Search

Metric studies of teeth is a rapidly developing direction in odontological research, which is supported by means of corresponding imaging techniques for obtaining detailed digital reconstructions, and by application of image analysis methods. The current article presents methodological extension of teeth 3D models’ orientation tactics, which have been used in measurement techniques in dental, palaeoanthropological and palaeontological studies. Today image analysis has sufficient potential to perform orientation of teeth on the bases of their natural features; at the same time teeth possesses all necessary morphological structures for performing orientation on 3D reconstructions obtained by means of widely used today imaging techniques. Our aim is in providing an approach to orientation of teeth for its further use in morphologically relevant, accurate and applicable for various types of research, measurement techniques. The palaeoanthropological material presented in this paper, on which the proposed technique has been tested, is from territories of European part of Russian Federation and Republic of Armenia; it has been classified as related to the Middle Bronze Age, and is planned to be studied in a wider scope in the future. X-ray micro-focus tomography has been used for obtaining reconstructions of lower molars, which were segmented from semi-mandible 3D models. These teeth were used for setting vertical axis direction by means of surface curvature analysis and calculations based on points’ coordinates, which delineate functionally and morphologically important parts of teeth. This approach to accurate and morphologically relevant orientation of the studied teeth uses more than one structure at a time for choosing correct orientation according to aims of research and features of the studied material. This provides the proposed technique necessary potential to be applied for measurements of teeth and studies of their functional changes.

Findings from Bronze Age burials of Shengavit settlement have become a source of multiple studies referred to anthropological, and especially odontological, research based on 3d imaging and image processing techniques. The currently presented case is an example of palaeopathological analysis of bone tissue resorption caused by complications of dental pathologies. Thus by analogy with diagnostic procedures in clinical dentistry, conventional x-ray based cone-beam tomographic scanning have been applied and have shown its effectiveness as a study method. Through CBCT imaging we managed to reveal a hidden pathological process in the body of the studied semi-mandible fragment, though initially another pathological area located on the same finding was planned to be studied. Application of micro-computed tomography has improved analytical, or diagnostic, part of the current palaepathological study. It has brought to finding unusual morphological features hypothetically causing bone resorption as a complication of dental pathological conditions. However our intention to obtain 3d reconstructions as evidence supporting the most likely version required several attempts to correct image processing in line with the increase of imaging resolution.

A wide variety of methods are used in archaeological research today, including 3D imaging techniques (photogrammetry) which are involved at different stages starting from explorations preceding excavation to multiple studies. The archaeologically obtained material includes anthropological findings, among which odontological (related to human teeth) are of interest as they are composed of resistible tissues (hence are preserved well) and can serve for biological as well as historical interpretations. However, among the methods employed in odontological studies some are destructive and bring to unwelcome irreversible changes or even complete loss of the analysed samples. However, the existing and rapidly-developing techniques, especially, referring to 3D imaging and prototyping, suggest different approaches which can facilitate avoiding undesirable consequences of invasive methods of research. Thus they can provide for either preservation of findings through development and application of non-invasive study techniques, or, at least, preserve data referring the findings which have to be destroyed in order to receive valuable, in terms of research, information. It is shown on the example of the studied mandibular fragment from the Early Bronze archaeological site of Shengavit how multidisciplinary cooperation and the described workflow contribute to preservation of information regarding the finding and possible restoration of its original features. An effective communication between different professionals was provided due to implementing non-contact measurements techniques, obtaining and processing 3D images and 3D printing.

In this paper we present a model of biometric identification system transformed into Petri Nets. Petri Nets, as a graphical and mathematical tool, provide a uniform environment for modelling, formal analysis, and design of discrete event systems. The main objective of this paper is to introduce the fundamental concepts of Petri Nets to the researchers and practitioners, both from identification systems, who are involved in the work in the areas of modelling and analysis of biometric identification types of systems, as well as those who may potentially be involved in these areas. In addition, the paper introduces high-level Petri Nets, as Colored Petri Nets (CPN). In this paper the model of Colored Petri Net describes the identification process much simpler.