APPROACHES TO ORIENTATION OF HIGH RESOLUTION TOMOGRAPHIC 3D RECONSTRUCTION OF TEETH IN METRIC STUDIES

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.