purpose, the second distal portion 6c may comprise a pointed end, e.g. having a decreasing cross-section in the way of departure from the second median portion 6b, or it may comprise a helical tip (as given by way of example in Figures 4, 7 and 8).

[0111] Again, the kit 13 comprises at least one zygomatic implant 7 comprising at least one threaded pin 7a which has a diameter corresponding to the predefined diameter and can be grafted into the housing H and in the apical hole F.

[0112] In this regard, it is specified that, in the context of this disclosure, to say that the diameter of the threaded pin 7a corresponds to the predefined diameter is to mean that the former is coincident with or slightly larger than the latter.

[0113] Indeed, the threaded pin 7a is intended to be screwed into the maxillary bone M and into the zygomatic bone Z within the space obtained therein by the dental burrs 5, 6, and the fact that the diameter of the threaded pin 7a is coincident with or slightly larger than the predefined diameter allows the threaded pin itself to self-thread into the housing H and into the apical hole F, ensuring a particularly stable fit.

[0114] The operation of this invention is as follows.

[0115] First, a digital reconstruction of the patient’s oral cavity is obtained, e.g. through radiological investigations.

[0116] In this way, it is possible, on the one hand, to precisely determine the placement of the zygomatic implant 7 (i.e., its depth and angle) and, on the other hand, to make the connecting body 9 and, consequently, the template 1 according to the specific anatomical characteristics of the patient to be operated on.

[0117] Having done so, the operator proceeds by applying the template 1 onto the patient’s maxillary bone M.

[0118] As anticipated, the template 1 can be simply rested on the maxillary bone M; alternatively, the template itself can be attached by using fasteners, e.g. of the threaded type, insertable into the seats of the template 1.

[0119] At this point, the operator inserts the first dental burr 5 into the seat 4 and moves it transversely to the median axes Al, A2, A3 along the entire length of the elongated slot 10a, 10b, 10c within the working volume V (Figure 5), so as to carve the housing H of the zygomatic implant 7 within the maxillary bone M (Figure 6).

[0120] As noted above, this movement is done in a fully guided manner due to the presence of the elongated slot 10a, 10b, 10c which supports the operator in performing the osteotomy.

[0121] When this is finished, the operator inserts the second dental burr 6 into the seat 4 and places the second distal portion 6c in contact with the zygomatic bone Z (Figure 7) so that the apical hole F is obtained on the latter (Figure 8).

[0122] Once the osteotomy has been prepared, the operator can place the zygomatic implant 7 within the seat 4, screwing it into the housing H carved out on the maxillary bone M and into the apical hole F carved out on the zygomatic bone Z (Figure 9).

[0123] This done, the guide 1 can be removed and an abutment with a structural function can then be attached to the zygomatic implant 7 to which a dental crown can be applied to replace the missing tooth in appearance and function.

[0124] It has in practice been ascertained that the described invention achieves the intended objects.

[0125] In the present case, the fact is emphasized that the special conformation of the first guiding body and, specifically, the presence of the slotted portion allows guiding the insertion and movement of the working tool inside the patient’s mouth in a precise manner.

[0126] This expedient allows, therefore, the first dental burr to be guided in its vestibular-palatal and palatal-vestibular movement accurately and effectively, controlling the strokes thereof and not requiring, for the purpose, having to rely solely on the manual skills of the operator.

[0127] This increases the safety of the procedure, avoiding the risk of dental burrs coming into contact with other tissues and ensuring the correct directionality of the osteotomy on the maxillary bone and on the zygomatic bone for the proper placement of the zygomatic implant.

Claims

CLAIMS1) Guide (1) for zygomatic implant surgery, comprising: at least one pair of guiding bodies (2, 3) defining at least one longitudinal seat (4) adapted to house at least one working tool (5, 6, 7), of which: at least a first guiding body (2) arranged, in use, in the proximity of the residual bone crest of a maxillary bone (M) of a patient; at least a second guiding body (3) arranged, in use, in the proximity of the base of a zygomatic bone (Z) of a patient and comprising at least one half-bushing (8) having a section which is substantially conformed to a semi-circumference and defining a respective first median axis (Al); at least one connecting body (9) positioned between said guiding bodies (2, 3); characterized by the fact that: said first guiding body (2) comprises at least one slotted portion (10) comprising, in turn, at least a first extremal stretch (10a), at least a second extremal stretch (10b) and at least a joint stretch (10c) positioned between said extremal stretches (10a, 10b); said first extremal stretch (10a) has a substantially semi-circumference conformation with concavity opposite that of said half-bushing (8) and defines a respective second median axis (A2) substantially coincident with said first median axis (Al); and that said extremal stretches (10a, 10b) and said joint stretch (10c) bound an elongated slot (10a, 10b, 10c) along a direction transverse to said median axes (Al, A2) and adapted to guide said working tool (5, 6, 7).2) Guide (1) according to claim 1, characterized by the fact that said second extremal stretch (10b) has a substantially semi-circumference conformation with concavity opposite that of said first extremal stretch (10a) and defines a respective third median axis (A3) substantially parallel to said first median axis (Al) and to said second median axis (A2).3) Guide (1) according to one or more of the preceding claims, characterized by the fact that said joint stretch (10c) has a substantially straight conformation.4) Guide (1) according to one or more of the preceding claims, characterized by the fact that at least one of either said first guiding body (2) or said second guiding body (3) comprises, respectively: at least a first anchoring portion (11) associated with said slotted portion (10) andadapted to anchor to said connecting body (9); and at least a second anchoring portion (12) associated with said half-bushing (8) and adapted to anchor to said connecting body (9).5) Guide (1) according to claim 4, characterized by the fact that at least one of said anchoring portions (11, 12) is at least partly threaded.6) Guide (1) according to one or more of the preceding claims, characterized by the fact that at least one of said guiding bodies (2, 3) is made at least partly of at least one metallic material.7) Guide (1) according to one or more of the preceding claims, characterized by the fact that: said slotted portion (10) and said half-bushing (8) define a working volume (V) within which said working tool (5, 6, 7) is movable; and by the fact that said connecting body (9) is arranged externally to said working volume (V).8) Guide (1) according to one or more of the preceding claims, characterized by the fact that said connecting body (9) is obtained from a digital reconstruction of at least part of the oral cavity of the patient.9) Guide (1) according to one or more of the preceding claims, characterized by the fact that said connecting body (9) is made at least partly of resin.10) Kit (13) for zygomatic implant surgery, characterized by the fact that it comprises: at least one guide (1) according to one or more of the preceding claims; a plurality of working tools (5, 6, 7), each insertable within said seat (4), of which:- at least a first dental burr (5) comprising:- at least a first proximal portion (5a) connectable to a device (D) for setting in rotation;- at least a first median working portion (5b) insertable within said slotted portion (10) and adapted to remove part of the maxillary bone (M) to obtain at least one substantially cylindrical housing (H) having a predefined diameter;- at least a first smooth distal portion (5c) which can be coupled to said halfbushing (8) and adapted to be placed in support on a corresponding apical portion of the zygomatic bone (Z) without removal of the zygomatic bone (Z);- at least a second dental burr (6) comprising:- at least a second proximal portion (6a) connectable to said device (D) for setting in rotation;- at least a second median non-working portion (6b) insertable within saidhousing (H) without removal of the maxillary bone (M);- at least a second distal working portion (6c) adapted to pierce the zygomatic bone (Z) so that at least one apical hole (F) is obtained on the latter. at least one zygomatic implant (7) comprising at least one threaded pin (7a) which has a diameter corresponding to said predefined diameter and can be grafted into said housing (H) and into said apical hole (F).

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