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Biomedical subjects

Z Böröcz

Publications and source records attributed to Z Böröcz.

5 recordsLinked to original sources
PubMed2005

[Objective assessment of cosmetic outcome of scars].

AIM OF THE STUDY: Cosmetic outcome of surgical treatment in the facial region is influenced by the appearance of the scar. The purpose of this investigation was to evaluate the objectivity and validity of various methods for the assessment of scars. MATERIAL AND METHODS: 45 patients undergoing facial surgery were examined three months after surgery. Three maxillofacial surgeons evaluated the wounds in a blinded manner using a visual analog scale (VAS). The patients also used the VAS for evaluation of their own scar. The surface of the scars was also measured by optical profilometry. Finally, the colour of the scars was analysed using both the RGB colour model and the HSV colour model. RESULTS: Interestingly, there was no significant correlation between the values of R (red) as assessed by the three surgeons. However, there was a very strong correlation between the values of H (hue) as assessed by the three raters. The appearance of the surface was more important in the patients' evaluation than in the raters' assessment. CONCLUSION: The hue of a scar as measured in terms of the H value in the HSV colour model is an objective and reliable measure for assessing the cosmetic outcome of facial surgery.

Adult↗
PubMed2004

[Investigation of influencing variables on the computer-aided simulation of contacts in dynamic occlusion based on optically digitized plaster casts].

In dentistry, mechanical articulators with which mandibular movements can be reproduced in dentals casts play a major role. Commonly used semiadjustable articulators, however, have major limitations: On the one hand, the movement of the mandible is not reproduced exactly, on the other, they do not provide time-related information on jaw movement. Both problems can be solved by replacing the mechanical articulator by a digital simulation ("virtual articulator") based on digitized plaster casts and electronically recorded masticatory movements. We present a system for the 3D measurement of plaster casts in a skull-related, anatomical coordinate system using the fringe projection technique, and electronically recorded condylar movements. Using numerical algorithms, the contacts between upper and low jaw, and the angle of rotation of the temporomandibular joint can be computed for each movement in dynamic occlusion. Taking the data recorded from a patient as an example, the influence of the accuracy of the digitization of plaster casts on the computation of the rotation of the temporomandibular joint is discussed in relation to the anatomy of the masticatory apparatus.

Computer Simulation↗
PubMed2002

[Computer-assisted development of epitheses after optical recording of facial defects].

A major drawback of conventional impression techniques used for customizing facial prostheses is the fact that pressure applied deforms soft tissue, thus reducing accuracy and causing patient discomfort. A possible solution is the use of optical 3-D coordinate measuring techniques, such as the fringe projection technique, which enables precise and contact-free recording of facial surfaces. The application of this method is demonstrated on a patient who lost his left eye and part of the jaw bone during surgery for cancer. 3-D CAD software that supports the construction of a facial prosthesis from the data obtained has been developed. For this purpose, spline functions are used to define border curves, and the intact half of the face is used as a model for the prosthetic surface. The resulting digital data are used to construct first a model made of synthetic resin, and then a final wax model with the aid of rapid prototyping techniques.

Computer-Aided Design↗
PubMed2001

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

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 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 30 seconds. The accuracy of the acquired 3-dimensional data was estimated to be better than 60 microm in lateral and 30 microm in height resolution. The data set was visualized and evaluated in a skull related 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.

Color↗