Patent Description:
In the field of oral implant surgery, computer-guided surgery methods are nowadays an increasingly popular choice for placing both dental implants, i.e., typically fixed implants intended to support artificial teeth, and orthodontic implants, i.e., temporary implants intended to fasten or provide anchor points for orthodontic treatment devices.

These methods are characterized by a preoperative planning step, carried out virtually using special software on the basis of the precise anatomy of a patient, previously acquired through three-dimensional radiographic investigations, and by a subsequent operative step, performed with the aid of surgical templates or guides especially created for the specific patient and the specific surgery on the basis of the virtual planning previously carried out. Compared with conventional implant surgery, the computer-guided approach makes it possible to plan and perform implant surgery with high precision and taking into account the actual and specific anatomy of each patient, thus improving the quality of results and reducing the invasiveness and duration of operations.

Surgical templates created and used in computer-guided implant surgery essentially consist of a shaped body that exactly reproduces the configuration of an oral cavity region of a patient where one or more implants are to be placed. One or more guiding openings are formed in the shaped body for inserting respective implants and corresponding placing tools. Each guiding opening, through its position in the template shaped body and its configuration, precisely defines the position of the respective implant in the oral cavity of the patient, as determined in the preoperative virtual planning step.

For example, <CIT> discloses a surgical template for dental and/or orthodontic implants, particularly palatal implants, comprising a palatal portion reproducing the shape of the palate of a patient and at least one substantially cylindrical guide formed in the palatal portion. The guide has an axial passage having an inlet cylindrical length with an inlet section and an outlet length with an outlet section for inserting a corresponding implant into the palate of a patient with a predetermined inclination and depth.

In such a surgical template, each guiding opening defines, among other parameters, a single predetermined insertion direction for the respective implant. This feature can be a constraint, particularly in the case of implants for orthodontic purposes.

In fact, placing of orthodontic implants, and in particular so-called temporary anchoring devices (TAD) in the form of screws, mini-screws, or similar threaded elements intended to create anchor points for orthodontic devices, may be necessary at many different sites in the oral cavity of a patient. Some of these sites, because of their location and/or morphology, do not allow an implant to be placed directly according to an intended insertion direction, requiring instead to start placing the implant according to another direction and to change the direction while placing the implant to achieve the intended final insertion direction, by pivoting on the predetermined and fixed implant insertion point.

The same need may also sometimes arise in connection with the placement of dental implants, because of the particular type or shape of the implant.

In all cases, an orthodontic or dental implant placement requiring maneuvers to change the insertion direction is not compatible with surgical templates whose guiding openings define a single and predetermined insertion direction for the respective implant.

<CIT> discloses an adjustable zygomatic alveolar ridge micro-implant implantation guide plate according to the preamble of claim <NUM>.

In view of the above, it is an object of the present invention to provide an improved surgical template for placing orthodontic or dental implants which allows the insertion direction of an implant to be changed in a controlled and continuous manner during its placement.

According to the invention, this object is achieved by means of a surgical template for orthodontic or dental implants having the features set forth in appended claim <NUM>. Preferred features of such a surgical template are the subject of the dependent claims.

In particular, the invention relates to a surgical template for placing orthodontic or dental implants, comprising a shaped body reproducing the shape of an oral cavity portion of a patient and at least one guiding opening formed in the shaped body for guiding an orthodontic or dental implant and/or a corresponding placing tool while placing the orthodontic or dental implant in a predetermined point of said oral cavity portion. The at least one guiding opening comprises a first guiding portion laterally delimited by a respective first guiding surface having a cylindrical development and defining a first guiding axis which extends through the at least one guiding opening, a second guiding portion laterally delimited by a second guiding surface having a cylindrical development and defining a respective second guiding axis which extends through the at least one guiding opening and crosses the first guiding axis, and a third guiding portion laterally delimited by a pair of mutually opposite guiding walls having a parallel course, which connects the first guiding portion and the second guiding portion with each other and is configured so as to guide a movement of the orthodontic or dental implant and/or of the corresponding placing tool between the first and the second guiding portions carried out by pivoting on an intersection point of said first and second guiding axes. The first guiding surface laterally delimiting the first guiding portion defines a first diameter, the second guiding surface laterally delimiting the second guiding portion defines a second diameter different from the first diameter, and the guiding walls laterally delimiting the third guiding portion have a distance from each other which is constant and equal to the smallest of said first and second diameters.

Advantageously, thanks to the special configuration of the at least one guiding opening, the surgical template of the invention allows placing in a guided manner and taking into account the specific anatomy of a patient even orthodontic or dental implants that, due to the position and/or morphology of the implant site, require changing the implant insertion direction while placing them.

In fact, the surgical template of the invention may be designed in such a way that the guiding axes defined at the first and second guiding portions of the at least one guiding opening correspond, respectively, to a predetermined initial insertion direction and a predetermined final insertion direction intended for the application of the orthodontic or dental implant, wherein the intersection point of said longitudinal axes corresponds to the fixed insertion point of the implant itself, and that the third guiding portion defines a predetermined guiding trajectory for the orthodontic or dental implant and/or its placing tool for passing from the first guiding portion to the second guiding portion of the guiding opening and, accordingly, from the initial insertion direction to the final insertion direction.

Moreover, the different diameters of the guiding surfaces defining the first and second guiding portion are advantageous for guiding with the same precision two different portions of the placing tool, such as for example a relatively wide engagement head and a thinner stem, which come in contact with the guiding opening while placing the orthodontic or dental implant.

By means of the surgical template of the invention it is therefore advantageously possible to extend the use of computer-guided operation techniques, along with the associated advantages in terms of precision, reliability, and less invasiveness, also to all cases in which placing an orthodontic or dental implant requires surgical maneuvers to change the insertion direction thereof.

Preferably, the guiding walls laterally delimiting the third guiding portions are defined by respective flat surfaces.

According to a preferred embodiment, the guiding walls laterally delimiting the third guiding portion are located, preferably symmetrically, on opposite sides of a plane defined by the first and second guiding axes.

In this case, the movement of the orthodontic or dental implant and/or the placing tool for passing from the first guiding portion to the second guiding portion of the at least one guiding opening occurs in a plane parallel to or coinciding with the plane defined by the first and second guiding axes. The corresponding movement performed by the surgeon during the insertion of the orthodontic or dental implant to change the insertion direction thereof is in this case particularly easy to perform and effective, as it takes place along a single direction in space and involves the shortest excursion length keeping the initial and final insertion directions the same.

Preferably, the first and second guiding axes form an angle between each other comprised between <NUM>° and <NUM>°, preferably between <NUM>° and <NUM>°.

Preferably, the shaped body forming the surgical template lacks metal parts and metal materials.

Conveniently, the shaped body is entirely made of a plastic material, in particular a resin suitable for dental use.

These features allow the surgical template to be made in a particularly simple way, through a single manufacturing process, e.g., an additive manufacturing process, with advantage in terms of manufacturing time and costs.

The surgical template of the invention has a preferred, although not exclusive, use for placing orthodontic implants, preferably, but not exclusively, TAD (Temporary Anchoring Device) screws or mini-screws, in regions of the oral cavity such as infra-zygomatic crests, mandibular buccal step, mandibular buccal shelf, portions of maxillary or mandibular intra-radicular alveolar bone, particularly within a computer-guided implant surgery method.

Further features and advantages of the invention will become more apparent from the following detailed description of a preferred embodiment thereof, made hereinafter, for indicating and non-limiting purposes, with reference to the drawings, in which:.

In <FIG> a preferred embodiment of a surgical template for placing orthodontic implants according to the present invention is generally indicated with reference numeral <NUM>.

The surgical template <NUM> essentially consists of a shaped body <NUM> reproducing the shape of an oral cavity portion of a patient at which an orthodontic implant is to be placed. In particular, the shaped body <NUM> comprises a portion delimited by a contact surface <NUM>, visible in <FIG>, which exactly reproduces, in negative, the morphology of the oral cavity portion in hand and contacts such oral cavity portion when the surgical template <NUM> is in use.

In the exemplary embodiment shown in the figures, the surgical template <NUM> is intended for placing an orthodontic implant <NUM> (see <FIG>), in particular a TAD screw or mini-screw, at a left infra-zygomatic crest of a patient, as hereinafter described in more detail with reference to <FIG>. Therefore, in this case the shaped body <NUM> reproduces an oral cavity portion of a patient at an outer back region of the upper left dental arch.

The shaped body <NUM> preferably has a monolithic structure and is preferably entirely made of plastic material, such as any known resin for dental use. In particular, the shaped body <NUM> is free of metal parts or inserts.

A guiding opening <NUM> positioned and configured to guide the insertion of the orthodontic implant <NUM> with the aid of a suitable placing tool <NUM> (see <FIG>) at a predetermined insertion point of the oral cavity portion in hand, here the left infra-zygomatic crest, is formed in the shaped body <NUM>.

The guiding opening <NUM> extends through the shaped body <NUM> between the contact surface <NUM> and a further surface <NUM>, hereinafter referred to as exposed surface, of the shaped body <NUM>, which is generically opposite the contact surface <NUM> and is intended to be exposed when the surgical template <NUM> is arranged in the oral cavity of the patient. The guiding opening <NUM> preferably ends flush with the contact surface <NUM>, whereas, if necessary, it may extend beyond the exposed surface <NUM>, as in the exemplary embodiment shown herein. In this case, part of the guiding opening <NUM> can be formed in a collar <NUM> projecting from the exposed surface <NUM>. The end of the guiding opening <NUM> at the exposed surface <NUM> or at the distal end of the collar <NUM> represents an inlet end of the guiding opening <NUM>, whereas the end of the guiding opening <NUM> at the contact surface <NUM> represents an outlet end of the guiding opening <NUM>.

Overall, the guiding opening <NUM> has a generically flared shape, designed to allow an operator to change the insertion direction of the orthodontic implant while placing the same.

To this end, the guiding opening <NUM> comprises a first guiding portion <NUM> configured to guide the orthodontic implant <NUM> and the placing tool <NUM> axially along a predetermined initial insertion direction, a second guiding portion <NUM> configured to guide the orthodontic implant <NUM> and the placing tool <NUM> axially along a predetermined final insertion direction, and a third guiding portion <NUM> configured to guide the orthodontic implant <NUM> and the placing tool <NUM> along a predetermined trajectory during a movement from the initial insertion direction to the final insertion direction performed by pivoting on the predetermined fixed insertion point of the orthodontic implant <NUM>. Said guiding portions <NUM>, <NUM>, <NUM> are configured to guide the orthodontic implant <NUM> and the placing tool <NUM> by direct contact with them. The guiding portions <NUM>, <NUM>, <NUM> conveniently have a continuous configuration. In particular, the guiding portions <NUM>, <NUM>, <NUM> are defined by respective walls lacking slots and through openings.

In more detail, the first guiding portion <NUM> of the guiding opening <NUM> is laterally delimited by a respective first guiding surface <NUM> having a cylindrical development, which defines a first guiding axis X1-X1 extending longitudinally along the guiding opening <NUM> and defining the predetermined initial insertion direction of the orthodontic implant <NUM>.

The first guiding surface <NUM> also defines a first diameter d1, which in this case is substantially equal to the diameter of an engagement head <NUM> of the placing tool <NUM>, through which the latter engages the orthodontic implant <NUM>.

The intersection of the first guiding surface <NUM> and the contact surface <NUM> of the shaped body <NUM> defines the outlet end of the guiding opening <NUM>. This end preferably has a circular shape with diameter d1.

The second guiding portion <NUM> of the guiding opening <NUM> is laterally delimited by a respective second guiding surface <NUM> having a cylindrical development, which defines a second guiding axis X2-X2 extending longitudinally along the guiding opening <NUM> and defining the predetermined final insertion direction of the orthodontic implant <NUM>.

The second guiding axis X2-X2 is incident to the first guiding axis X1-X1, and the intersection point P between these axes, visible in <FIG>, defines the predetermined insertion point of the orthodontic implant <NUM>.

In the case of a surgical template <NUM> designed for the application of orthodontic implants at the infra-zygomatic crests, as in the example shown here, the first guiding axis X1-X1 and the second guiding axis X2-X2 form an angle α between each other preferably comprised between <NUM>° and <NUM>°. In general, the angle α between the first guiding axis X1-X1 and the second guiding axis X2-X2 may be comprised between <NUM>° and <NUM>°.

The second guiding surface <NUM> also defines a second diameter d2, which in this case is substantially equal to the diameter of a stem <NUM> of the placing tool <NUM>.

The third guiding portion <NUM> of the guiding opening <NUM> is laterally delimited by a pair of mutually opposed guiding walls <NUM> having a parallel course, only one of which is visible in the views of <FIG>. Each of the guiding walls <NUM> joins the first guiding surface <NUM> of the first guiding portion <NUM> and the second guiding surface <NUM> of the second guiding portion <NUM>.

In the preferred embodiment shown herein, the guiding walls <NUM> are defined by respective plane surfaces and are symmetrically arranged at opposite sides of a plane defined by guiding axes X1-X1 and X2-X2.

Moreover, the guiding walls <NUM> preferably have a mutual distance which is constant and preferably equal to the smallest between diameters d1, d2 respectively of the first and second guiding portions <NUM>, <NUM>, here diameter d2.

Therefore, in this case the third guiding portion <NUM> has a straight development, and the plane defined by guiding axes X1-X1 and X2-X2 forms a midplane of the third guiding portion <NUM> in which the movement of the orthodontic implant <NUM> and the placing tool <NUM> from the first guiding portion <NUM> to the second guiding portion <NUM> of the guiding opening <NUM> takes place.

The surgical template <NUM> can be advantageously used in oral implant surgery performed with a computer-guided approach. In this case, the surgical template <NUM> can be designed virtually during the preoperative planning step, based on the precise and specific anatomy of the patient. In particular, in the case of surgical template <NUM>, besides the insertion point of the orthodontic implant, the most appropriate initial and final insertion directions for the implant itself are also precisely determined, i.e., the directions of the guiding axes X1-X1 and X2-X2 and their mutual inclination (angle α).

<FIG> schematically show the placement of the orthodontic implant <NUM>, in particular a TAD screw or mini-screw, at a predetermined point of the left infra-zygomatic crest of a patient using surgical template <NUM>. The placement is carried out by means of a placing tool <NUM>, in particular a suitable screw-driving tool, preferably manually operated, wherein only an end portion thereof, through which it engages the orthodontic implant <NUM>, is shown in the figures.

The orthodontic implant <NUM> is initially inserted with the applicator tool <NUM> into the guiding opening <NUM> at the first guiding portion <NUM> (<FIG>), whose guiding axis X1-X1 defines a predetermined initial insertion direction of the orthodontic implant <NUM>.

Next, the orthodontic implant <NUM> is screwed a few turns in the initial insertion direction, so as to incise the gingival mucosa and partially penetrate the bone tissue at the predetermined insertion point (point P in <FIG>). This is done in an axially guided manner due to the circumferential contact between the engagement head <NUM> of the placing tool <NUM> and the first guiding surface <NUM> that laterally delimits the first guiding portion <NUM>.

At this point, the orthodontic implant <NUM> is again unscrewed a few turns without causing it to be detached from the insertion point, and, still by means of the placing tool <NUM>, it is tilted in the guiding opening <NUM> until it reaches the second guiding portion <NUM>, whose guiding axis X2-X2 defines a predetermined final insertion direction of the orthodontic implant <NUM> (<FIG>). The tilting movement of the orthodontic implant <NUM> and the placing tool <NUM> is guided by the third guiding portion <NUM> of the guiding opening <NUM>. In particular, during this movement the stem <NUM> of the placing tool <NUM> moves along and in contact with the guiding walls <NUM> of the third guiding portion <NUM>.

At this point, the placement of the orthodontic implant <NUM> can be completed by screwing it in the final insertion direction to a predetermined depth in the bone tissue. This is also done in an axially guided manner thanks to the circumferential contact between the stem <NUM> of the placing tool <NUM> and the second guiding surface <NUM> laterally delimiting the second guiding portion <NUM>.

A person skilled in the art can make changes and variations to the embodiment described above of the surgical template of the invention, in order to meet specific and contingent application needs, still falling within the scope of protection defined by the appended claims.

In particular, it is possible to configure the guiding opening <NUM> such that its three guiding portions have relative dimensions different from those described above, and it is conceivable to configure the third guiding portion <NUM> in such a way as to guide the movement of the orthodontic implant and/or a related placing tool between the first and second guiding portions <NUM>, <NUM> even along a non-straight path.

Claim 1:
Surgical template (<NUM>) for placing orthodontic or dental implants, comprising:
- a shaped body (<NUM>) reproducing the shape of an oral cavity portion of a patient, and
- at least one guiding opening (<NUM>) formed in the shaped body (<NUM>) for guiding an orthodontic or dental implant (<NUM>) and/or a corresponding placing tool (<NUM>) while placing the orthodontic or dental implant (<NUM>) in a predetermined point of said oral cavity portion,
wherein the at least one guiding opening (<NUM>) comprises:
- a first guiding portion (<NUM>) laterally delimited by a first guiding surface (<NUM>) having a cylindrical development and defining a first guiding axis (X1-X1) which extends through the at least one guiding opening (<NUM>);
- a second guiding portion (<NUM>) laterally delimited by a second guiding surface (<NUM>) having a cylindrical development and defining a second guiding axis (X2-X2) which extends through the at least one guiding opening (<NUM>) and crosses said first guiding axis (X1-X1), and
- a third guiding portion (<NUM>), which connects the first guiding portion (<NUM>) and the second guiding portion (<NUM>) with each other and is configured so as to guide a movement of the orthodontic or dental implant (<NUM>) and/or of the corresponding placing tool (<NUM>) between the first (<NUM>) and the second guiding portion (<NUM>) carried out by pivoting on an intersection point (P) of said first (X1-X1) and second guiding axes (X2-X2),
wherein the third guiding portion (<NUM>) is laterally delimited by a pair of mutually opposite guiding walls (<NUM>) having a parallel course,
characterized in that said first guiding surface (<NUM>) defines a first diameter (d1), said second guiding surface (<NUM>) defines a second diameter (d2) different from the first diameter (d1), and said guiding walls (<NUM>) have a distance from each other which is constant and equal to the smallest of said first (d1) and second diameters (d2).