KLS Martin (Germany)

BackgroundConspicuous color patterns are traditionally believed to advertise the toxicity of prey to potential predators. However, many aposematic species show drastic variation in coloration, indicating the possibility of other functions of coloration such as intraspecific communication. To study these other functions, we can investigate the influence of intrinsic (e.g., sex) and external factors (e.g., climate) on color variation. We used the aposematic European fire salamander (Salamandra salamandra) to study drivers of variation in the yellow-to-black ratio of the dorsal coloration based on citizen science data available in a new online database.ResultsOur results suggest a widespread sexual dichromatism in fire salamanders in Germany with males displaying a larger yellow-to-black ratio, i.e. are more yellow, than females. This dichromatism persisted even after correcting for a sex-difference in body shape that accounts for some of the variation in the yellow-to-black ratio. Among six investigated putative drivers of this color variation, the proportion of the aposematic yellow coloration increased with latitude but showed no association with other environmental variables such as temperature or the productivity of the habitat.ConclusionsIntegrating citizen science data in this study enabled a comparison of fire salamander populations across large parts of their distribution and highlights widespread sexual dichromatism. Future studies should further investigate potential mechanisms of mate choice in fire salamanders and other selective forces on coloration such as differential predation pressure between both sexes or the role in crypsis. Lastly, multi-national studies supported by citizen science data could fully unravel the extent of color variation in this species.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12862-025-02461-0.

While several techniques have been established in the field of auricular reconstruction, these methods are often inadequate in restoring aesthetic function for cases involving significant defects of the temporal bone, particularly after a lateral temporal bone resection for malignancy. This case series describes a novel approach of auricular reconstruction using subperiosteal implants (IPS Implants Craniofacial Epithesis, KLS Martin Group, Tuttlingen, Germany) at an Australian tertiary cancer referral centre. The virtual surgical planning (VSP) process and operative technique for subperiosteal implant-retained auricular prosthetic reconstruction in conjunction with a free flap at our institution is described. A retrospective series of cases performed from November 2023 to July 2024 is presented. Three patients underwent auricular reconstruction with subperiosteal implants. Indications for reconstruction included basal cell carcinoma of the auricle (n = 1) and squamous cell carcinoma involving the ear canals (n = 2). Each patient received one subperiosteal implant (n = 3 retention posts per implant framework). Reconstruction was undertaken with an anterolateral thigh free flap (n = 2) or a radial forearm free flap with adipofascial extension (n = 1). No surgical complications or implant losses were observed in our cohort. Two patients underwent successful loading of an auricular prosthesis 4 and 7 months postoperatively, and retained a functional prosthesis on follow-up. One patient unfortunately died of distant disease at 9 months before prosthesis could be fabricated. Our series supports the feasibility of a subperiosteal implant-retained prosthetic auricular reconstruction after a temporal bone resection in the setting of malignancy. It provides opportunity for a reliable and robust aesthetic rehabilitation after oncological resection. Long-term data is required to establish the reliability and long-term quality-of-life outcomes associated with this novel application of this technique.

Modeling rib fracture stability is challenging. Computer-generated finite element analysis (FEA) is an option for assessment of chest wall stability (CWS). The objective is to explore FEA as a means to assess CWS, hypothesizing it is a reliable approach to better understand rib fracture pathophysiology. Thoracic anatomy was generated from standardized skeletal models with internal/external organs, soft tissue and muscles using Digital Imaging and Communications in Medicine data. Material properties were assigned to bone, cartilage, skin and viscera. Simulation was performed using ANSYS Workbench (2020 R2, Canonsburg, PA). Meshing the model was completed identifying 1.3 and 2.1 million elements and nodes. An implicit solver was used for a linear/static FEA with all bony contacts identified and applied. All material behavior was modeled as isotropic/linear elastic. Six load cases were evaluated from a musculoskeletal AnyBody model; forward flexion, right/left lateral bending, right/left axial rotation and 5-kg weight arm lifting. Standard application points, directions of muscle forces, and joint positions were applied. Ten fracture cases (unilateral and bilateral) were defined and 66 model variations were simulated. Forty-three points were applied to each rib in the mid/anterior axillary lines to assess thoracic stability. Three assessment criteria were used to quantify thoracic motion: normalized mean absolute error, normalized root mean square error, and normalized interfragmentary motion. All three analyses demonstrated similar findings that rib fracture deformation and loss of CWS was highest for left/right axial rotation. Increased number of ribs fracture demonstrated more fracture deformation and more loss of CWS compared with a flail chest segment involving less ribs. A single rib fracture is associated with ~3% loss of CWS. Normalized interfragmentary motion deformation can increases by 230%. Chest wall stability can decrease by over 50% depending on fracture patterns. Finite element analysis is a promising technology for analyzing CWS. Future studies need to focus on clinical relevance and application of this technology. Diagnostic Tests or Criteria; Level IV.

Maxillofacial trauma is a frequent cause for presentation at the emergency department. Maxillofacial trauma is often divided into midfacial or mandibular injury, and each of these regions are known for their characteristic and complex anatomy consequently leading to distinctive physical examination findings. Identification of maxillofacial fractures in an early stage of treatment is essential because of the potential functional and/or aesthetic consequences in case of delayed or lack of treatment. The first part of the thesis focusses on the diagnostic accuracy of physical examination finding for midfacial and mandibular fractures. We found that a simple clinical decision aid based on physical examination findings allows to reduce unnecessary CT scans in patient suspected of maxillofacial fractures. Also, another clinical decision aid safely rules out patients that require immediate surgical intervention. The second part of the thesis focuses on reducing radiation dose for patients that require a CT-scan of the maxillofacial region. The use of iterative reconstruction and deep learning algorithms substantially improve image quality of CT datasets. Moreover, the algorithms allow substantial reduction of the radiation dose while maintaining image quality. The combination of clinical decision aids and novel reconstruction techniques reduces the unnecessary use of CT scans and minimizes radiation exposure in patients that require radiological imaging of the maxillofacial region.