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Patent Application Titled "Method, Transfer Device and Template Body for Producing a Dental And/Or Bone Prosthesis for a Dentition" Published Online

May 8, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventors JASPER, Frank (Berlin, DE); ILLMER, Viola (Berlin, DE); KRISCHOLLEK, Michael (Berlin, DE), filed on October 10, 2013, was made available online on April 24, 2014.

The assignee for this patent application is Tridenta Dentaltechnik GmbH.

Reporters obtained the following quote from the background information supplied by the inventors: "The invention relates to a method for producing a dental and/or bone prosthesis for a dentition having a defect, to a template body and to a transfer device for producing the dental and/or bone prosthesis.

"A dentition having a defect is usually provided with a dental and/or bone prosthesis so as to compensate the functional deficiency resulting from the defect as completely as possible. The defect may be the result of abrasion of the chewing surfaces, loss of a tooth or a plurality of teeth or a complete row of teeth. Further, the defect in the dentition may be accompanied by a jaw fracture, a loss of bone or a deformation of the whole skull. When producing the dental and/or bone prosthesis, a model of the defective dentition is conventionally created, the upper jaw and the lower jaw of the dentition being modelled accordingly. Conventionally, this model may be a plaster model or exist virtually as a computer model.

"The lower jaw is articulated to the upper jaw via the temporomandibular joint, the defect in the dentition causing the position of the lower jaw and the teeth thereof relative to the upper jaw and the teeth thereof to be in a position other than the ideal position. The resulting mispositioning may for example lead to damage to the entire joint and backbone system, in particular to craniomandibular dysfunctions (CMDs) and, in connection therewith, to muscular tensions and headaches, which may impair the affected individual's sense of wellbeing. The problem is that when the dental and/or bone prosthesis is produced, the dentition is only available with the defect, and therefore the ideal position of the lower jaw relative to the upper jaw cannot be fully reconstructed.

"Conventionally, it is known to approximate the position of the lower jaw relative to the upper jaw by means of a jaw model, maximally optimal positioning of the lower jaw relative to the upper jaw being attempted by way of empirically acquired data. However, one-to-one positioning of the lower jaw relative to the upper jaw is not possible with this procedure, and degrees of freedom remain. As a result, the quality of the dental and/or bone prosthesis to be produced depends on the skill and experience of the dental technician in finding a positioning of the lower jaw relative to the upper jaw which comes as close as possible to the ideal position.

"As an aid for this purpose, the dental technical may turn to the 'Staub-Cranial' analysis and production system, by means of which the positioning of the lower jaw model relative to the upper jaw model can be approximated using specific anatomical data ('Staub-Cranial-System--Reliabilitat der Messpunkte zur Rekonstruktion zur Zahnstellung im zahnlosen Kiefer', inaugural dissertation at the Albert Ludwigs University of Freiburg im Breisgau, Panagiotis Lampropoulos, 2003). The Staub-Cranial system is based on anatomical cranial reference points on the upper jaw and the lower jaw. The upper jaw and the lower jaw each have four cranial reference points, each jaw having a right and left direction point and a front and rear induction point. The direction points are located in the molar region, whilst the induction points are located in the incisor region.

"It is known to position the upper jaw model with reference to a virtual plane by means of the cranial reference points of the upper jaw. Moreover, it is known to position the lower jaw model by means of the cranial reference points of the lower jaw with reference to a virtual plane. The position of the upper jaw model and the lower jaw model with respect to the virtual reference planes thereof results from empirical surveys on test subjects. However, this means that individual positioning, tuned to the person in question, of the lower jaw relative to the upper law cannot be achieved, and so the dentition having the conventionally produced dental prosthesis generally has mispositioning of the temporomandibular joint."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "The object of the invention is to provide a method for producing a dental and/or bone prosthesis for a dentition having a defect and a template body and a transfer device for producing the dental and/or bone prosthesis, the dental and/or bone prosthesis being configured in such a way that mispositioning in the temporomandibular joint is prevented in the dentition.

"The method according to the invention for producing a dental and/or bone prosthesis for a dentition having a defect, the dentition comprising an upper jaw and a lower jaw, comprises the steps of: determining the left and right direction point and an induction point of the upper jaw as three cranial reference points of the upper jaw and determining the left and right direction point and an induction point of the lower jaw as three cranial reference points of the lower jaw, the time when the six cranial reference points are determined being a time when the defect is not yet present; storing the relative spatial position of the cranial reference points, in such a way that the spatial position of the six cranial reference points with respect to one another is completely defined; creating a model of the defective dentition, one model half being produced for the upper jaw and one model half being produced for the lower jaw; identifying the three cranial reference points of the upper jaw on the upper jaw model half and identifying the three cranial reference points of the lower jaw on the lower jaw model half; arranging and fixing the upper jaw model half and the lower jaw model half relative to one another, in such a way that the spatial position of the six cranial reference points relative to one another corresponds to the stored spatial position; forming the dental and/or bone prosthesis by means of the model halves which are spatially fixed relative to one another, in such a way that the spatial position of the six cranial reference points is maintained.

"Particularly disclosed is a method for producing a dental and/or bone prosthesis for a dentition having a defect, the dentition comprising an upper jaw and a lower jaw, comprises the steps of: determining the left and right direction point and an induction point of the upper jaw as three cranial reference points of the upper jaw and determining the left and right direction point and an induction point of the lower jaw as three cranial reference points of the lower jaw, the time when the six cranial reference points are determined being a time when the defect is not yet present; storing the relative spatial position of the cranial reference points, in such a way that the spatial position of the six cranial reference points with respect to one another is completely defined; creating a model of the defective dentition, one model half being produced for the upper jaw and one model half being produced for the lower jaw; identifying the three cranial reference points of the upper jaw on the upper jaw model half and identifying the three cranial reference points of the lower jaw on the lower jaw model half; arranging and fixing the upper jaw model half and the lower jaw model half relative to one another, in such a way that the spatial position of the six cranial reference points relative to one another corresponds to the stored spatial position; forming the dental and/or bone prosthesis by means of the model halves which are spatially fixed relative to one another, in such a way that the spatial position of the six cranial reference points is maintained and wherein a template body is formed for storing the relative spatial position of the six cranial reference points, the vertices of the template body coinciding with the coordinates of the six cranial reference points.

"It is preferred for the induction point of the upper jaw to be the front induction point and the induction point of the lower jaw to be the front induction point or for the induction point of the upper jaw to be the rear induction point and the induction point of the lower jaw to be the rear induction point. It is further preferred for the relative spatial position of the six cranial reference points to be defined by the upper plane, which is spanned by the cranial reference points of the upper jaw, and the lower plane, which is spanned by the cranial reference points of the lower jaw, and by the distances from the two planes of the left intersection point, at which the straight line from the left upper direction point to the lower induction point and the straight line from the left lower direction point to the upper induction point intersect, and by the distances from the two planes of the right intersection point, at which the straight line from the right upper direction point to the lower induction point and the straight line from the right lower direction point to the upper induction point intersect. In this context, it is preferred for the template body according to the invention, the vertices of which coincide with the coordinates of the six cranial reference points, to be formed to store the relative spatial position of the six cranial reference points. The edges of the template body are preferably formed by the straight line from the left upper direction point to the lower induction point, the straight line from the left lower direction point to the upper induction point, the straight line from the right upper direction point to the lower induction point and the straight line from the right lower direction point to the upper induction point.

"Alternatively, it is preferred for the relative spatial position of the six cranial reference points to be defined by three spatial coordinates of each of the six cranial reference points.

"Moreover, determining the cranial reference points is preferably performed by an imaging method, in particular by a digital volume tomography method.

"The template body according to the invention is provided for storing the relative spatial position of the six cranial reference points of the dentition, the vertices of the template body coinciding with the spatial coordinates of the six cranial reference points of the dentition.

"Preferably, edges of the template body are formed by the straight line from the left upper direction point to the lower induction point, the straight line from the left lower direction point to the upper induction point, the straight line from the right upper direction point to the lower induction point and the straight line from the right lower direction point to the upper induction point. It is further preferred for the template body to comprise the left intersection point and the right intersection point, the left intersection point being on the edge from the left upper direction point to the lower induction point and the edge from the left lower direction point to the upper induction point, and the right intersection point being on the edge from the right upper direction point to the lower induction point and the edge from the right lower direction point to the upper induction point.

"The transfer device according to the invention is provided for arranging the upper jaw model half relative to the lower jaw model half, and comprises the template body, a gripping device having at least three gripping prongs projecting from the gripping device, and a holder to which the gripping device can be attached and by means of which the gripping device is movably mounted, in such a way that cranial reference points of the upper jaw model half and the lower jaw model half and vertices of the template body can be gripped by means of the gripping prongs.

"The holder preferably comprises a holding rail, on the longitudinal ends of which the gripping device can be detachable reciprocally attached. It is further preferred for the holder to comprise a mounting for mounting the holding rail, which is set up in such a way that the holding rail is movable vertically and horizontally in the longitudinal direction and perpendicular to the longitudinal direction. Further, the gripping device is preferably a gripping fork, and further, the transfer device preferably comprises a second gripping fork having at least three gripping prongs by means of which the gripping prongs of the first gripping fork can be gripped. In this context, it is preferred for the holder to comprise a second holding rail, on one longitudinal end of which the second gripping fork is attached, and for the holder to comprise a mounting for mounting the second holding rail, which is set up in such a way that the second holding rail is movable vertically and horizontally in the longitudinal direction and perpendicular to the longitudinal direction.

"At the reference time, from the end of the person's bone growth at approximately 18 years, the dentition can be determined by an imaging method and the cranial reference points can be determined. At this age, an arrangement of the person's jaw can generally be assumed in which mispositioning of the jaw as a result of wear has not yet noticeably occurred. At the age when the cranial reference points are to be determined, the defect of the dentition should not yet be present. Using the stored spatial position of the cranial reference points, the relative association of the lower jaw with the upper jaw in the ideal position is now available for the person. If a defect of the dentition should set in during the person's lifetime, and mean that the lower jaw is no longer in the ideal position relative to the upper jaw, this ideal position can be reproduced according to the invention with the aid of the cranial reference points of the dentition, which is subsequently provided with the dental and/or bone prosthesis. As a result, the person having the dental and/or bone prosthesis has his/her lower jaw repositioned relative to the upper jaw, any mispositionings of the temporomandibular joint which may have occurred previously being corrected. As a result, damage to the entire joint and spinal column system, craniomandibular dysfunctions (CMDs) and associated muscular tensions and headaches resulting from the mispositionings may be eliminated, increasing the person's sense of wellbeing.

"The straight lines connecting the direction points of the upper jaw to the induction point of the lower jaw and the straight lines connecting the direction points of the lower jaw to the induction point of the upper jaw form a triangle each, the limbs of which cross at the intersection points. The position of the intersection points relative to the direction points and the induction points does not change over the person's lifetime, and so the optimum three-dimensional association of the lower jaw with the upper jaw is always defined by the position of the intersection points. The vertices of the template body fixedly define the cranial reference points, which can thus be called up at any time if the template body is kept.

"The method according to the invention is particularly successful when positioning teeth in full denture, in which the entire rows of teeth of each of the upper jaw and the lower jaw are to be reproduced. By the method according to the invention, tooth shapes, the height of bite, the tooth positions and the positions of the dental and/or bone prosthesis can be set in such a way that the person having the dental and/or bone prosthesis obtains an optimal alignment of the temporomandibular joint again. As a result, it is easy for the person to become accustomed to the dental and/or bone prosthesis, since the dental and/or bone prosthesis is optimally adapted to the anatomical parameters.

DESCRIPTION OF THE DRAWINGS

"In the following, the invention is explained in greater detail with reference to the appended schematic drawings, in which:

"FIG. 1 is a three-dimensional drawing of a template body,

"FIGS. 2 to 5 show a transfer device, with details for arranging an upper jaw model half relative to a lower jaw model half, and

"FIGS. 6 to 9 show steps of a method for producing a dental prosthesis using the transfer device from FIGS. 2 to 5."

For more information, see this patent application: JASPER, Frank; ILLMER, Viola; KRISCHOLLEK, Michael. Method, Transfer Device and Template Body for Producing a Dental And/Or Bone Prosthesis for a Dentition. Filed October 10, 2013 and posted April 24, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=2973&p=60&f=G&l=50&d=PG01&S1=20140417.PD.&OS=PD/20140417&RS=PD/20140417

Keywords for this news article include: Tridenta Dentaltechnik GmbH.

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Source: Politics & Government Week


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