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Biomechanical evaluation of additively manufactured patient-specific mandibular cage implants designed with a semi-automated workflow: A cadaveric and retrospective case study

van Kootwijk, A. (author), Jonker, B. P. (author), Wolvius, E. B. (author), Cruz Saldivar, M. (author), Leeflang, M.A. (author), Zhou, J. (author), Tümer, N. (author), Mirzaali, Mohammad J. (author), Zadpoor, A.A. (author)

Objective: Mandibular reconstruction using patient-specific cage implants is a promising alternative to the vascularized free flap reconstruction for nonirradiated patients with adequate soft tissues, or for patients whose clinical condition is not conducive to microsurgical reconstruction. This study aimed to assess the biomechanical...

journal article 2023

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3D patellar shape is associated with radiological and clinical signs of patellofemoral osteoarthritis

Eijkenboom, J. F.A. (author), Tümer, N. (author), Schiphof, D. (author), Oei, E. H. (author), Zadpoor, A.A. (author), Bierma-Zeinstra, S. M.A. (author), van Middelkoop, M. (author)

Objective: To examine the association between 3D patellar shape and 1) isolated magnetic resonance imaging (MRI)-based patellofemoral osteoarthritis (PFOA), 2) the morphological features of PFOA, and 3) the clinical symptoms of PFOA. Design: MRI data from 66 women with isolated MRI-based PFOA and 66 age- and BMI-matched healthy women were...

journal article 2023

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Controlled metal crumpling as an alternative to folding for the fabrication of nanopatterned meta-biomaterials

Ganjian, M. (author), Janbaz, S. (author), van Manen, T. (author), Tümer, N. (author), Modaresifar, K. (author), Minneboo, M.B. (author), Fratila-Apachitei, E.L. (author), Zadpoor, A.A. (author)

We designed and fabricated a simple setup for the controlled crumpling of nanopatterned, surface-porous flat metallic sheets for the fabrication of volume-porous biomaterials and showed that crumpling can be considered as an efficient alternative to origami-inspired folding. Before crumpling, laser cutting was used to introduce pores to the...

journal article 2022

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Extrusion-based additive manufacturing of Mg-Zn/bioceramic composite scaffolds

Dong, J. (author), Lin, P. (author), Putra, N.E. (author), Tümer, N. (author), Leeflang, M.A. (author), Huan, Z. (author), Fratila-Apachitei, E.L. (author), Chang, J. (author), Zadpoor, A.A. (author), Zhou, J. (author)

The treatment of femoral nonunion with large segmental bone defect is still challenging. Although magnesium alloys have been considered potential materials for such a treatment, their application is limited by their fast degradation. Adding bioceramic particles into magnesium to form Mg-matrix composites is a promising strategy to adjust...

journal article 2022

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Semi-automated digital workflow to design and evaluate patient-specific mandibular reconstruction implants

van Kootwijk, A. (author), Moosabeiki, Vahid (author), Cruz Saldivar, M. (author), Pahlavani, H. (author), Leeflang, M.A. (author), Kazemivand Niar, S. (author), Tümer, N. (author), Mirzaali, Mohammad J. (author), Zhou, J. (author), Zadpoor, A.A. (author)

The reconstruction of large mandibular defects with optimal aesthetic and functional outcomes remains a major challenge for maxillofacial surgeons. The aim of this study was to design patient-specific mandibular reconstruction implants through a semi-automated digital workflow and to assess the effects of topology optimization on the...

journal article 2022

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Extrusion-based additive manufacturing of Mg-Zn alloy scaffolds

Dong, J. (author), Tümer, N. (author), Leeflang, M.A. (author), Taheri, P. (author), Fratila-Apachitei, E.L. (author), Mol, J.M.C. (author), Zadpoor, A.A. (author), Zhou, J. (author)

Porous biodegradable Mg and its alloys are considered to have a great potential to serve as ideal bone substitutes. The recent progress in additive manufacturing (AM) has prompted its application to fabricate Mg scaffolds with geometrically ordered porous structures. Extrusion-based AM, followed by debinding and sintering, has been recently...

journal article 2022

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Comparison in clinical performance of surgical guides for mandibular surgery and temporomandibular joint implants fabricated by additive manufacturing techniques

Oldhoff, M. G.E. (author), Mirzaali, Mohammad J. (author), Tümer, N. (author), Zhou, J. (author), Zadpoor, A.A. (author)

Additive manufacturing (AM) offers great design freedom that enables objects with desired unique and complex geometry and topology to be readily and cost-effectively fabricated. The overall benefits of AM are well known, such as increased material and resource efficiency, enhanced design and production flexibility, the ability to create...

journal article 2021

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Curvature Induced by Deflection in Thick Meta-Plates

Mirzaali, Mohammad J. (author), Ghorbani, Aref (author), Nakatani, Kenichi (author), Nouri Goushki, M. (author), Tümer, N. (author), Callens, S.J.P. (author), Janbaz, S. (author), Accardo, A. (author), Bico, José (author), Habibi, Mehdi (author), Zadpoor, A.A. (author)

The design of advanced functional devices often requires the use of intrinsically curved geometries that belong to the realm of non-Euclidean geometry and remain a challenge for traditional engineering approaches. Here, it is shown how the simple deflection of thick meta-plates based on hexagonal cellular mesostructures can be used to achieve...

journal article 2021

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Extrusion-based 3D printed magnesium scaffolds with multifunctional MgF₂and MgF₂-CaP coatings

Dong, J. (author), Tümer, N. (author), Putra, N.E. (author), Zhu, Jia-Ning (author), Li, Y. (author), Leeflang, M.A. (author), Taheri, P. (author), Fratila-Apachitei, E.L. (author), Mol, J.M.C. (author), Zadpoor, A.A. (author), Zhou, J. (author)

Additively manufactured (AM) biodegradable magnesium (Mg) scaffolds with precisely controlled and fully interconnected porous structures offer unprecedented potential as temporary bone substitutes and for bone regeneration in critical-sized bone defects. However, current attempts to apply AM techniques, mainly powder bed fusion AM, for the...

journal article 2021

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Deciphering the Roles of Interspace and Controlled Disorder in the Bactericidal Properties of Nanopatterns against Staphylococcus aureus

Modaresifar, K. (author), Kunkels, Lorenzo (author), Ganjian, M. (author), Tümer, N. (author), Hagen, C.W. (author), Otten, L.G. (author), Hagedoorn, P.L. (author), Angeloni, L. (author), Ghatkesar, M.K. (author), Fratila-Apachitei, E.L. (author), Zadpoor, A.A. (author)

Recent progress in nano-/micro-fabrication techniques has paved the way for the emergence of synthetic bactericidal patterned surfaces that are capable of killing the bacteria via mechanical mechanisms. Different design parameters are known to affect the bactericidal activity of nanopatterns. Evaluating the effects of each parameter, isolated...

journal article 2020

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Solvent-cast 3D printing of magnesium scaffolds

Dong, J. (author), Li, Y. (author), Lin, P. (author), Leeflang, M.A. (author), van Asperen, S. (author), Yu, K. (author), Tümer, N. (author), Norder, B. (author), Zadpoor, A.A. (author), Zhou, J. (author)

Biodegradable porous magnesium (Mg) scaffolds are promising for application in the regeneration of critical-sized bone defects. Although additive manufacturing (AM) carries the promise of offering unique opportunities to fabricate porous Mg scaffolds, current attempts to apply the AM approach to fabricating Mg scaffolds have encountered some...

journal article 2020

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Three-dimensional analysis of shape variations and symmetry of the fibula, tibia, calcaneus and talus

Tümer, N. (author), Arbabi, V. (author), Gielis, Willem Paul (author), de Jong, Pim A. (author), Weinans, Harrie (author), Tuijthof, Gabrielle J.M. (author), Zadpoor, A.A. (author)

The bones forming the talocrural joint (TCJ) and subtalar joint (STJ) are often assumed to be bilaterally symmetric. Therefore, the contralateral limb (i.e. the fibula, tibia, calcaneus and talus) is used as a template or an intra-subject control in clinical and research practice. However, the validity of the symmetry assumption is...

journal article 2019

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Towards osteogenic and bactericidal nanopatterns?

Widyaratih, Dwisetya S. (author), Hagedoorn, P.L. (author), Otten, L.G. (author), Ganjian, M. (author), Tümer, N. (author), Apachitei, I. (author), Hagen, C.W. (author), Fratila-Apachitei, E.L. (author), Zadpoor, A.A. (author)

Recent discoveries have shown that nanopatterns with feature sizes ≤100 nm could direct stem cell fate or kill bacteria. These effects could be used to develop orthopedic implants with improved osseointegration and decreased chance of implant-associated infections. The quest for osteogenic and bactericidal nanopatterns is ongoing but no...

journal article 2019

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Hyperbolic origami-inspired folding of triply periodic minimal surface structures

Callens, S.J.P. (author), Tümer, N. (author), Zadpoor, A.A. (author)

Origami-inspired folding methods present novel pathways to fabricate three-dimensional (3D) structures from 2D sheets. A key advantage of this approach is that planar printing and patterning processes could be used prior to folding, affording enhanced surface functionality to the folded structures. This is particularly useful for 3D lattices,...

journal article 2019

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Nature helps: Toward bioinspired bactericidal nanopatterns

Ganjian, M. (author), Modaresifar, K. (author), Ligeon, Manon R.O. (author), Kunkels, Lorenzo B. (author), Tümer, N. (author), Angeloni, L. (author), Hagen, C.W. (author), Otten, L.G. (author), Hagedoorn, P.L. (author), Apachitei, I. (author), Fratila-Apachitei, E.L. (author), Zadpoor, A.A. (author)

Development of synthetic bactericidal surfaces is a drug-free route to the prevention of implant-associated infections. Surface nanotopographies with specific dimensions have been shown to kill various types of bacterial strains through a mechanical mechanism, while regulating stem cell differentiation and tissue regeneration. The effective...

journal article 2019

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Typical shape differences in the subtalar joint bones between subjects with chronic ankle instability and controls

Tümer, N. (author), Vuurberg, Gwendolyn (author), Blankevoort, Leendert (author), Kerkhoffs, Gino M.M.J. (author), Tuijthof, G.J.M. (author), Zadpoor, A.A. (author)

Bone shapes, particularly those defining the subtalar joint (STJ), have not received much attention yet as a risk factor for developing chronic ankle instability (CAI) after sustaining a lateral ankle sprain (LAS). This study aimed to compare three-dimensional (3D) shape variations in the STJ bones within individuals with CAI and healthy...

journal article 2019

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Fatigue and quasi-static mechanical behavior of bio-degradable porous biomaterials based on magnesium alloys

Hedayati, R. (author), Ahmadi, S.M. (author), Lietaert, K. (author), Tümer, N. (author), Li, Y (author), Amin Yavari, S. (author), Zadpoor, A.A. (author)

Magnesium and its alloys have the intrinsic capability of degrading over time in vivo without leaving toxic degradation products. They are therefore suitable for use as biodegradable scaffolds that are replaced by the regenerated tissues. One of the main concerns for such applications, particularly in load-bearing areas, is the sufficient...

journal article 2018

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Fatigue performance of additively manufactured meta-biomaterials: The effects of topology and material type

Ahmadi, S.M. (author), Hedayati, R. (author), Li, Y (author), Lietaert, K. (author), Tümer, N. (author), Fatemi, A. (author), Rans, C.D. (author), Pouran, B. (author), Weinans, Harrie (author), Zadpoor, A.A. (author)

Additive manufacturing (AM) techniques enable fabrication of bone-mimicking meta-biomaterials with unprecedented combinations of topological, mechanical, and mass transport properties. The mechanical performance of AM meta-biomaterials is a direct function of their topological design. It is, however, not clear to what extent the material type...

journal article 2018

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Three-dimensional registration of freehand-tracked ultrasound to CT Images of the Talocrural Joint

Tümer, N. (author), Kok, A.C. (author), Vos, F.M. (author), Streekstra, Geert J. (author), Askeland, Christian (author), Tuijthof, G.J.M. (author), Zadpoor, A.A. (author)

A rigid surface–volume registration scheme is presented in this study to register computed tomography (CT) and free-hand tracked ultrasound (US) images of the talocrural joint. Prior to registration, bone surfaces expected to be visible in US are extracted from the CT volume and bone contours in 2D US data are enhanced based on monogenic signal...

journal article 2018

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In-silico quest for bactericidal but non-cytotoxic nanopatterns

Mirzaali, Mohammad J. (author), Van Dongen, I. C.P. (author), Tümer, N. (author), Weinans, Harrie (author), Amin Yavari, S. (author), Zadpoor, A.A. (author)

Nanopillar arrays that are bactericidal but not cytotoxic against the host cells could be used in implantable medical devices to prevent implant-associated infections. It is, however, unclear what heights, widths, interspacing, and shape should be used for the nanopillars to achieve the desired antibacterial effects while not hampering the...

journal article 2018