The most significant sexual differences in the human skull are located in the upper third of the face (the frontal bone), which is a useful research object, mainly in combination with virtual anthropology methods. However, the influence of biological relatedness on sexual dimorphism and frontal bone variability remains unknown. This study was directed at sexual difference description and sex classification using the form and shape of the external surface of the frontal bones from a genealogically documented Central European osteological sample (nineteenth to twentieth centuries). The study sample consisted of 47 cranial CT images of the adult members of several branches of one family group over 4 generations. Three-dimensional virtual models of the frontal bones were analyzed using geometric morphometrics and multidimensional statistics. Almost the entire external frontal surface was significantly different between males and females, especially in form. Significant differences were also found between this related sample and an unrelated one. Sex estimation of the biologically related individuals was performed using the classification models developed on a sample of unrelated individuals from the recent Czech population (Čechová et al. in Int J Legal Med 133: 1285 1294, 2019), with a result of 74.46% and 63.83% in form and shape, respectively. Failure of this classifier was caused by the existence of typical traits found in the biologically related sample different from the usual manifestation of sexual dimorphism. This can be explained as due to the increased degree of similarity and the reduction of variability in biologically related individuals. The results show the importance of testing previously published methods on genealogical data.

• Klíčová slova
• Forensic anthropology, Genealogical documented sample, Geometric morphometrics, Kinship,
• MeSH
• čelní kost * diagnostické zobrazování   anatomie a histologie   MeSH
• dospělí MeSH
• lidé MeSH
• počítačová rentgenová tomografie MeSH
• pohlavní dimorfismus MeSH
• soudní antropologie * metody   MeSH
• určení pohlaví podle kostry * metody   MeSH
• zobrazování trojrozměrné * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The skull, along with the pelvic bone, serves an important source of clues as to the sex of human skeletal remains. The frontal bone is one of the most significant sexually dimorphic structures employed in anthropological research, especially when studied by methods of virtual anthropology. For this reason, many new methods have been developed, but their utility for other populations remains to be verified. In the present study, we tested one such approach-the landmark-free method of Bulut et al. (2016) for quantifying sexually dimorphic differences in the shape of the frontal bone, developed using a sample of the Turkish population. Our study builds upon this methodology and tests its utility for the Czech population. We evaluated the shape of the male and female frontal bone using 3D morphometrics, comparing virtual models of frontal bones and corresponding software-generated spheres. To do so, we calculated the relative size of the frontal bone area deviating from the fitted sphere by less than 1 mm and used these data to estimate the sex of individuals. Using our sample of the Czech population, the method estimated the sex correctly in 72.8% of individuals. This success rate is about 5% lower than that achieved with the Turkish sample. This method is therefore not very suitable for estimating the sex of Czech individuals, especially considering the significantly greater success rates of other approaches.

• Klíčová slova
• 3D imaging methods, forensic anthropology, frontal bone, sex estimation, sexual dimorphism, virtual morphometrics,
• MeSH
• čelní kost anatomie a histologie   diagnostické zobrazování   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• počítačová rentgenová tomografie MeSH
• počítačová simulace * MeSH
• počítačové zpracování obrazu MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• soudní antropologie MeSH
• support vector machine MeSH
• určení pohlaví podle kostry metody   MeSH
• zobrazování trojrozměrné * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Sex estimation is a task of utmost importance in forensic anthropology and bioarcheology. Along with the pelvic bone, the skull is the most important source of sexual dimorphism. On the human skull, the upper third of the face (i.e., the frontal bone) is one of the most significant sexually dimorphic structures useful in anthropological research, especially when studied by methods of virtual anthropology. This study was focused on sex estimation using the form and shape of the external surface of the frontal bone with or without the inclusion of its sinuses. The study sample consisted of 103 cranial CT images from a contemporary Czech population. Three-dimensional virtual models of the frontal bones and sinuses were analyzed using geometric morphometrics and multidimensional statistics: coherent point drift-dense correspondence analysis (CPD-DCA), principal component analysis (PCA), and support vector machine (SVM). The whole external frontal surface was significantly different between males and females both in form and shape. The greatest total success rate of sex estimation based on form was 93.2%, which decreased to 86.41% after crossvalidation, and this model identified females and males with the same accuracy. The best estimation based on shape reached a success rate of 91.26%, with slightly greater accuracy for females. After crossvalidation, however, the success rate decreased to 83.49%. The differences between sexes were significant also in the volume and surface of the frontal sinuses, but the sex estimation had only 64.07% accuracy after crossvalidation. Simultaneous use of the shape of the frontal surface and the frontal sinuses improved the total success rate to 98.05%, which decreased to 84.46% after crossvalidation.

• Klíčová slova
• Forensic anthropology, Frontal bone, Frontal sinuses, Geometric morphometrics, Sex estimation, Sexual dimorphism,
• MeSH
• čelní kost anatomie a histologie   diagnostické zobrazování   MeSH
• lebka anatomie a histologie   diagnostické zobrazování   MeSH
• lidé MeSH
• pohlavní dimorfismus MeSH
• soudní antropologie metody   MeSH
• určení pohlaví podle kostry metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

The aim of this study is to compare two different methods of frontal bone surface model acquisition. Three dimensional models acquired by laser scanning were compared with models of the same bones acquired by virtual replicas reconstructed from a sequence of computed tomography (CT) images. The influence of volumetric CT data processing (namely thresholding), which immediately preceded the generation of the three-dimensional surface model, was also considered and explored in detail in one sample. Despite identifying certain areas where both models showed deviations across all samples, their conformity can be generally classified as satisfactory, and the differences can be regarded as minimal. The average deviation of registered surface models was 0.27 mm for 90% of the data, and its value was therefore very close to the resolution of the laser scanner used.

• MeSH
• anatomické modely * MeSH
• antropologie fyzická přístrojové vybavení   MeSH
• čelní kost anatomie a histologie   diagnostické zobrazování   MeSH
• lasery MeSH
• lidé MeSH
• počítačová rentgenová tomografie metody   normy   MeSH
• zobrazování trojrozměrné metody   normy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• validační studie MeSH

The objective of the skeletal defects reconstruction using individual implants is an attempt to replace lost and damaged anatomical bone structures, renew their original function, and at the same time, to restore the original aesthetic visual aspect. This work is focused on a demonstration of the design methods, fabrication and surgical techniques of the custom-made replacement of a large defect of the frontal bone on the skull. The patient was a 30-year-old woman with a defect of the frontal bone in the size of 7 x 3 x 2 cm after a serious polytrauma. The size and character of the defect excluded the use of commonly supplied augmentations. The geometry of the individual replacement was designed on the basis of a 3D model of the defect obtained from a series of CT scans. After verification of the shape accuracy of the defect made from plastic on a 3D printer, the individual replacement was fabricated from an ultra high molecular weight polyethylene (UHMWPE) by machining with the use of the CNC technology. The success of the augmentation depends on the accurate and precise fabrication of the individual replacement, which is highly demanding on the used advanced technologies.

• MeSH
• čelní kost diagnostické zobrazování   zranění   chirurgie   MeSH
• design s pomocí počítače * MeSH
• dospělí MeSH
• kostní náhrady * MeSH
• lidé MeSH
• počítačová rentgenová tomografie MeSH
• polyethylen MeSH
• protézy - design * MeSH
• vpáčené fraktury lebky diagnostické zobrazování   chirurgie   MeSH
• zákroky plastické chirurgie metody   MeSH
• zobrazování trojrozměrné MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kostní náhrady * MeSH
• polyethylen MeSH