System and method for use in dental surgery

Abstract

The invention concerns a system (S) for assisting a dental surgeon in dental surgery at an intervention site (IS) in a mouth (M) a patient, the system (S) comprising: • - at least one antenna arm (8) configured to be attached to a tool (5); • - an EM localization system (2).

Description

[0001] TITLE: System and method for use in dental surgery

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a system and method for use in dental surgery performed by a dental surgeon, especially for implanting a dental implant.

[0004] BACKGROUND OF THE INVENTION

[0005] Dental surgery such as implant surgery requires a high degree of precision and safety.

[0006] To date, more than 90% of dental surgeries are performed without assistance. What's more, the tools available to dental surgeons are inadequate.

[0007] New surgical techniques are available and are all based on preoperative planning using CT imaging.

[0008] Surgical guidance is now provided by mechanical solutions such as specific patient instruments (surgical guides) or navigation systems, all based on optical localization systems.

[0009] Optical localization is currently an obstacle to the adoption of guidance systems in dentistry. These systems require trackers that are cumbersome in size and weight in a small environment (mouth). Furthermore, the need for direct visibility between the camera and the trackers is also a limiting factor in surgery where space is at a premium (mouth). Also, this technology is very expensive.

[0010] BRIEF DESCRIPTION OF THE INVENTION

[0011] The invention aims at providing a locating technology for use in dental surgery which avoids the above-mentioned drawbacks.

[0012] According to a first aspect, the invention concerns a system for assisting a dental surgeon in dental surgery at an intervention site in a mouth a patient, the system comprising: - at least one antenna arm configured to be attached to a tool;

[0013] - an EM localization system comprising:

[0014] - an EM transmitter configured to generate an electromagnetic field within an operating area defined by a range of EM transmitter, the operating area being defined so as to comprise a mouth of a patient;

[0015] - an EM tool receiver attached to the antenna arm, the antenna arm permitting to keep away the EM tool receiver from the tool to which it is attached;

[0016] - an EM mouth receiver intended to be located inside the mouth of the patient, preferably rigidly attached to a tooth or a bone of the patient; wherein the EM transmitter, the EM tool receiver and the EM mouth receiver being configured for operating together by being arranged relative to each other within the operating area, the range being less or equal to 15 centimeters, wherein the antenna arm is configured not to interfere with a-magnetic-field in the operating area, wherein the antenna arm comprises a geometry designed to position the EM tool receiver as close as possible to the distal end of the tool, the distal end being intended to be in the operating area inside the mouth.

[0017] The system according to the first aspect comprises one or more of the following features alone in combination:

[0018] - The geometry of the antenna arm is designed so that the antenna arm extends from the tool towards the distal end while remaining spaced from the tool.

[0019] - The antenna arm comprises fastening means configured for attaching the antenna arm to the tool, the tool comprising a body extending along a longitudinal axis, and a proximal end, the antenna arm being configured to be attached to the proximal end and extends from the proximal end.

[0020] - It comprises a mounting plate configured not to interfere with a-magnetic-field in the operating area, the mounting plate being adapted to be glued, screwed or rigidly attached to a tooth or a bone of the patient, the EM mouth receiver being attached to the mounting plate.

[0021] - The EM transmitter, the EM tool receiver and the EM mouth receiver are intended to be disposed relative to each other at a distance between 5 and 15 cm, preferably 10 cm in the operating area.

[0022] - The antenna arm and / or the mounting plate and / or the patient’s headrest material is plastic or titanium in order not to interfere with a-magnetic-field the EM.

[0023] - The antenna arm comprises fastening means for attaching the antenna arm to the tool, the tool comprising a body extending along a longitudinal axis, a distal end and a proximal end, the distal end being adapted to be in the operating area inside the mouth, the antenna arm being attached to the proximal end.

[0024] - The fastening means comprises a sleeve for attaching the antenna arm to the tool.

[0025] - The antenna arm comprises a first part and a second part, each being two linear segments, connected by a junction the second part supporting the EM tool receiver to be as close as possible to the EM transmitter without disturbing the manipulation of the tool. - The junction is articulated or is a curved part, the antenna arm being curved by construction.

[0026] - It comprises at least one tool on which an antenna arm, is attached, the tool being chosen in the following group: a contra-angle, a dental handpiece, a dental turbine or a piezo handpiece.

[0027] According to a second aspect, the invention concerns a computer implemented method for assisting a dental surgeon for performing a dental surgery in a mouth of a patient, comprising a) registering at least one 3D image of the mouth of the patient, preferably a CBCT image with the mouth of the patient; b) locating a tool by means of a system according to the first aspect relative to the mouth during the dental surgery; c) displaying the location of the tool on the 3D image of the mouth of the patient. The invention is based on a non-optical tracking technology, i.e. an electromagnetic localization technology composed of miniature sensors, which greatly facilitates the gesture of the dental surgeon compared to the use of optical tracking.

[0028] BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further features and advantages of the invention will be apparent from the description that follows, based on the appended drawings, wherein:

[0030] Figure 1 illustrates a surgical theatre in which the invention is implemented.

[0031] Figure 2 illustrates a tool for use in a dental surgery with an antenna arm supporting an electro-magnetic tool receiver according to one embodiment.

[0032] Figure 3 illustrates an antenna arm supporting an electro-magnetic tool receiver according to one embodiment.

[0033] Figure 4 illustrates general steps of a method for assisting a dental surgeon in dental surgery according to the invention.

[0034] On the figures, similar elements have identical references.

[0035] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0036] The description relates to a system for use in dental surgery and for assisting a dental surgeon in performing such a surgery.

[0037] The system and the methods herein described are based on the use of electromagnetic (EM) based localization. Presentation of a surgical theatre and of a system for use in dental surgery

[0038] Figure 1 shows a surgical theatre ST in which the invention is implemented.

[0039] The invention aims to assist a dental surgeon for a dental surgery by means of a system S deployed in the surgical theatre ST comprising a mouth M of a patient with jawbones J.

[0040] This system S comprises a processing unit 1 connected to a localization system 2. A storage unit 3 and a display unit 4 are connected to the processing unit 1 for storing data acquired and for displaying images useful for the surgery.

[0041] Many types of instruments 5 are manipulated by the dental surgeon. These instruments need to be located relative to the patient during the surgery as such but also in preoperative steps such as steps of registering.

[0042] The localization system 2 comprises an EM transmitter 21 and at least two EM receivers 22, 23, at least one being attached to a tool 5 and one being attached to the jawbone J into the mouth M of the patient.

[0043] By processing the transmitted and received signals, the processing unit 1 permits to locate each EM receiver relative to each other and thus permits to locate the tool 5 during the preoperative steps or during the procedure. In particular, the EM receiver 23 attached to the tool 5 allows to establish a relationship between the EM transmitter 21 , the EM mouth receiver 22 in the patient's mouth and the EM tool receiver 23 attached to the tool 5. Indeed, the relative position between the EM tool receiver and the tool 5 as such is known by construction or calibration, the location of the EM tool receiver permits to deduce the location of the tool 5 in the reference frame attached to the EM mouth receiver and thus relative to the mouth.

[0044] The EM transmitter 21 , the EM receivers 22, 23 are located into the surgical theater ST into an operating area OA defined by the range of the EM transmitter 21 (illustrated by the circle on figure 1). Indeed, the EM transmitter 21 is configured to generate an electromagnetic signal within the operating area OA, the EM transmitter being detectable within this operating area OA. Indeed, the strength of the electromagnetic signal decreases as a function of d3, d being the distance between the EM transmitter 21 and one each of the EM receivers 22, 23. The operating area OA is preferably defined as a sphere centered on the EM transmitter 21 , the sphere having a given radius. Within this OA, the location is accurate and reliable.

[0045] Then, for ensuring such location, the EM receivers 22, 23 must be located within the operating area OA so that the electromagnetic signals are sufficient to ensure accurate localization. According to one embodiment, the operating area OA comprises a range of a couple of centimeters preferably between 5 and 20 centimeters, more preferably 15 centimeters or 10 centimeters.

[0046] Having a small operating area OA helps limit the presence of perturbators within this area. Moreover, since perturbations of electromagnetic signals are effectively prevented, low-power EM signals can be used, which reduces interference with motorized tools that are usually sensitive to EM signals while ensuring accurate localization.

[0047] The EM transmitter 21 is preferably attached to the patient itself or more generally as close as possible to mouth of the patient. Preferably, the EM transmitter 21 is attached to a patient’s headrest 7 close to the mouth M and outside the mouth M without risking disturbing the dental surgeon during the dental surgery. The patient’s headrest is configured not to interfere with a-magnetic-field in the operating area OA.

[0048] Depending on the anatomical area to operate on the maxillary or the mandible, the EM mouth receiver 22 may be placed in the opposite direction on the maxillary or the mandible to avoid obstructing the operating area OA or in the same area.

[0049] Localization system

[0050] The localization system 2 comprises the EM transmitter 21 and at least one EM tool receiver 23 (one for each tool or the same for several tools, being interchangeable) and an EM mouth receiver 22.

[0051] The EM mouth receiver 22 is attached to a body part. This EM mouth receiver 22 is important since the other EM receivers are located relative to this EM mouth receiver which is not moving during the surgery. The EM mouth receiver 22 is positioned so that it withstands vibration of the tool 5 and other phenomenon which occur during the surgery. The EM mouth receiver 22 is preferably rigidly attached to a tooth or to a jawbone of the patient. Alternatively, the EM mouth receiver 22 is attached to a structure intended to be fixed and unaltered during the surgery. Preferably, the EM mouth receiver 22 is attached to a mounting plate 6 that can be identifiable when imaged by an imaging device for instance. This mounting plate 6 is preferably glued or screwed into the mouth M: on a tooth or a bone (in case of edentulous patient). In case of a mounting plate 6, it can be attached to the patient before (for instance the day before) the surgery.

[0052] Each EM tool receiver 23 is rigidly attached to a corresponding tool 5 to be tracked or localized.

[0053] The EM transmitter 21 and the EM receiver 22, 23 are arranged so that

[0054] (i) each EM receivers 22, 23 are in a range of 5 to 15 centimeters, preferably 10 centimeters from the EM transmitter 21 within the operating area OA; and (ii) magnetic-field-disturbing object(s) are avoided between the EM transmitter 21 and the EM receivers 22, 23.

[0055] The idea is to define in the surgical theater ST perturbing emitting area(s), i.e., that is / are susceptible to perturb the localization system 2 based on EM waves. A perturbing area is for instance around one or more element(s) susceptible to perturb the components of the localization system 2.

[0056] The EM receivers 22, 23 and the EM transmitter 21 of the localization system 2 are connected to the processing unit 1 by means of wires 10. Wireless connections are, however, possible.

[0057] Using an EM localization system 2 is very advantageous since it increases access, precision, and navigation during procedures compared to optical localization system for instance.

[0058] Tool / Antenna arm (figure 2 and figure 3)

[0059] Each tool 5 is equipped with an antenna arm 8 supporting the EM tool receiver 23. This tool 5 is for instance a contra-angle or dental handpiece or dental turbine or a piezo handpiece.

[0060] The tool 5 is elongated and extends along a longitudinal axis XX from a proximal end 52 to a distal end 53 or tip intended to be in the operating area OA inside the mouth M.

[0061] The tool 5 comprises a body 51 from which a functional arm 54 extends. The distal end 53 of the tool is intended to be into the surgical theater ST in the operating area OA. The tool 5 is, for instance, manipulable through its functional arm 54.

[0062] The proximal end 52 is intended to be connected to a cable 9 for powering the tool 5.

[0063] The antenna arm 8 is secured to the tool 5 and its geometry is designed to position the EM tool receiver 23 as close as possible to the distal end 53. More precisely, the antenna arm 8 extends from tool 5 (in particular, from the proximal end 52) toward the distal end 53 while remaining spaced from the tool body. This aims at having EM tool receiver located above or nearly directly above the distal end 53.

[0064] Therefore, the antenna arm 8 is positioned in the same direction as the tool’s functional end (the distal end 53) for the implementation of the operation with the EM transmitter 21 preferably secured to the headrest positioned right next to the oral cavity within the operating area OA.

[0065] Alternatively, the antenna arm 8 is attached to the functional arm 54. In particular, the antenna arm 8 comprises fastening means 81 for attaching the antenna arm 8 to the tool 5 close to the proximal end 52. Alternatively, the antenna arm 8 can be attached to the distal end 51 in case of a contra-angle for instance. The fastening means 81 are various. For instance, a sleeve surrounding the body 51 on its proximal end 52 can be used. In that case, the sleeve extends from the proximal end 52 along the longitudinal axis XX towards the distal end 53 and permits attaching the antenna arm 8 to the tool 5 as such.

[0066] The antenna arm 8 is rigid and comprises a first part 82 and a second part 83. The first part 82 and the second part 83 are two linear segments. These two parts 82, 83 are for instance connected at a joint 85.

[0067] For instance, the first part 81 extending from the proximal end 52 of the tool 5 along a first axis YY forming an acute angle with the longitudinal axis XX. The antenna arm 8 also comprises a second part 82 extending from the first part 81 along a third axis ZZ forming an acute angle with the second axis YY, the second part 82 supporting the EM tool receiver 23 to be as close as possible to the EM transmitter 21 without disturbing the manipulation of the tool 5.

[0068] The antenna arm 8 is designed not to interfere with the handling of the tool 5 and can be adjusted according to the patient’s morphology. Indeed, the tool 5 is operated inside the patient’s mouth, which can be difficult to access, for example, if the patient has large cheeks or if the surgical area is located at the back of the mouth. The size of the segments 82, 83 making can also be adjusted for these same reasons.

[0069] More generally, it is possible to provide several antenna arms 8 of different sizes or shapes, as long as the antenna arm 8 supports the EM tool receiver 23 to keep it as close as possible to the EM transmitter 21 during surgery without hindering the surgeon or the patient. The EM tool receiver 23 is attached to a free end 84 of the second part 83 by any attaching means so that the EM tool receiver 23 is close to the EM transmitter 21 during the surgery procedure.

[0070] Alternatively, and as illustrated on figure 3, the antenna arm 8 comprises a curved part 86 between the first part 82 and the second part 83, so that the antenna arm 8 forms an elongated curved arm. The angle of the curved part 85 is chosen according to the same constraints of the design as explained above. On that figure, the antenna arm 8 comprises a sleeve 87 for attaching the antenna arm 8 to the tool 5. This sleeve 87 can be adjustable enabling secure attachments to cylindrical structures. This sleeve 87 can be used with the antenna arm 8 of figure 2.

[0071] When used during the surgery, each tool 5 is equipped with the corresponding antenna arm 8 on which a corresponding EM receiver is attached. The geometry of the antenna arm 8 is known and the relative position between the tip of the tool 5 and the antenna arm 8 is known so that the location of the EM tool receiver 23 permits to locate the tip of the tool 5 during the procedure. The antenna arm 8 can be preferably detachable. Therefore, one antenna arm 8 can be used with several tools. Also, the EM receiver 23 can be the same for each tool and is detachable.

[0072] The use of such antenna arm 8 permits to keep the EM tool receiver away from the tool 5 as such. Indeed, the tool 5 comprises materials (for instance metal) that can interfere with the EM field.

[0073] The antenna arm 8 is in close contact with the EM tool receiver, which is highly sensitive to magnetic disturbance. Antenna arm 8 is configured to be non-magnetic-field- disturbing (by its material and / or design). A non-magnetic-field-disturbing material is for instance plastic or titanium. A non-magnetic-field-disturbing design means that this property can be obtained with the design as such.

[0074] Advantageously, antenna arm 8 is in one piece and can be manufactured by 3D printing or injection molding or machining or any relevant manufacturing process.

[0075] Method (figure 4)

[0076] The present invention also concerns a computer implemented method for assisting a dental surgeon during a surgery procedure, comprising a) registering (step REG) at least one 3D image of the mouth of the patient, preferably a CBCT image; b) locating (step LOG) a tool 5 by means of the system herein described relative to the mouth during a surgery procedure; c) displaying (step DIS) the location of the tool on the 3D image of the mouth M of the patient;

[0077] The 3D image used at step c) is in particular a Cone Beam Computed Tomography Image, CBCT image. This image provides detailed visualization of anatomical structures. CBCT uses X-rays in a cone-shaped beam and a detector to capture a volumetric scan of the mouth of the patient. This 3D image is advantageously also used during step a) and is acquired before the dental surgery.

[0078] Registering step (step REG) (figure 4)

[0079] The aim of the registering step is to permits to display calibrated instruments with EM receivers in preoperative images. The aim is to be able to display the tools and the patient's jaw to assist the surgeon during the surgery.

[0080] Several workflows for the registering step can be implemented.

[0081] Each workflow comprises a step of acquiring a 3D image of the mouth of the patient (step SO) in particular a CBCT image. The advantage of the EM is that its small receiver are easy to fix onto the jaw and should not move during the surgery unlike big optical markers that may lead to reregistration issues. The dental surgery is therefore more robust, the registration is not lost during the surgery. On the contrary, with optical technology, the EM mouth receiver used to make the registration has to come out of the mouth to be detectable so there is a risk of bumping into it during surgery, and therefore of losing the registration. The EM is also robust because you can choose a place in the mouth that does not interfere with the surgery. The optical marker is often heavy (so there is a risk of the fixture moving). The patient can't close his mouth, and this interferes with swallowing. Also a close positioning of the receiver with regards to the anatomical site to or operate increases significantly navigation accuracy

Claims

CLAIMS1. A system (S) for assisting a dental surgeon in dental surgery at an intervention site (IS) in a mouth (M) a patient, the system (S) comprising:- at least one antenna arm (8) configured to be attached to a tool (5);- an EM localization system (2) comprising:- an EM transmitter (21) configured to generate an electromagnetic field within an operating area (OA) defined by a range of EM transmitter, the operating area (OA) being defined so as to comprise a mouth (M) of a patient;- an EM tool receiver (23) attached to the antenna arm (8), the antenna arm (8) permitting to keep the EM tool receiver away (22) from the tool (5) to which it is attached;- an EM mouth receiver (22) intended to be located inside the mouth of the patient, preferably rigidly attached to a tooth or a bone of the patient; wherein the EM transmitter (21), the EM tool receiver (23) and the EM mouth receiver (22) being configured for operating together by being arranged relative to each other within the operating area (OA), the range being less or equal to 15 centimeters, wherein the antenna arm (8) is configured not to interfere with a magnetic field in the operating area (OA), wherein the antenna arm (8) comprises a geometry designed to position the EM tool receiver (23) as close as possible to the distal end (53) of the tool (5), the distal end (53) being intended to be in the operating area (OA) inside the mouth (M).

2. The system of claim 1 , wherein the geometry of the antenna arm (8) is designed so that the antenna arm (8) extends from the tool (5) towards the distal end (53) while remaining spaced from the tool (5).

3. The system of claims 1 to 2, wherein the antenna arm (8) comprises fastening means configured for attaching the antenna arm (8) to the tool (5), the tool (5) comprising a body(51) extending along a longitudinal axis (XX), and a proximal end (52), the antenna arm (8) being configured to be attached to the proximal end (52) and extends from the proximal end(52).

4. The system of claim 3, wherein the fastening means comprises a sleeve for attaching the antenna arm (8) to the tool (5).

5. The system of claims 1 to 4, wherein the antenna arm (8) comprises a first part (82) and a second part (82), each being two linear segments (82, 83), connected by a junction (85, 86) the second part (82) supporting the EM tool receiver (23) to be as close as possible to the EM transmitter (21) without disturbing the manipulation of the tool (5).

6. The system of claim 5, wherein the junction (85) is articulated or is a curved part (86), the antenna arm (8) being curved by construction.

7. The system of claims 1 to 6, comprising a mounting plate (6) configured not to interfere with a-magnetic-field in the operating area (OA), the mounting plate (6) being adapted to be glued, screwed or rigidly attached to a tooth or a bone of the patient, the EM mouth receiver (22) being attached to the mounting plate (6) .

8. The system of claims 1 to 7, wherein the range is greater than 5 centimeters, preferably equal to 10 centimeters.

9. The system of claims 1 to 8, comprising a patient’s headrest configured for supporting a head of the patient, the EM transmitter (21) being attached to the patient’s headrest.

10. The system of claims 1 to 9, wherein the antenna arm and / or the mounting plate and / or the patient’s headrest (7) material is plastic or titanium in order not to interfere with a- magnetic-field the EM.11 . The system of any one of claims 1 to 10, comprising at least one tool (5) on which the antenna arm (8), is attached, the tool (5) being chosen in the following group: a contraangle, a dental handpiece, a dental turbine, or a piezo handpiece.

12. A computer implemented method for assisting a dental surgeon for performing a dental surgery in a mouth (M) of a patient, comprising a) registering (REG) at least one 3D image of the mouth of the patient, preferably a CBCT image with the mouth of the patient; b) locating (LOG) a tool (5) by means of a system of any one of claims 1 to 11 relative to the mouth during the dental surgery; c) displaying (DIS) the location of the tool on the 3D image of the mouth (M) of the patient.

Images