Abstract: The purpose of the present invention is to develop an apparatus that can examine the occlusal contact patterns during the sleep bruxism, which can not be evaluated by the observation of the interior of oral cavity or by means of the articulator, in order to establish a convenient evaluation means for employing bruxism in daily and clinical diagnosis. The present invention relates to a bruxism evaluation sheet having a layer comprising an aqueous solution composition of an organic solvent comprising a dye and a thermosetting resin on a base sheet made of a thermoplastic resin, and a method for producing a convenient bruxism evaluation apparatus comprising heating the bruxism evaluation sheet, vacuum pressing it onto a model and then molding, and the like.

Abstract: A system and method for determining condyle displacement during jaw articulation includes a physical model with corresponding reference points. The physical model is positioned and scanned to obtain positional data representing a first and second bite position. This positional data is used to generate a transformation matrix. The position of at least one condyle is determined in reference to positional data scanned from the physical model. The transformation matrix is used to map the position of the condyle with respect to the second bite position.

Abstract: A method for bite-setting computer models of teeth on a first jaw and a second jaw includes determining an initial position of the first jaw; and determining an optimal bite based on the initial position of the first jaw.

Abstract: An oral appliance having upper and lower channel elements attached, respectively, to upper and lower bite blocks. The two channel elements are oriented at a right angle with respect to each other. One of the channel elements carries a removable insert having an array of adjustment holes. A removable coupling member has a support rod with an anchor piece and anchor pin at one of its ends. The anchor piece is received by the channel element carrying the insert, while the anchor pin is received by one of the insert's adjustment holes. A base at the other end of the support rod is received by the other channel element, so that the coupling member may releasably connect the two channel elements together.

Abstract: A tracing device for use in the mouth cavity can include an upper jaw plate, a lower jaw plate, and a coupling tool that connects the above jaw plates. The upper jaw plate can be provided with a guide prop stud, a stud installation pore, a tracing pin, a tracing pin installation pore as well as an auxiliary stud. The lower jaw plate can include a guide tracing table, a connection pore, as well as a movement line formation table. Different structures can be made of a magnetic material or associated with a magnet. A lower jaw inducement guide plate can be made of plastic and have three dimensional slopes, and a guide tracing table can have a tracing plate, and can be freely attachable/detachable to/from the main body of the lower jaw plate.

Abstract: To provide a chewing evaluation method capable of easily measuring chewing by an easy method without using a special expensive apparatus, together with a chewing determination kit, the chewing determination kit comprises testing food which contains ascorbic acid, an ascorbic acid derivative, and/or ethanol as detection components, and an indicator reacted with the components, based on a fact that there appears a difference in a leaching out state of components for chewing determination depending on a chewing degree when testing food containing the components for chewing determination is used as a factor which is necessary for chewing determination in a wide sense but lacks in the conventional chewing determination method.

Abstract: An apparatus for use in dentistry to obtain positional data related to movement of a mandible about a maxilla comprises a rigid support frame for supporting a maxilla support member, a positionable mandibular member and sensing assemblies. The support member fixedly attaches to the support frame. The mandibular member is positionable proximate the maxilla member. The sensing assemblies attach to the support frame and connect to the mandibular member to obtain positional data related to the movement of the mandibular member. The positional data is collected by a computing device and stored in a data storage medium as time history files. The files can then be transformed into usable information to replicate the mandibular movement in real time either virtually or mechanically.

Abstract: An apparatus to replicate and analyze movement of a mandible relative to a maxilla with dental casts thereof includes a base frame, an arm connected to the base frame and a suspension assembly positionable by a plurality of electro-mechanical actuators. The arm connects to the base frame and supports the dental cast of the maxilla in a fixed position relative to the base frame. The suspension assembly, having opposing first and second sides, supports the dental cast of the mandible in working relation to the dental cast of the maxilla. The plurality of actuators each selectively impart movement to the sides of the suspension assembly such that the movement of the mandible obtained during a recording process can be replicated on the apparatus in real time.

Abstract: A system and method for determining condyle displacement during jaw articulation includes a physical model with corresponding reference points. The physical model is positioned and scanned to obtain positional data representing a first and second bite position. This positional data is used to generate a transformation matrix. The position of at least one condyle is determined in reference to positional data scanned from the physical model. The transformation matrix is used to map the position of the condyle with respect to the second bite position.

Abstract: A computer implemented method includes providing a first set of digital data corresponding to an upper arch image of at least a portion of an upper dental arch of a patient, providing a second set of digital data corresponding to a lower arch image of at least a portion of a lower dental arch of the patient, providing bite alignment data representative of the spatial relationship between the upper dental arch and the lower dental arch of the patient, and aligning the upper and lower arch images relative to one another based on the bite alignment data until an aligned upper and lower arch image is attained. The aligned upper and lower arch images are moved towards each other until a first contact point is detected and at least one of the upper and lower arch images is moved relative to the other in one or more directions to a plurality of positions for determining optimal occlusion position of the lower and upper dental arches.

Abstract: A dental bite configuration recording device comprises an upper base, a lower base, a first biting portion, a second biting portion, and a movable guiding portion. After the user's lower jaw moves to the front, to the left and to the right respectively, these guiding rods of the movable guiding portion will move or slide along the corresponding guiding recessed surfaces of the guiding recessed blocks. And, these recording rods will leave the three-dimensional moving paths on the path recording materials. So, this invention has multiple-positional and three-dimensional bite configuration recording. The guiding recessed blocks are replaceable. And, It will not yield the tongue of the user.

Abstract: A system arranges a computer model of teeth by displaying an outline of the first jaw on the screen; overlaying the teeth on the second jaw with the outline on the screen; and aligning the outline with the teeth on the second jaw.

Abstract: A system for simulating an orthognatic surgery action, including an X-ray scanner, a device of three-dimensional localization of relative positions of dental castings, each associated with a unit locatable in position and orientation by the localization device, and an image processing system for combining tomographic images provided by the scanner with positioning data provided by the localization device to obtain three-dimensional images.

Abstract: The invention concerns a fast transfer yoke for the cranium-calculated transfer of a maxilla plaster model from a patient into a dental articulator as well as for the recording of axis-related individual mandibular joint geometry of the patient in question. The invention is to create a fast transfer yoke that, with easy handling, facilitates fast recording of patient data, i.e., of the mandible movements as well as of the patient axis and their transfer into a dental articulator or to an mounting apparatus.

Abstract: A bite registration appliance includes an upper base plate and a two-piece lower plate, one carrying a tracing stylus and the other carrying a tracing plate, for making a Gothic arch tracing in a patient having natural dentition without interfering with the patient's bite. One embodiment is arranged to fit within the arches, engaging undercut areas of the lingual sides of the arches, the lower plate being formed by two members that are movable laterally about a slot to engage extension wings against the inner sides of the mandible. In the second embodiment, both the maxillary and mandibular plates are two-piece units, each having a pair of arcuate extension arms that clamp around the lingual side of the patient's dental arches. The extension wings or arms in both embodiments fit loosely against a typical patient's archform and then custom fitted to the patient by trimming and molding a self-curing acrylic to the extension wings or arms.

Abstract: A computer implemented method of creating a dental model for use in dental articulation includes providing a first set of digital data corresponding to an upper arch image of at least a portion of an upper dental arch of a patient, providing a second set of digital data corresponding to a lower arch image of at least a portion of a lower dental arch of the patient, and providing hinge axis data representative of the spatial orientation of at least one of the upper and lower dental arches relative to a condylar axis of the patient. A reference hinge axis is created relative to the upper and lower arch images based on the hinge axis data. Further, the method may include bite alignment data for use in aligning the lower and upper arch images. Yet further, the method may include providing data associated with condyle geometry of the patient, so as to provide limitations on the movement of at least the lower arch image when the arch images are displayed.

Abstract: In a jaw movement simulator in which an upper jaw model patterned after an upper jaw and a lower jaw model patterned after a lower jaw are mounted, and the lower jaw model is relatively moved with respect to the upper jaw model. A jaw movement simulation system causes the jaw movement simulator to reproduce a movement of the jaw of a test subject in accordance with data obtained through imaging a movement of the jaw of the test subject. The lower jaw model is fixed on an operating plate having 6 degree of freedom by parallel mechanism, and is moved on the basis of data obtained through a movement of the jaw of the human body, thereby simulating a movement of the jaw with great accuracy.

Abstract: A jaw tracking device, which fits entirely in the mouth and can be attached to conventional removable dental appliances, tracks the location and movement of the lower jaw with high precision and speed when the mouth is closed or nearly closed by recording the projection of light from a light emitting diode, laser diode, or fiberoptic source fixed to the lower dental arch onto one or two position sensitive detectors (PSDS) fixed to the upper dental arch. Since the system acquires data quickly enough to record the minute deflections of the lower jawbone which occur each time the jaw is closed eccentrically, it can be used with acoustic sensors attached to the individual teeth in order to analyze a person's bite. Since each PSD relies on only four outputs, its data can be easily transmitted by telemetry so that it can be used to track the location of the jaw during sleep without requiring wires protruding from the mouth of the sleeping subject.

Abstract: This invention consists of a method and apparatus which establish specific central and vertical dimensions and positions for patterns for the making of dentures which will provide a natural occlusion upon replacement of natural teeth.

Abstract: A simulation method of jaw movement comprising:a superimposing process step of reading dentition configuration data and jaw movement data, calculating a coordinate transformation matrix for matching a coordinate system of the dentition configuration data with a coordinate system in a jaw movement basic state in the jaw movement data, and transforming the dentition configuration data to coordinates on the coordinate system in the jaw movement basic state to obtain superimposed dentition configuration data; anda simulation process step of calculating superimposed dentition configuration data in another jaw movement state and superimposedly displaying a dentition configuration diagram obtained by converting the superimposed dentition configuration data to an image and a jaw movement state diagram obtained by converting the jaw movement data to an image.

Abstract: The jaw of a person and a model thereof is represented with a series of steps. A device for positional determination, which has marking points, is inserted into the oral cavity of the person, at least one picture of the jaw of the person is taken with an imaging process, such as X-ray, CT, MRI or the like, including the marking points in the picture. The picture is stored as a data set and the marking points are identified. After an impression is taken of the jaw, a model is created. The representation itself includes the following steps: a further 3D sensor is brought to the model of the jaw. Next, the device for positional determination is reinserted into the model of the jaw in the same position as when the picture was taken. The positional relationship is determined between a 3D sensor on the device and the 3D sensor on the model of the jaw. After the device has been removed, a further 3D sensor is brought to the model of the jaw and inserted in the same position as when the picture was taken.

Abstract: The present invention is concerned with apparatus and methods in the field of dentistry and in the field of design and testing of dental fixtures, components and materials. The apparatus comprises a jaw model having a mandible and a maxilla; a loading mechanism, coupled to the jaw model, for imposing an occlusal force on the mandible and maxilla; a mechanism(s), coupled to the mandible of the jaw model, for moving the mandible relative to the maxilla; and a load or force sensing device for sensing occlusal forces on the mandible and the maxilla of the jaw model. The mandible is caused to move laterally and protrusively using electric motors. A strain gauge meter may be coupled to the load sensing device, for measuring and displaying the forces sensed by the sensing device. A digital processor may also be employed for storing and recording the forces measured by the meter.

Abstract: A method and device for developing the ability to demonstrate graded jaw closure and repetitive, rhythmical mandibular movement over an improved range of motion in those suffering from limiting oral motor dysfunction. The method begins with providing an embodiment of the inventive device. Essentially, the inventive device may be comprised of a non-nutritive, non-toxic and elongated biting portion comprised of a yieldable and resilient tube which has a given effective lateral thickness and is adapted to be received between an upper and a lower biting surface of an orally dysfunctional person's mouth and a handle position securely connected to the biting position for enabling manipulation of the device from a position external to a user's mouth. Next, the orally dysfunctional person is instructed and, if necessary, assisted in holding the biting position of the device between the person's biting surfaces for progressively greater length's of time.

Abstract: A dental recording apparatus for recording the movements of the jaw joints in relation to the skull includes (A) an adjustable upper recording bow which is secured on the bridge of the nose, the top of the skull and the sides of the head and which has a nose bridge support, vertical frame, rubber strap and positioning units or measuring/recording plates, and (B) a lower recording bow. The apparatus permits an exact positioning of the apparatus on the head of the patient, both in terms of an exact positioning of the upper recording bow and also of the lower recording bow.

Abstract: An apparatus and method for producing a gothic arch tracing representative of the natural range of motion of a patient's mandible. The apparatus consists of a kit including a mandibular bite rim having a tracing plate; a maxillary bite rim having a tracing arm; and a stylus releasably connectable to the tracing arm for extending between the tracing arm and the tracing plate externally of the patient's mouth. The stylus has a marker on one end thereof for drawing a gothic arch tracing on a removable paper substrate, such as a post-it note, attachable to the tracing plate. The tracing is used in the fabrication of a dental bite registration mold for the patient. The mold may in turn be used to mount casts of the patient's dentition in a specific relationship as required for prosthetic or therapeutic purposes.

Abstract: The invention relates to a device and method for confirming bite registration for dental implants. The device has an elongated plate having one or more openings formed at an angle to a longitudinal axis of the plate. A hollow post has an exterior wall corresponding in size and shape to the openings in the plate so as to fittingly slide through a selected plate opening. An inner aperture in the post is suitable for engaging with a portion of the dental implant that extends above the healed gumline of a patient. When the post is engaged with the implant, and the plate is placed over the post, an outer surface of the plate is oriented in a substantially parallel relationship to an occlusal plane. The post and the plate are secured together to register orientation of the dental implant in relation to the occlusal plane.

Abstract: A method and apparatus are disclosed for exercising small joints such as the temporomandibular joint connecting the upper and lower jaws, fingers and toes of a user and for toning jaw muscles of the user. First and second members coupled together so that at least one of the members is movable relative to the other member. An expandable and contractible fluid reservoir is positioned between the first and second members so that the first and second members will move relative to each other as the expandable and contractible reservoir expands and contracts. At least one of the members is then positioned to exercise the joint, specifically to exercise the jaw. To use the apparatus, the user places the first and second members gently into the mouth and then squeezes a fluid source connected to the expandable and contractible reservoir to expand and contract the reservoir thereby moving the jaws or joint to be exercised.

Abstract: A method and apparatus for tracking, recording and analyzing a subject's jaw motion is provided. Cross-haired targets are non-intrusively fixed in relation to the subject's upper and lower jaws. Three video cameras are disposed about the subject's head, each camera lens being focused on the targets. Each video camera is equipped with a charge control device chip which includes an array of light sensitive pixels defining a two dimensional image coordinate system. The charge control device chip converts a light image indicative of a target's cross-hair position into a series of amplitude signals. A computer is used to receive, process and display said camera chip amplitude signals. The computer includes a pre-processor board for timing, synchronizing and transforming said camera chip amplitude signals into address record information representing the targets' relative positions as a function of time.

Abstract: A device for intraoral determination of the two-dimensional mandibular moent and of the jaw closing force has a supporting pin carrier arrangement (3) which can be inserted in one jaw (2) and a carrier arrangement (10) which holds a counter plate (11) is mounted in a three-point mounting on a force sensor (14,15) connected to the carrier arrangement (10) and is arranged in a statically determined position.

Abstract: An intraoral appliance to be worn for the diagnosis and treatment of temporomandibular joint dysfunction. The appliance has upper and lower members which fit respectively on the person's maxillary and mandibular arch. The lower member has an upward projection which makes low friction gliding contact against a smooth surface located anteriorly on the upper member. This maintains vertical clearance between the maxillary arch and the mandibular arch and ensures free horizontal movement of the mandible to allow it to assume a position wherein the masticatory muscles are allowed to relax. Wearing the appliance for a period of time relieves the symptoms of acute and/or chronic headaches which result from temporomandibular joint dysfunction.

Abstract: For static fixation of the jaw relation in intraoral recording, a recording instrument set is used that includes a pin holder with a vertically adjustable stylus for placement in one jaw, and a writing or recording plate with an alignment clamp mounted on it for placement in the other jaw. The stylus, initially vertically locked on the pin holder, can be locked in stationary fashion in the ascertained jaw relation in the alignment clamp. By means of this locking, the jaw relation is keyed, and the use of hardenable material such as molding plaster previously used for this purpose can be dispensed with. This dental treatment process can thus be done in less time and with less material, and once the jaw relation has been keyed it is retained reliably until further processing in the dental laboratory. This locking can be attained particularly advantageously if a pan bearing that receives the lower end of the stylus, embodied as a writing ball, is provided in the alignment clamp.

Abstract: To make Gothic tracings, a Gothic scribe comprising a movable member adapted to be mounted by a universal joint to wing members in a plurality of different angles with respect to the wing members and a scribe vertically adjustable with respect to and mounted to the movable member are adjusted with the wing members, and the movable member is locked in the same plane to measure the vertical opening by moving the scribe up to a striking plate and then used to measure the centric relationship. After proper adjustment, another measurement is made with the base plates in place and the movable member unlocked to permit movement. The base plates are locked in place after the jaws have been relaxed with the point of the scribe in the centric relationship and used to make the denture.

Abstract: A method and apparatus are disclosed for exercising small joints such as the temporomandibular joint connecting the upper and lower jaws, fingers and toes of a user. First and second members are coupled together so that at least one of the members is movable relative to the other member. An expandable and contractible fluid reservoir is positioned between the first and second members so that the first and second members will move relative to each other as the expandable and contractible reservoir expands and contracts. At least one of the members is then positioned to exercise the joint specifically to exercise the jaw, the user will place the first and second members gently into the mouth and then squeezing a fluid source connected to the expandable and contractible reservoir to expand and contract said reservoir thereby moving the jaws or joint to be exercised.

Abstract: Simultaneous measurement of a border position of a mandible joint opening and the "end-feel" force required to achieve the border position are effectuated through a single apparatus which applies a force to the upper and lower jaw of a patient and continuously measures the degree of opening of the jaw as the mandible joint opens. When a predetermined amount of force is achieved as measured by either a detected degree of spring compression within the device or release of a detent mechanism, the force is automatically or manually withdrawn leaving an indicator showing the maximum jaw opening. Simultaneous border position and "end-feel" force can also be measured in alternative embodiment through reverse scissors and a mechanical dial and slider for continuously measuring the degree of opening while an electrical transducer measures the force applied until the "end-feel" force has been achieved as digitally read out.

Abstract: A device for determining mandibular motion wherein three light emitting diodes at the vertices of a triangle are temporarily fixed to teeth of the subject, the light emitting diodes are sequentially energized, and two sensors responsive to the light emitting diodes are mounted on a headpiece applied to the head of the subject and are trained on the light emitting diodes.

Abstract: A mandibular movement measuring device for measuring the angular movment of the mandibular incisal edge between the mandibular closed position and the maximum mandibular open position and for measuring mandibular deflection and deviation between the mandibular closed position and the maximum mandibular open position.

Abstract: A training device for therapeutically exercising a protruding mandible of an edentulous individual to reposition the same to an optimal position. The training device is part of a total system for fitting an edentulous individual with dentures that includes first repositioning the mandible to its optimal position using the training device, and then maintaining the repositioned mandible in place using dentures having a concave masticating surface and a ridge along one edge of the masticating surface.

Abstract: A method for constructing dentures which completely accommodate a patient's mandibular movements is provided. The method includes the steps of mounting a three dimensional recording device to the patient's jaws and forming intra-oral tracings of the patient's mandibular excursions and a Gothic arch tracing of the patient's mandibular excursions. The recordings and the tracing are utilized to mount upper and lower denture bases in a dental articulator, which also forms a part of the present invention, and to calibrate the articulator to precisely duplicate the patient's mandibular movements. Teeth are mounted on the upper and lower denture bases and ground to provide dentures which completely accommodate the patient's mandibular movements.

Abstract: An apparatus for producing a desired balanced vertical jaw closure in a human mouth. First and second platform members, each capable of being respectively mounted in a fixed, known relation on the upper and lower jaws in spaced, vertically aligned juxtaposition are provided. A closed-air cell spacer member is connected between the platform members for providing an adjustable isometric pressure resistance against vertical closure of the jaws. A selectively movable piston action pin member is also connected between the platform members for selectively controlling the rest-close vertical relationship desired between the mounted platform members to protect against overclosure and damage to the ear canal and blood circulation to the cranium.

Abstract: A device for determining optimum jaws position when full denture is prepared, comprising a height adjustable means to be inserted between upper and lower jaws and a means for detecting and indicating biting pressure applied on the height adjustable means. User of the device, e.g. a denter, can precisely determine the optimum jaws position by detecting a position where the maximum biting pressure is obtained by means of the device.

Abstract: Upper and lower frames of jaw movement analyzing apparatus is disclosed. A segmented clamp interconnects the side arms of the lower frame to a forward transverse rod in a manner to simplify locating the jaw hinge axis. The clamp includes a screw for gripping the rod with two of the clamp segments for maintaining the arms in adjusted angular positions while permitting further easy adjustment. The clamp also includes separate ball screws engaging a side arm to maintain axial positioning of the arm and permitting further easy adjustment. A lock screw extends through the clamp segments to lock the arms in the located hinge axis position.

Abstract: A process and apparatus for three-dimensional determination of the relative movement between the upper and lower human jaws by affixing at least one reference element to each of the jaws, one of the reference elements having four spatially staggered reference marks and the other having at least three spatially staggered reference marks. The position of each reference marks is optically detected along at least two viewing axes. The relative movement of the jaws is then determined from the change in the mutual position of the reference marks.

Abstract: A method and apparatus for monitoring, storing and displaying movements of a person's mandible in relation to the cranium, comprises a plurality of infrared LED's securely mounted to the cranium and to the jaw, in immovable relation to the mandible. The location of each LED, as determined by photodiodes as the LED's are sequentially turned on and off, is compared against an established three dimensional system frame of reference and through distinct local frames of reference associated with the cranium and the jaw, respectively, within the system frame of reference. A pointer, also provided with LED's is used to locate specific points on the mandible in reference to the movement described by the LED's attached to the lower jaw. The data is collected, calibrated and stored by a computer for subsequent display and analysis, either alone or in conjunction with a video display of the person's actual head and jaw as the data was taken.

Abstract: An improved analog preprocessor for a jaw tracking device having a plurality of magnetic sensors (44), each of which produces a first analog signal corresponding to the position of a magnet fixed with respect to the patient's mandible. The preprocessor includes analog means (200) for electrically combining the first analog signals to produce at least one analog position signal representing the position of the magnet along one axis, a gain select circuit (302) for providing a gain select signal, a variable slope ramp generator that provides a ramp signal having a slope corresponding to the gain select signal, a comparator for comparing the position and ramp signals and generating an output pulse having a length corresponding to the magnitude of the position signal, and a low pass filter for receiving the output pulse and producing an analog movement signal having a magnitude corresponding to the pulse length.

Abstract: An apparatus for measuring the location and attitude, as well as, locational and attitudinal changes of a rigid body in space has a transmission system which is composed of at least three current-permeated elements arranged at right angles relative to one another and supplied with different operating frequencies by an alternating current generator. The alternating magnetic field thereby generated are received by a plurality of magnetic field sensors arranged perpendicular to one another. The magnetic field sensors are attached to the rigid body. An evaluation electronic instrument separately evaluates the signals obtained from the three different alternative fields and converts them into quantities corresponding to the position to at least one point of the body. The magnetic field sensors are preferably magnetic coils which are arranged perpendicular to one another on a coil body of non-ferromagnetic material.

Abstract: Disclosed herein is a device for the representation of condylar movements of a patient and their correct simulation which includes models of sets of teeth to determine the required corrections to the biting surfaces in order to obtain ideal occlusion. The device includes an articulator with the lower part thereof able to be brought into a predetermined three-dimensional relation with respect to an upper part of the articulator and having two blocks having guide elements on the lower part of the articulator to support condyle balls of the upper part of the articulator. The device further includes a lower jaw recording bow and an upper jaw recording bow which can be brought into an active and predetermined relation with respect to the articulator and which disposes of at least three recording plates with corresponding recording pins as well as positioning spoons for the combination of a lower jaw dentition model.

Abstract: A magnetic field sensor for use in a jaw tracking device. The sensor includes a Hall effect generator (110) and a pair of flux concentrators (112, 114). The Hall effect generator has first (116) and second (118) sensing faces disposed on opposite sides of the generator. Each flux concentrator comprises a strip of concentrator material formed into a U-shape, with a pair of opposed, mutually parallel side members (120, 122, 130, 132) interconnected at one end by a cross member (124, 134). The generator and flux concentrators are positioned such that the cross members are adjacent and parallel to the respective sensing faces, with the side members extending away from one another in a direction normal to the sensing faces. The sensor also preferably includes a metal-filled adhesive (140) having a high thermal conductivity bonding each cross member to its respective sensing face.

Abstract: The apparatus comprises a first holder (10) fixed stationarily relative to the upper jaw to the patient's head, and a second holder (16) which is secured to the lower jaw. The second holder contains a number of distributed transmitters (S1, S2, S3) which successively supply stepwise ultrasonic pulses. A supplied ultrasonic pulse is successively received by all of the receivers (E1, E2, E3) of the other holder (10). By the transit times, the distances between the receivers and the activated transmitter may be noted. Changes of the sound velocity are detected by a reference path (S4R, E3; S3, E4R) and used for the correction of the transit time signals. By means of an additional, freely movable holder which also carries a number of transmitters and which contains a scanning tip, the position, data of individual teeth or of other points of the mouth may be imputted into the computer.

Abstract: An apparatus for measuring the three-dimensional position and attitude of upper and lower clutches attached on patient's maxillary and mandibular teeth for computerized measurement of the mandibular movements necessary for the fabrication of dental prostheses is disclosed. The apparatus includes a part of a sphere that is fixed to the mandible and which is marked with a reference line and a part of another sphere of substantially the same radius as that of the above sphere, which is fixed to the maxilla and which is also marked with a reference line. The surfaces of the two spheres are caused to slide against each other, with their centers being in alignment, thereby achieving the measurement of the relative attitude of the two spheres.

Abstract: In an exemplary embodiment, one or more flux pickups with ferromagnetic properties, preferably Hall generators provided with antennas, are provided for the detection of a field flux or of a change of field flux proceeding from a field generator. Magnetization pulses (I.sub.2) are provided in periodic sequence to the flux pickups (I through VIII), the pulse height and width (t.sub.im) being selected in such manner that the saturation field strength (M.sub.s) of the flux pickups is therewith achieved, so as to produce a maximum residual magnetization (M.sub.R). The flux pickups (I through VIII) are preferably driven by means of pulse-shaped signals (I.sub.1), with the magnetization pulses being supplied in the pulse interval (i.sub.s) of these signals synchronous to the pulse repetition rate. The method is particularly employed in gnathography for recording the lower jaw movement of a human being.