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Item type:Publication, Access status: with files , Primary fixation stability evaluation of pre-bent titanium miniplate configurations in mandibular reconstruction(Frontiers Media S.A., 2026-02-12); ; ; ; Mandibular reconstruction is a commonly performed procedure in maxillofacial surgery with many different possible reconstructive strategies. Generally, modular fixation with miniplates has the advantage of an easier plate removal, mostly possible through an intraoral access. For patient-specific plates, the combination of reconstruction plates in the posterior area with anterior miniplates has been described as biomechanically and clinically beneficial. To our knowledge, conventional miniplates have not been biomechanically assessed in combination with reconstruction plates. Therefore, the present study aimed to evaluate combinations of pre-bent anterior miniplates with a posterior pre-bent reconstruction plate in silico as an alternative to pre-bent fixation strategies including only miniplates. The results indicate, that from a biomechanical perspective, the combination of a posterior pre-bent short reconstruction plate with anterior pre-bent miniplates is a viable alternative to fixation strategies including solely pre-bent miniplates. The process of pre-bending did not affect intersegmental strains. Analogously to patient-specific plates, the combination of a posterior pre-bent reconstruction plate with pre-bent anterior miniplates seems a surgically and biomechanically promising alternative to fixation strategies with pre-bent miniplates alone.Publicationtype: Journal Article12 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Prospective functional assessment after mandible reconstruction and bone healing assessmentObjectives: Mandibular reconstruction remains a clinical challenge due to a high rate of osseous non-unions. Mechanical factors are known to influence the bone regeneration process. Therefore, bite force levels, both immediately after surgery and during the bone healing process, are believed to play a critical role in the healing outcome. The aim of this study was to evaluate bite force and mandibular mobility measurements over time following mandibular reconstruction and to relate these measurements to the bone healing outcome. Materials and methods: In this prospective study, 28 patients were included and underwent functional measurements pre-operatively and at two weeks, four weeks, eight weeks, three months, and six months post-reconstruction. Additionally, the healing outcome was assessed using post-operative imaging. Results: After surgery, the functional parameters - including bite force, mouth opening, protrusion, and laterotrusion - significantly decreased. However, between the initial post-operative measurement and the final follow-up six months after surgery, all parameters showed a significant increase. Two weeks post-operatively, only 9 of the 28 patients were able to participate in the bite force measurement. However, 6 of these patients exhibited incomplete osseous union, which was associated with a mean bite force of 166 N at two weeks (mean over the whole cohort after six months of 154 N). Conclusions: This study demonstrated the trends in functional measurements over time following mandibular reconstruction and identified a significant trend in association between excessive post-operative bite force and incomplete osseous union. Clinical relevance: In consequence, clinical strategies to reduce mechanical over-stimulation could be evaluated in future studies, such as soft food intake for 3 months after mandibular reconstruction.Publicationtype: Journal Article16 21 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Biomechanical evaluation of shape-optimized CAD/CAM magnesium plates for mandibular reconstruction(Elsevier, 2026-01); ; ; ; Magnesium CAD/CAM miniplates are a promising alternative to titanium plates for mandibular reconstruction. However, gas formation is an inherent part of the magnesium degradation process, and thus, the quantity of magnesium used in fixation scenarios should be limited. Previous studies described several strategies to limit material volume, such as plate thickness reduction and shape-optimization. In particular, shape-optimization has been described as a strategy to limit material volume while maintaining mechanical integrity. In consequence, the present study compared a shape-optimized CAD/CAM magnesium miniplate with standard CAD/CAM magnesium miniplates of varying thicknesses using a biomechanical finite element model. A single-segment mandibular reconstruction was chosen as the investigative scenario, evaluated under different biting tasks to assess the different plate shapes. The shape-optimized magnesium plate demonstrated similar primary fixation stability compared to standard CAD/CAM magnesium miniplates, despite having reduced plate material and surface area. Shape optimization could help minimize magnesium volume and surface area to mitigate the issue of gas formation during the degradation process in vivo while maintaining biomechanical performance comparable to common CAD/CAM miniplates.Publicationtype: Journal Article18 24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impact of osteotomy angle on bone failure risk in a modified pull-through approach: a finite element analysis(BioMed Central, 2025-12-01); ; ; ; Background: A modified pull-through approach represents a promising treatment strategy to access tumors in the posterior oral cavity. The design of the wedge osteotomy plays a key role in preserving postoperative mechanical stability while enabling surgical access. However, the optimal osteotomy design to reduce fracture risk remains unclear. Therefore, this study aimed to test osteotomy wedge designs that have the potential to lower the bone fracture risk. Methods: Four wedge osteotomy configurations were compared using finite element analysis based on a realistic mandible model. Each design differed in the angles and curvature of the osteotomy planes. Unilateral molar clenching was simulated, and mechanical strains were quantified and compared to the yield strain of cortical bone in the canine region to evaluate the risk of bone failure. Results: The finite element analysis showed that a wedge osteotomy with less acute angles in the canine region has a lower fracture risk when compared to osteotomies with sharp angles. Peak bone strain values could be reduced by half by changing the osteotomy angle at the canine region. Conclusions: A larger angle between the osteotomy cutting planes offers mechanical advantages by reducing strain concentrations in critical regions. These findings provide valuable guidance for refining the current surgical technique and support the integration of biomechanical analyses into osteotomy planning to optimize surgical outcomes.Publicationtype: Journal Article20 21 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , First-in-human application of dynamic fluoroscopic analysis to quantify intersegmental motion in mandibular free flap reconstruction(Nature Publishing Group, 2025-10-20); ; ; ; Osseous non-union following free flap reconstruction of segmental mandibular defects can prolong patients’ dental rehabilitation. Various plating systems have been developed to optimize biomechanical fixation, but healing may be retarded. Quantifying intersegmental micromovements could help monitor healing but remains challenging. This study investigates a novel method to visualize segmental movements during healing using a fluoroscopy-based approach. To track segment movements, tantalum beads were implanted intraoperatively in the osseous flap and native mandibular segments. Additionally, single-plane fluoroscopic imaging was performed to assess bead position at maximum mouth opening and intercuspation. Bead positions were merged as three-dimensional objects. Intersegmental movements were quantified using model-based roentgen stereophotogrammetry (mbRSA). Exemplarily, preliminary images were collected from one patient. Fluoroscopic imaging with mbRSA effectively displayed movements and allowed quantification. Translation and rotation were assessed between the native mandible and the flap during maximum mouth opening and intercuspation. For the first time, our analyses demonstrate the feasibility of quantifying segment mobility during healing. This first in men study illustrates the feasibility of the method to monitor intersegmental movements in cases of maxillofacial reconstructions. Further research involving larger patient cohorts is necessary to identify relevant thresholds and differentiate from those that result in lack of healing.Publicationtype: Journal Article5 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Local mechanical stresses can explain the mechanoregulation of bone healing after mandibular reconstruction: an in silico studyObjectives: Recent advancements in mandibular reconstruction, including virtual surgical planning and patient-specific 3D-printed reconstruction plates, have improved surgical precision but have not yet fully optimized the mechanical environment for bone healing. This study aimed to investigate the level of mechanical signals that may promote bone regeneration in mandibular reconstruction with patient-specific plates. Materials and methods: A coupled finite‑element and agent‑based mechanobiological model for mandibular bone healing was developed to predict bone formation after mandibular reconstruction. A finite element model (FEM) of a monosegmental mandibular reconstruction with a patient-specific 3D-printed plate during unilateral clenching was coupled with a 3D agent-based model to simulate cellular activities at the osteotomy sites. Using an established mechano-regulation theory, tissue formation and resorption were simulated based on mechanical signals. The latter were systematically varied to identify thresholds matching clinical observations. Results: Increasing the ossification threshold from 0.15 MPa to 0.30 MPa improved agreement with clinical data, leading to 39% and 69% of bone formation in the anterior and posterior gaps, respectively, after 90 days. Conclusions: The model was able to predict levels of newly-formed bone as per clinical observations. Adaptation of the mechano-regulation theory to the mandibular environment suggested that mandibular bone regeneration might occur at a higher level of mechanical stress than in long bones. Clinical relevance: This study presented a computational framework that could, in the future, be incorporated into the clinical workflow during virtual surgical planning to support the mechanical optimization of patient-specific fixation devices and ultimately enhance the healing outcome.Publicationtype: Journal Article15 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Influence of pre-bending on primary fixation stability in one-segmental mandibular reconstruction(Elsevier, 2025-09-01); ; ; ; Background: The fixation of osseous free flaps for segmental mandible reconstruction after resection is most commonly performed with patient-specific 3D printed or conventional load-bearing reconstruction plates. The main challenge with conventional plates is the step of manual bending to adjust the plate to the specific mandible of the patient. To date, the influence of this permanent plate deformation on the biomechanical conditions within the healing regions remains unknown. The present study aimed to investigate the effect of plate pre-bending on intersegmental strains, known to influence the healing outcome. Methods: To achieve this, biomechanical finite element models were developed to simulate plate pre-bending and biting in a one-segmental mandibular reconstruction. The biomechanics induced within the healing region were compared between a pre-stressed conventional reconstruction plate and a customized conventional reconstruction plate. Results: Higher stresses were predicted in the pre-stressed plate. However, the mechanical strains within the healing regions were not influenced by plate pre-bending. Conclusions: The increased levels of mechanical strains under both pre-stressed and customized conventional plates in comparison to common patient-specific plates could be a reason for the higher rates of osseous union under conventional fixation. Since customized conventional reconstruction plates additionally presented elastic stresses and include the advantages of patient-specific plates, those plates are biomechanically and clinically promising.Publicationtype: Journal Article7 17 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Biomechanical evaluation of CAD/CAM magnesium miniplates as a fixation strategy for the treatment of segmental mandibular reconstruction with a fibula free flapTitanium patient-specific (CAD/CAM) plates are frequently used in mandibular reconstruction. However, titanium is a very stiff, non-degradable material which also induces artifacts in the imaging. Although magnesium has been proposed as a potential material alternative, the biomechanical conditions in the reconstructed mandible under magnesium CAD/CAM plate fixation are unknown. This study aimed to evaluate the primary fixation stability and potential of magnesium CAD/CAM miniplates. The biomechanical environment in a one segmental mandibular reconstruction with fibula free flap induced by a combination of a short posterior titanium CAD/CAM reconstruction plate and two anterior CAD/CAM miniplates of titanium and/or magnesium was evaluated, using computer modeling approaches. Output parameters were the strains in the healing regions and the stresses in the plates. Mechanical strains increased locally under magnesium fixation. Two plate-protective constellations for magnesium plates were identified: (1) pairing one magnesium miniplate with a parallel titanium miniplate and (2) pairing anterior magnesium miniplates with a posterior titanium reconstruction plate. Due to their degradability and reduced stiffness in comparison to titanium, magnesium plates could be beneficial for bone healing. Magnesium miniplates can be paired with titanium plates to ensure a non-occurrence of plate failure.Publicationtype: Journal Article11 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Comparative study of CAD/CAM reconstruction and miniplates for patient-specific fixation in LCL-type mandibular reconstruction(2024); ; ; Objective: Miniplates offer superior clinical handling and facilitate postoperative removal after mandibular reconstruction but unfavorable load distribution under high stress has been shown. This study aimed to compare the clinical outcome of patient-specific 3D-printed (PS-3D) titanium miniplate with reconstruction plate fixation in three-segmental LCL-type reconstructions for the first time. Methods: Patients undergoing three-segmental LCL-type mandibular reconstruction after malignant tumor resection between April 2017 and July 2023 were analyzed in a retrospective single-center study. Inclusion criteria were primary reconstruction using a fibula free flap and PS-3D titanium mini- or reconstruction plate fixation. Complication rates were recorded and analyzed within 6 months after surgery using the N – 1 Chi2- and unequal variance t-test. Results: 38 patients (10 females, 28 males; mean age 61.4 ± 7.6 years) met the inclusion criteria. In 14 patients (36.8%) miniplates were used in the anterior region. Rates of fixation failure, plate exposure, incomplete osseous union, wound infection, soft tissue, and overall complications did not differ significantly between the two plate systems. Conclusion: Complication rates did not differ significantly between PS-3D mini- and reconstruction plates in three-segmental LCL-type mandibular reconstructions. Given their advantages in clinical handling and postoperative removal, PS-3D miniplates can be a viable alternative also in larger mandibular reconstructions.Publicationtype: Journal Article13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Patients‘ perspectives on bone replacement materials in a German university hospital setting(BioMed Central, 2023-12-01); ; ; ; Background: The challenges in developing new bone replacement materials and procedures reside not solely in technological innovation and advancement, but also in a broader patient therapy acceptance. Therefore, there is a need to assess patients’ perspectives on the materials and approaches in use as well as the ones being developed to better steer future progress in the field. Methods: A self-initiating cross-sectional questionnaire aimed at people seeking treatment at the university hospital environment of Charité Berlin was formulated. The survey contained 15 close-ended questions directed toward the participant’s epidemiological profile, willingness, acceptance, and agreement to receive different bone replacement materials, as well as, worries about the post-surgical consequences that can arise post bone replacement surgery. Descriptive and categorical analysis was performed to compare the observed number of subjects, their profile and each related response (Pearson’s chi-square test or Fischer’s test, p < 0.05). Results: A total of 198 people engaged with the questionnaire, most of them Millennials. Overall patients trusted scientifically developed biomaterials designed for bone replacement, as demonstrated by their willingness to participate in a clinical trial, their acceptance of alloplastic materials, and the none/few worries about the presence of permanent implants. The data revealed the preferences of patients towards autologous sources of cells and blood to be used with a biomaterial. The data have also shown that both generation and education influenced willingness to participate in a clinical trial and acceptance of alloplastic materials, as well as, worries about the presence of permanent implants and agreement to receive a material with pooled blood and cells. Conclusion: Patients were open to the implantation of biomaterials for bone replacement, with a preference toward autologous sources of blood and/or tissue. Moreover, patients are concerned about strategies based on permanent implants, which indicates a need for resorbable materials. The knowledge gained in this study supports the development of new bone biomaterials.Publicationtype: Journal ArticleScopus© Citations 1 3 47