In order to reduce the stress caused to patients by conventional methods of modeling using computed tomography (CT) or magnetic resonance imaging (MRI), an optical modeling process has been developed for extraoral defects and body areas. The selected body part is digitized using optical 3-coordinate measuring technology, providing an extensive data record. This is adapted for further use by equalizing the point clouds to obtain a Computer Aided Design (CAD) model, which is converted to a physical model by means of a stereolithographic process. With this technology, the patient's physical and psychological stress may be reduced. This article describes a technique for optical modeling of an ocular prosthesis. (J Prosthet Dent 2004;91:80-4.) Unti l recently, conventional impression materials such as silicones or irreversible hydrocolloid and technologies (single or dual cycle processes with or without molding aids) have been used to fabricate maxillofacial prostheses, individual respiratory masks, and extraoral radiation devices. Depending on the impression material and the method of positioning the patient during the impression procedure, displacement of the soft tissues can occur. 1 Various materials have been used to support the impression materials during the procedure. 2 Industrially preproportioned, mechanically miscible, irreversible hydrocolloids (for example, Algicap; Ivoclar, Schaan, Fuerstentum, Liechtenstein) have been used. These materials had the advantage of preventing errors in proportioning and mixing when silicones were used; cartridge systems provided the same advantage. [3][4][5][6][7][8] Newer technologies are oriented to computed tomography (CT) or magnetic resonance imaging (MRI) data, whereby the patient undergoes considerable exposure to radiation. 9-11 To avoid these disadvantages, an optical modeling process for extraoral defects and body areas was developed. The development was based on experience in the collection of digitized data for toothrelated, model-dependent representations. 12-15 The optical 3-dimensional (3-D) scanning unit provides a point cloud or virtual model of the face. The primary principle used to obtain digitized data for extraoral areas is the method of structured light illumination with a digitallight projection unit. 16,17 Use of 3-D scanning in medical applications has specific system requirements: the body part (for example, the face) should be viewed from different directions simultaneously; the measurements should be made within seconds; and the system should be mobile and simple to use.Such a system was developed by the Fraunhofer Institute for Applied Optics and Precision Engineering in Jena, Germany. It is a mobile, multiview 3-D measuring system (called "kolibri-mobile") based on self-calibrating fringe projection technology, which facilitates the fully automatic recording of the body part from various directions in one measuring process. 17 Thus, it is possible to view the face in one complete sweep, from ear to ear and from below the chin to the forehea...

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.

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.

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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.For technical applications, the industrial computer tomography becomes more and more important. Compared with devices from the medical area, industrial CT devices have a significantly higher radiation power and a much higher resolution. Thus, these data are not only suitable for the reconstruction of a 3D model in the sense of reverse engineering, but also for the inspection of components of metal workpieces (density differences, cavities, joint connection). The known CT evaluation procedures from medical use have been qualified and further modified in the research group. The developed software solution allows the generation of free-form sections through a layer image stack e.g. to evaluate the quality of a soldered connection in a tube. This procedure is also suitable to detect and determine density differences and the detachment of individual layers of a generative produced component. The topic is illustrated by selected practical examples.