Christine Schöne

Planning implant positions for an auricular prosthesis with digital data

The esthetic result of an auricular prosthesis is influenced by the position of the prosthesis incorporating the implants. The entire surface of the patients head is captured by means of a conventional computed tomography (CT). The digital data are used to mirror the contralateral unimpaired ear for restoration of the impaired side. The virtual ear is integrated into a template covering the auricular defect and indexed to the nasal area with computer-aided technology (CAD/CAM). This virtual template is converted into an acrylic resin template. With that the surgeon and the anaplastologist should determine the optimal implant position of the auricular prosthesis.

Creation and utilization of a digital database for nasal prosthesis models.

Background: The study describes the development and implementation of a digital nose database in order to provide patients with nasal prostheses following rhinectomy. Mirrored data for computer-aided design (CAD) cannot be used due to the unpaired structure of the nose. Materials and Methods: The faces of 202 people were digitized using a 3-dimension (3D) scanner. The noses were scaled, measured and classified according to objective criteria. The physician, the patient and the anaplastologist can collaborate in order to select an appropriate nose from the multitude of existing nose types and sizes. Virtual ‘fittings’ and an individual adaptation of the nose are feasible. For this purpose the epiTecture software was applied. The selected nose is then created on a 3D printer as a thermopolymer model. This model can be fitted and corrected as a physical model on the patient. The remaining steps are identical to conventional prosthesis production. Results: A digital nose database was developed at the University Hospital Dresden with the help of the epiTecture software. Instructions for usage are illustrated using the example of a patient. Conclusions: The process of providing nasal prostheses described in this paper is different from conventional processes. This is primarily due to the elimination of physical modeling, causing substantially less strain for the patient.

Intelligent Software Support for Cutting Process

The current developing trend to Simultaneous Engineering require a new level in integration. Main aspects for practical steps in this direction are the parallel realization of different tasks by better providing of necessary information. Important tools for a suitable user support are a production data bank and knowledge based systems for operational planning and NC-programming.

Contour identical implants to bridge mandibular continuity defects - individually generated by LaserCUSING ® - A feasibility study in animal cadavers

BackgroundAblative tumor surgery often results in continuity defects of the mandible. When an immediate reconstruction using autologous bone grafts is not possible the bridging of the defects with a variety of bridging plates might be achieved. However, those bridging plates have the risk of plate fractures or exposure. Customized titanium implants manufactured using CAD/CAM and the LaserCUSING® technique might be an alternative.MethodsIn the present study, computed tomographies (CT) of porcine cadaver mandibles were generated and transferred into DICOM data. Following, different continuity defects were surgically created in the mandibles. Based on the DICOM data customized titanium implants were manufactured using CAD/CAM procedures and the LaserCUSING® technique. The implants were fixed to the remaining stumps with screws. Subsequently, the accuracy of the reconstructed mandibles was tested using plaster casts.ResultsThe workflow from the CT to the application of the customized implants was proved to be practicable. Furthermore, a stable fixation of the customized implant to the remaining stumps could be achieved. The control of the accuracy showed no frictions or obstacles.ConclusionThe customized titanium implant seems to be a promising approach to bridge continuity defects of the mandible whenever an immediate reconstruction with autologous bone is not possible.

Pharma News / PharmaTicker

Mit Aflibercept wurde eine innovative antiangiogene Substanz entwickelt, die sich vor allem durch ihren 3-fachen Wirkansatz von bisherigen Angiogenesehemmern unterscheidet. Im Unterschied zu Anti-VEGFR-Antikörpern oder sogenannten Small-MoleculesVEGFR-Tyrosinkinase-Inhibitoren agiert das aus löslichen VEGF-R1 und VEGF-R2 zusammengesetzte Fusionsprotein wie eine Falle. Es fängt zirkulierende VEGF-A, VEGF-B und zudem PlGF, verhindert so die Kompensation der untereinander interagierenden Wachstumsfaktoren und blockiert die Tumorangiogenese nicht nur umfassender, sondern zudem vergleichsweise rasch und teilweise 1000fach stärker als z.B. Bevacizumab [1–3]. Signifikant verbesserte Ansprechrate und Überlebenszeit Dass Aflibercept bei Patienten mit metastasiertem kolorektalen Karzinom hochwirksam ist – unabhängig davon, ob sie bereits antiangiogen vorbehandelt sind oder nicht –, zeigen die Ergebnisse der VELOUR-Studie auf [4]. In dieser großen multinationalen randomisierten Phase-III-Studie waren 1226 Patienten nach Versagen einer Oxaliplatin-basierten Therapie mit Aflibercept versus Placebo in Kombination mit FOLFIRI behandelt worden – ein Drittel nach Vorbehandlung mit Bevacizumab. Die zusätzliche Behandlung mit Aflibercept zur Chemotherapie erbrachte einen signifikanten Überlebensvorteil bzw. senkte das Sterberisiko um knapp 20% (HR 0,817; p = 0,0032) [4]. Die effektive antiangiogene Wirkung des Fusionsproteins bilde sich insbesondere in der vergleichsweise hohen und gegenüber dem Kontrollarm signifikant erhöhten Ansprechrate (19,8 vs. 11,1%; p = 0,0001) ab. Mit der therapieinduzierten Reduktion des Tumorvolumens gingen tumorbedingte Beschwerden zurück. Auch im Hinblick auf die Verträglichkeit schnitt Aflibercept gut ab [4].

Customized craniofacial implants: Design and manufacture

Abstract: This chapter provides an overview of the different methods currently available to design and manufacture customized craniofacial implants. Tools and techniques, such as computer tomography, CAD/CAM systems, 3D scanning, single point incremental forming, CNC milling and rapid prototyping are highlighted.

Additional Methods to Analyze Computer Tomography Data for Medical Purposes and Generatively Produced Technical Components

The result of a computer tomography (CT) record is an image layer stack, which can be applied for medical diagnostic purposes, as well for virtual 3D object representation (e.g. for a skull bone) depending on the used threshold values. Based on these representations, medical 3D objects could be easily produced by generative manufacturing processes. The additive manufacturing of individual implants is also based on the use of CT data for the representation of the remaining bone. This knowledge was further used for the evaluation of industrial CT data.

Topology-Oriented Deformation of FE-Meshes in Iterative Reverse Engineering Processes

Reverse Engineering methods are becoming more and more important in product development processes in cases without CAD models or modified physical objects. For numerical calculations of scanned components, using, for instance, the Finite Element Method (FEM) to look at strength or vibration characteristics, we need the previously scanned data, obtained via Geometric Reverse Engineering, to be converted into CAD surface data, a Finite Element-meshing and a determination of material parameters and constraints. Tremendous effort must be expended in the course of performing repeated Geometric Reverse Engineering and FE-meshing, which must be done when there are iterative, largely local changes in real geometry (such as when incorporating forming dies) or in the case of topologically similar objects, which must be scanned again and again.This project is aimed at the generation of new calculation models using an appropriate adaption of existing FE meshes (made using a CAD model, for example) or FE meshes previously created with the help of scan data through the retention of intelligent meshing (constraints, material, element type etc.). In terms of their topology, these new meshes should adapt themselves to changes in geometry. Time-consuming Geometric Reverse Engineering, as well as re-meshing, can thus be bypassed. Product development cycles frequently proceed in an iterative manner. Repetition of process steps is intended to improve the product in order to achieve an optimum result in design and dimensioning. The goal of these research activities is to reduce the process steps from 3D scan data to FE-meshing, in particular in development cycles. The paper introduces the project’s concept, its initial results, and further steps.Copyright

Reverse Engineering in der Einarbeitungsphase der Blechumformung

Kurzfassung In diesem Beitrag wird die Verknüpfung der Umformprozesssimulation mit innovativer Mess- und Auswertetechnik dargestellt. Damit werden die der Simulation zugrunde liegenden Modelle weiterentwickelt und die Einarbeitung von Umformwerkzeugen wissenschaftlich durchdrungen. Das bedeutet, dass mittels Reverse Engineering die „erweiterte Methodenplanung“ am realen Einarbeitungsprozess nachgewiesen wird. Mit dem Vergleich der Simulations- und Messergebnisse wird die Realitätsnähe der untersuchten Modelle bewertet. Mit der Weiterentwicklung von zur Rückfederungskompensation verwendeten Optimierungsalgorithmen auf die Problematik der Werkzeugeinarbeitung wird die Anpassung der Werkzeugtopologie durch neue Softwarefunktionalitäten automatisiert ablaufen.