Gordon CR, Fisher M, Liauw J, Lina I, Puvanesarajah V, Susarla S. et al. Multidisciplinary Approach for Improved Outcomes in Secondary Cranial Reconstruction: Introducing the Pericranial-onlay Cranioplasty Technique. Neurosurgery 2014; 10(2): 179–189. Chen X, Xu L, Wang Y, Wang H, Wang F, Zeng X, et al. Development of a surgical navigation system based on augmented reality using an optical see-through head-mounted display. J Biomed Inform. 2015; 55: 124–31. pmid:25882923 Dewan, M.C.; Rattani, A.; Gupta, S.; Baticulon, R.E.; Hung, Y.C.; Punchak, M.; Agrawal, A.; Adeleye, A.O.; Shrime, M.G.; Rubiano, A.M.; et al. Estimating the Global Incidence of Traumatic Brain Injury. J. Neurosurg. 2018, 130, 1080–1097. [ Google Scholar] [ CrossRef] [ PubMed]

Li, J.; Egger, J. (Eds.) Towards the Automatization of Cranial Implant Design in Cranioplasty II. In Proceedings of the Second Challenge, AutoImplant 2021, Held in Conjunction with MICCAI 2021, Strasbourg, France, 1 October 2021. [ Google Scholar] [ CrossRef] In this contribution, we developed a planning prototype for 3D cranial implants within the freely available medical research platform MeVisLab ( http://www.mevislab.de/) [ 18]. To the best of our knowledge, this is the first time cranioplasty has been introduced to the MeVisLab platform. We decided for the semi-commercial platform MeVisLab, because it is currently more stable and user friendly than the pure open source platforms, like Slicer or the two MITK toolkits ( www.mitk.org/ and http://www.mitk.net/ from Germany and China). In summary, our method uses the mirrored skull as a template for generating a good fitting and aesthetic looking implant. Fitting in terms of no gaps between the bone and the implant. However, since surgeons have an interest in modifying the implants individually to a certain level, we did not design a fully-automated system performing all operations without any user interaction. Rather, the user can manually intervene in every step for specific modifications of the implant. Finally, the implant model can be stored as STL file to be used with 3D printing technology [ 19]. As audience for this contribution, we want primarily to target clinical/biomedical end users of our prototype. However, we also try to target researches that may want to build upon our solution. Thus, we also provide a more detailed technical description and code-sections like the paragraphs concerning the "Smoother module". We hope that the technical description makes it easier to understand the network/module and enables extensions for further features.Antoniac, V.I.; Mohan, A.G.; Semenescu, A.; Doicin, C.V.; Ulmeanu, M.E.; Costoiu, M.C.; Cavalu, S.; Murzac, R.; Doicin, I.E.; Săceleanu, V.; et al. Cranial Implant with Osteointegration Structures and Functional Coating. Patent RO 132417, 30 October 2019. [ Google Scholar] Chulvi V, Cebrian-Tarrasón D, Sancho Á, Vidal R. Automated design of customized implants. Revista Facultad de Ingeniería Universidad de Antioquia 2013; 68: 95–103. We are grateful to Lorenzo Rook, Pasquale Raia, and Josep Fortuny for inviting us to contribute to this volume. We are also especially grateful to Paul Palmqvist for his comments on an earlier version of this manuscript. We are specially grateful to Jordi Marcé-Nogué and Vincent Fernandez for their highly constructive review of our paper. Supplementary Material

Sampat MP, Wang Z, Markey MK, Whitman GJ, Stephens TW, Bovik AC. Measuring intra- and inter-oberserver agreement in identifying and localizing structures in medical images. IEEE International Conference on Image Processing 2006; pp. 1–4. Amenta N, Bern M, Eppstein D. Optimal point placement for mesh smoothing. Journal of Algorithms 1999; 30(2): 302–322. Birk, H.; Demand, A.; Kandregula, S.; Notarianni, C.; Meram, A.; Kosty, J. Wound vacuum-assisted closure as a bridge therapy in the treatment of infected cranial gunshot wound in a pediatric patient: Illustrative case. J. Neurosurg. Case Lessons 2022, 3, 1–5. [ Google Scholar] [ CrossRef] Jindal, P.; Chaitanya; Bharadwaja, S.S.S.; Rattra, S.; Pareek, D.; Gupta, V.; Breedon, P.; Reinwald, Y.; Juneja, M. Optimizing cranial implant and fixture design using different materials in cranioplasty. Proc. Inst. Mech. Eng. L J. Mater. Des. Appl. 2023, 237, 107–121. [ Google Scholar] [ CrossRef] printing parameter optimization for the manufacture of the bespoke cranial implant and defected skull for Patient 1. 3D-Printed Part

Author Contributions

Singh, J.; Singh, R.; Singh, H. Experimental Investigations for Dimensional Accuracy and Surface Finish of Polyurethane Prototypes Fabricated by Indirect Rapid Tooling: A Case Study. Prog. Addit. Manuf. 2017, 2, 85–97. [ Google Scholar] [ CrossRef] Yu W, Lia M, Lib X. Fragmented skull modeling using heat kernels. Graphical Models. 2012; 74(4): 140–151. This section describes the most common methods used for reconstructing the 3D models of fossil skulls following different sources (i.e., Zollikofer and Ponce de León, 2005; Abel et al., 2012; Cunningham et al., 2014; Sutton et al., 2014; Tallman et al., 2014; Lautenschlager, 2016; Mostakhdemin et al., 2016; Gunz et al., 2020). Moreover, for a correct anatomical reconstruction, one usually has to use different specific bibliographic sources on the anatomy of the group studied. In our case, we have followed Moore (1982) and Novacek (1993), and we have also relied on the anatomy of the skull of living bears, especially those species with a closer phylogenetic relationship with the cave bear (i.e., U. arctos, Ursus americanus, Ursus maritimus, and Ursus thibetanus).