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    • 专利摘要:
    Method for determining an optimal tilting instant for a mixed orthodontic treatment of a patient's teeth, comprising the following operations: 1) production of an initial three-dimensional reference model of an arch bearing said teeth, and for each of said teeth, definition of a three-dimensional model of said tooth in the initial reference model; 2) deformation of the initial reference model, by moving the tooth models, until said tooth models are in an objective position, so as to obtain an “objective reference model”; 3) at a current instant, acquisition of at least one updated image of said teeth; 4) deformation of the initial reference model, by displacement of the tooth models, until said at least one updated image corresponds to a view of the initial reference model thus deformed, called “updated reference model”; 5) determining, from said updated reference model and said objective reference model, a plurality of residual treatment scenarios for moving said teeth to their position represented in the objective reference model; 6) determination, for each scenario, of a profile; 7) evaluation of each profile by means of an evaluation rule; and 8) determining an optimal switchover time to replace the arch and bracket orthodontic appliance with a splint.
    公开号:FR3066903A1
    申请号:FR1754755
    申请日:2017-05-30
    公开日:2018-12-07
    发明作者:Philippe Salah；Thomas PELLISSARD；Guillaume GHYSELINCK；Laurent DEBRAUX
    申请人:Dental Monitoring SAS；
    IPC主号:
    专利说明:

    The present invention relates to a method for determining a tilting instant from which a patient wearing an orthodontic appliance with arch and fasteners will wear one or more orthodontic aligners.
    The invention also relates to a computer program for implementing this method.
    State of the art
    Among orthodontic appliances, a distinction is made between orthodontic braces and braces on the one hand, and orthodontic aligners on the other.
    An orthodontic appliance with arch and fasteners comprises fasteners, or "brackets", fixed on the teeth and connected to each other by means of an arch, conventionally made of a shape memory material. It exerts a rapid action on the movement of the teeth of the treated patient. However, this action gradually decreases and it is necessary for the patient to make a regular appointment with the orthodontist in order to modify the Tare setting or change it. In addition, an orthodontic appliance with arch and fasteners is often unsightly.
    A gutter, "align" in English, is conventionally in the form of a removable one-piece device, conventionally made of a transparent polymer material. It has a trough shaped so that several teeth of an arch, generally all the teeth of an arch, can be accommodated there. The shape of the chute is adapted to hold the gutter in position on the teeth, while exerting an action to correct the positioning of certain teeth. An orthodontic appliance has a slower initial action than that of an orthodontic appliance with an arch and fasteners. Advantageously, the gutter can however be replaced by the patient himself. In addition, the gutters are more discreet than arc and fasteners.
    A "mixed" orthodontic treatment allows you to benefit from the advantages of each of these two types of orthodontic appliance. In fact, it conventionally comprises a first treatment phase during which the patient wears an orthodontic appliance, or “arc phase”, followed, from an instant of tilting, by a second treatment phase using orthodontic aligners, or "gutter phase". The treatment then continues with aligners.
    There is an ongoing need for a method for optimizing a mixed treatment, in particular for reducing its duration.
    An object of the invention is to meet this need.
    Summary of the invention
    The invention provides a method for determining an optimal tilting instant of a mixed orthodontic treatment of a patient's teeth, said method comprising the following operations:
    1) preferably at the start of treatment or before the start of treatment, production of a three-dimensional digital model of at least part of an arch bearing said teeth, or “initial reference model”, and for each of said teeth, definition of a digital three-dimensional reference model of said tooth in the initial reference model, or "tooth model";
    2) after operation 1), preferably at the start of treatment or before the start of treatment, deformation of the initial reference model, by displacement of the tooth models, until said tooth models are in an objective positioning , so as to obtain an "objective reference model",
    3) after operation 2), at an instant in a phase of treatment during which the patient is wearing an orthodontic appliance with arch and fasteners, known as “current instant”, acquisition of at least a two-dimensional image of said teeth, known as “ updated image ”, under actual acquisition conditions;
    4) deformation of the initial reference model, by displacement of the tooth models, until said at least one updated image corresponds to a view of the initial reference model thus deformed, called "updated reference model", searching for the updated reference model preferably being carried out by means of a metaheuristic method, preferably evolutionary, preferably by simulated annealing;
    5) determination, from said updated reference model and said objective reference model, of a plurality of residual treatment scenarios for moving said teeth from their position represented in the updated reference model to their position represented in the model of objective reference, each scenario comprising, from an instant of changeover, at least one phase of treatment using an orthodontic splint;
    6) determination, for each scenario, of a profile comprising at least one value for an evaluation parameter chosen from the group formed by:
    - the duration of the residual processing of said scenario;
    - the duration of complete treatment;
    - a coefficient of clinical complexity or "severity score";
    - a pain coefficient for the residual treatment of said scenario,
    - a pain coefficient for the complete treatment;
    - the duration of the treatment phase (s) by means of an orthodontic archwire with arch and fasteners during the residual treatment;
    - a comfort coefficient for the residual processing of said scenario,
    - a comfort coefficient for the complete treatment;
    - a cost for the residual processing of said scenario,
    - a cost for the complete treatment,
    - a function of the previous evaluation parameters;
    7) evaluation of each profile using an evaluation rule; and
    8) determination, from the scenario with the optimal profile, or "optimal scenario", of an optimal tilting moment to replace the orthodontic appliance with arch and fasteners by a splint.
    As will be seen in more detail in the following description, a method according to the invention makes it possible to adapt the treatment to specific constraints, and in particular to constraints imposed by the patient. For example, if the patient imposes a maximum duration of treatment of six months and a longest gutter phase possible, the method according to the invention makes it possible to test different scenarios in order to find the profile that best meets this need.
    Operations 5) to 8) can be successive or not. When they are successive, they are called "steps" 5 ’) to 8’), respectively.
    In a preferred embodiment, they are nested and constitute the following successive steps 5 ”) to 8”):
    5) determination, from said updated reference model and from said objective reference model, of a residual treatment scenario for moving said teeth from their position represented in the updated reference model to their position represented in the reference model objective, a residual treatment scenario comprising, from an instant of changeover, at least one phase of treatment using an orthodontic splint;
    6) determination, for said scenario, of a profile comprising at least one value for an evaluation parameter chosen from the group formed by:
    - the duration of the residual processing of said scenario;
    - the duration of complete treatment;
    - a coefficient of clinical complexity or "severity score";
    - a pain coefficient for the residual treatment of said scenario;
    - a coefficient of clinical complexity;
    - a pain coefficient for the complete treatment;
    - the duration of the treatment phase (s) by means of an orthodontic archwire with arch and fasteners during the residual treatment;
    - a comfort coefficient for the residual processing of said scenario,
    - a comfort coefficient for the complete treatment;
    - a cost for the residual processing of said scenario,
    - a cost for the complete treatment,
    - a function of the previous evaluation parameters;
    7) evaluation of the profile using an evaluation rule and, if the profile is not optimal with regard to the evaluation rule, determination of a new residual treatment scenario and repeated in step 6 ” );
    8) determination, from the scenario with the optimal profile, or "optimal scenario", of an optimal tilting moment to replace the orthodontic appliance with arch and fasteners by a splint.
    Preferably, a method according to the invention also has one or more of the following optional characteristics:
    - more than 5, 10, 50 or 100 scenarios are determined in operation 5);
    - in operation 3), the updated image is taken by means of an image acquisition device chosen from the group consisting of a mobile phone, a connected camera, a smart watch, a tablet and or a personal computer, desktop or portable;
    - operation 4) comprises the following steps:
    c) analysis of the updated image and creation of an updated map relating to discriminating information;
    d) optionally, determination, for the updated image, of coarse virtual acquisition conditions approximating the actual acquisition conditions of said updated image;
    e) search, for the updated image, of an updated reference model corresponding to the positioning of the teeth during the acquisition of the updated image, the research being preferably carried out by means of a metaheuristic method, preferably evolutionary , preferably by simulated annealing;
    - step e) includes the following steps:
    el) definition of a reference model to be tested as being the initial reference model then, e2) following the following steps, testing of virtual acquisition conditions with the reference model to be tested in order to finely approximate said conditions of actual acquisitions;
    e21) determination of virtual acquisition conditions to be tested;
    e22) production of a two-dimensional reference image of the reference model to be tested under said virtual acquisition conditions to be tested;
    e23) processing of the reference image to produce at least one reference card representing, at least partially, said discriminating information;
    e24) comparison of the updated and reference cards so as to determine a value for a first evaluation function, said value for the first evaluation function depending on the differences between said updated and reference cards and corresponding to a decision to continue or to stop the search for virtual acquisition conditions approximating said real acquisition conditions with more accuracy than said virtual acquisition conditions to be tested determined at the last occurrence of step e21);
    e25) if the said value for the first evaluation function corresponds to a decision to continue the said search, modification of the virtual acquisition conditions to be tested, then repeated in step e22);
    e3) determination of a value for a second evaluation function, said value for the second evaluation function depending on the differences between the updated and reference cards in the virtual acquisition conditions approximating at best said real acquisition conditions and resulting from the last occurrence of step e2), said value for the second evaluation function corresponding to a decision to continue or stop the search for a reference model approximating the positioning of the teeth during the acquisition of the image updated with more accuracy than said reference model to be tested used at the last occurrence of step e2), and if said value for the second evaluation function corresponds to a decision to continue said research, modification of the reference model to be tested by moving one or more models of teeth, then resumed at step e2);
    - The method includes a step 9) in which the optimal switching time, preferably the optimal scenario and / or the optimal profile, are presented to a doctor, in particular an orthodontist, and / or to the patient;
    - in step 1), a digital three-dimensional reference model of a gum is defined from which said tooth models emerge, or “gum model”, and, in step 4), said tooth models are moved and modifying said gum model to deform the initial reference model;
    - To deform the initial reference model, a deformation of the gum model is calculated from said displacements of said tooth models.
    The invention also relates to a method for adapting an orthodontic splint, a method in which a method for determining an optimal tilting instant according to the invention is implemented, then, depending on the result of said evaluation, manufactures a groove suitable for at least part of the orthodontic treatment of teeth from said optimal tilting instant.
    The invention also relates to:
    a computer program, and in particular a specialized application for a mobile phone, comprising program code instructions for the execution of one or more, preferably all of the operations 3) to 8), when said program is executed by a computer,
    a computer medium on which such a program is recorded, for example a memory or a CD-ROM, and
    - a calculation tool, in particular a personal device, in particular a mobile phone or a tablet, in which such a program is loaded.
    Preferably, the calculation tool includes a scenario simulator capable of creating scenarios, determining profiles of said scenarios and evaluating said scenarios with regard to an evaluation rule. More preferably still, it includes a "machine" interface and means for determining the evaluation rule from data entered with said interface.
    The invention also relates to a system comprising a three-dimensional scanner capable of producing an initial reference model, and a calculation tool, in particular a personal device, preferably a mobile telephone, capable of acquiring an updated image and loaded with a program according to the invention.
    Definitions
    By "residual processing" is meant the portion of processing from the current time.
    By "patient" is meant any person for whom a process according to the invention is implemented, whether this person is sick or not.
    The "acquisition conditions" specify the position and orientation in space of an image acquisition device relative to the patient's teeth (actual acquisition conditions) or to a three-dimensional model of the patient's teeth ( virtual acquisition conditions), and preferably the calibration of this image acquisition device. Acquisition conditions are said to be virtual, or “simulated”, when they correspond to a simulation in which the acquisition device is in said acquisition conditions (positioning and preferably virtual calibration of the acquisition device ).
    The "calibration" of an acquisition device consists of all the values of the calibration parameters. A calibration parameter is a parameter intrinsic to the acquisition device (unlike its position and orientation) whose value influences the acquired image. Preferably, the calibration parameters are chosen from the group formed by the aperture of the diaphragm, the exposure time, the focal distance and the sensitivity.
    A 3D scanner is a device used to obtain a three-dimensional representation of an object.
    By image is meant a two-dimensional image, such as a photograph. An image is made up of pixels.
    An updated image "corresponds to" a view of the updated reference model when this view is substantially identical to said updated image.
    "Understand", "comprise" or "present" must be interpreted in a broad, non-limiting manner, unless otherwise indicated.
    Brief description of the figures
    Other characteristics and advantages of the invention will become apparent on reading the detailed description which follows and on examining the appended drawing in which:
    - Figure 1 shows different temporal changes for a positioning parameter of a tooth, depending on the nature of the residual treatment considered;
    - Figure 2 shows a flowchart illustrating the implementation of a prediction method according to the invention.
    detailed description
    Operation 1) is preferably carried out at the start of treatment or before the start of treatment, and consists in producing a three-dimensional digital model of an arch bearing the treated teeth, or "initial reference model".
    The initial reference model is for example of the type .stl or .Obj, .DXF 3D, IGES, STEP, VDA, or Point clouds. Advantageously, such a model, called "3D", can be observed at any angle.
    The initial reference model can be prepared from measurements made on the patient's teeth or on a physical model of his teeth, for example a plaster model.
    The initial reference model is preferably created using a professional device, for example using a 3D scanner, preferably implemented by a healthcare professional, for example by an orthodontist or an orthodontic laboratory. . In an orthodontic practice, the patient or the physical model of his teeth can advantageously be placed in a precise position and the professional apparatus can be perfected. The result is a very precise initial reference model. The initial reference model preferably provides information on the positioning of the teeth with an error of less than 5/10 mm, preferably less than 3/10 mm, preferably less than 1/10 mm.
    In the initial reference model, a part which corresponds to a tooth, or "tooth model", is delimited by a gingival border which can be broken down into an internal gingival border (on the side of the interior of the mouth relative to the tooth), an outer gingival edge (oriented towards the outside of the mouth relative to the tooth) and two lateral gingival edges. The tooth models can be defined as described, for example, in international application PCT / EP2015 / 074896.
    Preferably, the initial reference model also models the gum which surrounds the teeth. The part of the initial reference model that represents the gum is called the "gum model".
    Operation 2) comprises a modification of the initial reference model, by moving the tooth models, until a desired positioning of the teeth is obtained, called "objective positioning". The objective positioning can be that desired at the end ίο of the treatment (“final set-up”) or at a predetermined intermediate stage of the treatment (“intermediate set-up”).
    Preferably, operation 2) also includes a deformation of the gum model. In a preferred embodiment, the deformation of the gum model is, at least in part, the result of a simulation obtained from the displacement of the tooth models. Advantageously, the search for the updated reference model is accelerated.
    Preferably, operation 2), after operation 1), is carried out immediately after operation 1).
    The operations 3) and 4), subsequent to operation 2), aim to update the initial reference model so that the tooth models are in a position identical to that of the actual teeth at the present time.
    In operation 3), using an image acquisition device, under actual acquisition conditions, an updated image of the part of the arch bearing the teeth to be treated is taken.
    The image acquisition device is preferably a mobile telephone, a so-called “connected” camera, a so-called “smart” watch, or “smartwatch”, a tablet or a personal computer, fixed or portable, comprising a system. acquisition of images, such as a webcam or a camera.
    The acquisition is preferably carried out by the patient or a close relative of the patient, but can be carried out by any other person, in particular a dentist or an orthodontist, preferably without imposing a precise positioning of the image acquisition device by report to the teeth.
    Preferably, the updated image is a photograph or is taken from a film. It is preferably in color, preferably in real color.
    Preferably, in operation 3), the procedure follows step b) described in PCT / EP2015 / 074896.
    Operation 4), subsequent to operation 3), preferably consists of an iterative process according to which, at each iteration, one or more models of teeth are moved, then optimal observation conditions of the initial reference model as well modified (called “reference model to be tested”) are determined, the optimal observation conditions being defined as the conditions making it possible to observe the reference model to be tested so that the view of said model is as close as possible to the updated image.
    Preferably, at each iteration, the gum model is also deformed so that the initial reference model modified by the displacement of the tooth models and the deformation of the gum model is as compatible as possible with the updated image. In one embodiment, a first deformation of the gum model is calculated as a function of the displacement of the tooth models. The first deformation may be sufficient. Otherwise, it is completed by a second deformation, preferably determined by means of a metaheuristic method, preferably evolutionary, preferably by simulated annealing.
    Steps c) to e) described in PCT / EP2015 / 074896 are preferably implemented:
    c) analysis of the updated image and creation of an updated map relating to discriminating information;
    d) optionally, determination, for the updated image, of coarse virtual acquisition conditions approximating the actual acquisition conditions of said updated image;
    e) search, for the updated image, of an updated reference model corresponding to the positioning of the teeth during the acquisition of the updated image, the research being preferably carried out by means of a metaheuristic method, preferably evolutionary , preferably by simulated annealing.
    All the characteristics of steps c) to e) described in PCT / EP2015 / 074896 are applicable.
    According to step c), the updated image is analyzed so as to produce an updated map relating to at least one discriminating item of information.
    Discriminatory information is characteristic information which can be extracted from an image (image feature), conventionally by computer processing of this image.
    Discriminatory information can have a variable number of values. For example, contour information can be equal to 1 or 0 depending on whether a pixel belongs to a contour or not. Brightness information can take a large number of values. Image processing makes it possible to extract and quantify discriminating information.
    The updated card represents discriminating information in the repository of the updated image. The discriminating information is preferably chosen from the group consisting of contour information, color information, density information, distance information, brightness information, saturation information, reflection information and combinations of this information.
    In the optional step d), the real conditions of acquisition of the image updated in operation 3) are roughly evaluated, that is to say the position and orientation in space. of the acquisition device with respect to the teeth and its calibration. Step d) advantageously makes it possible to limit the number of tests on virtual acquisition conditions during step e), and therefore makes it possible to considerably speed up step e).
    One or more heuristic rules are preferably used. For example, preferably, virtual acquisition conditions that can be tested in step e) are excluded, conditions that correspond to a position of the image acquisition device behind the teeth or to a distance teeth greater than 1 m. In a preferred embodiment, reference marks represented on the updated image are used to determine a region of the substantially conical space delimiting virtual acquisition conditions capable of being tested in step e), or cone test.
    The objective of step e) is to modify the initial reference model until obtaining an updated reference model which corresponds to the updated image, that is to say such that the models of teeth as shown in the updated image. Ideally, the updated reference model is therefore a digital three-dimensional reference model from which the updated image could have been taken if this model had been real.
    We therefore test a succession of reference models "to test", the choice of a reference model to test preferably depends on the level of correspondence of the reference models "to test" previously tested with the updated image. This choice is preferably made by following a known optimization method, in particular chosen from metaheuristic optimization methods, preferably evolutionary, in particular in simulated annealing methods. The optimization methods described in PCT / EP2015 / 074896 can be used in particular.
    Preferably, step e) comprises the following steps:
    el) definition of a reference model to be tested as being the initial reference model then, e2) following the following steps, testing of virtual acquisition conditions with the reference model to be tested in order to finely approximate said conditions of actual acquisitions;
    e21) determination of virtual acquisition conditions to be tested;
    e22) production of a two-dimensional reference image of the reference model to be tested under said virtual acquisition conditions to be tested;
    e23) processing of the reference image to produce at least one reference card representing, at least partially, said discriminating information;
    e24) comparison of the updated and reference cards so as to determine a value for a first evaluation function, said value for the first evaluation function depending on the differences between said updated and reference cards and corresponding to a decision to continue or to stop the search for virtual acquisition conditions approximating said real acquisition conditions with more accuracy than said virtual acquisition conditions to be tested determined at the last occurrence of step e21);
    e25) if said value for the first evaluation function corresponds to a decision to continue said research, modification of the virtual acquisition conditions to be tested, then repeated in step e22);
    e3) determination of a value for a second evaluation function, said value for the second evaluation function depending on the differences between the updated and reference cards in the virtual acquisition conditions approximating at best said real acquisition conditions and resulting from the last occurrence of step e2), said value for the second evaluation function corresponding to a decision to continue or stop the search for a reference model approximating the positioning of the teeth during the acquisition of the image updated with more accuracy than said reference model to be tested used at the last occurrence of step e2), and if said value for the second evaluation function corresponds to a decision to continue said research, modification of the reference model to be tested by moving one or more models of teeth, then resumed at step e2).
    Steps e1) to e3) are described in detail in PCT / EP2015 / 074896, or WO2016066651.
    According to steps c) to e), the updated reference model is a three-dimensional model resulting from successive modifications of the initial, very precise reference model. Advantageously, it is thus itself very precise, although it was obtained from simple photographs taken without particular precautions.
    These steps therefore make it possible, from one or more simple images of the teeth, taken without precise pre-positioning of the image acquisition device relative to the teeth, for example from a photograph taken by the patient. , to accurately assess the position of the teeth at the current time. This evaluation can also be carried out remotely, using simple photographs taken by a mobile phone, without the patient having to travel, to the orthodontist in particular.
    Operation 4) leads to an updated reference model representing the teeth with great precision, in their position at the present time.
    According to a first embodiment, the process continues with the succession of steps 5 ’) to 8’):
    In step 5 ’), a set of residual treatment scenarios is determined, that is to say adapted to achieve a positioning of the teeth substantially identical to that of the corresponding tooth models in the objective reference model.
    FIG. 1 represents for example three temporal evolutions of the x coordinate of a point of a tooth in space, as a function of the residual treatment, that is to say of the treatment adopted from the current instant to . The objective positioning of this point is reached when x is equal to ^ objective
    The curve So represents the evolution of x if the treatment continues exclusively with an orthodontic appliance with arch and brackets. This development is typical of this type of orthodontic appliance, with an efficiency that is gradually reducing. The residual treatment is the fastest, the objective positioning being reached at the instant tso. However, it takes the longest time to wear a brace and brace orthodontic appliance (tso - to).
    The curve Si represents a first scenario for a mixed treatment. According to this scenario, the orthodontic appliance with arch and fasteners worn until then is replaced, at present, by a splint. The switching instant tm is therefore equal to to. The residual treatment then continues exclusively with one or more gutters. The evolution of x is therefore substantially linear and illustrates the typical efficiency of this type of orthodontic appliance. The duration of the wearing of an orthodontic appliance with arch and fasteners is advantageously zero. Residual processing, however, is the slowest, with objective positioning being achieved at the instant tsi.
    Curve S2 represents a second scenario for mixed processing. According to this scenario, the orthodontic appliance with arch and fasteners is worn, during an arc phase Pà2, until an instant of tilting tB2, then is replaced by a splint. The residual treatment then continues exclusively with one or more gutters (PG2 gutter phase).
    The duration of the wearing of an orthodontic appliance with arch and fasteners (ts2 - tB2) and the duration of the residual treatment are intermediate between those of the two previous situations.
    Preferably, more than 3, more than 5, more than 10, more than 50, or more than 100 scenarios of mixed residual treatment are determined.
    Residual treatment scenarios can be determined by an orthodontist and / or by means of simulation software capable of simulating the effect of different orthodontic appliances according to the updated positioning of the teeth and the objective positioning, for example the Insignia ™ software of the Ormco ™ company
    In step 6 ’), a profile is determined for each scenario determined in step 5’). A "profile" is made up of a set of values for evaluation parameters, that is to say relevant to evaluate a scenario according to an evaluation rule.
    The evaluation parameters may relate to the duration, cost, pain, and / or comfort, and / or clinical severity associated with each scenario.
    Pain can be measured by a pain coefficient associated with treatment, for example assessed from surveys of people who have been treated in a similar way.
    Comfort can in particular refer to the aesthetic impact of the treatment. For example, the comfort coefficient can be the ratio between the total duration of the gutter phases over the total duration of the arc phases for the residual treatment.
    The profile of the scenario Si can be for example (Residual treatment duration = 3/10; Coefficient of comfort = 9/10; Pain coefficient = 8/10; Cost = 7/10).
    The profile of scenario S2 can be for example (Residual treatment duration = 7/10; Coefficient of comfort = 6/10; Pain coefficient = 5/10; Cost = 9/10).
    In step 7 ’), the profiles are evaluated with regard to the evaluation rule. The evaluation rule is preferably established by the patient, depending on the importance he attaches to the evaluation parameters. It can be established at any time before step 7 '). Preferably, the acquisition device asks the patient questions and the answers to these questions allow him to define the evaluation rule.
    The preferred profile, with regard to the evaluation rule, is said to be "optimal".
    An evaluation rule can establish a constraint. For example, an evaluation rule may require that the duration of the residual treatment is less than 6 months or that all the arc phases of the complete treatment last less than 2 months.
    An evaluation rule can establish a conditional constraint. For example, an evaluation rule may require that, if the duration of the residual treatment is more than 6 months, all of the arc phases of the residual treatment must not last more than 2 months.
    An evaluation rule can establish an optimization rule. For example, an evaluation rule may require seeking the shortest residual treatment, with a maximum duration of treatment with an orthodontic appliance with a bow and braces of 1 month.
    With this last example, scenario S2 could be optimal if the duration between tB2 and to is 1 month.
    Of course, an evaluation rule can be complex and establish, for example, that all of the arc phases of the residual treatment last as little as possible, at a determined total cost.
    An evaluation rule could be, in the example of FIG. 1, to minimize the function F = kD Residual treatment duration + k2 * Comfort coefficient + k3 * Pain coefficient + k4 * Cost, the weighting coefficients ki being preferably determined by the patient or by an algorithm, based on the patient's answers to questions.
    If ki = l, k2 = 2, k3 = l and k4 = 3, the function F for the scenarios Si and S2 is equal, respectively, to F (Si) = 50 and F (S2) = 51.
    In step 8 ’), we compare the evaluations of the profiles carried out in step 7’) in order to select a scenario considered optimal with regard to the evaluation rule.
    The so-called "optimal" switching time te * associated with this optimal scenario can then be proposed, for example displayed on a screen.
    In the example in Figure 1, F (Si) (= 50) is less than F (S2) (= 51). The profile of S2 is therefore optimal, S2 is the optimal scenario and the so-called "optimal" switching instant te * is therefore tB2.
    In a preferred embodiment, operations 5) to 7) are not carried out successively. The operations 5) to 8) are preferably carried out in the form of steps 5 ”) to 8”).
    More precisely, a first scenario is determined and its profile evaluated before determining a second scenario. The second scenario can thus advantageously be determined according to the evaluation of the first scenario.
    Preferably, the new residual treatment scenario is determined from the scenarios whose profiles have been evaluated previously. For example, if the two scenarios evaluated previously show that the increase in the duration of the arc phases degrades the score of the profiles with regard to the evaluation rule, for example because this rule is strongly influenced by a comfort coefficient, the new scenario will be sought among the scenarios presenting a total duration of the reduced arc phases.
    The search for an optimal scenario is thus considerably accelerated. All known optimization methods can be used. The search for the optimal scenario preferably carried out by means of a metaheuristic method, preferably evolutionary, preferably by simulated annealing, preferably by means of a method described in PCT / EP2015 / 074896.
    Steps 5 ”) to 8”) are particularly suitable when scenario creation and the evaluation of scenario profiles is automated in a simulator. Preferably, such a simulator is programmed in a calculation tool, for example a computer or the acquisition device, in which the evaluation rule has been programmed.
    A scenario simulator can be created from statistical analyzes of historical data. In particular, a statistical analysis of historical data can be used to simulate the effect of a determined orthodontic appliance on the positioning of teeth, but also to define a profile, for example a pain coefficient or a comfort coefficient for the residual treatment depending on the duration of the arc phases, or a full treatment cost depending on the durations of the arc and gutter phases.
    In a preferred embodiment, the method comprises a step 9) in which the optimal scenario and / or the optimal profile are presented to the patient, preferably on a screen, preferably on the screen of his mobile phone. Of course, the method can lead to the determination of several optimal scenarios. Preferably, all the optimal scenarios and / or optimal profiles are presented to the patient, preferably on the acquisition device used in step 3).
    If the patient is not satisfied, he can establish a new evaluation rule, for example by modifying the coefficients ki, and repeat the process in step 5 ’) or 5”).
    The optimal changeover point of the optimal scenario chosen allows the residual treatment to be precisely adapted to the patient's needs. In particular, it is possible to manufacture one or more gutters which can be used from this moment.
    As is now clear, the invention provides an effective means for optimizing mixed orthodontic treatment according to an evaluation rule. Advantageously, this evaluation rule can take into account many evaluation parameters, which makes it possible to respond precisely to the specific expectations of the patient. Finally, a method according to the invention can be programmed, in particular on a mobile phone. At any time, the patient can remotely carry out assessments of different scenarios and decide, therefore, on the moment of changeover. The method can be carried out as many times as desired, for example more than 1 time, more than 2 times, or more than 5 times per month.
    The number of orthodontist appointments is also advantageously limited.
    权利要求:
    Claims (12)
    [1" id="c-fr-0001]
    1. Method for determining an optimal tilting instant of a mixed orthodontic treatment of a patient's teeth, said method comprising the following operations:
    1) preferably at the start of treatment or before the start of treatment, production of a three-dimensional digital model of at least part of an arch bearing said teeth, or “initial reference model”, and for each of said teeth, definition of a digital three-dimensional reference model of said tooth in the initial reference model, or "tooth model";
    [2" id="c-fr-0002]
    2) after operation 1), preferably at the start of treatment or before the start of treatment, deformation of the initial reference model, by displacement of the tooth models, until said tooth models are in an objective positioning , so as to obtain an "objective reference model",
    [3" id="c-fr-0003]
    3) after operation 2), at an instant in a phase of treatment during which the patient is wearing an orthodontic appliance with arch and fasteners, known as “current instant”, acquisition of at least a two-dimensional image of said teeth, known as “ updated image ”, under actual acquisition conditions;
    [4" id="c-fr-0004]
    4) deformation of the initial reference model, by displacement of the tooth models, until said at least one updated image corresponds to a view of the initial reference model thus deformed, called "updated reference model", searching for the updated reference model preferably being carried out by means of a metaheuristic method, preferably evolutionary, preferably by simulated annealing;
    [5" id="c-fr-0005]
    5) determination, from said updated reference model and said objective reference model, of a plurality of residual treatment scenarios for moving said teeth from their position represented in the updated reference model to their position represented in the model of objective reference, each scenario comprising, from an instant of changeover, at least one phase of treatment using an orthodontic splint;
    [6" id="c-fr-0006]
    6) determination, for each scenario, of a profile comprising at least one value for an evaluation parameter chosen from the group formed by:
    - the duration of the residual processing of said scenario;
    - the duration of complete treatment;
    - a coefficient of clinical complexity or "severity score";
    - a pain coefficient for the residual treatment of said scenario,
    - a pain coefficient for the complete treatment;
    - the duration of the treatment phase (s) by means of an orthodontic archwire with arch and fasteners during the residual treatment;
    - a comfort coefficient for the residual processing of said scenario,
    - a comfort coefficient for the complete treatment;
    - a cost for the residual processing of said scenario,
    - a cost for the complete treatment,
    - a function of the previous evaluation parameters;
    [7" id="c-fr-0007]
    7) evaluation of each profile using an evaluation rule; and
    [8" id="c-fr-0008]
    8) determination, from the scenario with the optimal profile, or "optimal scenario", of an optimal tilting moment to replace the orthodontic appliance with arch and fasteners by a splint.
    2. Method according to claim 1, in which more than 50 scenarios are determined in operation 5).
    3. Method according to any one of the preceding claims, in which the operations 5) to 8) are nested so as to take place according to the following steps 5 ”) to 8”):
    5) determination, from said updated reference model and said objective reference model, of a residual treatment scenario for moving said teeth from their position represented in the updated reference model to their position in the objective reference model , a residual treatment scenario comprising, from an instant of changeover, at least one phase of treatment using an orthodontic splint, and, optionally, one or more phase (s) of treatment using a bow orthodontic arch and fasteners;
    6) determination, for said scenario, of a profile comprising at least one value for an evaluation parameter chosen from the group formed by:
    - the duration of the residual processing of said scenario;
    - the duration of complete treatment;
    - a coefficient of clinical complexity or "severity score";
    - a pain coefficient for the residual treatment of said scenario,
    - a pain coefficient for the complete treatment;
    - the duration of the treatment phase (s) by means of an orthodontic archwire with arch and fasteners during the residual treatment;
    - a comfort coefficient for the residual processing of said scenario,
    - a comfort coefficient for the complete treatment;
    - a cost for the residual processing of said scenario,
    - a cost for the complete treatment,
    - a function of the previous evaluation parameters;
    7) evaluation of the profile using at least one evaluation rule and, if the profile is not optimal with regard to the evaluation rule, determination of a new residual treatment scenario and resumption at the stage 6 ”);
    8) determination, from the scenario with the optimal profile, or "optimal scenario", of an optimal tilting moment to replace the orthodontic appliance with arch and fasteners by a splint.
    4. Method according to any one of the preceding claims, in which, in operation 3), the updated image is taken by means of an image acquisition device chosen from the group consisting of a mobile telephone, a connected camera, a smart watch, a tablet and or a personal computer, fixed or portable.
    5. Method according to any one of the preceding claims, in which operation 4) comprises the following steps:
    c) analysis of the updated image and creation of an updated map relating to discriminating information;
    d) optionally, determination, for the updated image, of coarse virtual acquisition conditions approximating the actual acquisition conditions of said updated image;
    e) search, for the updated image, of an updated reference model corresponding to the positioning of the teeth during the acquisition of the updated image, the research being preferably carried out by means of a metaheuristic method, preferably evolutionary , preferably by simulated annealing.
    6. Method according to the immediately preceding claim, in which step e) comprises the following steps:
    el) definition of a reference model to be tested as being the initial reference model then, e2) following the following steps, testing of virtual acquisition conditions with the reference model to be tested in order to finely approximate said conditions of actual acquisitions;
    e21) determination of virtual acquisition conditions to be tested;
    e22) production of a two-dimensional reference image of the reference model to be tested under said virtual acquisition conditions to be tested;
    e23) processing of the reference image to produce at least one reference card representing, at least partially, said discriminating information;
    e24) comparison of the updated and reference cards so as to determine a value for a first evaluation function, said value for the first evaluation function depending on the differences between said updated and reference cards and corresponding to a decision to continue or to stop the search for virtual acquisition conditions approximating said real acquisition conditions with more accuracy than said virtual acquisition conditions to be tested determined at the last occurrence of step e21);
    e25) if the said value for the first evaluation function corresponds to a decision to continue the said search, modification of the virtual acquisition conditions to be tested, then repeated in step e22);
    e3) determination of a value for a second evaluation function, said value for the second evaluation function depending on the differences between the updated and reference cards in the virtual acquisition conditions approximating at best said real acquisition conditions and resulting from the last occurrence of step e2), said value for the second evaluation function corresponding to a decision to continue or stop the search for a reference model approximating the positioning of the teeth during the acquisition of the image updated with more accuracy than said reference model to be tested used at the last occurrence of step e2), and if said value for the second evaluation function corresponds to a decision to continue said research, modification of the reference model to be tested by moving one or more models of teeth, then resumed at step e2).
    7. Method according to any one of the preceding claims, comprising a step
    [9" id="c-fr-0009]
    9) in which the optimal switching time, preferably the optimal scenario and / or the optimal profile, is presented on a screen.
    8. Method according to any one of the preceding claims, in which, in step 1), a digital three-dimensional reference model of a gum is defined from which said tooth models emerge, or "gum model", and , in step 4), said tooth models are moved and said gum model is modified to deform the initial reference model.
    9. Method according to the immediately preceding claim, in which to deform the initial reference model, a deformation of the gum model is calculated from said displacements of said tooth models.
    [0010]
    10. Calculation tool, preferably mobile phone, comprising a program comprising program code instructions for the execution of one or more, preferably all operations 3) to 8), when said program is executed.
    [0011]
    11. Calculation tool according to the immediately preceding claim, comprising a scenario simulator capable of creating scenarios, determining profiles of said scenarios and evaluating said scenarios with regard to an evaluation rule.
    [0012]
    12. Calculation tool according to the immediately preceding claim, comprising a
    5 "man-machine" interface and means for determining the evaluation rule from data entered with said interface.
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    同族专利:
    公开号 | 公开日
    US20180344430A1|2018-12-06|
    EP3410443A1|2018-12-05|
    FR3066903B1|2022-02-18|
    引用文献:
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    US20050026102A1|2000-12-29|2005-02-03|Align Technology, Inc.|Methods and systems for treating teeth|
    US20160228212A1|2013-09-19|2016-08-11|H 43 Development S.A.R.L|Method for monitoring the position of teeth|
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    法律状态:
    2018-05-02| PLFP| Fee payment|Year of fee payment: 2 |
    2018-12-07| PLSC| Publication of the preliminary search report|Effective date: 20181207 |
    2020-03-25| PLFP| Fee payment|Year of fee payment: 4 |
    2021-04-28| PLFP| Fee payment|Year of fee payment: 5 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1754755|2017-05-30|
    FR1754755A|FR3066903B1|2017-05-30|2017-05-30|METHOD FOR DETERMINING AN ORTHODONTIC TREATMENT|FR1754755A| FR3066903B1|2017-05-30|2017-05-30|METHOD FOR DETERMINING AN ORTHODONTIC TREATMENT|
    US15/990,950| US20180344430A1|2017-05-30|2018-05-29|Method of determining an orthodontic treatment|
    EP18175040.7A| EP3410443A1|2017-05-30|2018-05-30|Method for determining an orthodontic treatment|
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