WO2017068391A1

WO2017068391A1 - Device for the calibration of a masticatory simulator and process for the calibration of said simulator

Info

Publication number: WO2017068391A1
Application number: PCT/IB2015/058078
Authority: WO
Inventors: Luca FINI
Original assignee: Fini Luca
Priority date: 2015-10-20
Filing date: 2015-10-20
Publication date: 2017-04-27

Abstract

A device for the calibration of a masticatory simulator is disclosed, comprising sensing means (15) carried by a suitable support, movable on a sliding path (7) dimensioned so as to surround a patient (6) at a desired height thereof and it contains translation means of the sensing means (15) along said entire sliding path (7). A calibration process of a masticatory simulator is also disclosed, which provides to sense the landmarks of a patient' s head with a device as in any one of the preceding claims and to use them for the reconstruction thereof on said masticatory simulator. Finally, a masticatory simulator is disclosed, which is manufactured starting from the layout of the normotype, which has the opportunity of independently acting on the different landmarks thereof.

Description

DEVICE FOR THE CALIBRATION OF A MASTICATORY SIMULATOR AND PROCESS FOR THE CALIBRATION OF SAID SIMULATOR

DESCRIPTION

FIELD OF THE INVENTION

The present invention falls in the sector of apparatuses for measuring the masticatory organ and the posture connected thereto and, in particular, it refers to a device for the calibraton of a masticatory simulator, as well as to a process for such calibration and to a masticatory simulator which can be calibrated with said device and process.

BACKGROUND OF THE INVENTION

The care of postural problems and of the intrinsic relations thereof with the masticatory, swallowing, language, bust especially stress-management organ is extremely important and bas been retained such virtually forever. The malaise which dental conditions may cause is serious, especially when it results into often really unbearable pain, as well as in the case of pains in the cervical or lumbar area, of the spine, or of problems specific of the masticatory organ and annexa.

Over time the dentist character has thus developed, capable of taking care of the main malaises linked to one's teeth.

The need to remedy and the advancement in this specific medical sector have caused the contribution of various types of widely specialised operators to become important. Thus, in aid of the dentist, dental technicians, chair assistants, orthognathodontists and others are today involved.

In relatively recent times, it has been discovered that the shape itself of one's mouth in connection with the ontogenetical development of the sphenoid bone, at the end of the day, of a person's head, severely affect a patient's overall postural relationship, including his teeth (think of the various phenomena of teeth grinding and bruxism) . The phenomena originated by these less-than-ideal operations sometimes lead to more serious problems, linked for example to posture. In some cases, one arrives to have headache, cervical pain or back ache. These types of problems may be congenital or due also to incorrect manipulations, operated by the dentist on one's teeth.

A further professional figure has thus arisen, that of the orthognathodontist and/or posturologist who take care of the malaises linked to posture and the like.

Of course, attempts have been made to effectively remedy these drawbacks. Since the source of such problems has been identified in teeth, attempts have been made in the medical and technical field which relate thereto.

In the specific case of the masticatory organ, for therapy development, masticatory simulators or aticulators have been devised. These are devices at the dental technician's disposal, which reproduce the main features of the parts of the human head and which may serve to manufacture dental prosthesis and apparatuses .

In general, the imprint taken by the dentist with a specific "paste" or with scanning techniques, operating directly on the patient's mouth, is delivered to the dental technician who manufactures the mould or moulded unit, casting the plaster therein, in order to then manufacture on this base the required object. Generally, the dental technician plasters the two dental moulds in the functional space of such articulator, so as to lock it and have the ratio thereof between both moulds. Thereby, the dental technician builds the prosthesics, the implants (ucla) the orthodontics or the mouthguards, so that the prosthesis or the apparatus may, at least theoretically, adapt to the patient's mouth, possibly after a few adaptation manoeuvres by the dentist, upon application or immediately afterwards .

Masticatory simulators are usually manufactured basing oneselves on some morphological features of the human head, called landmarks and axes. Among these landmarks, the most important ones are maybe Camper's plane and the condyles, in connection with the jaw axis.

In order to be able to manufacture masticatory simulators in the most versatile way possible (avoiding having to build an articulator for each patient, which would be too expensive both in economic terms and in terms of time) the landmarks of the so- called "normotype" (perfect ideal patient, but non existent in actual fact) are normally taken into consideration. Ideal landmarks are thus supplied to the simulator, accomplished as statistical abstraction from a certain number of human heads, obtaining therefrom the "best" morphological features and which lead to maximum face symmetry. Thereby, it has always been believed that masticatory simulators may lead to the manufacturing of prostheses and appliances which adapt to the majority of the population. However, if that may actually occur from a practical point of view (the products obtained require on the whole fewer adaptations than manufacturing them under other conditions) , there are some drawbacks which originate precisely from this way of acting.

As a matter of fact, it must be taken into account that, precisely owed to how it has been created, the normotype does not non exist in nature or, even if it existed, it would be extremely rare. Moreover, the normotype would represent, per se, a situation to which patients should tend, since it has been detected that patients having landmarks more similar to those of the normotype see their masticatory and posture altering over longer periods of time than patients who deviate more from such normotype. That may be done by rebuilding and applying to the single patient Spee's and Wilson's compensation planes and curves. However, the use of masticatory simulators with the normotype' s features does not manage to overcome the problems which are intended to be dealt with or, at least, it does not manage to overcome them in a fully satisfactorily manner. That is due, among other things, to the fact that it is desired to act on the patient' s mouth so as to correct some defects encountered, but the correction which is being operated does not start from the actual (real) situation thereof, but rather from an "ideal" situation, which is not the one in which the patient is found, thus renouncing, in actual fact, to a suitable correction, since part of the defect is not taken into consideration at all and, hence, one cannot act for example gradually, provided a patient's conditions allow it (on an elderly patient, or with traumas, it is often better not to act in order not to create more problems than he or she already has, because he or she would not be able to implement, with bone or muscle changes, the changes and in any case it is essential that the health operator has available tools which represent him/her in his/her normal condition, be it pathological, physiological or compensated, to be able to possibly provide to rehabilitations without or with the opportunity for change, but only if it is necessary or it is feasible) . Moreover, if Spee's and Wilson's planes and/or curves are not built and correlated, at angular level for the planes and at spatial level for the landmarks, correctly in relation to the ground and to the axial inclinations of the skull in the 3D spatial position thereof, through the action of muscle levers, the postural error is increased rather than alleviated.

In the light of what has just been set forth, it would hence be auspicable to succeed in contextualising the patient's habitual and relaxed posture in an erect position with double visual focus, not ideally, so as to push the correction of postural defects to a limit so far never reached the really individual one. A big step forward in this direction would be if one were able to "personalise" the masticatory simulator, causing it to come out from the idealness situation. (All common articulators are, in the structure thereof, ideal normotype and cannot be suitable to the patient's individuality, but for the condylar movements, but not of the skull structure on all 3D axes) and causing the landmarks reproduced thereon to match as far as possible those of the specific patient, however, without building an articulator especially for each patient, which, as stated earlier, would have prohibitive costs and would represent an all but negligible waste of material. In order to obtain this result, firstly it is necessary to identify where the masticatory simulator (common articulators in use up until today) , which reproduces the normotype, creates problems due to the fact of not taking into account the patient' s actual morphological conditions and the conditions of the head posture (inclination which changes from individual to individual, with a change with respect to the normotype of the angular relations of dental planes and disclusions, as well as of the angles of the condyle dynamics and of the spatial position of the landmarks of the structural determination, by which the articulator is build) .

Not only, the idea is also that of arranging the moulds, inserted in the functional space of the articulators, in the correct spatial relationship between articulator-skull and moulds, however, in the correct relationship also with the three-dimensional space surrounding the patient, the ground and the median overall foot centre of the two feet and of the individual foot and, last but not least, the individual line of bars, not necessarily perpendicular to the (individual) ground.

Only after this tuning of the three-axial simulator, which represents the patient in his/her habitual condition, will the doctor issue a diagnosis and therapy to change and quantify the correction, direct it or with the opportunity - should the patient need it - not to change the patient's compensated position, which as such, must not be altered. A first problem lies in the fact that the normotype is created considering the human head as perfectly symmetrical, which in actual fact does virtually never happen. In actual fact, a slight right-left dissymmetry is present in one's entire body: suffice it to when one shops for a pair of shoes and to the fact that, almost always, one fits perfectly and the other one requires some adaptation. Even the face has in the left-hand half some measurements and shapes which are not exactly identical to the corresponding ones of the right-hand side. The top/bottom dissymmetry is apparent to anyone (one's mouth is apparently different from one's eyes), but there are still further skewness in the head, generally known to the person skilled in the field. Such skewness may be congenital or they may arise while growing up or due to other reasons during the years (for example due to phenomena such as arthritis or due to bad behavioural habits) . Hence, owed to what has just been set forth, it can be reasonably stated that the perfect face symmetry is only an abstraction, used for convenience and economic saving, but which represents only an approximation of reality.

Our body cannot be symmetrical, because for each effort a resting or balancing part and an effort part are required.

It depends on the fact that an individual has a dominant (right-handed or left-handed) limb with which he puts strain on and which develops differently from the balancing or supporting limb, because it performs different functions.

Our very brain, being a bipolar entity, has the location of the functions delegated to one or the other lobe.

So vision etc. Moreover, neither a person's movements occur symmetrically. The sole fact that people are mostly right-handed or left-handed and that the number of perfect ambidextrous individuals is extremely low and in any case all to be verified, causes dissymmetry in the movements and of the body position during such movements. On the other hand, also ambidextrous individuals show some differences in the use of either one hand and/or of either foot. Moreover, each of us has an ear from which he hears better, so that we tend to arrange that ear oriented so as to be as close as possible to the source of sounds or noise which one wants to listen to; typically, in a conversation, people's head is slightly turned ' sideways . Also as regards vision, skewness is frequent. In the presence of optical defects it very often occurs that they have measurements even substantially different between one eye and the other. It often also happens that a person, especially when tired, keeps one eye more closed than the other, with an evident difference in light reception and, hence, deforming (even though not in such a ways as to become aware of it) the vision itself. Also phenomena of this type contribute to an incorrect posture of the head, to compensate such differences and to have a complete and even vision. Hence, observing objects in a distorted manner may even lead to head movements which then lead to postural defects.

This applies also to the skull structure and to the two masticatory sides, the curves thereof, the planes thereof, the disclusions thereof.

Moreover, if condyles are taken into consideration, they are normally sensed inserting two ogives in the auditory meatus, more backwards with respect to the condyles. In order to overcome this error, when transferring the face arch, a front adjustment is calculated. However, such adjustment is exclusively statistical and not individual, hence always incorrect in practice.

Even during the manufacture of moulds and moulded units first, and of prostheses and of apparatuses then, a series of variables are introduced which are normally neglected: chemically and physically different waxes are used, the wax is heated according to the operator' s mostly visual experience and .not at an always equal and precise temperature; the imprint is taken with extremely changeable pressures each time, even when the operator is the same one. Another non negligible variable is the evenness of the pressure imparted by the patient closing his/her mouth upon the operator's order who, more or less manipulating the patient, decides the closing trajectory thereof and the height of masticatory. As can be understood, this method is excessively empirical and subject to too many variables. This alteration is made worse also by the fact that, normally, in the taking of dental imprints, frenula and ligaments are not taken into account, so that the imprints and what derives therefrom in the subsequent processing are instable. All that rules out a perfect reproducibility of the patient's masticatory relationships, impairing the manufacture of the prosthetic products which must be adapted and readapted several times, negatively affecting their physical and chemical aspects to the point of causing the product to lose the meaning of the use thereof not purely for economic reasons. Many times, due to how imprints are habitually taken in a patient's mouth, they do not take into account a number of variables and, as a result, the shape of the resulting mould is imprecise. That often occurs because waxes and resins are instable and movable, so as not to guarantee a credible definition of relationship of the arches. It is also the case of taking into account the fact that, usually, the operator himself must strongly manipulate the patient inducing him to a position which has nothing postural, for the manipulation itself. Once hence bases itself on the operator's manipulative skills, all to be verified, so that one hardly manages to operate effectively from a posture point of view .

Another normally neglected factor is the relationship which exists in nature among the various parts of the body and the ground and which, up until today, is not taken into account whatsoever in the manufacture of moulds and moulded units.

Finally, an enormous importance has the position which the landmarks take up with respect to the ground. As a matter of fact, the normotype provides that both the Frankfurt plane and the condyles be perpendicular and parallel to the ground, which is again mostly an abstraction. Misalignments even of angles normally considered negligible cause the results to be very different from the expected ones. The majority of patients keeps their head (when it is in a natural position) almost always at least partly misaligned and, in certain cases, even very misaligned. It has been detected that this moving away from the perpendicular position parallel to the ground has even remarkable consequences and, hence, it is another correction which must be introduced in a masticatory simulator if one wants it to be able to be helpful in bringing the patient towards the desired condition, that is, the one most suitable to the individual case, which is never perfectly normotype, on the contrary, it is often very distant from that ideal.

A different approach, which so far has given more reliable results, is the so-called photogrammetry . It consists in performing a series of simple photographs, at a distance of 3-4 metres, of the body parts of a patient standing on a platform, whereon the pressure centre of the feet and the landmarks threof have been marked with a drawing. However, not even such technique allows to arrive at a precise diagnosis, since it still has several non negligible drawbacks. Firstly, the photographs are performed one per each patient's side, hence at time distance and, hence, with the need to rearrange the patient there is no posture stability. The orientation ^' of the apparatus occurs in a mostly visual way, hence often not exactly reproducible, which also introduces measurement errors. The orientation of the platform occurs by a plumbline, but that does not allow to ensure perpendicularity with the camera lens, usually orientable by manipulating a tripod; sometimes it is sufficient the very photograph, done in an inexperienced manner or paying less attention than usually, to displace the camera outside of the sought after perpendicularity. Usually, a single camera is used, so that, in actual fact, one cannot manage to have a three-dimensional view, even though three photographs are taken, each one following each dimension. Thereby, there is no certainty that the patient does not change position, even by little. Ά change by 1/5 of degree of the sternum position, for example, significantly affects the shoulder position.

The axial study occurs on this photograph which is dimensionally unrelated to the patient, but fully randomly and unpredictably.

Based on the photographs obtained, operators trace axial lines on the photograph and obtain diagnoses based on landmarks parallel and perpendicular to the ground. The image is reduced and thereby traced lines and segments are hardly precise and reliable as regards the measurements thereof. This type of examination does not take into account any determining aspect of the mouth and of the features thereof (occlusal plane, compensation curves, maxillary or mandibular deviation) .

In some cases it is resorted to scans of the photographs with suitable scanners, using rather sophisticated computer programmes. Thereby, the reconstruction of the individual is finally three-dimensional and the image can be caused to rotate around the axis thereof. The opportunity of making visible the bone-muscle profiles is also gained. However, such profiles are not so reliable from the point of view of the skeletal axial detections. It must furthermore be taken into consideration that the scanner, even the most sophisticated one, gives a countless amount of points, but there is no opportunity of a choice of such points made directly on the patient. It is instead made on the screen, with no opportunity of control.

It does not appear that scanning techniques, even associated with radiographics , on the masticatory organ are related to the ground in all the axes and to the skull- surrounding environment, but conditioned in connection with the mandibular axis, without having a relationship thereof with the ground, and with manipulative detection techniques of the skull position and of bite matching (a plastic or metal fork, for detection, inserted between the two arches, causes the. habitual relationship therebetween to be lost) .

Axial detection techniques, which, however, are exclusively diagnostic and hence non therapeutic, are condylograph, which detects with high precision condylar travels, with an adjustment of the hinge axis, however, they do not take into account in any way the ground and the relationship of the axes with the same, moreover they do not alter the position of the glenoid fossa of the temporal bone and hence of the skull, but on a single axis (narrow, broaden); the axiograph which has the same drawbacks; the stabilometric platform, which detects with precision the pressure centres of the feet and the patient's equilibrium displacements, however, does not give with precision the determinant variables of the masticatory organ, impossible to detect with this system of direct relationships.

It is difficult to imagine to obtain with precision relationships between the two dental arches, starting from a pressure analysis of the feet which are very distant from the masticatory organ, as well as a somewhat certain relationship can be highlighted even with the platform, but nothing comparable to the system described here.

Patent EP 1 079 759 discloses an articulator for the creation of dental prostheses comprising two upper and lower planar elements, articulated on a horizontal pin,, parallel to the two planar elements. Said planar elements carry fastened the two models of a patient's dental arches.

Italian patent IT 1 318 694 discloses a device for determining face asymmetries with a plate element . to which a support is fastened for arranging the tool in a patient's mouth. The plate element is provided with a series of pins the position of which can be adjusted, which carry measuring tools arranged on a vertical plane with respect to the plane of the plate element .

Patent EP 1 725 183 discloses a method for determining the motion of the temporomandibular joint.

Patent US 7 955 077 discloses an occlusion correction tool, comprising an upper mould-mounting element, parallel to Camper's plane. The lower element instead can be mounted on a jaw model with model teeth, adjustable through pins.

Application WO2009/50 455 discloses a masticatory simulator which can be adjusted based on an absolute piece of data which can be measured due to means presents on the simulator.

EP 1 952 783 discloses a measuring device of face parameters which provides a unit arranged perpendicularly to a vertical columns of a frame, aligned with a patient's eye apple, such unit comprising a rigid rod (for example made of plexiglas) parallel to Camper's plane and apt to the adjustment of a masticatory fork.

Patent US 8 556 626 relates to a device for identifying the jaws position. The fastening of a pantograph to a patient's upper teeth is provided, so as to monitor point by point the patient's mastication. The collected data is compared with that of a model.

Application WO2013/63 629 relates to a device and to a method for cutting out the upper part of a model of the mouth. There are elements for the arrangement within the device of some reference points of the upper part of the model of the mouth.

Patent JP 2 013 192 865 discloses a masticatory reinforcement, for the use especially by elderly people and it provides within the same measuring devices of the pressure imparted on the individual teeth.

Also utility model RU 117 802 starts from a model of the mouth (this time the lower part) and provides screw-like adjustment means for adapting the model to the patient's bite.

Patent US 6 081 739 discloses a radiographic unit, with sonic or three-dimensional optic detector and a colour screen for the graphic reconstruction of a patient's head through cephalometry .

US2009/0 305 185 and DE 102 011 117 550 disclose articulators and methods for the calibration thereof.

BRIEF DESCRIPTION OF THE INVENTION

None of the documents just listed teaches to create a masticatory simulator which takes simultaneously into account face asymmetry, the natural posture of the head, the relationship conditions between the moulds and the moulded units and the patient' s spatial relationships with respect to the ground and to the three-dimensional space which surrounds him. The problem at the bottom of the present invention is to propose a masticatory simulator which can be adapted to the individual patient. It is possible to arrive thereto performing a suitable calibration of the same. Such calibration must overcome the mentioned drawbacks and allow the manufacture of moulds and moulded units referred to the patient's actual situation, so as to be able to then lead him/her towards the most suitable layout to the specific case. This object is achieved through a device for the calibration of a masticatory simulator, comprising sensing means of patient' s landmarks carried by a suitable support, movable on a sliding path, said sliding path being dimensioned so as to surround the patient at a desired height thereof and containing translation means of the sensing means along all said sliding path, characterised in that the height of said sliding path can be adjusted through displacement means along a guiding column perpendicular to the ground.

According to another aspect, the present invention provides a calibration process of a masticatory simulator which resorts to the device just seen. Based on a third aspect, the present invention refers to a masticatory simulator which can be calibrated with the device and the process seen earlier.

The dependent claims describe preferential features of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention are in any case more apparent from the following detailed description of a preferred embodiment, given purely as a, non-limiting example and illustrated in the attached drawings, wherein:

fig. 1 is a side schematic view of a device according to the present invention, partly in cross section;

fig. 2 is a detail of fig. 1 in a top plan view, in cross section ;

fig. 3 is a top plan view of the device of fig. 1 ;

fig. 4 is a cross section view of another detail of fig. 1 ; fig. 5 is a side cross section view of a masticatory simulator according to an embodiment of the present invention; fig. 6 is a top plan view of the masticatory simulator according to fig. 5; and

fig. 7 illustrates a detail of fig. 5.

BEST WAY TO CARRY OUT THE INVENTION

As stated earlier, the present invention relates to a device for the calibration of a masticatory simulator, comprising sensing means which can be made to translate around a patient's body, after having adjusted the height, so as to be able to detect all the desired points.

As can be seen from the attached drawings, the device according to the present invention comprises a base plate 1 on which a platform 2 rests, which carries a stiffening rod 3

1 parallel thereto and a guiding column 4, whereon a carriage 5 can slide in height.

Platform 2 can be of any type, provided it is dimensioned so as to be able to carry rod 3 and column 4 and to be able to contain a standing patient 6 in an erect position. Advantageously, platform 2 is a stabilometric platform. However, guiding column 4 can be fastened directly to the ground, renouncing to platform 2, so that a perpendicular arrangement of the column is obtained more easily. The perpendicular arrangement and the centre of the platform (starting centre of the machine-software calculations) is very important to be able to then correlate the landmarks sensed on the patient to the ground and to the spatial relationship, which is the focus point of the present invention.

Carriage 5 carries a rail 7, apt to surround patient 6 in any point along the height thereof. The shape of rail 7 is not particularly important, provided it is capable of surrounding the patient and to cause to slide thereon at least a second carriage 8. Advantageously, rail 7 has a protection device, preferably a carter 11. Carriage 5 carries also a motorisation 9, which determines the upward or downward movement thereof. There is no limitation to the type of motor 9 which is to be considered of a type known per se. It can be controlled manually, adjusting the height visually; in a guided manner, sensing on a suitable instrument the height at which carriage 5 is found; or automatically, controlled for example by a computer (not shown in the drawings) . Motorisation 9 illustrated in the drawings acts in the direction of causing a series of wheels 10 to move in one direction or in the other.

As regards second carriage 8, it comprises a bracket 12, fastened to the inner wall of carter 11, a wheel 13 actuated by a motorisation 14 which, acting on wheel 13, determines the movement of rail 7 and hence of a sensing device 15. Sensing device 15 can be of any type. It can be a standard video camera, a camera or another type of sensor. The preferred sensing devices 15 are chosen from the group comprising scanner, laser, TAC. Particularly advantageous is a laser, since the beam issued is extremely collimated, so much so as to allow an extremely precise and accurate analysis of the measurements. The type of preferred sensing device 15 is a laser sensor diode of class 2. In this device, the laser beam is seen as a red dot and, even in case of random aiming at the eyes, it does not cause harm to the patient, so as to be perfectly safe. It must be pointed out that, should an intraoral camera be used, which gives very clear images, the device according to the present invention gives the precise spatial arrangement, increasing the value of said images. With sensing device 15 a further video camera may be associated (not shown in the drawings for clarity's sake), which may be used to identify the patient' s landmarks on which to then aim sensing device 15. Thereby, the operator does not need to get closer to patient 6 to mark the landmarks on him/her with a pencil and then to aim the sensin devices at such pencil marks and he/she can operate directly from the operating centre, of the device, possibly also from another room.

Moreover, imaging techniques, arranged on the shaft, set up the correction of the calculations relating to the measurement performed by the laser, to keep under control the patient' s oscillations and relate them to a setting between said laser, the viewer and markers arranged on the patient's head and in connection with the machine centre arranged on the platform.

When one wants to use the device according to the present invention, a patient 6 is caused to get onto platform 2. Patient 6 is asked to look at a leadline and he/she is put at ease, so that he/she can reach and maintain a position as natural as possible .

Another patient position, which the machine is designed to contain in itself is the patient's sitting position, on a postural chair which self-centres the patient's baricentre and locked with brackets, when the patient has reached his/her postural stability.

This chair too is set with the machine-platform centre. In order to obtain that, the operator (physician, nurse or technician) can, initially, give a shrug to the patient's 6 shoulders and arms, then he can start a casual conversation with patient 6, so that the patient abandons the inevitably rigid position which each of us takes up when we feel observed. In this step, the operator will act on motorisation 9 which causes carriage 5 to slide, so as to bring rail 7 and sensing device 15 to the height of patient's 6 head, so as to be able to identify the landmarks thereof. In order to help maintain the position for a long time, a locking helmet can be arranged on patient's 6 head, which limits the movements thereof. Such helmet may be fastened to the device through an articulated arm.

Alternatively to the helmet, a viewer can be used which detects cross-shaped markers on patient 6. Looking with sensing devices 15 for a closed group of landmarks and using said viewer, the device can be set according to the present invention on these points and on the markers. Thereby, patient's 6 (per se inevitable) oscillations are compensated, with deviations which vary from a minimum of 0.25 (intrinsic to the viewer) and 1.00 mm .

When the operator can be reasonably sure that patient 6 is in a natural position, he/she asks the patient to aim his eyes also onto an object in line with the leadline and begins the sensing operations. The data coming from platform 2, should it be a stabilometric platform, allow, owed to the distribution of the pressure imparted by patient's 6 feet on the ground, to give a precise idea of the way in which patient 6 relates with the ground. They must then be correlated to the data coming from sensing device 15. Sensing device 15 is dragged by rail 7 due to motorisation 14 and projects a laser beam onto the patient whenever it identifies a position useful for determining the landmarks. Based on the reflection of the beam it obtains, sensing device 15 transmits to a reading' unit (not shown in the drawings) the incidence data on the patient's 6 head, so as to perfectly define the features of the actual landmarks on patient 6.

Advantageously, sensing device 15 also comprises an aiming device (not shown in the drawings for clarity's sake), which can be of any known type, such as a video camera_„ or a camera. The operator can, helping himself with the image received by the aiming device, correctly arrange sensing device 15; should said device be a laser beam, a perfect aiming of such beam on the patient can be obtained. The data can be obtained manually. In this case, motorisation 7 is guided by the operator with means known per se, until reaching the desired height of carriage 5. On the screen, the operator will see the patient's head. Owed to aids, for example a superimposition representation on a computer screen of a normotype head, the operator can, again manually, act on motorisation 14, causing carriage 8 to rotate around the patient's 6 head and capturing data in the desired points. This could be obtained, for example, owed to a touch-screen with suitable controls.

At least in principle, however, it is possible to assume a fully automatic system, managed by a computer programme. When the operator has established that the patient is in a sufficiently natural attitude, he pushes a start button and, based of a programme routine, the system moves motorisations 9 and 14 and acquires the data of interest.

The data obtained allow to obtain the actual landmarks, relating to that specific patient. Thus, it can be taken into face dissymmetry, misalignment of the head with respect to the normotype and the position of patient 6 with respect to the ground can be taken into account. If one uses a platform 2 and platform 2 is a stabilometric platform, moreover, it may help rebuild the arrangement of the actual landmarks with respect to the ground, as they are set by patient 6 in his daily life.

The rotation of sensing device 15 dragged by rail 7 allows to have an almost simultaneous sensing of all the landmarks, avoiding the problems of lag detected in the devices and in the processes of the prior art.

The calibration process of a masticatory simulator according to the present invention provides to sense the landmarks of a patient with a device as just described, to refer them to the ground and to the three-dimensional spatial position of said patient 6 and to use them for the reconstruction thereof on said masticatory simulator.

Advantageously, in case there is a stabilometric platform

2, it is useful that the data on the sensed landmarks be related to data on the pressure imparted by the feet onto said stabilometric platform 2.

Alternatively to the standing position described so far, patient 6 can sit on a postural chair. Said char rocks until it finds its baricentre; when that occurs, the chair stops in position. The oscillations of patient 6 are thereby fewer than when he/she stands. The baricentre is related to the machine centre .

The intraoral camera may be integrated in the system, through the image superimposition between the images which the camera itself can reproduce and the position of the scanned dental moulds and carries (for example with . stl file) with respect to the dental points sensed by the laser in the robot.

Therefore, the present invention relates to a masticatory simulator, an embodiment of which is represented in figs. 5 to 7.

The masticatory simulator is divided into a lower part 16 and into an upper part 17.

Advantageously, lower part 16 rests on suitable feet 18. On lower part 16 a longitudinal sliding body 19 rests. The lower part 16 and upper part 17 are joined, on one side, by a vertical sliding element 20 and, on the other, by a reference rod 21, carried by a locking screw 22 - present on upper part 17 - and which rests onto a suitable rest 23 - present in lower part 16. Rest 23 can be adjusted in height due to a suitable adjustment screw 24.

An assembly 25 introducing the lower mould and an assembly 26 introducing the upper mould are present in between upper part 17 and lower part 16 there. Each one thereof carries an orientable retinated plate 27.

The sliding of body 19 is adjusted by stopping screws 28 and adjustment screws 29.

Finally, the upper part comprises a tiltable body 30.

Based on the reconstruction of the patient's landmarks, based both on the dissymmetry, and on the arrangement thereof with respect to the ground, it is now possible to correctly calibrate the masticatory simulator just described, since the illustrated adjustments allow, starting from a standard layout (usually that of the normotype) to act independently on the different landmarks. That is, it will be possible to act on longitudinal sliding bodies 19 and vertical sliding bodies 20, which adjust condyle position. Moreover, it will be possible to act on the position of reference rod 21, as well as orienting plates 27 and 30. If one wants to act manually, a series of punctual data is obtained from the device according to the invention, which series allows to act on one or more points of the masticatory simulator so as to reconstruct the desired situation .

A possible automatic mechanism, instead, can read the data file obtained from the device according to the invention and can act directly, in a way known per se in the field of automation, on the simulator.

In each one of the two cases, the masticatory simulator will nevertheless account for the peculiarities of the specific patient 6, much more than normally used simulators, solving all the problems met so far. Thereby, any prostheses and orthodontic appliances will be manufactured taking into account a series of the patient's defects (deviations from the normotype) which are currently not even sensed. The correction which is obtained is thereby much more extreme than the one possible so far, without this having, however, unpleasant effects on the patient.

In order to obtain more realistic results, it is suitable to proceed to multiple series of sensings, so as to average out errors, reducing the scope thereof. Thereby, a better reconstruction of patient' s 6 posture is obtained and the results are even more effective.

The present invention furthermore allows, to determine the height of the arches with respect to the ground, which was impossible .or done in an unreliable way up until today. It also allows to study any misalignment of the masticatory apparatus, which allows to obtain extremely important data with reference to the posture of patient 6. In principle, it could be assumed to extend the use of the device according to the present invention also to the rest of the human skeleton, so that an even more accurate assessment of the posture of patient 6 becomes possible and it can be acted thereon in the most correct way possible. As a matter of fact, there are landmarks relating to parts of the body other than the head and, given the presence of platform 2, sensing device 15 can operate from the heel upwards, hence the landmarks of the entire body of patient 6 can be sensed. In this case, the operating ways would be the same seen in the general case, but it would be advisable to use two different processing programmes, one dedicated to the head and the set of teeth and one dedicated to the rest of the body.

The present invention hence allows to perfectly reconstruct the patient's head, so as to attack more deeply the masticatory defects and it can help, unlike what happens with masticatory simulators currently in use, to correct the patient's imperfections. The calibration performed according to the present invention allows to correctly set and arrange the masticatory simulator, so that the moulds and the moulded units obtain the correct arrangement in the simulator and with respect to the ground and to the mutual relationship and to the arrangement thereof in space.

It can also be provided to use both a scan with the scanner and a CAT scan and to superimpose, through the landmarks, the two images, so as to calibrate even more simply and precisely the masticatory simulator, resorting to the direct image of the CAT scan. In general, images sensed by two sensing detection means 15 can be obtained and they can be mutually superimposed due to the landmarks .

However, it is understood that the invention must not be considered limited to the special arrangement illustrated above, which represents only an exemplifying embodiment thereof, but that different variants are possible, all within the reach of a person skilled in the field, without departing from the scope of protection of the invention, as defined by the following claims. LIST OF REFERENCE CHARACTERS

1 Base plate

2 Platform

3 Stiffening rod

4 Guiding column

5 Carriage

6 Patient

7 Rail

8 Carriage

9 Motorisation (of 5)

10 Wheels

11 Carter (of 7)

12 Bracket

13 Wheel

14 Motorisation (of 7)

15 Sensing device

16 Lower part of the masticatory simulator

17 Upper part of the masticatory simulator

18 Feet of the masticatory simulator

19 Longitudinal sliding body

20 Vertical sliding body

21 Reference rod

22 Locking screw

23 Rest (of 21)

24 Adjustment screw (of 23)

25 Assembly introducing the lower mould

26 Assembly introducing the upper mould

27 Retinated plate (of 25 or of 26)

28 Stopping screw (of 19)

29 Adjustment screw (of 19)

30 Tiltable body (of 17)

Claims

1) Device for the calibration of a masticatory simulator, comprising sensing means (15) of landmarks of a patient (6) carried by a suitable support (8) , movable on a sliding path (7), said sliding path (7) being dimensioned so as to surround the patient (6) at a desired height thereof and containing translation means (7, 13, 14) of the sensing means (15) along said entire sliding path (7), characterised in that the height of said sliding path (7) may be adjusted due to displacement means (5) along a guiding column (4), perpendicular to the ground .

2) Device as in 1) , characterised in that said guiding column (4) is carried by a platform (2) .

3) Device as in 1) or in 2), characterised in that said sliding path (7) consists of a rail surrounding the patient

(6) .

4) Device as in 2) or in 3), characterised in that said platform (2) is a stabilometric platform (2) .

5) Device as in any one of the preceding claims, characterised in that said sensing means (15) are chosen in the group comprising scanner, laser, CAT scan and intraoral camera .

6) Device as in 5), characterised in that said sensing device (15) is a laser sensor.

7) Device as in any one of the preceding claims, characterised in that said sensing device (15) furthermore carries an additional video camera, to sense the landmarks of the patient (6) onto which to then aim the sensing means (15) .

8) Device as in any one of the preceding claims, characterised in that it carries with an articulated arm a helmet for maintaining the patient (6) in position.

9) Device as in any one of claims 1) to 7), characterised in that it furthermore comprises a viewer which identifies cross-shaped markers on the patient (6) to compensate the oscillations thereof.

10) Process for the calibration of a masticatory simulator, characterised in that it provides to sense the landmarks of a patient (6) with a device as in any one of the preceding claims, to refer them to the ground and to the three- dimensional spatial position of said patient (6) and to use them for the reconstruction thereof on said masticatory simulator .

11) Process as in 10), characterised in that the data on the detected landmarks are linked to date on the pressure imparted by one's feet on a stabilometric platform (2) .

12) Process as in 10) , characterised in that the patient

(6) is arranged sitting on a postural chair.

13) Process as in any one of claims 10) to 12), characterised in that multiple measurements are performed, which are averaged with one another.

14) Process as in 10), characterised in that images sensed by two different sensing means (15) are obtained and they are mutually superimposed due to the landmarks.

15) Masticatory simulator which can be calibrated based on the reconstruction of the patient's landmarks, based on the dissimmetry thereof, characterised in that it is calibrated also based on the arrangement of said landmarks with respect to the ground, sensed with a device as claimed in any one of claims 1) to 6) .