This study aimed to evaluate the efficacy and safety of a digitally guided dual technique during esthetic crown lengthening surgery. In addition, patient satisfaction and patient-reported outcomes were assessed.

A prospective case series study was conducted. Cone-beam computed tomography and intraoral scans were used to design surgical guides, which were manufactured via 3D printing. The primary outcome was surgical accuracy, assessed by measuring the distance between the planned and final gingival margin positions using overlapping intraoral scans. Secondary outcomes included clinical crown length, gingival margin stability, pain, and patient satisfaction. Statistical analyses were performed using multilevel linear regression models, with significance set at p < 0.05.

Ten participants (87 teeth) were treated without complications. The mean duration of surgery was 66.5 min. The overall absolute deviation was 0.56 mm (95% CI: 0.48 to 0.65) at 6 months postoperatively. Clinical crown length increased significantly from baseline to the end of surgery (p < 0.001), with minimal reduction at 6 months (p = 0.479). Patient-reported outcomes indicated mild postoperative pain and high satisfaction with esthetic results.

The digitally guided dual technique for esthetic crown lengthening surgery is safe and effective, providing highly accurate outcomes. The technique also results in excellent patient satisfaction.

The use of digitally guided dual techniques for ACL surgery enhances precision and safety, leading to highly accurate outcomes and improved patient satisfaction. This approach could be beneficial in clinical settings to ensure better esthetic and functional results.

Carbon nanotubes (CNTs) have attracted significant attention across various fields due to their exceptional electrical, thermal, and mechanical properties. Integrating CNTs with 3D patterning technology, particularly in the manufacturing of vertically stacked CNT fibers, is becoming increasingly important. The objective of this study is to utilize 3D patterning techniques to fabricate CNT nanofibers and to conduct in situ Raman spectroscopy analysis. Precise control of the water meniscus by a quartz tuning fork (QTF)-based atomic force microscopy (AFM) allows the simultaneous execution of nanoscale 3D patterning and in situ Raman analysis. The QTF-AFM technology offers high accuracy and precision without the need for high voltage or high-pressure conditions of conventional lithography techniques, which is a significant advantage in the fabrication of CNT nanofibers. The fabricated CNT nanofibers were then subsequently analyzed using in situ Raman spectroscopy, allowing for real-time monitoring of their structural properties. The results of this research provide a valuable methodology for advancing various fields, including electronic devices and catalysis, through an integrated platform. This study highlights the potential of merging nanoscale 3D patterning technology with real-time analytical techniques. The innovative approach demonstrated here is expected to contribute to the advancement of nanomaterial applications and pave the way for future innovations in the field.

Preservation of bone and anatomic structures during oral and maxillofacial resections are common goals of using custom cutting guides. Nonlinear cutting guides may offer improved patient care over linear cutting guides by allowing for additional areas of fixation, additional support for bony reconstructions, expanded use of nonvascular reconstructions, improved identification and preservation of anatomy, and improved cosmesis. A retrospective case series of 7 patients was created through a chart review of all patients undergoing resections at Augusta University between July 1, 2020, and January 31, 2025, for the purpose of identifying any close or positive margins on final pathology. No close or positive margins were noted. The use of nonlinear cutting guides for resection of oral and maxillofacial pathologies requires careful consideration of resection margins, precision and accuracy of virtual surgical planning and manufacturing constraints, and surgeon comfort. It is reasonable to consider more widespread adoption within 5 years.

Modern pelvic surgery is essentially influenced by technological innovations. One of the most impressive advances in this field is the integration of 3D printing and the associated possibility for the production of 1:1 models of the pelvic skeleton. Using these models, conventional pelvic implants can preoperatively be more exactly and patient-specifically contoured. The use of this technology has the potential to substantially improve the quality of care and simultaneously to optimize the surgical results. By the use of 3D-printed implants, which are individually adapted to the anatomical conditions of the patient, operations can not only be carried out more quickly and efficiently but also with a greater accuracy and potentially fewer complications. This article presents two instructive cases. Case 1 demonstrates how a proximal femoral fracture with a pre-existing deformity of the femur can be treated with a patient-specific implant. Treatment with conventional intramedullary or extramedullary implants was not possible. Case 2 illustrates the treatment of a pelvic ring fracture and the advantage of 3D printing for the preoperative patient-specific contouring of conventional plate systems.

There are strong torsional forces acting on the anterior mandible fractures. Maxillofacial surgery makes extensive use of digital technology, and three-dimensional printing is now an integral element of the workflow in several areas of oral and maxillofacial surgery. Three-dimensional (3D) miniplates had been proposed by several researchers as a good option for mandibular fracture fixation. This clinical trial was conducted to evaluate the accuracy of virtual planning in anterior mandibular fixation by comparing postoperative outcomes with preoperative virtual planning and to evaluate bone healing by measuring bone density after using pre-bent 3D miniplates on a 3D model to complete a 3D workflow and to fix the mandible in 3D.

15 Patients with anterior mandibular fractures were included in the study. All patients underwent computer tomography (CT) scan, and the data were imported into Mimics software. The unaffected healthy side was mirrored to the fractured side. Bone fixation three-dimensional plates were prebent and adapted on the model printed by the three-dimensional printing machine, submitted to sterilization, and were used for bone reduction and fixation. An immediate postoperative CT scan was taken to evaluate the accuracy of virtual planning and after 3 months for evaluation of bone healing.

Clinical observation revealed good stable occlusion, and there was no significant difference between the postoperative three-dimensional image of the mandible and the virtually reduced mandible in the preoperative plan, as there was no significant difference between the length and width between anatomical landmarks of the virtually reduced mandible and the postoperative plan (p > 0.05). The bone density measured by Hounsfield units (HU) measured on CT images after 3 months revealed good bone healing as compared to immediate postoperative values (P value < 0.05).

Digital workflow provides an accurate method for the reduction and fixation of anterior mandibular fractures. Also, 3D miniplates provide a good option for symphyseal and parasymphyseal fractures despite their limitations, as in some cases, like comminuted fractures and fractures in and around the mental foramen.

This clinical trial was registered at Alexandria university, on 02/11/2021 under the registration number 0308 - 10/2021. All procedures involving human participants were performed in accordance with Research Ethics Committee, Faculty of Dentistry, Alexandria University under IRB No 00010556 and IORG No 0008839. The current study was retrospectively registered at ClinicalTrials.gov with the identification number NCT06898736 on 27/3/2025. However, all study protocols were predefined, with no deviations from the original methodology.

Amphibious warships are now being deployed with established 3D printing departments capable of designing and manufacturing parts for aircraft or ship engineering needs. The ability to print with a variety of materials from heat stable polymers to metal constructs can be useful to shipboard medical departments to replenish consumable and durable supplies. This report aims to demonstrate the potential benefit of leveraging the afloat additive manufacturing capabilities for medical parts and supplies while deployed at sea.

Shipboard additive manufacturing was used to re-supply a sevoflurane vaporizer key for the primary anesthesia machine which was found to be damaged and non-function during deployment. A surgical retractor intended for open surgical procedures and a scrub sink knee control lever were also manufactured. All items were rendered on the 3D computer-aided design program interface to match the desired part specifications, and a functional new part or instrument was printed while deployed at sea.

Printed items were manufactured to acceptable specifications. The primary sevoflurane vaporizer key was tested and found to function as intended, allowing the primary operating room anesthesia machine to maintain functionality. The surgical retractor was sterilized at high pressure and high temperature with preserved material stability and deemed appropriate for clinical use. The scrub sink knee lever functioned appropriately once installed. No modifications were required post-manufacturing.

This proof of concept report conducted onboard a forward-deployed amphibious warship provides a basis on which future applications can be applied. Digital libraries of medical and surgical supplies can be used to obviate supply chain costs and delays by manufacturing items afloat. 3D printing for on-demand use can decrease the risk of resource depletion and capability degradation in the shipboard medical department.

The rising volume of primary hip and knee arthroplasties has led to a parallel increase in revision surgeries, creating significant clinical and economic challenges for healthcare systems worldwide. This study synthesizes national arthroplasty registry data to evaluate trends in revision aetiology, associated costs and regional disparities. While advancements in prosthetic design have reduced aseptic loosening rates (declining to 35.1% for hips and 18.3% for knees), septic complications now account for a growing proportion of revision cases, rising to 18.2% for hips and 21.6% for knees. Additionally, instability and malalignment persist at 15.9% and 14.1%, respectively. Revision procedures are 76% more costly than primary surgeries, with two-stage septic revisions incurring costs of up to $37,297 per case. Beyond direct surgical costs, prolonged recovery and productivity loss contribute to a broader economic impact. Regional variations, such as higher periprosthetic fracture rates in England and Wales, highlight inconsistencies in data reporting and healthcare practices. Addressing these challenges requires standardized infection definitions, enhanced registry collaboration and investment in infection prevention strategies. The role of referral centres in improving outcomes and reducing costs through multidisciplinary care is increasingly recognized. By integrating evidence-based infection management protocols and leveraging emerging technologies, the orthopaedic community can optimize patient outcomes and reduce the financial burden of revising arthroplasties. LEVEL OF EVIDENCE: Level IV.

Postoperative malunion following distal femoral Hoffa fractures is rare yet challenging. We present a novel approach using customized lateral unicompartmental knee arthroplasty (UKA) to address malunion with traumatic osteoarthritis, emphasizing functional restoration.

A 52-year-old male presented with persistent right knee pain (VAS score: 7/10), restricted range of motion (ROM: 0°-60° flexion), and gait instability two years after open reduction and internal fixation (ORIF) of a lateral Hoffa fracture. Imaging confirmed malunion of the fracture with traumatic osteoarthritis. A customized lateral femoral condyle prosthesis was designed using three-dimensional Computed Tomography (CT) reconstruction and implanted via a lateral parapatellar approach. Postoperative imaging (8-12 weeks) revealed optimal alignment and resolved fracture gaps. At 12 weeks, pain resolved (VAS: 1/10), ROM improved to 0°-125°, and Knee Society Score reached 85/100, with no complications.

Malunion after Hoffa fracture fixation is uncommon. Traditional revision ORIF may fail due to bone loss, while UKA preserves healthy compartments by restoring biomechanics. Customized implants address anatomical complexity, though long-term efficacy requires further study.

Customized UKA offers a viable solution for Hoffa fracture malunion with traumatic osteoarthritis, prioritizing joint preservation. This approach highlights the potential of patient-specific implants in complex orthopaedic salvage.

Preoperative planning is crucial for successful surgical outcomes. 3D printing technology has revolutionized surgical planning by enabling the creation and manufacturing of patient-specific models and instruments. This review explores the applications of 3D printing in pediatric orthopedics, focusing on image acquisition, segmentation, 3D model creation, and printing techniques within specific applications, including pediatric limb deformities, pediatric orthopedic oncology, and pediatric spinal deformities. 3D printing simultaneously enhances surgical precision while reducing operative time, reduces complications, and improves patient outcomes in various pediatric orthopedic conditions. 3D printing is a transformative technology in pediatric orthopedics, offering significant advantages in preoperative planning, surgical execution, and postoperative care.

Three-dimensional (3D) food printing holds the potential to help reduce food waste by precise portion control and use of materials that are produced in excess or are otherwise discarded. This relatively new technology is likely to undergo decreases in equipment costs. To take advantage of such prospects, we developed a novel micellar casein-based edible 3D printing formulation. Our formulation relies on a highly concentrated micellar casein solution (27.75%, wt/wt, final) along with pH adjustments (3.5, 4.0, 4.8, 6.7, 7.2, and 8.2) at chilled temperature (4-9°C) to avoid premature aggregation. In comparison to the natural pH of 6.7, both alkalinization and acidification past the isoelectric point of 4.6 enhanced both elastic and viscous moduli that enable for shape retention during and after extrusion from a 3D food printer. However, alkalinization led to smaller increases in the viscous modulus and did not lead to the shape retention that acidification to 4.0 or 3.5 does. Both acidification and alkalinization also resulted in rougher surface textures compared with the formulation at pH 6.7. Whereas the pH 4.8 formulation had inferior shape retention qualities compared with those at the other pH values tested, it had optimized water resilience, defined here as minimized swelling and dissolution of dried structures placed in water. Overall, we present a novel casein-based 3D printing formulation that could be printed while chilled, and with properties that could be modified by pH adjustments.

Interfacing artificial devices with the human brain is the central goal of neurotechnology. Yet, our imaginations are often limited by currently available paradigms and technologies. Suggestions for brain-machine interfaces have changed over time, along with the available technology. Mechanical levers and cable winches were used to move parts of the brain during the mechanical age. Sophisticated electronic wiring and remote control have arisen during the electronic age, ultimately leading to plug-and-play computer interfaces. Nonetheless, our brains are so complex that these visions, until recently, largely remained unreachable dreams. The general problem, thus far, is that most of our technology is mechanically and/or electrically engineered, whereas the brain is a living, dynamic entity. As a result, these worlds are difficult to interface with one another. Nanotechnology, which encompasses engineered solid-state objects and integrated circuits, excels at small length scales of single to a few hundred nanometers and, thus, matches the sizes of biomolecules, biomolecular assemblies, and parts of cells. Consequently, we envision nanomaterials and nanotools as opportunities to interface with the brain in alternative ways. Here, we review the existing literature on the use of nanotechnology in brain-machine interfaces and look forward in discussing perspectives and limitations based on the authors' expertise across a range of complementary disciplines─from neuroscience, engineering, physics, and chemistry to biology and medicine, computer science and mathematics, and social science and jurisprudence. We focus on nanotechnology but also include information from related fields when useful and complementary.

This case describes an early adolescent boy with severe pectus carinatum, managed with a complex surgical approach after bracing was deemed unfeasible. A multidisciplinary team collaborated, using advanced three-dimensional (3D) imaging, digital segmentation and a patient-specific 3D-printed model to plan and rehearse the surgery. The operation involved sternum repositioning and rib plating with polyether ether ketone plates. The procedure resulted in favourable chest stability and minimal blood loss. Postoperatively, the patient's pain was well-controlled, and he was discharged on day 7. The patient expressed satisfaction with the outcome and resumed normal activities within a month.

Three-dimensional (3D) printing technology has emerged as a revolutionary tool in orthopedic trauma surgery, offering unprecedented opportunities for personalized patient care. This comprehensive review explores the current developments and applications of 3D printing in orthopedic trauma, highlighting its potential to address complex surgical challenges. We provide an in-depth analysis of various 3D printing technologies applicable to orthopedic surgery, including vat photopolymerization, material extrusion, powder bed fusion, and sheet lamination. The review examines the use of 3D printing in preoperative planning, surgical simulation, and the creation of patient-specific implants and surgical guides. We discuss applications across different anatomical regions, including upper limb, lower limb, and pelvic and spinal trauma. Evidence from recent studies demonstrates that 3D printing-assisted surgeries can lead to reduced operative times, decreased blood loss, improved fracture reduction quality, and potentially better clinical outcomes. This review synthesizes the latest research and clinical experiences, providing insights into the current state of 3D printing in orthopedic trauma and its future perspectives. As the technology continues to evolve, 3D printing holds promise for increasingly personalized and effective treatments in orthopedic trauma care, potentially transforming surgical practices and improving patient outcomes.

Adult spinal deformity (ASD) is a spectrum of abnormalities of the thoracic and lumbar spine and has an increasing prevalence. It is associated with significant physical and mental disability in symptomatic patients. Given the increased rates and the morbidity associated with this disease, novel innovation in the diagnosis and treatment of such deformity is required. The SRS-Schwab classification system described coronal scoliotic deformity with sagittal modifiers. Other parameters, such as the sagittal vertical axis, pelvic tilt, T1 pelvic angle, pelvic incidence and lumbar lordosis attempted to quantify global sagittal balance. More recently, a focus on more patient specific parameters has been targeted to improve patient outcomes. The Roussouly classification system attempted to predict sagittal alignment parameters based on fixed parameters of the pelvis. Others determined the parameters based on patient age. Technological advances have also enhanced our understanding of ASD. Long cassette films and automated analyses have allowed standardization of these measurements across physicians. 3D printing has been used as an adjunct for both surgical planning and implants, both generic and patient specific, to improve outcomes. With these, advances in minimally invasive approaches have allowed ASD correction with lower complications and blood loss. Intraoperative navigation and the use of robotics has allowed improved accuracy in the care of these patients. Development of complex osteotomies have allowed for correction of advanced deformity. Fusion, however, is the ultimate goal of surgical ASD correction. Advances in biologics such as the use of recombinant Human Bone Morphogenetic Protein-2 have been used to improve fusion rates and combat pseudoarthrosis. Finally, post-operative advances in ASD patient care with emphasis on enhanced recovery after surgery has allowed improvements in hospital length of stay and pain scores. ASD is becoming a more ubiquitous diagnosis for spine surgeons with an increasing aging population. Improvement in the understanding of the diagnosis, spinopelvic parameters, imaging techniques, and post operative care are all aimed toward helping patients in whom care can be extremely difficult. Further study in ASD patient care will target advanced innovation to provide optimal treatment to these patients and allow for best possible outcomes.

Technological advancements have made three-dimensional printing prevalent in orthopedic surgery. It facilitates the production of customized implants and tailored patient instruments, enhancing surgical planning and results. This review focuses on the uses and effectiveness of patient-specific products manufactured using three-dimensional printing in ankle surgery.

A search of databases-PubMed, Embase, Cochrane Library, and Google Scholar-yielded 41 articles for review.

Total talus replacement offers a viable alternative to standard treatments like arthrodesis and total ankle arthroplasty. Custom implants and patient-specific instrumentation in total ankle arthroplasty procedures guarantee a tailored fit and accurate alignment. For arthrodesis, three-dimensional printing enables the production of cages, effectively solving issues associated with conventional bone grafts, such as poor bone quality, significant defects, and nonunion. Additionally, patient-specific instrumentation facilitates the swift and accurate placement of Kirschner wires at the correct sites. When performing supramalleolar osteotomy, patient-specific instrumentation leads to shorter operation times, reduced blood loss, and less radiation exposure.

Three-dimensional printing is increasingly employed in ankle surgeries, and as technology advances, it is anticipated to become critical for addressing complex ankle issues.

The maturation of 3D printing technologies has opened up a new space for patient advancements in healthcare from trainee education to patient specific medical devices. Point-of-care (POC) manufacturing, where model production is done on-site, includes multiple benefits such as enhanced communication, reduced lead time, and lower costs. However, the small scale of many POC manufacturing operations complicates their ability to establish quality assurance practices. This study presents a novel low-cost quality assurance protocol for POC 3D printing.

Four hundred specially designed quality assurance cubes were printed across four material jetting printers (J5 Medijet, Stratasys, Eden Prairie, Minnesota, USA) at two large medical centers. Three inner dimension and three outer dimension measurements as well as edge angles were measured for every cube by trained research personnel. The delta and absolute error was calculated for each cube and then compared across variables (axis, material, inner vs. outer dimension, swath and machine/site/personnel) using ANOVA analysis.

Print axis and inner vs. outer dimension of the model produced statistically significant differences in error while there was no statistically significant difference in the error for material, print swath, or machine/site/personnel. For the print axes, the printers produced an average error of 26, 53, and 57 μm and the error at three sigma was found to be 100, 158, and 198 μm for the Z, R, and Theta axes, respectively.

This study demonstrates that this novel protocol is both feasible and reliable for quality assurance in POC 3D printing across multiple sites. This protocol offers an adaptable framework that allows users to tailor the QA process to their specific needs. Through the comprehensive method, users can measure and identify all relevant factors that might introduce error into their printed product and then follow the most critical aspects for their situation across every print. The QA cubes produced via this protocol can provide guidance on print quality and alert users to unsatisfactory machine operation which could cause prints to fall outside of engineering and clinical tolerances.

We evaluated the utility of 3D printing technology for preoperative planning in the treatment of intra-articular fractures of the distal radius in relation to the improvement of surgical technique, radiological and clinical results.

A total of 30 patients with 2B and C fractures of the AO classification were operated on by a single surgeon with a volar plate, randomly divided into two groups, 15 of them with conventional planning (Rx and CT) and 15 adding a 3D model of the fracture and the previous simulation of the intervention. Simulation time, surgical time in minutes, radioscopy time in minutes, loss of material expressed in lost screws were recorded. Clinical evaluation based PRWE questionnaire and full radiographic analysis was done for all patients with a mean follow-up of 6 months by an independent, blinded observed.

No statistically significant differences were observed in the PRWE questionnaire (p=0.22), nor were we observed differences in the radiological values, except in relation to the articular step (p=0.028), which represents statistical significance, but in both groups the median was of 0.0 (0.0-0.0). We also did not see statistically significant differences in surgical times (p=0.745), radioscopy (p=0.819) or in the loss of synthesis material (p=0.779).

3D printing has not improved the parameters studied in relation to routinely operated patients.

We evaluated the utility of 3D printing technology for preoperative planning in the treatment of intra-articular fractures of the distal radius in relation to the improvement of surgical technique, radiological and clinical results.

A total of 30 patients with 2B and C fractures of the AO classification were operated on by a single surgeon with a volar plate, randomly divided into two groups, 15 of them with conventional planning (Rx and CT) and 15 adding a 3D model of the fracture and the previous simulation of the intervention. Simulation time, surgical time in minutes, radioscopy time in minutes, loss of material expressed in lost screws were recorded. Clinical evaluation based PRWE questionnaire and full radiographic analysis was done for all patients with a mean follow-up of 6 months by an independent, blinded observed.

No statistically significant differences were observed in the PRWE questionnaire (p=0.22), nor were we observed differences in the radiological values, except in relation to the articular step (p=0.028), which represents statistical significance, but in both groups the median was of 0.0 (0.0-0.0). We also did not see statistically significant differences in surgical times (p=0.745), radioscopy (p=0.819) or in the loss of synthesis material (p=0.779).

3D printing has not improved the parameters studied in relation to routinely operated patients.

Perhaps the most innovative branch of medicine is represented by regenerative medicine. It deals with regenerating or replacing tissues damaged by disease or aging. The innovative frontier of this branch is represented by bioprinting. This technology aims to reconstruct tissues, organs, and anatomical structures, such as those in the head and neck region. This would mean revolutionizing therapeutic and surgical approaches in the management of multiple conditions in which a conspicuous amount of tissue is lost. The application of bioprinting for the reconstruction of anatomical areas removed due to the presence of malignancy would represent a revolutionary new step in personalized and precision medicine. This review aims to investigate recent advances in the use of biomaterials for the reconstruction of anatomical structures of the head-neck region, particularly those of the oral cavity. The characteristics and properties of each biomaterial currently available will be presented, as well as their potential applicability in the reconstruction of areas affected by neoplasia damaged after surgery. In addition, this study aims to examine the current limitations and challenges and to analyze the future prospects of this technology in maxillofacial surgery.

Surgical guides are integral tools in orthodontics, enhancing the precision and predictability of mini-implant placement. These guides facilitate accurate positioning, reduce risks to surrounding anatomical structures, and ensure proper angulation and depth during procedures. The aim of the present paper is to present a detailed review of the surgical guides used in orthodontics, focusing on their classification, mechanical properties, biocompatibility, and future developments. The advantages, disadvantages, clinical steps, and implications are also described based on the data in recent scientific literature. Future developments may incorporate artificial intelligence and augmented reality, further optimizing treatment planning and patient outcomes, thus solidifying the role of surgical guides in efficient orthodontic care.

Currently, bone tissue engineering is a research hotspot in the treatment of orthopedic diseases, and many problems in orthopedics can be solved through bone tissue engineering, which can be used to treat fractures, bone defects, arthritis, etc. More importantly, it can provide an alternative to traditional bone grafting and solve the problems of insufficient autologous bone grafting, poor histocompatibility of grafts, and insufficient induced bone regeneration. Growth factors are key factors in bone tissue engineering by promoting osteoblast proliferation and differentiation, which in turn increases the efficiency of osteogenesis and bone regeneration. 3D printing technology can provide carriers with better pore structure for growth factors to improve the stability of growth factors and precisely control their release. Studies have shown that 3D-printed scaffolds containing growth factors provide a better choice for personalized treatment, bone defect repair, and bone regeneration in orthopedics, which are important for the treatment of orthopedic diseases and have potential research value in orthopedic applications. This paper aims to summarize the research progress of 3D printed scaffolds containing growth factors in orthopedics in recent years and summarize the use of different growth factors in 3D scaffolds, including bone morphogenetic proteins, platelet-derived growth factors, transforming growth factors, vascular endothelial growth factors, etc. Optimization of material selection and the way of combining growth factors with scaffolds are also discussed.

Over the last decades, three-dimensional (3D) printing has emerged as one of the most promising alternative tissue and organ regeneration technologies. Recent advances in 3D printing technology, particularly in hydrogel-derived bioink formulations, offer promising solutions for fabricating intricate, biomimetic scaffolds that promote vascularization. In this review, we presented numerous studies that have been conducted to fabricate 3D-printed hydrogel vascularized constructs with significant advancements in printing integumentary systems, cardiovascular systems, vascularized bone tissues, skeletal muscles, livers, and kidneys. Furthermore, this work also discusses the engineering considerations, current challenges, proposed solutions, and future outlooks of 3D bioprinting.

The objective of this systematic review is to present a comprehensive summary of existing research on the use of 3D printing in spinal surgery.

The researchers conducted a thorough search of four digital databases (PubMed, Web of Science, Scopus, and Embase) to identify relevant studies published between January 1999 and December 2022. The review focused on various aspects, including the types of objects printed, clinical applications, clinical outcomes, time and cost considerations, 3D printing materials, location of 3D printing, and technologies utilized. Out of the 1620 studies initially identified and the 17 added by manual search, 105 met the inclusion criteria for this review, collectively involving 2088 patients whose surgeries involved 3D printed objects.

The studies presented a variety of 3D printed devices, such as anatomical models, intraoperative navigational templates, and customized implants. The most widely used type of objects are drill guides (53%) and anatomical models (25%) which can also be used for simulating the surgery. Custom made implants are much less frequently used (16% of papers). These devices significantly improved clinical outcomes, particularly enhancing the accuracy of pedicle screw placement. Most studies (88%) reported reduced operation times, although two noted longer times due to procedural complexities. A variety of 3DP technologies and materials were used, with STL, FDM, and SLS common for models and guides, and titanium for implants via EBM, SLM, and DMLS. Materialise software (Mimics, 3-Matic, Magics) was frequently utilized. While most studies mentioned outsourced production, in-house printing was implied in several cases, indicating a trend towards localized 3D printing in spine surgery.

3D printing in spine surgery, a rapidly growing area of research, is predominantly used for creating drill guides for screw insertion, anatomical models, and innovative implants, enhancing clinical outcomes and reducing operative time. While cost-efficiency remains uncertain due to insufficient data, some 3D printing applications, like pedicle screw drill guides, are already widely accepted and routinely used in hospitals.

The aim of this study was to evaluate the feasibility of using patient-specific implants (PSI) for complex shaft corrective osteotomies in multiplanar deformities of long bones in the lower extremities. Additionally, it aimed to investigate the added value of these implants by quantifying surgical accuracy on postoperative CT, comparing their outcomes to two commonly used techniques: 3D virtual visualizations and 3D-printed surgical guides.

Six tibial and femoral shaft corrective osteotomies were planned and performed on three Thiel embalmed human specimen. Depending on the specimen a different respective technique was used; 1) '3D Visualization' using 3D virtual plan preoperatively and free-hand corrective osteotomy techniques with standard manually contoured plates; 2) '3D guided' utilizing 3D surgical guides and manually contouring of conventional implant; and 3)'3D PSI' utilizing a 3D surgical guide with a patient-specific implant. Accuracy of the corrections was assessed through measurements for varus/valgus angulation, ante/recurvation, rotation and osteotomy plane error as quantified on postoperative CT-scans.

Twelve corrective osteotomies were performed. For, the median difference between the surgical plan and postoperative CT assessment was 3.4°, 4.6°, and 2.2° for the '3D visualization', '3D guided', and '3D PSI' methods respectively. Regarding ante/recurvation, the differences were 3.8°, 43.8°, and 1.2°, respectively. For rotation, the differences were 11.9°, 18.7°, and 3.5°, respectively. Discrepancies between planned and executed levels of osteotomy plane were 6.2 mm, 3.2 mm, and 1.4 mm, respectively.

PSIs with 3D-printed drilling guides for complex multiplanar corrective osteotomies of femoral and tibial shaft malunions is feasible and achieves accurate corrections. This technique enables precise determination of the osteotomy plane, guides correction in all three planes, and ensures satisfactory implant fitting; thus accurately translating the virtual surgical plan into clinical practice. The 3D PSI method is beneficial for complex cases with significant multiplanar deformities in bone anatomy, particularly with rotational malalignment.

Background/Objectives: Vascularized bone grafts have been successfully established for complex bone defects. The integration of three-dimensional (3D) simulation and printing technology may aid in more precise surgical planning and intraoperative bone shaping. The purpose of the present study was to describe the implementation and surgical application of this innovative technology for bone reconstruction. Methods: This prospective pilot study was conducted between June 2019 and June 2024. For this evaluation, patients who received vascularized bone reconstruction assisted with 3D technology were included. For reconstruction, the free medial femoral condyle (MFC) flap was used as the vascularized bone graft. Patient-specific 3D-printed templates, based on individual 3D simulations according to defect characteristics, were used for surgical planning, including flap elevation, shaping and inset. Results: A total of six patients (five male) with an average age of 39 years (range 19-62 years) and a mean follow-up time of 15 months (range 5-24 months) were analysed. The indications were as follows: avascular necrosis of the carpal bones, a metacarpal defect after tumor resection and pseudoarthrosis after a fractured ulna. Three patients received an osteochondral and three patients received a cortico-cancellous MFC flap. Conclusions: Our evaluation of clinical application revealed enhanced preoperative planning as well as intraoperative performance. Although the implementation for this technology is challenging, the new insights gained in planning and surgical guidance have led us to incorporate this technology into our standard routine.

This review article delves into the cutting-edge realm of 3D printing and its impact on the fabrication of customised orthodontic retainers, which is an essential utility in the prevention of relapse post orthodontic treatment. This review evaluates the use of biocompatible materials and provides insight into future perspectives and improvements in this field. It highlights the potential of data collecting method and 3D printing to improve orthodontic retainers' fabrication and emphasises the importance of using biocompatible materials for patient safety and efficacy. It also explains cytotoxic qualities of retainer fabrication materials, which are vital for safeguarding the oral health of the patient. The evaluation procedure enables the early diagnosis and correction of any potential difficulties, such as maladjustment or inappropriate fit, allowing for a more effective treatment. It illustrates the breakthroughs and innovations in the field of orthodontics, the advantages of 3D printing over conventional methods, as well as the advantages and disadvantages of various fabrication method. Incorporating 3D printing and review into the production of orthodontic retainers enhances the overall effectiveness and efficiency of patient treatment.

3D technologies [Virtual and Augmented 3D planning, 3D printing (3DP), Additive Manufacturing (AM)] are rapidly being adopted in the healthcare sector, demonstrating their relevance in personalized medicine and the rapid development of medical devices. The study's purpose was to understand the state and evolution of 3DP/AM technologies at the Point-of-Care (PoC), its adoption, organization and process in Spanish hospitals and to understand and compare the evolution of the models, clinical applications, and challenges in utilizing the technology during the COVID-19 pandemic and beyond.

This was a questionnaire-based qualitative and longitudinal study. Data on 3DP and AM activities in Spain were collected from 73 hospitals/institutions falling under the ITEMAS (Platform for Innovation in Medical and Health Technologies) and the Plataforma ISCIII Biomodelos y Biobancos from January 2019 to May 2020 for the first study, and at the end of 2022 and 2023 for the second study.

A total of 23 (31.5%) hospitals during the first study, while 30 (41.09%) during the second study reported having at least one 3DP/AM initiative. Post-covid, the majority of hospitals had onsite 3DP/AM services with a well-defined, structured, and centralized system. Traumatology and maxillofacial surgery services were found to be the most involved in 3DP projects for the production of custom-made surgical guides, prostheses and orthoses. Bioprinting initiatives were also noted to be expanding. Human resources, cost, and regulatory compliance were the key hurdles in introducing 3D/AM in hospitals.

In-house 3DP/AM units, with Mixed-Model is the most common model in Spain; The COVID-19 pandemic influenced the 3D planning activity and adoption. Further research and clinical trials, and improvements in resources, reimbursement and regulatory compliance are critical for the Point-of-care hospital growth of this breakthrough technology.

In the latter part of the 20th century, remarkable developments in new dental materials and technologies were achieved. However, regarding the impact of dental resin-based materials 3D-printed on cellular responses, there have been a limited number of published studies recently. The biocompatibility of dental restorative materials is a controversial topic, especially when discussing modern manufacturing technologies. Three-dimensional printing generates the release of residual monomers due to incomplete polymerization of materials and involves the use of potentially toxic substances in post-printing processes that cannot be completely eliminated. Considering the issue of biocompatibility, this article aims to establish an overview of this aspect, summarizing the different types of biocompatibility tests performed on materials used in 3D printing in dentistry. In order to create this comprehensive review, articles dealing with the issue of 3D printing in dentistry were analysed by accessing the main specialized search engines using specific keywords. Relevant data referring to types of materials used in 3DP to manufacture various dental devices, polymerization methods, factors affecting monomer release, cytotoxicity of unreacted products or post-curing treatments, and methods for assessing biocompatibility were analysed. Although the introduction of new restorative materials used in dental treatments is subject to national and international regulations and standards, it is necessary to investigate them regarding biocompatibility in order to support or deny the manufacturers' statements regarding this aspect.

Three-dimensional printing (3DP) enables the production of highly customised, cost-efficient devices in a relatively short time, which can be particularly valuable to clinicians treating patients with palliative care intent who are in need of timely and effective solutions in the management of their patients' specific needs, including the relief of distressing symptoms.

Four online databases were searched for articles published by December 2020 that described studies using 3DP in palliative care. The fields of application, and the relevant clinical and technological data were extracted and analysed.

Thirty studies were reviewed, describing 36 medical devices, including anatomical models, endoluminal stents, navigation guides, obturators, epitheses, endoprostheses and others. Two-thirds of the studies were published after the year 2017. The main reason for using 3DP was the difficulty of producing customised devices with traditional methods. Eleven papers described proof-of-concept studies that did not involve human testing. For those devices that were tested on patients, favourable clinical outcomes were reported in general, and treatment with the use of 3DP was deemed superior to conventional clinical approaches. The most commonly employed 3DP technologies were fused filament fabrication with acrylonitrile butadiene styrene and stereolithography or material jetting with various types of photopolymer resin.

Recently, there has been a considerable increase in the application of 3DP to produce medical devices and bespoke solutions in the delivery of treatments with palliative care intent. 3DP was found successful in overcoming difficulties with conventional approaches and in treating medical conditions requiring highly customised solutions.

The realm of precision medicine, particularly its application within various sectors, shines notably in neuroradiology, where it leverages the advancements of three-dimensional (3D) printing technology. This synergy has significantly enhanced surgical planning, fostered the creation of tailor-made medical apparatus, bolstered medical pedagogy, and refined targeted therapeutic delivery. This review delves into the contemporary advancements and applications of 3D printing in neuroradiology, underscoring its pivotal role in refining surgical strategies, augmenting patient outcomes, and diminishing procedural risks. It further articulates the utility of 3D-printed anatomical models for enriched comprehension, simulation, and educational endeavors. In addition, it illuminates the horizon of bespoke medical devices and prosthetics, illustrating their utility in addressing specific cranial and spinal anomalies. This narrative extends to scrutinize how 3D printing underpins precision medicine by offering customized drug delivery mechanisms and therapies tailored to the patient's unique medical blueprint. It navigates through the inherent challenges of 3D printing, including the financial implications, the need for procedural standardization, and the assurance of quality. Prospective trajectories and burgeoning avenues, such as material and technological innovations, the confluence with artificial intelligence, and the broadening scope of 3D printing in neurosurgical applications, are explored. Despite existing hurdles, the fusion of 3D printing with neuroradiology heralds a transformative era in precision medicine, poised to elevate patient care standards and pioneer novel surgical paradigms.

To explore the advantages and effectiveness of preoperative 3D printing planning technology combined with orthopedic surgical robot-assisted screw placement in the minimally invasive treatment of pelvic fractures compared to orthopedic surgical robot-assisted screw placement alone.

A retrospective analysis of the clinical data of 29 patients with unstable pelvic fractures treated with orthopedic surgical robot-assisted percutaneous screw fixation from July 2021 to August 2023 was conducted. Among them, 13 patients who underwent preoperative 3D printing technology for screw planning were assigned to the experimental group, and the remaining 16 patients were assigned to the control group. All patients underwent screw fixation alone or combined with other fixation methods for fracture fixation. The application of preoperative 3D printing planning in orthopedic surgical robot operations was described. The intraoperative screw drawing time, invasive operation time, number of fluoroscopies during invasive operation, postoperative evaluation of screw accuracy, fracture healing, complications, and functional outcomes were recorded and compared between the two groups.

All patients successfully underwent surgery, with one patient in the control group experiencing numbness in the sciatic nerve innervation area. All patients were followed up for 4-15 months, with an average of 8 months, and all fractures achieved healing. The experimental group had a total of 26 screws inserted, while the control group had 30 screws. In the experimental group, the intraoperative screw drawing time was 3.0 (3.0, 3.37) min, significantly shorter than 4.0 (3.6, 4.0) min in the control group (P < 0.05). The proportion of screws not penetrating the bone postoperatively was 88.5% in the experimental group, significantly higher than 63.3% in the control group (P < 0.05). In the experimental group, the postoperative screw position, compared to the planned screw position, had an average position deviation of 3.05 ± 0.673 mm and an average spatial angle deviation of 2.22 ± 0.605°. At the last follow-up, the Majeed score was used to assess function, with the experimental group having an excellent and good rate of 84.6%, slightly higher than 75.0% in the control group, but the difference was not statistically significant (P > 0.05).

In the treatment of pelvic fractures using screw fixation, preoperative 3D printing technology planning combined with orthopedic surgical robots, compared to orthopedic surgical robot-assisted screw placement alone, can significantly reduce intraoperative screw drawing time, decrease drawing difficulty, enhance screw placement accuracy, and does not increase invasive operation time or the number of fluoroscopies. This approach makes the surgery safer and is a method worth applying.

Introduction: 3D printing technology has gained considerable interest in the domain of orbital illnesses owing to its capacity to transform diagnosis, surgery planning, and treatment. This systematic review seeks to deliver a thorough examination of the contemporary applications of 3D printing in the treatment of ocular problems, encompassing tumors, injuries, and congenital defects. This systematic review of recent studies has examined the application of patient-specific 3D-printed models for preoperative planning, personalized implants, and prosthetics. Methods: This systematic review was conducted according to the PRISMA guidelines. The PICOS is "What are the current advances and applications of 3D printing for the management of orbital pathology?" The databases analyzed for the research phase are MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, ScienceDirect, Scopus, CINAHL, and Web of Science. Results: Out of 314 studies found in the literature, only 12 met the inclusion and exclusion criteria. From the included studies, it is evident that 3D printing can be a useful technology for the management of trauma and oncological pathologies of the orbital region. Discussion: 3D printing proves to be very useful mainly for the purpose of improving the preoperative planning of a surgical procedure, allowing for better preparation by the surgical team and a reduction in operative time and complications. Conclusions: 3D printing has proven to be an outstanding tool in the management of orbit pathology. Comparing the advantages and disadvantages of such technology, the former far outweigh the latter.

Patient specific (PS) technology has become popular in the field of spine surgery, as it gives surgeons control over the manufacturing of implants based on a patient's anatomy. Patient specific surgical guides, preoperative planning software, and patient specific implants - such as rods and cages, have demonstrated promising results in the literature for helping surgeons achieve spinal alignment goals.

A review of the literature regarding PS technology in spine surgery for the correction of spinal deformity was performed and is compiled here.

A description of the PS tools currently used for deformity correction and treatment of degenerative spine pathology with example cases are included in this manuscript.

The use of PS technology in spine surgery is an important development in the field that should continue to be studied.

Carry out an update and systematic review on the use of three-dimensional printing (3DP) in spinal surgery.

A systematic literature review was performed using the PubMed database in March 2024. "Spine surgery" and "3DP" were the search terms. Only articles published from 2014 to 2024 and clinical trails were selected for inclusion. Non-English or Spanish articles were excluded. This review complied with the Preferred Reported Items for Systematic Reviews and Meta-Analysis guideline.

Ten articles were included after screening and evaluation. The majority of the studied diseases were deformities (n = 3) and traumas (n = 3), followed by degenerative diseases (n = 2). Two articles dealt with surgical techniques. Six articles studied the creation of personalized guides for inserting screws; 2 were about education, one related to educating patients about their disease and the other to teaching residents surgical techniques; 2 other articles addressed surgical planning, where biomodels were printed to study anatomy and surgical programming.

3DP is one of the most-used tools in spine surgeries, but there are still randomized articles available on the subject. Using this technology seems to have a positive effect on patient education regarding their disease and surgical planning.

Objectives: Three-dimensional (3D) technology is increasingly applied in the surgical treatment of distal radial fractures and may optimize surgical planning, improve fracture reduction, facilitate implant and screw positioning, and thus prevent surgical complications. The main research questions of this review were as follows: (1) "How do 3D-assisted versus 2D-assisted distal radius fracture surgery compare in terms of intraoperative metrics (i.e., operation time and fluoroscopy frequency)?", and (2) "What are the effects of 3D-assisted versus 2D-assisted surgery on postoperative outcomes (patient-reported outcome measures (PROMs), range of motion (ROM), fracture reduction, complication rate, and screw placement accuracy)?" Methods: This review was performed according to the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. In total, 873 articles were found between 1 January 2010 and 1 April 2024, of which 12 (718 patients) were suitable for inclusion. The quality of the studies, assessed using the McMaster quality assessment, ranged from moderate to excellent, although the surgical techniques and outcome measures varied widely. Articles comparing a 3D group to a 2D group (conventional imaging) and reporting on primary or secondary outcomes were included in the analysis, for which weighted means and ranges were calculated. Results: Three different concepts of 3D-assisted surgery techniques were identified: (1) 3D virtual surgical planning (VSP), (2) 3D-printed handheld models, and (3) 3D intraoperative guides. Differences between 3D-assisted and conventional 2D-assisted surgery were evaluated. Regarding intraoperative metrics, 3D-assisted surgery significantly reduced operation time by 6 min (weighted mean 66.9 versus 73.2 min) and reduced the fluoroscopy frequency by 1.1 images (5.8 versus 4.7 times). Regarding postoperative outcomes, the weighted mean of the DASH score differed between the 3D- and 2D-assisted groups (17.8 versus 23.9 points), and no differences in PRWE or VAS score were found. Furthermore, our results showed no significant differences in the ROM and fracture reduction parameters. In terms of complications, the application of 3D-assisted surgery decreased the complication rate from 10.7% to 3.6%, and the use of screws with appropriate lengths improved from 75% to 86%. Conclusions: Applications of 3D-assisted surgery in distal radial fracture surgery can slightly reduce the operation time and fluoroscopy frequency. Evidence for the improvement of fracture reduction and functional outcomes is still lacking, although it likely reduces the complication rate and improves the use of appropriate screw lengths.

Background: Three-dimensional (3D) printer technology has seen a surge in use in medicine, particularly in orthopedics. A recent area of research is its use in peripheral nerve repair, which often requires a graft or conduit to bridge segmental defects. Currently, nerve gaps are bridged using autografts, allografts, or synthetic conduits. Purpose: We sought to improve upon the current design of simple hollow, cylindrical conduits that often result in poor nerve regeneration. Previous attempts were made at reducing axonal dispersion with the use of multichanneled conduits. To our knowledge, none has attempted to mimic and test the anatomical topography of the nerve. Methods: Using serial histology sections, 3D reconstruction software, and computer-aided design, a scaffold was created based on the fascicular topography of a rat sciatic nerve. A 3D printer produced both cylindrical conduits and topography-based scaffolds. These were implanted in 12 Lewis rats: 6 rats with the topographical scaffold and 6 rats with the cylindrical conduit. Each rodent's uninjured contralateral limb was used as a control for comparison of functional and histologic outcomes. Walking track analysis was performed, and the Sciatic Functional Index (SFI) was calculated with the Image J software. After 6 weeks, rats were sacrificed and analyses performed on the regenerated nerve tissue. Primary outcomes measured included nerve (fiber) density, nerve fiber width, total number of nerve fibers, G-ratio (ratio of axon width to total fiber width), and percent debris. Secondary outcomes measured included electrophysiology studies of electromyography (EMG) latency and EMG amplitude and isometric force output by the gastrocnemius and tibialis anterior. Results: There were no differences observed between the cylindrical conduit and topographical scaffold in terms of histological outcomes, muscle force, EMG, or SFI. Conclusion: This study of regeneration of the sciatic nerve in a rat model suggests the feasibility of 3D-printed topographical scaffolds. More research is required to quantify the functional outcomes of this technology for peripheral nerve regeneration.