Dental imaging device

Abstract

An imaging device including a support, a mouth retractor fastened to the support and defining a retractor opening and structure for fastening an image acquisition apparatus to the support in a position in which the acquisition apparatus is oriented so as to receive an image of the retractor opening.

Claims

1. An imaging device including: a support; a mouth retractor fastened to the support and defining a retractor opening; and a mechanism for fastening an image acquisition apparatus to the support in a position in which the acquisition apparatus is oriented so as to receive an image of the retractor opening, wherein the support takes the form of a box that is in communication with the outside via the retractor opening and via an acquisition opening through which the acquisition apparatus fastened to the support receives said image of the retractor opening, the support being configured so that the acquisition apparatus observes the retractor opening regardless of a configuration of said support, said mechanism being chosen from the group consisting of clip-fastening means, self-gripping strips of hook and loop fastener type, clamping jaws, screws, magnets, and complementarity of shape between the support and the acquisition apparatus, or consisting of a cover that may be clamped against the support.

2. The device as claimed in claim 1, in which said mechanism is magnetic and configured so that the acquisition apparatus may be fastened to the support in only one predetermined position.

3. An imaging kit including: an imaging device as claimed in claim 1; and an image acquisition apparatus that is fastened to the device in a position in which the acquisition apparatus is oriented to receive an image of the retractor opening.

4. The kit as claimed in claim 3, in which the imaging device includes a detection member and the image acquisition apparatus includes a detector that is configured to detect the detection member when the detection member is less than 20 cm from the imaging device.

5. The kit as claimed in claim 4, in which the detector is configured so as to detect the detection member only when the detection member is less than 20 cm from the imaging device.

6. The kit as claimed in claim 4, in which the detection member is positioned less than 5 cm from the edge of the acquisition opening.

7. The kit as claimed in claim 4, in which the detector includes a magnetometer.

8. The kit as claimed in claim 4, in which the detector is configured to trigger an execution of a computer program loaded on a processing module of the image acquisition apparatus in the event that the detection member is detected.

9. The kit as claimed in claim 8, in which the processing module is configured to acquire, in response to the detection of the detection member by the detector, one or more updated images, then analyze them to detect an incorrect positioning of the image acquisition apparatus and/or of the retractor and/or a poor illumination of the retractor opening and/or an unsuitable support length.

10. The kit as claimed in claim 4, in which the image acquisition apparatus transmits a message in response to the detection of the detection member by the detector, the message relating to the use of the imaging device and/or relating to the fastening of the acquisition apparatus and/or relating to the fastening of the dental retractor and/or relating to the timing of the updated images to be acquired.

11. The kit as claimed in claim 1, in which said fastening means include the detection member.

12. The device as claimed in claim 1, in which the support defines a closed chamber when the opening of the retractor and the acquisition opening are obturated.

13. The device as claimed in claim 1, in which the retractor includes lobes that are arranged so as to spread cheeks of a patient away from teeth of said patient.

14. The device as claimed in claim 1, including a light source that is oriented toward the retractor opening so as to illuminate teeth of a patient through the retractor opening.

15. The device as claimed in claim 14, in which the light source is configured so as to project, onto the teeth, through the retractor opening, a reference frame.

16. The device as claimed in claim 14, including a monitoring module configured to monitor properties of radiation emitted by the light source as a function of the luminous radiation received by the retractor opening.

17. The device as claimed in claim 1, in which the image acquisition apparatus has an objective and is positioned with respect to the acquisition opening so that said objective is maintained in the centre of the acquisition opening.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Additional features and advantages of the invention will become further apparent upon reading the following detailed description and from studying the attached drawing, in which:

(2) FIG. 1 shows, in perspective, a device according to the invention, seen through the side of the retractor;

(3) FIG. 2 shows, in perspective, a device according to the invention shown from the acquisition opening side;

(4) FIG. 3 shows an example of a composite image;

(5) FIGS. 4a, 4b and 4c show the device of FIG. 1 seen from above, seen from the acquisition opening side and seen from the retractor opening side, respectively;

(6) FIGS. 5a and 5b show the device of FIG. 2 with the support in retracted and deployed positions, respectively;

(7) FIGS. 6a, 6b and 6c show, in perspective (FIGS. 6a and 6b) and from above (FIG. 6c), the portion of the support of a device according to the invention on which a retractor may be mounted, as shown in FIG. 6b; and

(8) FIG. 7 show a kit according to the invention comprising a side view of an imaging device according to the invention.

(9) In the various figures, identical or analogous members have been denoted by the same references.

DETAILED DESCRIPTION

(10) Device

(11) The imaging device 10 shown in FIG. 1 includes a support 12, taking the form of an, optionally telescopic, box, a dental retractor 14, preferably at least one mirror 16, and fastening means 18 of an image acquisition apparatus 19, shown in FIG. 2.

(12) In one embodiment, the support 12 includes a male portion 12a and a female portion 12b that are mounted so as to slide one inside the other, along a retractor axis X, between retracted (FIG. 5a) and deployed (FIG. 5b) positions.

(13) In one embodiment, a scale is arranged on the male portion 12a of the support. Preferably, this scale provides indications facilitating the adjustment of the length, along the X axis, of the support 12, for example by bearing a mark for each type of image acquisition apparatus.

(14) The support 12 defines a chamber 20, the length of which along the X axis depends on the relative position of the male and female portions of the support 12 when the box is telescopic, or is constant.

(15) In one preferred embodiment, the box is not telescopic (FIG. 7). When the box is not telescopic, the distance between the retractor and acquisition openings is advantageously constant. The analysis of the updated images is facilitated thereby. Furthermore, this embodiment is advantageously simple, inexpensive and ergonomical.

(16) In the embodiment shown, the chamber 20 is in communication with the outside at two opposite end faces of the support 12, via a retractor opening 24 and an acquisition opening 26, respectively.

(17) The lateral wall 30 of the support 12, which extends between the two end faces, is preferably substantially cylindrical along the X axis, and preferably rectangular in cross section.

(18) In one embodiment, the support 12 is provided with a window through which light from the surroundings may reach inside the chamber 20 in order to illuminate the teeth.

(19) Preferably, however, the chamber 20 is only in communication with the outside via the retractor, opening and acquisition opening.

(20) The box thus composed may for example be made of plastic or of cardboard.

(21) The fastening means 18 are configured so that the image acquisition apparatus may be fastened in an acquisition position in which its objective faces the acquisition opening 26, or else obturates the acquisition opening 26.

(22) The means 18 for fastening the acquisition apparatus to the support 12 may be of any type. Preferably, they allow rigid fastening. Preferably, they can be reversibly deactivated, i.e. the user may fix the acquisition apparatus to, and dissociate the acquisition apparatus from, the support at will.

(23) Preferably, the fastening means 18 of the acquisition apparatus are chosen from the group consisting of clip-fastening means, self-gripping strips of Velcro type, clamping jaws, screws, magnets, and complementarity of shape between the support and the acquisition apparatus. In the embodiment shown in FIG. 2, the fastening means 18 consist of a cover that may be clamped against the support 12.

(24) In one embodiment, the fastening means 18 of the acquisition apparatus are suitable for fastening a conventional camera, for example of reflex type.

(25) Preferably, as shown in FIG. 7, the means 18 for fastening the acquisition apparatus are magnetic. In particular, one or more magnets 18.sub.1, 18.sub.2 may be provided on the support and one or more metal parts may be fastened to the image acquisition device so as to cooperate with the one or more magnets. In particular, a metal plate 32 may be held fast on the image acquisition apparatus, preferably sandwiched between the acquisition apparatus and a protective shell that is fastened to the acquisition apparatus.

(26) In one embodiment, the acquisition apparatus includes multiple metal parts and/or the support includes multiple magnets.

(27) Advantageously, it is therefore sufficient for the operator to bring the acquisition device close to the support for the acquisition apparatus to be fastened to the support. The use of magnetic fastening also allows very precise and reliable fastening, even when the operator is not looking at the support or the acquisition apparatus.

(28) Preferably, the means 18 for fastening the acquisition apparatus, and in particular the one or more magnets and metal parts, are configured so that the acquisition apparatus may be fastened to the support in only one predetermined position. The fastening of the acquisition apparatus therefore requires no particular training for the operator. Where appropriate, visual guides may be present to guide the operator and to ensure the correct positioning of the acquisition apparatus.

(29) The retractor 14 may have the features of conventional retractors. It conventionally includes a rim 34 extending around the retractor opening 24 and arranged in such a way that the patient's lips may rest on it, leaving the patient's teeth visible through said retractor opening. In the embodiment shown, the retractor 14 also includes lobes 36 that are arranged so as to spread the cheeks away from the teeth and right 38a and left 38b tabs, which are substantially perpendicular to the X axis, facilitating the handling thereof.

(30) The rim 34 has the shape of a channel configured to hold the patient's lips.

(31) The retractor 14 is preferably made of a biocompatible material, for example of a plastic material.

(32) The retractor 14 may be formed as an integral part of the support 12 or be fastened, preferably rigidly, to the support 12 by any means.

(33) Preferably, the retractor is removable, i.e. it may be mounted on and dismounted from the support by the operator. Advantageously, the same support may therefore be used for multiple retractors, and in particular for multiple retractors of different sizes.

(34) The means for fastening 15 the retractor to the support may be for example clip-fastening means, self-gripping strips of Velcro type, clamping jaws, screws, magnets, and complementarity of shape between the support and the retractor.

(35) In one embodiment, the retractor 14 is fastened by means of insertion of one of the right 38a and left 38b tabs into a compartment of the support, then clipping the other tab onto the support.

(36) In one embodiment, the retractor 14 is fastened by means of clipping the tabs into respective compartments of the support.

(37) In one preferred embodiment, illustrated by FIG. 6, the means for fastening 15 the retractor to the support include a hook onto which the retractor 14 may be hooked. The means for fastening 15 the retractor to the support preferably include a right hook 40a and a left hook 40b that are arranged so as to accommodate the right 38a and left 38b transverse tabs of the retractor, respectively. Since the right and left hooks are similar, only one hook is described in detail below.

(38) Preferably, said hook protrudes from the rear face 44 of the support, substantially perpendicularly to the X axis, as shown in FIG. 1. The rear face 44 is preferably defined by a plate 47 (FIG. 6a) that is fastened to an edge of the lateral wall 30 of the support 12.

(39) Preferably, the hook takes the form of an angle 45. The angle preferably includes first and second wings that are perpendicular to one another. The first wing 48.sub.1, fastened to the rear face 44 of the support, is preferably substantially parallel to the X axis and the second wing 48.sub.2 is preferably substantially perpendicular to the X axis and, preferably, extends upward from the first wing. Along with the rear face 44 of the support, the angle 45 defines a compartment with a U-shaped profile, the main, upward-oriented opening 46 of which is sized so as to accommodate a tab of the retractor. Again preferably, the profiled compartment is open at its two right and left ends via right 48 and left 50 openings through which a tab of the retractor may be slid into the hook, i.e. between the rear face 44 of the support and the second wing 48.sub.2 of the angle 45, until abutting against the first wing 48.sub.1.

(40) Preferably, the hooks are configured so that the retractor may be inserted therein only by force, preferably by elastically opening the hooks.

(41) Preferably, the hooks are configured so that the retractor may be inserted therein without being deformed, preferably by flexing around an axis Y that is substantially perpendicular to the X axis, preferably substantially vertical in the service position.

(42) Again preferably, in the position in which the retractor is mounted on the support, fastening means 15 hold the retractor flexed around the Y axis.

(43) In the embodiment of FIG. 6 (FIG. 6c), the axes Z.sub.a and Z.sub.b of the angles of the left and right hooks are thus inclined with respect to a transverse plane P that is perpendicular to the X axis, while the right and left tabs of the retractor are substantially coplanar when the retractor is at rest, dissociated from the support. The width of the main openings 46 of the right and left hooks is substantially identical to the thickness of the right and left tabs of the retractor, respectively, which obliges the operator to flex the retractor around the Y axis in order to insert these tabs into these hooks. The shape of the hooks then prevents the retractor from returning to its rest position.

(44) The elastic bearing of the retractor on the support thus obtained advantageously favors its being held in position.

(45) In one preferred embodiment, the device includes a light source 51 that is preferably oriented toward the retractor opening 24 (FIG. 5a) so as to illuminate the teeth of the patient through the retractor opening 24. The light source 51 may in particular emit white light, monochromatic light, infrared radiation or, preferably, ultraviolet radiation.

(46) The light source 51 may be a flash.

(47) The light source is preferably fastened to the box. It preferably comprises LEDs.

(48) In one embodiment, the light source 51 is configured so as to project, onto the teeth, through the retractor opening 24, a reference frame, preferably a laser grid.

(49) Advantageously, the representation of a reference frame on the images facilitates the determination of the shape of the teeth. A first estimation of the shape of the teeth is thus possible without implementing the method described in PCT/EP2015/074896.

(50) In one embodiment, threading is formed on the lateral wall 30 of the box, preferably on the lateral wall of the female part 12b of the box. The threading is preferably shaped so as to allow the support to be fastened to a camera tripod.

(51) In one embodiment, the device also includes an acquisition cover and a retractor cover, which covers are shaped so as to selectively obturate the acquisition opening and the retractor opening in order to facilitate the storage of the device. Preferably, the retractor cover is shaped so as to selectively obturate the retractor opening after dismounting the retractor.

(52) According to the first main refinement of the invention, the device includes a mirror 16.

(53) The mirror 16 is fastened to the inner face of the lateral wall 30.

(54) The mirror 16 is preferably planar.

(55) The number and the shape of the mirrors are not limiting. In particular, the mirror may be rectangular, spherical, oval, octagonal or hexagonal in shape.

(56) In the embodiment shown, mirrors 16 cover the entire inner face of the lateral wall of the chamber 20, at least in the female portion 12b of the support 12 and, preferably, also in the male portion 12a of the support.

(57) In one embodiment, the device includes four mirrors each positioned on one of the four faces of the lateral wall of the support, and in particular of the female portion 12b and, preferably, of the male portion 12a of the support. In one preferred embodiment, each mirror entirely covers the face of the support 12 over which it extends.

(58) The length of a mirror may be greater than 3 cm, greater than 5 cm and/or smaller than 30 cm, smaller than 20 cm, smaller than 15 cm, or smaller than 10 cm. The width of a mirror may be greater than 2 cm, greater than 3 cm and/or smaller than 10 cm or smaller than 8 cm.

(59) In the embodiment shown, the mirrors are fastened to the support, preferably definitively, for example by means of an adhesive.

(60) The mirror 16, preferably each mirror 16, preferably extends in parallel to the X axis. In the embodiment shown, the mirror 16 extend perpendicularly to one another, pairwise.

(61) The simultaneous presence of a mirror and of a light source 51 is particularly advantageous since it makes it possible to acquire images of the teeth that simultaneously show the reflection of the light source 51 off the teeth, but also the reflection of the fictive light source obtained by reflection of the light source 51 by the mirror. Analyzing the relative position of these reflections in the images advantageously makes it possible to roughly determine the orientation of the surface of the teeth returning them, as well as the position of this surface with respect to the acquisition apparatus.

(62) According to the second main refinement of the invention, the device includes a colorimetric calibration chart 52 and/or a translucence calibration chart 54 that is fastened to the support, preferably in the chamber 20, or to the retractor cover, or to the mouth retractor.

(63) The number and the shape of the calibration charts are not limiting. In one embodiment of FIG. 6a, the support bears for example three colorimetric calibration charts 52 and three translucence calibration charts 54.

(64) Advantageously, the colorimetric 52 and translucence 54 calibration charts make it possible, for each image, to correct hue errors specific to each image acquisition apparatus.

(65) The colorimetric 52 and translucence 54 calibration charts also advantageously make it possible to determine the exact colors and translucence of the teeth or of the gums, thereby allowing any variation in these properties to be detected.

(66) Preferably, the colorimetric 52 and translucence 54 calibration charts are fastened in proximity to the retractor opening, preferably at less than 5 cm, less than 3 cm, less than 1 cm from the retractor opening. Preferably, the colorimetric 52 and translucence 54 calibration charts are fastened substantially in the plane of the retractor opening, as shown in FIG. 6a.

(67) Preferably, the monitoring module 60 monitors the properties of the radiation emitted by the light source 51, preferably as a function of the luminous radiation received by the retractor opening. A light sensor may be provided, in proximity to the retractor opening, for the purpose of evaluating the luminous radiation received by said retractor opening.

(68) In one embodiment, the monitoring module 60 controls the power of the light source 51 so that more than 50%, more than 70%, more than 90%, or even substantially 100% of the intensity of the radiation received by the retractor opening comes from the light source 51.

(69) According to the third main refinement of the invention, the support takes the form of a box that is in communication with the outside substantially only via the retractor and acquisition openings. Advantageously, the influence of the outside environment on the box is limited, thereby allowing images to be acquired under constant conditions.

(70) Furthermore, when the device includes a light source 51, a closed box advantageously makes it possible to limit the power of the light source 51.

(71) Preferably, the total area of the openings other than the spacer and acquisition openings represents less than 10%, preferably less than 5%, preferably less than 1% of the area of the lateral wall of the box delimiting the chamber 20. Preferably, the box includes no such other openings.

(72) In one embodiment, the lateral wall delimiting the chamber 20 is formed or consists of a material that does not allow the content of the chamber 20 to be accurately discerned, including the arches of the patient when the device is in a service position in which a patient has placed his or her lips in the channels of the retractor. Advantageously, such a lateral wall specifically completely protects the user's privacy while acquiring the updated images.

(73) In one embodiment, the lateral wall is translucent.

(74) Preferably, the lateral wall is opaque. Advantageously, the inner volume of the chamber receives substantially no light from the outside, thereby guaranteeing constant conditions for acquiring updated images.

(75) Imagine Kit

(76) An imaging kit according to the invention includes an imaging device according to the invention and an image acquisition apparatus 19.

(77) The image acquisition apparatus 19 preferably provides color images, and/or infrared images. Infrared images advantageously make it possible to view the teeth with an excellent level of contrast.

(78) Preferably, the image acquisition apparatus 19 is a personal device commonly available on the market, for example a mobile phone, a connected camera, a smartwatch, a tablet or a fixed or portable personal computer, including an image acquisition system, such as a webcam or a camera, preferably a digital camera. It preferably weighs less than 3 kg, less than 2 kg, less than 1 kg, less than 500 g, preferably less than 300 g.

(79) The image acquisition apparatus 19 may be integrated within the support 12 or, preferably, be fastened temporarily to the support 12, by virtue of the fastening means 18 of the acquisition apparatus.

(80) In one preferred embodiment, the image acquisition apparatus includes a processing module 59 configured to guide the operator during the imaging operation, in particular so that he or she adjusts the length of the support 12 appropriately and/or so that he or she correctly positions his or her mouth on the retractor 14.

(81) In one preferred embodiment, the imaging device includes a detection member 70 that a detector 72 of the image acquisition apparatus may detect (FIG. 5a).

(82) Preferably, the detection member 70 and the detector 72 are configured so that detection is possible only when the imaging device is in the immediate proximity of the image acquisition apparatus. Advantageously, the image acquisition apparatus therefore does not react when the imaging device is remote therefrom. Preferably however, the detection member 70 and the detector 72 are configured so that the remote detection is possible, preferably at a distance that is greater than 5 cm, or even greater than 10 cm.

(83) Advantageously, the image acquisition apparatus may thus react very quickly.

(84) The position of the detection member on the support is not limiting. Preferably however, it is positioned less than 5 cm, preferably less than 3 cm, more preferably less than 2 cm from the edge of the acquisition opening. Advantageously, the acquisition apparatus is thus detected only when the image acquisition apparatus is brought close to the acquisition opening.

(85) In one preferred embodiment, the detection member is a magnet and the detector 72 of the image acquisition apparatus includes a magnetometer. A magnetometer is capable of detecting a change in the magnetic field surrounding it, and is therefore capable of detecting the approach of a magnet.

(86) Since mobile phones are generally provided with a magnetometer, the image acquisition apparatus is preferably a mobile phone.

(87) The detector 72 is configured so as to control the processing module 59, according to the detection of the detection member 70.

(88) In one preferred embodiment, the detector 72 triggers the execution of the computer program loaded on the processing module 59 in the event that the detection member 70 is detected. It is therefore sufficient for the operator to bring the image acquisition apparatus, preferably a phone, close to the support to be guided in his or her image acquisition operations. Such an embodiment advantageously allows an operator who has received no prior training to acquire images.

(89) Preferably, the image acquisition apparatus transmits a message in response to the detection of a detection member 70 by the detector 72. The message preferably relates to the use of the imaging device. Preferably, the image acquisition apparatus is configured to transmit messages relating to the fastening of the acquisition apparatus, for example by means of a voice message saying place your camera against the blue face of the support, and/or relating to the fastening of the dental retractor, for example by transmitting a voice message saying bend the retractor to fasten it onto the green tabs, and/or relating to the timing of the updated images to be acquired, for example by transmitting a voice message saying take three photos and send them to your orthodontist.

(90) The message may be purely informative. In one preferred embodiment, the message transmitted by the image acquisition apparatus depends however on the interactions between the operator and the image acquisition apparatus. For example, the image acquisition apparatus may transmit a message saying the camera is upside down/backwards or the camera is not oriented correctly or your lips are not correctly positioned in the retractor channel.

(91) The detection member and the detector thus facilitate the acquisition of updated images.

(92) Preferably, the detector 72 and/or the detection member 70 also play a role in fastening the image acquisition apparatus to the support. In particular, the detection member 70 is preferably a magnet 18. The use of a magnet that serves both to detect and to fasten the image acquisition apparatus is advantageously simple, inexpensive and very practical.

(93) Operation

(94) The operation of the kit is directly evident from the description above.

(95) It is described for the embodiment shown in FIG. 7.

(96) Initially, the metal plate 32 is preferably fastened to the image acquisition apparatus 19, in this instance under the protective shell of a mobile phone.

(97) As soon as the operator brings the image acquisition apparatus 19 close to the acquisition opening 26, the metal plate 32 is attracted by the magnets 18.sub.1 and 18.sub.2, and cooperates with these magnets to fasten the image acquisition apparatus in a predetermined position, suitable for acquiring updated images according to a predetermined framing. In particular, in this position, the objective of the image acquisition apparatus is correctly positioned with respect to the acquisition opening, preferably substantially in the center of the acquisition opening, and observes the inside of the chamber 20, in this position, the image acquisition apparatus 19 may observe both the direct image and the reflected image.

(98) Furthermore, on approaching the support, at least one of the magnets 18.sub.1 and 18.sub.2 of the support is detected by the magnetometer of the detector 72.

(99) As a result, the magnetometer automatically launches, i.e. without the intervention of the operator, the computer program loaded on the processing module 59 to guide to the operator in his or her operations.

(100) If the box is telescopic, the operator then adjusts the position, along the X axis, of the female portion with respect to the male portion 12a, according to the image acquisition apparatus 19 and its settings.

(101) The scale arranged on the male portion 12a of the support and bearing a mark for each type of image acquisition apparatus facilitates the adjustment.

(102) Preferably, the operator switches on the light source 51 so as to illuminate the teeth and to project the reference frame, in particular a laser grid, on the teeth.

(103) The operator also fastens the retractor to the support. In one embodiment shown, he or she inserts a first of the right and left tabs behind a first of the right and left hooks, respectively, then slightly bends the retractor in order to allow the second tab to be inserted behind the second hook. When the operator releases his or her action, the retractor attempts to return to its initial shape, but this return to the initial shape is hindered by the hooks. The pressure of the retractor on the support thus obtained ensures that the retractor is held in position behind the hooks.

(104) Preferably, the processing module 59 is configured to control the automatic acquisition of one or more updated images and analyze them to detect any incorrect positioning of the image acquisition apparatus and/or of the retractor and/or poor illumination and/or an unsuitable support length. More preferably, the image acquisition apparatus immediately informs the operator thereof so that he or she corrects the detected defects.

(105) A device according to the invention thus makes it possible to provide a predetermined positioning of the image acquisition apparatus with respect to the spread opening, and therefore facilitates the acquisition of updated images. It allows high-quality updated images to be obtained, in particular images that are substantially identical in size, framed in the same way and suitably sharp. The invention therefore facilitates the later analysis of the updated images.

(106) The patient, who may also be the operator, then places his or her lips in the channels defined by the rim 34 of the retractor. As shown in FIG. 3, the teeth of the patient are then clearly visible. The closed box advantageously masks the teeth, thereby protecting the patient's privacy.

(107) The device is then in a service position and the image acquisition apparatus 19 views a composite image I.sub.c of the type of that shown in FIG. 3. In this figure, the composite image includes a direct image I.sub.d and eight reflected images I.sub.r reflected by the various mirrors 16 positioned in the chamber 20.

(108) By actuating the trigger of the acquisition apparatus, the operator acquires the composite image I.sub.c. Advantageously, he or she simultaneously acquires, like in the embodiment of FIG. 3, a front view (direct image I.sub.d) and a set of oblique views (reflected images I.sub.r). Of course, the reflected images are inverted with respect to reality. For example, in the reflected image located above the direct image I.sub.d, the upper arch is shown below the lower arch.

(109) The reflected images may advantageously correspond to acquisition conditions in which the optical axis of the acquisition apparatus is strongly inclined with respect to the sagittal plane. Using the acquisition apparatus under these conditions, with direct observation, i.e. without a mirror, would often be difficult for the patient.

(110) The composite image is next transmitted to the processing module 59, by wired or wireless means, for example by Wi-Fi or by Bluetooth.

(111) Image processing makes it possible in particular, according to conventional processing methods, to isolate the direct image and the one or more reflected images. In one embodiment, the processing operation also includes an operation of inverting the reflected images and/or an operation of correcting perspective effects and/or an operation of correcting colors by means of the colorimetric calibration chart 34.

(112) Analyzing one of the direct and reflected images, preferably the direct image, makes it possible to determine the acquisition conditions of said image, preferably according to the teaching of PCT/EP2015/074896, incorporated by reference. The acquisition conditions of the other images may advantageously be deduced therefrom, simply by taking the geometry of the support 12 into account. In particular, the calibration of the acquisition apparatus is the same for all of the direct and reflected images. Additionally, simple geometric considerations make it possible to determine the position and the orientation of the acquisition apparatus in space which, in the absence of a mirror, would have allowed the acquisition apparatus to acquire a reflected image.

(113) In one embodiment, the processing module 59, preferably integrated within the image acquisition apparatus 19, controls the acquisition of multiple composite images under different acquisition conditions, and in particular with different focal lengths. For example, first, second and third composite images may be acquired by successively focusing the acquisition apparatus on the incisors, on the premolars and on the molars.

(114) Advantageously, each tooth is thus shown clearly in at least one of the composite images.

(115) In one embodiment, taking multiple successive images under different acquisition conditions is the result of a single actuation of the trigger of the image acquisition apparatus. In particular, the image acquisition apparatus may be configured to take multiple photographs in succession, with different focal lengths, as a result of a single trigger action.

(116) Furthermore, the acquisition apparatus preferably acquires an image of the teeth of the patient also showing the translucence and colorimetric calibration charts.

(117) The processing module 59, having knowledge of the real color and translucence properties of the calibration charts, then corrects the image until the representations of said calibration charts in the image have these properties.

(118) In order to make the correction accurate, the light source 51 is preferably adjusted so that, at the time of acquisition of the image, the calibration charts are illuminated under the same conditions as when measuring the real properties. Using a closed box makes it easier to control the illumination.

(119) All of the images acquired by the acquisition apparatus are thus advantageously comparable, regardless of the lighting environment outside the device at the moment of their acquisition.

(120) As is now clearly apparent, the invention significantly facilitates the analysis of the updated images.

(121) A device according to the first main refinement advantageously makes it possible to acquire multiple images very quickly, typically in less than a minute, without recourse to a specialist, in particular to a dentist or an orthodontist. The images may in particular be acquired by the patient him- or herself or by one of his or her kin, using a simple mobile phone, anywhere, and in particular outside of any medical, dental or orthodontics practice.

(122) In addition, if the geometry of the support, and in particular the orientation and the positioning of a mirror, is known, it is enough to determine the acquisition conditions of the direct image in order to be able to determine, by way of simple calculation, the acquisition conditions of the image reflected by this mirror. The implementation of the method described in PCT/EP2015/074896 is considerably accelerated as a result.

(123) Lastly, since the acquisition apparatus 19 is immobile with respect to the teeth, the composite image is advantageously clear and, if the device includes a controlled light source, exhibits good contrast.

(124) A device according to the second main refinement makes it possible to track variation in the properties of the appearance of the teeth. It also makes it possible for the patient himor herself to accurately measure these properties at any time, and in particular shortly before a prosthesis is produced, for example. The appearance of the prosthesis is thus particularly close to that of the teeth of the patient.

(125) A device according to the third main refinement facilitates the control of the illumination during the acquisition of updated images and allows the patient's privacy to be protected.

(126) A kit according to the invention substantially facilitates the use of an imaging device according to the invention. In particular, it makes it possible, in one preferred embodiment, to automatically guide the user in his or her operations. The quality of the updated images is advantageously improved thereby.

(127) Of course, the invention is not restricted to the embodiments described and shown, which are provided for illustrative purposes only.

(128) In particular, the shape of the box is not limiting.

(129) Furthermore, although this embodiment is not preferred, the fastening of the image acquisition apparatus may employ one or more magnets that are fastened to the image acquisition apparatus and one or more metal parts that are fastened to the support.

(130) The metal parts of the means for fastening the image acquisition apparatus may also be replaced, at least partially, with magnets that are arranged so as to attract the magnets fastened to the support.

(131) The mirror is not necessarily planar. It may in particular be configured to compensate for perspective effects and/or to reflect particular regions of the mouth.

(132) The mirror may be movable with respect to the support, and in particular may be translatably movable, in particular to make it possible to modify the distance between the mirror and the retractor opening and/or the acquisition opening.

(133) The mirror may also be rotatably movable, in particular about an axis of rotation that is perpendicular to the X axis of the retractor, two axes being referred to as perpendicular when two planes that are orthogonal to these axes are perpendicular to one another.

(134) Preferably, the image acquisition apparatus includes an app configured to guide the operator so that he or she correctly positions and orients the mirror. In one embodiment, the positioning and/or the orientation of the mirror are facilitated by a scale bearing indications relating to various acquisition apparatuses. The operator may thus easily position the mirror according to the acquisition apparatus used.

(135) In one embodiment, the device includes one or more actuators that are suitable for adjusting the length of the support and/or the positioning and/or the orientation of the mirror according to setpoints, preferably according to setpoints received from the image acquisition apparatus 19.

(136) In one embodiment, the device also includes one or more sensors configured to measure the length of the support 12 and/or the positioning and/or the orientation of the mirror, and a transmitter capable of transmitting said measurement to the image acquisition apparatus.

(137) Advantageously, the device may be optimally configured by controlling the actuators according to a setpoint, preferably provided by the image acquisition apparatus, said setpoint preferably being based on the image observed by the image acquisition apparatus and/or by the measurements taken by the sensors.

(138) In addition, the number of mirrors is not limited and multiple mirrors, preferably all of the mirrors, preferably have one or more of the preferred features of the mirror 16 described above. In particular, one or more of the mirrors may be provided with a sensor, with an actuator and with means for communicating with the image acquisition apparatus, as described above.