The virtual approach in physical and forensic anthropology is increasingly used to further analyze human remains, but also to propose new didactic means for visualization and dissemination of scientific results. Computerized facial approximation (FA) offers an alternative to manual methods, but usually requires a complete facial skeleton to allow for the estimation of the facial appearance of an individual. This paper presents the case of Tycho Brahe, Danish astronomer born during the XVIth century, whose remains were reanalyzed at the occasion of a short exhumation in 2010. Cranial remains of Brahe were poorly preserved, with only a partial facial skeleton, and virtual anthropology tools were used to estimate the missing parts of his skull. This 3D restoration was followed by a FA using TIVMI-AFA3D, subsequently textured with graphic tools. The result provided an interesting estimate that was compared with portraits of the astronomer. The impact of the missing data estimation was investigated by performing FAs on 10 complete test subjects and the same 10 subjects after cropping and estimating 50% of the landmarks (reproducing the preservation state of Tycho Brahe's cranial remains). The comparison between the FA based on the complete and incomplete skulls of the same subject produced a visual assessment of the estimation impact on FAs which is relatively low. This procedure is an alternative to manual methods and offers a reproducible estimate of a face based on incomplete cranial remains. Although the case report concerns a historical individual, the robust automatic estimation of missing landmarks followed by a FA has value for forensic caseworks as a support to the identification process.

Department of Anthropology National Museum Václavské náměstí 68 CZ 115 79 Prague 1 Czech Republic

Department of Archaeology National Heritage Institute Regional Office Prague Na Perštýně 356 12 110 00 Prague 1 Czech Republic

Department of Culture and Society Section for Medieval and Renaissance Archaeology Aarhus University Moesgaard Alle 20 DK 8270 Højbjerg Denmark

Department of Radiology Na Homolce Hospital Roentgenova 2 150 30 Prague 5 Czech Republic

Institute of Chemical Process Fundamentals of the CAS Rozvojová 135 CZ 165 02 Prague 6 Czech Republic

Institute of Physics Chemistry and Pharmacy University of Southern Denmark Campusvej 55 DK 5230 Odense M Denmark

Laboratory of Biological Anthropology Institute of Forensic Medicine University of Copenhagen Blegdamsvej 3 DK 2200 Copenhagen Denmark

Nuclear Physics Institute of the CAS CZ 250 68 Husinec Řež 130 Czech Republic

UMR 5199 PACEA Université de Bordeaux CNRS MCC Allée Geoffroy St Hilaire B8 33615 Pessac France

UMR 5199 PACEA Université de Bordeaux CNRS MCC Allée Geoffroy St Hilaire B8 33615 Pessac France; Department of Anthropology and Human Genetics Faculty of Science Charles University Prague Albertov 6 CZ 128 43 Prague 2 Czech Republic

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