Geometric morphometric methods for three-dimensional virtual reconstruction of a fragmented cranium: The case of Angelo Poliziano

Department of Palaeoanthropology and Messel Research, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany.
Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin (Impact Factor: 2.71). 04/2009; 123(4):333-44. DOI: 10.1007/s00414-009-0339-6
Source: PubMed


The process of forensic identification of missing individuals is frequently reliant on the superimposition of cranial remains onto an individual's picture and/or facial reconstruction. In the latter, the integrity of the skull or a cranium is an important factor in successful identification. Here, we recommend the usage of computerized virtual reconstruction and geometric morphometrics for the purposes of individual reconstruction and identification in forensics. We apply these methods to reconstruct a complete cranium from facial remains that allegedly belong to the famous Italian humanist of the fifteenth century, Angelo Poliziano (1454-1494). Raw data was obtained by computed tomography scans of the Poliziano face and a complete reference skull of a 37-year-old Italian male. Given that the amount of distortion of the facial remains is unknown, two reconstructions are proposed: The first calculates the average shape between the original and its reflection, and the second discards the less preserved left side of the cranium under the assumption that there is no deformation on the right. Both reconstructions perform well in the superimposition with the original preserved facial surface in a virtual environment. The reconstruction by means of averaging between the original and reflection yielded better results during the superimposition with portraits of Poliziano. We argue that the combination of computerized virtual reconstruction and geometric morphometric methods offers a number of advantages over traditional plastic reconstruction, among which are speed, reproducibility, easiness of manipulation when superimposing with pictures in virtual environment, and assumptions control.

Download full-text


Available from: Stefano Benazzi
    • "Since it is essential to use a method based on a population as similar as possible with respect to the one under analysis, we used the soft tissue thickness table proposed by Helmer (1984) for male Caucasian subjects, taking into consideration the slender body of subject and the biological age suggested by the analysis of the remains (40–50 years). The same table had been previously used for the superimposition of the skull produced by geometric and morphometric techniques and the Italian humanist iconography, as described by Benazzi et al. (2009b) in order to perform an identification attempt. 46 pegs were cut at specific length according with the Helmer table and fixed in the corresponding anatomical land- mark. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Frequently, identification of individuals is problematical due to the level of associated decomposition and even more when the skeletal remains are incomplete or fragmented. The identikit, which includes a sketch or a facial reconstruction, could assist investigators with determining the identity of the decedent. Similarly, in archeology and physical anthropology it gives a realistic appearance to a historical character known only through iconography. We examined the skull of Angelo Poliziano, an Italian humanist of the 15th century. Previously, his facial approximation was completed in clay according to the Manchester protocol and then a duplication was prepared in ultra-realistic materials. This technique returns a long lasting 3D model of the individual and provides the perception to be in front of a real person and, although expensive, applied in forensic context could it improve the recognition of the individual.
    No preview · Article · Feb 2015 · Anthropologischer Anzeiger
  • Source
    • "example, need a preliminary restoration before any further analyses or for exhibition (Fantini et al., 2005; Benazzi et al., 2010). In forensics, the recovery of the craniofacial skeleton in a fragmentary state could hamper any attempted facial reconstruction useful for positive identification (e.g., Wilkinson and Neave, 2003; Benazzi et al., 2009b). Finally, bone reconstruction presents a fundamental issue within several surgical disciplines, mainly in orthodontics and maxillofacial surgery (Mehta and Deschler, 2004; Young et al., 2007; Madsen et al., 2008; Baumann et al., 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Reconstruction of fractured, distorted, or missing parts in human skeleton presents an equal challenge in the fields of paleoanthropology, bioarcheology, forensics, and medicine. This is particularly important within the disciplines such as orthodontics and surgery, when dealing with mandibular defects due to tumors, developmental abnormalities, or trauma. In such cases, proper restorations of both form (for esthetic purposes) and function (restoration of articulation, occlusion, and mastication) are required. Several digital approaches based on three-dimensional (3D) digital modeling, computer-aided design (CAD)/computer-aided manufacturing techniques, and more recently geometric morphometric methods have been used to solve this problem. Nevertheless, comparisons among their outcomes are rarely provided. In this contribution, three methods for hemimandibular body reconstruction have been tested. Two bone defects were virtually simulated in a 3D digital model of a human hemimandible. Accordingly, 3D digital scaffolds were obtained using the mirror copy of the unaffected hemimandible (Method 1), the thin plate spline (TPS) interpolation (Method 2), and the combination between TPS and CAD techniques (Method 3). The mirror copy of the unaffected hemimandible does not provide a suitable solution for bone restoration. The combination between TPS interpolation and CAD techniques (Method 3) produces an almost perfect-fitting 3D digital model that can be used for biocompatible custom-made scaffolds generated by rapid prototyping technologies.
    Full-text · Article · Jul 2011 · The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology
  • Source
    • "In order to test the reliability of this procedure, the 3D model was previously superimposed to a fronto-lateral view of the reconstructed face. As suggested by Benazzi et al. (2009b) the pictures and the digital model of the skull were imported in Amira, and the orthogonal view was set. By means of dynamic translation, rotation and uniform scaling process, the skull was aligned either to the reconstructed face or to the portraits using virtual tissue depth markers (virtual pegs) defined on the digital skull to aid the process Table 1 List of landmarks and curves identified on the 3D digital models of the hemimandibles. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In the last few years virtual anthropology has been used to solve different problems that could not be properly addressed using a traditional anthropological approach. Mainly when dealing with mummies or embalmed bodies, the virtual approach is the only solution to carry out a detailed analysis of the skeleton without jeopardizing the integrity of the physical remains.Based on these new technologies, the embalmed body of Ferrante Gonzaga (1507–1557), an Italian noblemen of the Renaissance period, was CT scanned and the digital three-dimensional data were used for virtual anthropological analysis. A physical model of the skull was obtained by rapid prototyping technique and used for facial reconstruction according to forensic art methods. Finally, the reconstructed face was compared with two portraits of Ferrante Gonzaga (Uffizi and Ambras portraits) using a virtual skull-painting superimposition technique. Despite the limits of the superimposition method when dealing with historical portraits in fronto-lateral view, our results pointed out more similarities with the Ambras portrait. By means of this multi-disciplinary approach, doubts regarding the reliability of historical portraits could be resolved.
    Full-text · Article · Jul 2010 · Journal of Archaeological Science
Show more