Christoph Runte

Publications of Christoph Runte

• Image-based biomimetric approach to design and fabrication of tissue engineered bone.

  Authors: Ulrich Meyer, Christoph Runte, Dieter Dirksen, T. Stamm, T. Fillies, Ulrich Joos, Hans-Peter Wiesmann

  CARS 2003. Computer Assisted Radiology and Surgery. Proceedings of the 17th International Congress and Exhibition, London, June 25-28, 2003; 01/2003

• Three-dimensional quantification of color-marked occlusal paths on anatomically oriented casts

  Authors: Dieter Dirksen, Christoph Runte, Zoltán Böröcz, Carsten Thomas, Gert von Bally, Friedhelm Bollmann

  The Journal of Prosthetic Dentistry.

  Statement of problem. The analysis of occlusal contacts on mounted diagnostic casts is an important task in prosthetic diagnostics. However, it is still restricted mainly to qualitative aspectsStatement of problem. The analysis of occlusal contacts on mounted diagnostic casts is an important task in prosthetic diagnostics. However, it is still restricted mainly to qualitative aspects because existing measuring techniques fail to provide 3-dimensional data for more than a few single points in acceptable time. Purpose. The aim of this study was to develop a method for quantifying occlusal contacts and paths by using anatomically oriented diagnostic casts and to design the method to allow fast acquisition of digital 3-dimensional coordinates. Material and methods. Plaster casts with color-marked contacts were digitized optically with a profilometric system based on the fringe projection technique. Digital camera images taken simultaneously were used to define the contact areas by marking them either manually or automatically with the help of image-processing routines. Three-dimensional coordinates were determined by finding the corresponding points within the profilometric data set. Results. Color-marked contact areas on diagnostic casts were successfully digitized with a computer-controlled, automatic setup in approximately 30seconds. The accuracy of the acquired 3-dimensional data was estimated to be better than 60 μm in lateral and 30 μm in height resolution. The data set was visualized and evaluated in a skullrelated coordinate system. Summary. This study verified the use of a new tool to quantify color-marked occlusal contacts on diagnostic casts in terms of spatial coordinates. The resulting digital data may be stored easily and analyzed numerically as well as visualized 3-dimensionally with computer graphic equipment. Because the anatomic orientation of the casts is maintained throughout the measurement process, it is possible to compare the data with electronically registered condyle paths and therefore to investigate, for example, their relation to the corresponding guidance paths of the frontal teeth and the canines in dynamic occlusion. (J Prosthet Dent 2001;85:156-61.)

• Bone loading pattern around implants in average and atrophic edentulous maxillae: a finite-element analysis

  Authors: Ulrich Meyer, Dirk Vollmer, Christoph Runte, Christoph Bourauel, Ulrich Joos

  Journal of Cranio-Maxillofacial Surgery.

  Introduction: Oral implants placed in the maxilla, especially the posterior region, have a lower success rate than those placed in the mandible. Poor bone quantity and quality have been suggested asIntroduction: Oral implants placed in the maxilla, especially the posterior region, have a lower success rate than those placed in the mandible. Poor bone quantity and quality have been suggested as a reason for this differential success rate. Objective: The purpose of this study was, therefore, to evaluate stress and strain distributions around loaded implants in the normal and atrophic maxilla by finite-element (FE) analyses. Material: FE models of a solitary implant were generated to determine stresses and strains in the bone adjacent to the implant surface under loading conditions. Study design: Different bony situations and implant lengths were used in a FE model. Static loads were applied axially and the resulting stresses and strains calculated. Results: Bone quality and quantity play a major role in decreasing bone strains adjacent to the implant surface under loading. It was found that stresses were more homogeneously distributed when more spongy bone was present. Decreased bone height was found to have less pronounced effects on strain and stress alterations than poor bone quality. Atrophic bony dimensions in combination with poor bone quality were associated with surface strains exceeding physiological levels (>6000 microstrains). Conclusion: Our investigation indicates that supraphysiological bone strains adjacent to the implant surface should be expected under mechanical loading in the atrophic maxilla.

• Spectral analysis of /s/ sound with changing angulation of the maxillary central incisors.

  Authors: Christoph Runte, Djafar Tawana, Dieter Dirksen, Bettina Runte, Antoinette Lamprecht-Dinnesen, Friedhelm Bollmann, Eberhard Seifert, Gholamreza Danesh

  The International journal of prosthodontics. 15(3):254-8.

  PURPOSE: The aim of the study was to measure the influence of the maxillary central incisors free from adaptation phenomena using spectral analysis. MATERIALS AND METHODS: The maxillary dentures ofPURPOSE: The aim of the study was to measure the influence of the maxillary central incisors free from adaptation phenomena using spectral analysis. MATERIALS AND METHODS: The maxillary dentures of 18 subjects were duplicated. The central incisors were fixed in a pivoting appliance so that their position could be changed from labial to palatal direction. A mechanical push/pull cable enabled the incisor section to be handled extraorally. Connected to the control was a sound generator producing a sinus wave whose frequency was related to the central incisor angulation. This acoustic signal was recorded on one channel of a digital tape recorder. After calibration of the unit, the denture duplicate was inserted into the subject's mouth, and the signal of the /s/ sounds subsequently produced by the subject was recorded on the second channel during alteration of the inclination angle simultaneously with the generator signal. Spectral analysis was performed using a Kay Speech-Lab 4300B. RESULTS: Labial displacement in particular produced significant changes in spectral characteristics, with the lower boundary frequency of the /s/ sound being raised and the upper boundary frequency being reduced. CONCLUSION: Maxillary incisor position influences /s/ sound production. Displacement of the maxillary incisors must be considered a cause of immediate changes in /s/ sound distortion. Therefore, denture teeth should be placed in the original tooth position as accurately as possible. Our results also indicate that neuromuscular reactions are more important for initial speech sound distortions than are aerodynamic changes in the anterior speech sound-producing areas.

• Optical data acquisition for computer-assisted design of facial prostheses.

  Authors: Christoph Runte, Dieter Dirksen, Holger Deleré, Carsten Thomas, Bettina Runte, Ulrich Meyer, Gert von Bally, Friedhelm Bollmann

  The International journal of prosthodontics. 15(2):129-32.

  PURPOSE: The conventional impression technique for manufacturing facial prostheses has the disadvantage of deforming the soft tissues because of the tension caused by the impression material, as wellPURPOSE: The conventional impression technique for manufacturing facial prostheses has the disadvantage of deforming the soft tissues because of the tension caused by the impression material, as well as causing discomfort to the patient. The purpose of this study was to establish a system that allows contact-free reproduction of the facial surface combined with computer-assisted design and fabrication of facial prostheses. MATERIALS AND METHODS: Three-dimensional data of the facial surface were obtained using an optical acquisition system based on the method of phase-measuring profilometry. A sensor head with a fringe projector and two CCD cameras for photogrammetric triangulation were used in connection with a PC for measurement control and data evaluation. Software for computer-assisted design of the facial surface to be reconstructed was developed. A prototype facial prosthesis was fabricated using stereolithography. The system was tested using a modified puppet head. First clinical tests were performed with a patient who had undergone maxillofacial surgery including the resection of one eye. RESULTS: Three-dimensional data acquisition and imaging allow visualization of a whole face without causing tension or neuromuscular reaction. As surface brightness is also part of the digital model, it is even more realistic than a plaster cast. The stereolithographic object showed good marginal fit and satisfactory shape. CONCLUSION: The presented technique allows three-dimensional data reproduction of the facial surface, computer-assisted design of a facial prosthesis, and transfer to a rapid prototyping unit. The system has obvious advantages over conventional impression techniques. Further clinical trials are planned to evaluate the clinical success of the technique.

• Image-based extracorporeal tissue engineering of individualized bone constructs.

  Authors: Ulrich Meyer, Andre Büchter, Ariane Hohoff, Elke Stoffels, Thomas Szuwart, Christoph Runte, Dieter Dirksen, Hans-Peter Wiesmann

  The International journal of oral & maxillofacial implants. 20(6):882-90.

  PURPOSE: Computer-aided technologies have been recently employed for use in extracorporeal bone tissue engineering strategies. In this pilot animal experimental study, the intention was to testPURPOSE: Computer-aided technologies have been recently employed for use in extracorporeal bone tissue engineering strategies. In this pilot animal experimental study, the intention was to test whether autologous osteoblast-like cells cultured in vitro on individualized scaffolds can be used to support bone regeneration in a clinical environment. MATERIALS AND METHODS: For this purpose, mandibular bone defects were surgically introduced into the mandibles of minipigs and the scaffold of the defect site was modeled by computer-aided design/computer-aided manufacturing technique. Autologous bone cells from porcine calvaria were harvested from minipigs and grown in culture. Cells were seeded on scaffolds generated by rapid prototyping of polylactic acid/polyglycolic acid copolymers. The defects were then reconstructed by implanting the tissue constructs. RESULTS: The intraoperative sites as well as the postoperative computerized tomographic scans demonstrated an accurate fit in the defect sites. The implanted scaffold constructs enriched with osteoblast-like cells were well tolerated and appeared to support bone formation, as revealed by histologic and immunohistochemical analyses. DISCUSSION: These results indicated that in vitro expanded osteoblast-like cells spread on a resorbable individualized scaffold can be capable of promoting the repair of bony defects in vivo. CONCLUSION: These results warrant further attempts to combine computer modeling and tissue engineering for use in bone reconstructive surgery.

• EMail-Verteiler zur Distribution digitaler Informationen im Zentrum für ZMK-Münster.

  Authors: Karl-Ludwig Mischke, Gholamreza Danesh, Christoph Runte, Ulrike Ehmer

  127. Jahrestagung der Deutschen Gesellschaft für Zahn-, Mund- und Kieferheilkunde e.V., 2003.

  Auf der Basis verschiedener in HTML-Seiten integrierter PHP-Scripte können EMails an vordefinierte Zielgruppen, z.B. an alle Studenten, an alle Mitarbeiter einer Poliklinik oder auch an eine manuellAuf der Basis verschiedener in HTML-Seiten integrierter PHP-Scripte können EMails an vordefinierte Zielgruppen, z.B. an alle Studenten, an alle Mitarbeiter einer Poliklinik oder auch an eine manuell selektierbare individuelle Liste von Personen geschickt werden. Der PHP-Server des Apache-Webserves sorgt für eine augenblickliche, schnelle Distribution ohne Abhängigkeit von Mail-Servern der Universität, persönlichen Providern oder lokalen EMail-Programmen. Digitale Verteiler sind herkömmlichen 'Snail-Mail'-Verteilern in Geschwindigkeit und Qualität weit überlegen und werden diese vermutlich bald vollständig ersetzen können.