3D Printing and Virtual Surgical Planning in Oral and Maxillofacial Surgery

Current Trends and Innovations in Oral and Maxillofacial Reconstruction

This review examines the latest advancements in maxillofacial reconstruction, focusing on transformative innovations in dentistry. Traditional surgical techniques, although effective, are accompanied by challenges such as inherent risks, complications, and inconsistent outcomes that can be influenced by variations in surgeon skill. To address these drawbacks, cutting-edge technologies have emerged, emphasizing enhanced precision, safety, and efficiency in treatment modalities. Key innovations in this field include 3-dimensional printing (additive manufacturing), virtual surgical planning, computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and tissue engineering. These advancements not only revolutionize diagnostics but also streamline workflow processes, offering sustainable, timely treatments while improving therapeutic results and aesthetic outcomes. The integration of CAD/CAM technology enhances workflow efficiency by simplifying complex processes in dental prosthetic design. Simultaneously, additive manufacturing facilitates the creation of intricate dental implants with superior accuracy. Virtual surgical planning provides clinicians with valuable preoperative insights, enabling tailored surgical interventions, while tissue engineering presents regenerative solutions to complex reconstructive challenges. Despite these technological breakthroughs, the adoption of these innovations requires significant initial investments and extensive training for healthcare professionals. While logistical and financial obstacles can arise, the long-term benefits, such as enhanced patient care and superior aesthetic results, are considerable. In conclusion, this article aims to evaluate the transformative impact of digital and additive manufacturing technologies on maxillofacial reconstruction and to underscore their crucial role in advancing modern dentistry.

Evaluating Osteotomy Accuracy in Mandibular Reconstruction: A Preliminary Study Using Custom Cutting Guides and Virtual Reality

BACKGROUND

Mandibular reconstruction has evolved significantly since its inception in the early 1900s. Currently, the fibula free flap (FFF) is considered the gold standard for mandibular and maxillary reconstructions, particularly for extensive defects, and the introduction of Extended Reality (XR) and virtual surgical planning (VSP) is revolutionizing maxillofacial surgery.

METHODS

This study focuses on evaluating the accuracy of using in-house cutting guides for mandibular reconstruction with FFF supported by virtual surgical planning (VSP). Planned and intraoperative osteotomies obtained from postoperative CT scans were compared in 17 patients who met the inclusion criteria. The proposed analysis included measurements of deviation angles, thickness at the centre of gravity, and the maximum thickness of the deviation volume. Additionally, a mandibular resection coding including 12 configurations was defined to classify and analyze the precision of mandibular osteotomies and investigate systematic errors. Preoperative, planned, and postoperative models have been inserted in an interactive VR environment, VieweR, to enhance surgical planning and outcome analysis.

RESULTS

The results proved the efficiency of adopting customized cutting guides and highlighted the critical role of advanced technologies such as CAD/CAM and VR in modern maxillofacial surgery. A novel coding system including 12 possible configurations was developed to classify and analyze the precision of mandibular osteotomies. This system considers (1) the position of the cutting blade relative to the cutting plane of the mandibular guide; (2) the position of the intersection axis between the planned and intraoperative osteotomy relative to the mandible; (3) the direction of rotation of the intraoperative osteotomy plane around the intersection axis from the upper view of the model.

CONCLUSIONS

This study demonstrates the accuracy and reliability of in-house cutting guides for mandibular reconstruction using fibula free flaps (FFF) supported by virtual surgical planning (VSP). The comparison between planned and intraoperative osteotomies confirmed the precision of this approach, with minimal deviations observed. These findings highlight the critical role of CAD/CAM and XR technologies in modern maxillofacial surgery, offering improved surgical precision and optimizing patient outcomes.

The Evolution of Virtual Surgical Planning in Craniomaxillofacial Surgery: A Comprehensive Review

PURPOSE

Virtual surgical planning (VSP) has significantly transformed craniomaxillofacial surgery over the past 2 decades, leading to diverse applications and improved surgical outcomes. However, variations in technological approaches, clinical outcomes, and economic implications persist. This review aims to comprehensively examine the evolution of VSP in craniomaxillofacial surgery, assess its impact on surgical precision and patient outcomes, and identify current trends and future directions. A synthesis of current knowledge is essential to establish evidence-based guidelines for VSP implementation and optimize patient care in this rapidly advancing field.

METHODS

A systematic literature search was conducted in PubMed, Embase, and IEEE Xplore databases from their inception to September 2024. Search terms included combinations of "virtual surgical planning" OR "computer-assisted surgery" AND "craniomaxillofacial" OR "maxillofacial" OR "craniofacial" AND "evolution" OR "development" OR "advancement". From 540 initially identified articles, studies focusing on VSP in craniomaxillofacial surgery that reported technological advancements, surgical outcomes, or precision metrics were included. Eligible studies comprised case series with 5 or more subjects, comparative studies, and validation studies. Data extraction included study characteristics, technology details, surgical applications, outcome measures, and economic factors. Quality assessment was performed using appropriate tools based on study design.

RESULTS

Out of 540 articles, 36 studies spanning from 1999 to 2024 met the inclusion criteria. The evolution of VSP was categorized into 3 phases: early foundations (1999 to 2004), expansion of applications and improved accuracy (2005 to 2014), and advanced integration with emerging technologies (2015 to 2024). Orthognathic surgery was the commonest application (52.8% of studies), followed by tumor resection and reconstruction (22.2%). Studies consistently demonstrated smaller linear discrepancies between planned and actual outcomes with VSP compared to conventional methods (VSP: 0.04 to 0.25 mm vs conventional: 0.29 to 1.33 mm). Recent advancements include the integration of artificial intelligence, mixed reality, and robotic systems, enhancing both preoperative planning and intraoperative guidance.

CONCLUSION

VSP has considerably evolved in craniomaxillofacial surgery, improving accuracy as demonstrated by reduced linear discrepancies between planned and actual outcomes across various procedures. While promising, challenges remain, including the need for standardization, comprehensive cost-effectiveness analyses, and long-term outcome studies.

Combined Orthodontic, Orthognathic Surgical, and Prosthodontic Treatment for Severe Class III Malocclusion Using Digital Workflows

The patient underwent combined orthodonticorthognathic surgical treatment due to her skeletal Class III malocclusion. In the first phase, orthodontic decompensation was performed with maxillary and mandibular fixed appliances. The maxillary first premolars were extracted; the created space was closed by anterior retraction. The posterior anchorage was reinforced with interradicular temporary anchorage devices. In the second phase, a digital surgical treatment plan was made with intra- and extraoral simulation (including occlusion and profile). During the orthognathic surgery, a bilateral sagittal split osteotomy with mandibular setback was combined with maxillary movements, using 3D-printed surgical splints. In the third phase, the orthodontic treatment continued to finish and settle the occlusion. Spaces were created between the upper incisors for ceramic veneers to gain proper overjet and occlusion. The last phase was prosthetic and esthetic rehabilitation. During the planning, a 2Dand 3D-smile design was created and presented to the patient as a mock-up. After digital impression and design, four E-max veneers were milled and cemented using dual cement to finish the workflow. Retention splints were created to preserve the new status as a final step.

Patient-Specific Solutions for Cranial, Midface, and Mandible Reconstruction Following Ablative Surgery: Expert Opinion and a Consensus on the Guidelines and Workflow

Reconstruction of cranio-maxillofacial defects following ablative surgeries requires a comprehensive approach that balances functional restoration with aesthetic outcomes. Advances in computer-aided design and manufacturing (CAD/CAM) technology have revolutionized this field, enabling precise preoperative planning, including 3D modeling, segmentation, and virtual resection planning. These methods allow for the production of patient-specific implants and surgical templates while facilitating the evaluation of treatment outcomes. CAD/CAM technology offers numerous benefits, such as enhanced surgical accuracy, improved aesthetic results, reduced operative times, and the possibility of single-stage resection and reconstruction. However, limitations exist, including high costs, the need for specialized expertise, and dependency on accurate imaging data. This paper provides a surgeon-centric evaluation of the advantages and limitations of CAD/CAM in cranio-maxillofacial reconstruction. The discussion encompasses the technological workflow, clinical applications, and recommendations for optimizing outcomes. Future perspectives highlight ongoing developments, such as integrating non-ionizing imaging techniques and expanding the applicability of virtual and augmented reality. By synthesizing technical advancements and clinical expertise, this review aims to establish practical guidelines for implementing CAD/CAM technology in routine surgical practice.

Advancements in Bone Replacement Techniques-Potential Uses After Maxillary and Mandibular Resections Due to Medication-Related Osteonecrosis of the Jaw (MRONJ)

Maxillofacial bone defects can have a profound impact on both facial function and aesthetics. While various biomaterial scaffolds have shown promise in addressing these challenges, regenerating bone in this region remains complex due to its irregular shape, intricate structure, and differing cellular origins compared to other bones in the human body. Moreover, the significant and variable mechanical loads placed on the maxillofacial bones add further complexity, especially in cases of difficult-to-treat medical conditions. This review provides a brief overview of medication-related osteonecrosis of the jaw (MRONJ), highlighting the medication-induced adverse reactions and the associated clinical challenges in treating this condition. The purpose of this manuscript is to emphasize the role of biotechnology and tissue engineering technologies in therapy. By using scaffold materials and biofactors in combination with autologous cells, innovative solutions are explored for the repair of damaged facial bones. The ongoing search for effective scaffolds that can address these challenges and improve in vitro bone preparation for subsequent regeneration in the maxillofacial region remains critical. The primary purpose of this review is to spotlight current research trends and novel approaches in this area.

Maxillectomy Guided by 3D Printing Versus Conventional Surgery for Patients with Head and Neck Cancer

BACKGROUND

This study evaluates the impact of three-dimensional (3D) printing-guided maxillectomy compared with conventional maxillectomy on surgical precision and oncological outcomes in patients with head and neck cancer.

MATERIALS AND METHODS

A retrospective analysis was conducted on 42 patients undergoing maxillectomy (16 in a 3D printing-guided group and 26 in a conventional group). Patient demographics, tumor characteristics, and outcomes were compared. Survival outcomes were analyzed using the Kaplan-Meier method.

RESULTS

The 3D printing group showed higher rates of negative resection margins (81.3% vs. 76.9%) compared with the conventional group and a trend toward improved 5-year local recurrence-free survival (87.5% vs. 58.7%, respectively) and overall survival (84.4% vs. 70.1%, respectively). However, the differences were not statistically significant.

CONCLUSIONS

Maxillectomy guided by 3D printing may offer enhanced surgical precision and improved local control in patients undergoing head and neck cancer surgeries. Further research with larger cohorts is necessary to confirm these findings.

Three-dimensional digital model of the facial nerve assisted in the excision of benign parotid tumors based on 3D-DESS-WE-MRI

This study proposes a novel surgical technique for the excision of benign parotid tumors, utilizing a extracapsular dissection guided by a three dimensional digital model of the facial nerve(3DFN-ECD) and compares its clinical efficacy with the extracapsular dissection (ECD) method. This prospective study included 68 patients with benign parotid tumors. The control group (40 patients) received the ECD treatment, while the experimental group (28 patients), underwent the 3DFN-ECD approach proposed in this study. Preoperative three-dimensional double-echo steady-state water excitation sequence (3D-DESS-WE) of MRI was employed to visualize the tumor and facial nerve, and the Mimics software was used to reconstruct a three-dimensional digital model of the facial nerve and parotid tumor. The surgical incision and facial nerve dissection were planned based on the relationship between the tumor and the facial nerve. Postoperative facial nerve function and aesthetic outcomes of the incisions were compared between the two surgical techniques. There was no significant difference in the postoperative complications between the two groups. Postoperative facial nerve function scores in the 3DFN-ECD group were significantly higher than those in the control group at 1 week (p < 0.001) and 4 weeks (p < 0.001). The incidence of temporary facial nerve paralysis was significantly lower in the 3DFN-ECD group (P = 0.036), and the visual analogue scale score for aesthetic outcomes of the surgical incision was significantly improved (p < 0.001). The novel 3DFN-ECD surgical approach proposed in this study significantly reduces the risk of facial nerve injury and improves the aesthetic outcomes of the parotid tumor surgical incision.

Immersive learning in medical education: analyzing behavioral insights to shape the future of VR-based courses

BACKGROUND

The emergence of virtual reality (VR) for medical education enables a range of new teaching opportunities. Skills and competences can be trained that cannot be demonstrated in any other way due to physical or ethical limitations. Immersion and presence may play an important role for learning in this context. This study investigates whether this VR-based, immersive software is an effective tool for assessing medical learning objectives by comparing behavioral outcomes in VR and actor-based simulations, and examines how these behaviors relate to immersion levels and their impact on learning success.

METHODS

To evaluate the effectiveness of the new teaching method, objective behavioral outcomes were identified as part of a dermatological learning unit and VR as a method was compared with actor-based simulation training. In addition, subjective questionnaires were collected to compare the levels of immersion in both concepts.

RESULTS

It was shown that primary learning objectives can be addressed well in VR. However, secondary learning objectives that fall into the field of basic skills seem to be delivered better in the actor-based training than in VR. This appears to be an effect of weaker immersion measured in VR training.

CONCLUSIONS

It can be said that the implementation of basic skills training depends largely on the level of immersion in the teaching method used. While primary learning subjectives can be trained and assessed well, at present, it does not appear to be fully possible to train secondary skills with the technical status quo in VR. However, the observation of secondary learning objectives can serve as an indicator for the assessment of immersion in the future.

Striving for excellence in a little red dot: Exploring the evolution of oral and maxillofacial surgery training and practice in Singapore

Oral and maxillofacial surgery (OMS) is a field that straddles knowledge and clinical experience from both medical and dental specialties. In the small island nation of Singapore, the rapidly and constantly changing needs of its diverse and aging population, as well as changes in the mindsets of both students and educators have led to many developments in the local OMS program. Tied to the only dental school in the country, the curriculum of the training program has kept up with the changes in the demographics and attitudes of the local patient pool, which comprises a multicultural population with both traditional and modern mindsets. Since its inception, the training program has also shifted away from the traditional apprenticeship model of surgical specialties to include more integrated and modular learning with a heavy emphasis on evidence-based medicine, simulation training workshops, and more focus on digital planning and other technological advancements. This review explores the current scope of training and practice in the Singapore landscape, and how it has evolved and been tailored to meet the needs of its patients and future clinicians.

Virtual surgical planning in tripod zygomatico-maxillary complex fractures: A prospective comparison between two different strategies

Multifragmentary and displaced zygomaticomaxillary complex (ZMC) fractures are often a challenge for the maxillofacial surgeon. The aim of this study was to evaluate the improved performance in the management of patients with tripod fracture of the orbito-zygomaticomaxillary complex, using two different methods of virtual surgical planning - virtual reduction and mirroring - compared with traditional management. A cohort of 60 patients was selected and divided into three groups, each consisting of 20 individuals. Patients in the first group were managed using the virtual reduction method, those in the second group using the mirroring method, and those in the third group using a traditional surgical approach. Having achieved virtual fracture reduction, a stereolithographic model was printed, on which preplating of the plates was performed. The results showed that virtual reduction was the most accurate in absolute terms, with a mean discrepancy in juxtaposition of the preoperative and postoperative CT images of 0.175 mm (SD ± 0.147), compared with 0.403 (SD ± 0.166) for the mirror method (and traditional method (0.875, SD ± 0.112; p > 0.0001). The average surgical time for virtual reduction (89.5 min) was faster than for mirroring (94.25 min) and for the traditional approach (96.75 min). In conclusion, the use of virtual surgical planning allows greater intraoperative accuracy, reduced surgical time, and reduced postoperative complications compared with traditional surgery. Of the two methods, virtual reduction performed best for the outcomes decribed.

Qualitative exploration of 3D printing in Swedish healthcare: perceived effects and barriers

BACKGROUND

Three-dimensional (3D) printing produces objects by adding layers of material rather than mechanically reducing material. This production technology has several advantages and has been used in various medical fields to, for instance, improve the planning of complicated operations, customize medical devices, and enhance medical education. However, few existing studies focus on the adoption and the aspects that could influence or hinder the adoption of 3D printing.

OBJECTIVE

To describe the state of 3D printing in Sweden, explore the perceived effects of using 3D printing, and identify barriers to its adoption.

METHODS

A qualitative study with respondents from seven life science regions (i.e., healthcare regions with university hospitals) in Sweden. Semi-structured interviews were employed, involving 19 interviews, including one group interview. The respondents were key informants in terms of 3D printing adoption. Data collection occurred between April and May 2022 and then between February and May 2023. Thematic analysis was applied to identify patterns and themes.

RESULTS

All seven regions in Sweden used 3D printing, but none had an official adoption strategy. The most common applications were surgical planning and guides in clinical areas such as dentistry, orthopedics, and oral and maxillofacial surgery. Perceived effects of 3D printing included improved surgery, innovation, resource efficiency, and educational benefits. Barriers to adoption were categorized into organization, environment, and technology. Organizational barriers, such as high costs and lack of central decisions, were most prominent. Environmental barriers included a complex regulatory framework, uncertainty, and difficulty in interpreting regulations. Technological barriers were less frequent.

CONCLUSIONS

The study highlights the widespread use of 3D printing in Swedish healthcare, primarily in surgical planning. Perceived benefits included improved surgical precision, innovation, resource efficiency, and educational enhancements. Barriers, especially organizational and regulatory challenges, play a significant role in hindering widespread adoption. Policymakers need comprehensive guidance on 3D printing adoption, considering the expensive nature of technology investments. Future studies could explore adoption in specific clinical fields and investigate adoption in non-life science regions within and outside Sweden.

Three-Dimensionally-Printed Polymer and Composite Materials for Dental Applications with Focus on Orthodontics

Three-dimensional printing has transformed dentistry by enabling the production of customized dental restorations, aligners, surgical guides, and implants. A variety of polymers and composites are used, each with distinct properties. This review explores materials used in 3D printing for dental applications, focusing on trends identified through a literature search in PubMed, Scopus, and the Web of Science. The most studied areas include 3D-printed crowns, bridges, removable prostheses, surgical guides, and aligners. The development of new materials is still ongoing and also holds great promise in terms of environmentally friendly technologies. Modern manufacturing technologies have a promising future in all areas of dentistry: prosthetics, periodontology, dental and oral surgery, implantology, orthodontics, and regenerative dentistry. However, further studies are needed to safely introduce the latest materials, such as nanodiamond-reinforced PMMA, PLA reinforced with nanohydroxyapatite or magnesium, PLGA composites with tricalcium phosphate and magnesium, and PEEK reinforced with hydroxyapatite or titanium into clinical practice.

Three-dimensional printing for preoperative rehearsal and intraoperative navigation during laparoscopic rectal cancer surgery with left colic artery preservation

BACKGROUND

Prior studies have shown that preserving the left colic artery (LCA) during laparoscopic radical resection for rectal cancer (RC) can reduce the occurrence of anastomotic leakage (AL), without compromising oncological outcomes. However, anatomical variations in the branches of the inferior mesenteric artery (IMA) and LCA present significant surgical challenges. In this study, we present our novel three dimensional (3D) printed IMA model designed to facilitate preoperative rehearsal and intraoperative navigation to analyze its impact on surgical safety.

AIM

To investigate the effect of 3D IMA models on preserving the LCA during RC surgery.

METHODS

We retrospectively collected clinical dates from patients with RC who underwent laparoscopic radical resection from January 2022 to May 2024 at Fuyang People's Hospital. Patients were divided into the 3D printing and control groups for statistical analysis of perioperative characteristics.

RESULTS

The 3D printing observation group comprised of 72 patients, while the control group comprised 68 patients. The operation time (174.5 ± 38.2 minutes vs 198.5 ± 49.6 minutes, P = 0.002), intraoperative blood loss (43.9 ± 31.3 mL vs 58.2 ± 30.8 mL, P = 0.005), duration of hospitalization (13.1 ± 3.1 days vs 15.9 ± 5.6 days, P < 0.001), postoperative recovery time (8.6 ± 2.6 days vs 10.5 ± 4.9 days, P = 0.007), and the postoperative complication rate (P < 0.05) were all significantly lower in the observation group.

CONCLUSION

Utilization of a 3D-printed IMA model in laparoscopic radical resection of RC can assist surgeons in understanding the LCA anatomy preoperatively, thereby reducing intraoperative bleeding and shortening operating time, demonstrating better clinical application potential.

Customized 3D-Printed Mesh, Membrane, Bone Substitute, and Dental Implant Applied to Guided Bone Regeneration in Oral Implantology: A Narrative Review

Background: The new frontiers of computer-based surgery, technology, and material advances, have allowed for customized 3D printed manufacturing to become widespread in guided bone regeneration (GBR) in oral implantology. The shape, structural, mechanical, and biological manufacturing characteristics achieved through 3D printing technologies allow for the customization of implant-prosthetic rehabilitations and GBR procedures according to patient-specific needs, reducing complications and surgery time. Therefore, the present narrative review aims to elucidate the 3D-printing digital radiographic process, materials, indications, 3D printed manufacturing-controlled characteristics, histological findings, complications, patient-reported outcomes, and short- and long-term clinical considerations of customized 3D printed mesh, membranes, bone substitutes, and dental implants applied to GBR in oral implantology. Methods: An electronic search was performed through MEDLINE/PubMed, Scopus, BioMed Central, and Web of Science until 30 June 2024. Results: Three-dimensionally printed titanium meshes and bone substitutes registered successful outcomes in vertical/horizontal bone defect regeneration. Three-dimensionally printed polymeric membranes could link the advantages of conventional resorbable and non-resorbable membranes. Few data on customized 3D printed dental implants and abutments are available, but in vitro and animal studies have shown new promising designs that could improve their mechanical properties and tribocorrosion-associated complications. Conclusions: While 3D printing technology has demonstrated potential in GBR, additional human studies are needed to evaluate the short- and long-term follow-up of peri-implant bone levels and volumes following prosthetic functional loading.

Three-dimensional printed model reconstruction in intraoperative use for glass penetrating facial tissue removal

Key Clinical Message

In the anatomically complex terrain of the head and neck, the use of 3D intraoperative models serves as an effective verification tool, determining the size, shape, and number of foreign bodies. This allows the main operator to maximize their capacities for careful wound revision and receive real-time information about the remaining content of the sought-after bodies.

Abstract

Penetrating foreign bodies of various origins in the head and neck are uncommon, but potentially hazardous injuries. Complete removal of foreign bodies from soft tissues is essential for optimal healing, minimizing complications, and significantly reducing the risk of the need for reoperation. Despite various technological systems and safeguards available, unintentionally retained surgically placed foreign bodies remain difficult to eliminate completely. A 34-year-old female patient with a cut on the right side of her face who was initially treated with sutures at a general surgical clinic presented for a follow-up examination. A foreign body was verified subcutaneously on the anterior-posterior x-ray image on the right side. Computed tomography confirmed a total of 7 foreign bodies with a density corresponding to dental enamel, distributed subcutaneously, subfascially, and intramuscularly in the right temporal region. As part of the preoperative preparation and analysis, the bone segment of the right temporal fossa with the zygomatic bone and the glass fragments were segmented from the CT data and printed on an SLA printer. The physical 3D models were autoclave sterilized and present during surgery. The position, shape, and number of each individual glass fragment was compared with 3D-printed one. The benefits of producing 3D models of foreign bodies are undeniable, particularly in their perioperative comparison with the removed foreign bodies from wounds.

Evolution of Virtual Surgical Planning Use Among Craniofacial Surgeons

Virtual surgical planning (VSP) has benefits in craniofacial surgery with growing popularity. However, while specific use cases are highlighted in the literature, no studies exist providing an overview of VSP use among craniofacial surgeons, and little is known about the extent of exposure to VSP during plastic surgery training. This study surveyed members of The American Society of Maxillofacial Surgeons (ASMS) to better characterize both the landscape of VSP use among practicing craniofacial surgeons and the extent of exposure to VSP throughout surgical training. An electronic survey was administered in the fall of 2023. Response data included surgeon demographics, VSP usage, including the use in residency/fellowship, procedures for which VSP is used, and assessment of VSP's impact on the surgeon's practice. Demographics and VSP use were analyzed using descriptive statistics, while categorical and continuous variables were analyzed using χ2 tests and t-tests, respectively. Of the 44 respondents, 40 (90.9%) completed a craniofacial surgery fellowship, and 18 (40.9%) utilized VSP in either residency or fellowship. In respondents' current practice, VSP is utilized most commonly for orthognathic surgery (n=32, 91.4%), postablative reconstruction (n=23, 82.1%), and facial feminization (n=11, 73.3%). Shorter operative time and improved esthetic outcomes were frequently reported as benefits derived from VSP use. Finally, surgeons in practice for less than 10 years were significantly more likely to have used VSP in both residency (OR=20.3, P<0.01) and in fellowship (OR=40.6, P<0.01) than those practicing for more than 10 years. These findings suggest that craniofacial surgeons apply VSP more commonly for certain procedure types. Our results additionally suggest that incorporation of VSP into residency and fellowship training has become significantly more common over time, with a pivot towards integration in the last decade.

Advancements and Applications of Three-dimensional Printing Technology in Surgery

Three-dimensional (3D) printing technology has revolutionized surgical practices, offering precise solutions for planning, education, and patient care. Surgeons now wield tangible, patient-specific 3D models derived from imaging data, allowing for meticulous presurgical planning. These models enhance surgical precision, reduce operative times, and minimize complications, ultimately improving patient outcomes. The technology also serves as a powerful educational tool, providing hands-on learning experiences for medical professionals and clearer communication with patients and their families. Despite its advantages, challenges such as model accuracy and material selection exist. Ongoing advancements, including bioactive materials and artificial intelligence integration, promise to further enhance 3D printing's impact. The future of 3D printing in surgery holds potential for regenerative medicine, increased global accessibility, and collaboration through telemedicine. Interdisciplinary collaboration between medical and engineering fields is crucial for responsible and innovative use of this technology.

The role of 3D printing in chest wall reconstruction

Technology is advancing fast, and chest wall surgery finds particular benefit in the broader availability of three-dimensional (3D) reconstruction and printing. An increasing number of reports are being published on the use of these resources in virtual 3D reconstructions of chest walls in computed tomography (CT) scans, virtual surgeries, 3D printing of real-size models for surgical planning, practice, and education, and of note, the manufacture of customized 3D printed implants, changing the fundamental conception from a surgery that fits all, to a surgery for each patient. In this review, we explore the evidence published on simple chest wall reconstruction, including the use of 3D technology to assist in the improvement of the repair of the most frequent chest wall deformities: pectus excavatum and carinatum. Current studies are oriented to the automatization and customization of transthoracic implants, as well as education on real-size models. Next, we investigate the implementation of 3D printing in the repair of complex chest wall reconstruction, comprised of infrequent chest wall deformities such as pectus arcuatum and Poland syndrome. These malformations are very heterogeneous resulting in a high degree of improvisation during the surgical repair. In this setting, 3D technology plays a role in the standardization of a process that contemplates customization, concepts that may seem contradictory. Finally, 3D printing with biocompatible materials is rapidly becoming the first choice for the reconstruction of wide chest wall oncological resections. In this work, we review the first and most important current publications on the subject.

Digital Implant-Supported Restoration Planning Placed in Autologous Graft Using Titanium Implants Produced by Additive Manufacturing

This clinical report presents a technique to reconstruct extensively resected mandibles using a combination of autologous bone grafts and additive manufacturing techniques. Mandibular defects, often arising from trauma, tumors, or congenital anomalies, can severely impact both function and aesthetics. Conventional reconstruction methods have their limitations, often resulting in suboptimal outcomes. In these reports, we detail clinical cases where patients with different mandibular defects underwent reconstructive surgery. In each instance, autologous grafts were harvested to ensure the restoration of native bone tissue, while advanced virtual planning techniques were employed for precise graft design and dental implant placement. The patients experienced substantial improvements in masticatory function, speech, and facial aesthetics. Utilizing autologous grafts minimized the risk of rejection and complications associated with foreign materials. The integration of virtual planning precision allowed customized solutions, reducing surgical duration and optimizing implant positioning. These 2 cases underscores the potential of combining autologous grafts with virtual planning precision and dental implants produced by additive manufacturing for mandible reconstruction.

Interdisciplinary innovative approach to an aggressive ossifying fibroma case: Integrating 3D surgery and customized reconstruction in maxillofacial and dental care

Aggressive ossifying fibroma is a benign fibro-osseous disorder characterized by its aggressive behavior, which complicates its management. In this article, we present a case involving the recurrence of this condition in the maxillary region, with orbital and dental involvement, in a patient who had previously undergone surgery and reconstruction with a microvascularized free fibula flap. A multidisciplinary approach involving maxillofacial surgery and dentistry was employed to deliver a customized and entirely satisfactory solution for the patient. The use of 3D surgery was integral to our approach, encompassing pre-surgical digital planning and the transfer of this planning to the operating room via navigation software. Customized surgical cutting guides facilitated precise resection, while a personalized polyether ether ketone (PEEK) prosthesis was utilized for reconstruction of the malar and infraorbital region. Pre-prosthetic computer-aided design/computer-aided manufacturing (CAD/CAM) surgery, along with dental rehabilitation using transepithelial abutments and dental prostheses on a titanium framework, were employed for dental restoration. During the postoperative period, mobility in the reconstructed maxilla was observed due to the loss of support from the initial reconstruction plate. This was addressed by replacing the plate with a custom-made titanium plate, designed to accommodate the location of the transepithelial abutments and prevent disruption of the dental rehabilitation. This case demonstrates the potential of new technologies when applied within the collaborative framework of maxillofacial surgeons and dentists, enabling effective and definitive solutions in complex reconstruction cases. Key words:Aggressive ossifying fibroma; 3D surgery; customized reconstruction; complex dental reconstruction.

Three-dimensional measurements of symmetry for the mandibular ramus

BACKGROUND

The study examines a sample of patients presenting for viscerocranial computer tomography that does not display any apparent signs of asymmetry, assesses the three-dimensional congruency of the mandibular ramus, and focuses on differences in age and gender.

METHODS

This cross-sectional cohort study screened viscerocranial CT data of patients without deformation or developmental anomalies. Segmentations were obtained from the left and right sides and superimposed according to the best-fit alignment. Comparisons were made to evaluate three-dimensional congruency and compared between subgroups according to age and gender.

RESULTS

Two hundred and sixty-eight patients were screened, and one hundred patients met the inclusion criteria. There were no statistical differences between the left and right sides of the mandibular ramus. Also, there were no differences between the subgroups. The overall root mean square was 0.75 ± 0.15 mm, and the mean absolute distance from the mean was 0.54 ± 0.10 mm.

CONCLUSION

The mean difference was less than one millimetre, far below the two-millimetre distance described in the literature that defines relative symmetry. Our study population displays a high degree of three-dimensional congruency. Our findings help to understand that there is sufficient three-dimensional congruency of the mandibular ramus, thus contributing to facilitating CAD-CAM-based procedures based on symmetry for this specific anatomic structure.

Trueness of five different 3D printing systems including budget- and professional-grade printers: An In vitro study

Problem

Several types of 3D printers with different techniques and prices are available on the market. However, results in the literature are inconsistent, and there is no comprehensive agreement on the accuracy of 3D printers of different price categories for dental applications.

Aim

This study aimed to investigate the accuracy of five different 3D printing systems, including a comparison of budget- and higher-end 3D printing systems, according to a standardized production and evaluation protocol.

Material and methods

A maxillary reference model with prepared teeth was created using 16 half-ball markers with a diameter of 1 mm to facilitate measurements. A reference file was fabricated using five different 3D printers. The printed models were scanned and superimposed onto the original standard tesselation language (.stl) file, and digital measurements were performed to assess the 3-dimensional and linear deviations between the reference and test models.

Results

After examining the entire surface of the models, we found that 3D printers using Fused filament fabrication (FFF) technology -120.2 (20.3) μm create models with high trueness but high distortion. Distortions along the z-axis were found to be the highest with the stereolithography (SLA)-type 3D printer at -153.7 (38.7) μm. For the 4-unit FPD, we found 201.9 (41.8) μm deviation with the digital light processing (DLP) printer. The largest deviation (-265.1 (55.4) μm) between the second molars was observed for the DLP printer. Between the incisor and the second molar, the best results were produced by the FFF printer with -30.5 (76.7) μm.

Conclusion

Budget-friendly 3D printers are comparable to professional-grade printers in terms of precision. In general, the cost of a printing system is not a reliable indicator of its level of accuracy.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.

Combination of CAD/CAM technologies and conventional processing in the fabrication of a maxillary obturator prosthesis: a clinical report

Soft and hard tissue defects resulting from resective surgeries for carcinomas located in the maxillary arches can cause functional, esthetic, and psychological damage. A removable obturator prosthesis offers several advantages, restoring oral functions and improving patients' quality of life. Technological advancements, such as the use of intraoral scanning and computer-aided design (CAD) and manufacturing, reduce laboratory working time, eliminate the risk of impression material aspiration, and address challenges related to whole tissue undercut impression. Here, we report the case of a partially edentulous female patient with a velo-palatal defect for whom a rigid maxillary obturator prosthesis was fabricated. Digital impressions were taken and the standard tessellation language files of the scans were sent to the laboratory. Using dental CAD software, the maxillary metallic framework was designed and manufactured using selective laser melting technology. The obturators and artificial teeth were conventionally processed, with acrylic resin used for the rigid obturators. The resulting obturator prosthesis made it possible to close the oro-nasal communication and to improve swallowing, speaking, and chewing.

Surface scanned 3D designed customized chinstrap for the treatment of intraoral dehiscence in polytraumatized patient. Technical note

The advent of 3D surgical technology has revolutionized personalized medicine, enabling the development of tailored solutions for individual patients. This technical note presents the application of 3D technology in designing a customized chin guard using flexible 3D resin. The process involves surface scanning the lower facial region of a polytraumatized patient with a structured-light surface 3D scanner, generating a detailed point cloud. The acquired data undergoes meticulous processing within an specific professional software, including erasing unwanted portions, aligning frames, and mesh consolidation. Subsequently, the mesh is exported as an STL file and further refined using a 3D mesh management software. A customized chin support is designed for the specific patient's needs, exported in STL format, and 3D printed using a stereolithography (SLA) printer with Flexible 80A resin. Post-printing procedures involve washing and curing to ensure biocompatibility and optimal mechanical characteristics. The resultant customized chin guard, attached to elastic support straps, offers a precise fit to the patient's anatomy, enhancing comfort and allowing for extended wear. This innovative approach addresses the challenge of surgical intraoral wound dehiscence in a polytraumatized patient, showcasing the potential of 3D technology in personalized medical solutions for complex cases. Key words:Surface scanner, 3D surgery, customized surgery, chinstrap.

3D Printing: Opening New Horizons in Dentistry

The proper treatment of diseases has greatly benefited from dental technological advancements. The dentist may view, precisely measure, and create models of both hard and soft tissue using 3D printing. The most cutting-edge technique in dentistry is 3D printing; but it also lacks the user-training trainee. In this paper, we will demonstrate how it is employed in various dental procedures.

Impact of 3D imaging techniques and virtual patients on the accuracy of planning and surgical placement of dental implants: A systematic review

Aim

The integration of advanced technologies, including three-dimensional (3D) imaging modalities and virtual simulations, has significantly influenced contemporary approaches to preoperative planning in implant dentistry. Through a meticulous analysis of relevant studies, this review synthesizes findings related to accuracy outcomes in implant placement facilitated by 3D imaging in virtual patients.

Methods

A comprehensive literature search was conducted across relevant databases to identify relevant studies published to date. The inclusion criteria were studies utilizing 3D imaging techniques, virtual patients, and those focusing on the accuracy of dental implant planning and surgical placement. The selected studies were critically appraised for their methodological quality.

Results

After a rigorous analysis, 21 relevant articles were included out of 3021 articles. This study demonstrates the versatility and applicability of these technologies in both in vitro and in vivo settings. Integrating Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), cone bean computed tomography (CBCT), and advanced 3D reconstruction methodologies showcases a trend toward enhanced precision in implant planning and placement. Notably, the evaluation parameters varied, encompassing distances, discrepancies, and deviations in the implant placement. The ongoing integration of systems such as dynamic navigation systems, augmented reality, and sophisticated software platforms shows a promising trajectory for the continued refinement of virtual reality applications in dental implantology, providing valuable insights for future research and clinical implementation. Moreover, using stereolithographic surgical guides, virtual planning with CBCT data, and 3D-printed templates consistently demonstrates enhanced precision in dental implant placement compared to traditional methods.

Conclusion

The synthesis of the available evidence underscores the substantial positive impact of 3D imaging techniques and virtual patients on dental implant planning and surgical placement accuracy. Utilizing these technologies contributes to a more personalized and precise approach that enhances overall treatment outcomes. Future research directions and potential refinements to the application of these technologies in clinical practice should be discussed.

Biomaterials Adapted to Vat Photopolymerization in 3D Printing: Characteristics and Medical Applications

Along with the rapid and extensive advancements in the 3D printing field, a diverse range of uses for 3D printing have appeared in the spectrum of medical applications. Vat photopolymerization (VPP) stands out as one of the most extensively researched methods of 3D printing, with its main advantages being a high printing speed and the ability to produce high-resolution structures. A major challenge in using VPP 3D-printed materials in medicine is the general incompatibility of standard VPP resin mixtures with the requirements of biocompatibility and biofunctionality. Instead of developing completely new materials, an alternate approach to solving this problem involves adapting existing biomaterials. These materials are incompatible with VPP 3D printing in their pure form but can be adapted to the VPP chemistry and general process through the use of innovative mixtures and the addition of specific pre- and post-printing steps. This review's primary objective is to highlight biofunctional and biocompatible materials that have been adapted to VPP. We present and compare the suitability of these adapted materials to different medical applications and propose other biomaterials that could be further adapted to the VPP 3D printing process in order to fulfill patient-specific medical requirements.

Role of Three-Dimensional Printing in Treatment Planning for Orthognathic Surgery: A Systematic Review

Three-dimensional (3D) printing refers to a wide range of additive manufacturing processes that enable the construction of structures and models. It has been rapidly adopted for a variety of surgical applications, including the printing of patient-specific anatomical models, implants and prostheses, external fixators and splints, as well as surgical instrumentation and cutting guides. In comparison to traditional methods, 3D-printed models and surgical guides offer a deeper understanding of intricate maxillofacial structures and spatial relationships. This review article examines the utilization of 3D printing in orthognathic surgery, particularly in the context of treatment planning. It discusses how 3D printing has revolutionized this sector by providing enhanced visualization, precise surgical planning, reduction in operating time, and improved patient communication. Various databases, including PubMed, Google Scholar, ScienceDirect, and Medline, were searched with relevant keywords. A total of 410 articles were retrieved, of which 71 were included in this study. This article concludes that the utilization of 3D printing in the treatment planning of orthognathic surgery offers a wide range of advantages, such as increased patient satisfaction and improved functional and aesthetic outcomes.

Analysis of the Effectiveness of 3D Printed Patient-Specific Implants for Reconstruction of Maxillary Defect Secondary to Mucormycosis

Introduction

Patients affected with mucormycosis of maxilla have been increasing following Covid-19 infections. We followed the reconstruction of the maxilla using 3D manufactured patient-specific implants. The additive manufacturing technology is capable of fabricating custom-made titanium implants precisely for oral and maxillofacial reconstructions.

Aim

To analyse the effectiveness of 3D manufactured patient-specific implants in the reconstruction of maxilla affected by mucormycosis secondary to Covid-19. Methodology: This study was conducted among 20 patients receiving patient-specific implants for surgical and prosthetic reconstruction of the maxilla. The parameters analysed at baseline, 3 months, 6 months, and 12 months were pain, implant exposure, infection, wound dehiscence, fit of implant, postoperative surgical rating scale, and patient experience evaluation rating scale.

Results

Inferential Statistics revealed a positive correlation.

Conclusion

From the present data, it can be concluded that within the limitations of the study, patient-specific implant systems are an effective treatment strategy for the reconstruction of the maxilla affected by mucormycosis secondary to Covid-19. More studies with larger sample size and longer follow-up periods are required to substantiate the results from the present study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12663-023-01922-7.

Augmented and Virtual Reality for Preoperative Trauma Planning, Focusing on Orbital Reconstructions: A Systematic Review

BACKGROUND

This systematic review summarizes recent literature on the use of extended reality, including augmented reality (AR), mixed reality (MR), and virtual reality (VR), in preoperative planning for orbital fractures.

METHODS

A systematic search was conducted in PubMed, Embase, Web of Science and Cochrane on 6 April 2023. The included studies compared extended reality with conventional planning techniques, focusing on computer-aided surgical simulation based on Computed Tomography data, patient-specific implants (PSIs), fracture reconstruction of the orbital complex, and the use of extended reality. Outcomes analyzed were technical accuracy, planning time, operative time, complications, total cost, and educational benefits.

RESULTS

A total of 6381 articles were identified. Four articles discussed the educational use of VR, while one clinical prospective study examined AR for assisting orbital fracture management.

CONCLUSION

AR was demonstrated to ameliorate the accuracy and precision of the incision and enable the better identification of deep anatomical tissues in real time. Consequently, intraoperative imaging enhancement helps to guide the orientation of the orbital reconstruction plate and better visualize the precise positioning and fixation of the PSI of the fractured orbital walls. However, the technical accuracy of 2-3 mm should be considered. VR-based educational tools provided better visualization and understanding of craniofacial trauma compared to conventional 2- or 3-dimensional images.

The Progress in Bioprinting and Its Potential Impact on Health-Related Quality of Life

The intensive development of technologies related to human health in recent years has caused a real revolution. The transition from conventional medicine to personalized medicine, largely driven by bioprinting, is expected to have a significant positive impact on a patient's quality of life. This article aims to conduct a systematic review of bioprinting's potential impact on health-related quality of life. A literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was undertaken using the PubMed, Scopus, Google Scholar, and ScienceDirect databases between 2019 and 2023. We have identified some of the most significant potential benefits of bioprinting to improve the patient's quality of life: personalized part production; saving millions of lives; reducing rejection risks after transplantation; accelerating the process of skin tissue regeneration; homocellular tissue model generation; precise fabrication process with accurate specifications; and eliminating the need for organs donor, and thus reducing patient waiting time. In addition, these advances in bioprinting have the potential to greatly benefit cancer treatment and other research, offering medical solutions tailored to each individual patient that could increase the patient's chance of survival and significantly improve their overall well-being. Although some of these advancements are still in the research stage, the encouraging results from scientific studies suggest that they are on the verge of being integrated into personalized patient treatment. The progress in bioprinting has the power to revolutionize medicine and healthcare, promising to have a profound impact on improving the quality of life and potentially transforming the field of medicine and healthcare.

A Custom-Made Surgical Guide for Accurate Enucleation of Nasopalatine Duct Cysts: A Technical Note and Case Report

Nasopalatine cysts are common nonodontogenic cysts that occur in the maxilla. During the nucleation of large cysts extending to the floor of the nasal cavity, care must be taken to avoid damage to the nasal mucosa. In the present report, an innovative custom-made surgical guide made by a Three-dimensional printer is introduced for accurate enucleation surgery. The patient's cone-beam computerized tomography and dental model scan data were obtained, and a tooth-supported type of surgical guide was designed containing a circular plate structure showing the size of the cystic region, an indicator that showed the position of the bottom of the cyst, and a sliding stopper that was used to accurately indicate the position of the deepest cyst wall. The surgical tool enabled us to indicate the accurate size, location of the cysts, and approach direction. Although effective and accurate navigation systems have become increasingly available, the cost-effective and accurate computer-aided design/computer-aided manufacturing surgical guide system introduced in the present report could support the safe enucleation of large nasopalatine duct cysts.

Optimizing efficiency in the creation of patient-specific plates through field-driven generative design in maxillofacial surgery

Field driven design is a novel approach that allows to define through equations geometrical entities known as implicit bodies. This technology does not rely upon conventional geometry subunits, such as polygons or edges, rather it represents spatial shapes through mathematical functions within a geometrical field. The advantages in terms of computational speed and automation are conspicuous, and well acknowledged in engineering, especially for lattice structures. Moreover, field-driven design amplifies the possibilities for generative design, facilitating the creation of shapes generated by the software on the basis of user-defined constraints. Given such potential, this paper suggests the possibility to use the software nTopology, which is currently the only software for field-driven generative design, in the context of patient-specific implant creation for maxillofacial surgery. Clinical scenarios of applicability, including trauma and orthognathic surgery, are discussed, as well as the integration of this new technology with current workflows of virtual surgical planning. This paper represents the first application of field-driven design in maxillofacial surgery and, although its results are very preliminary as it is limited in considering only the distance field elaborated from specific points of reconstructed anatomy, it introduces the importance of this new technology for the future of personalized implant design in surgery.

3D printing titanium grid scaffold facilitates osteogenesis in mandibular segmental defects

Bone fusion of defect broken ends is the basis of the functional reconstruction of critical maxillofacial segmental bone defects. However, the currently available treatments do not easily achieve this goal. Therefore, this study aimed to fabricate 3D-printing titanium grid scaffolds, which possess sufficient pores and basic biomechanical strength to facilitate osteogenesis in order to accomplish bone fusion in mandibular segmental bone defects. The clinical trial was approved and supervised by the Medical Ethics Committee of the Chinese PLA General Hospital on March 28th, 2019 (Beijing, China. approval No. S2019-065-01), and registered in the clinical trials registry platform (registration number: ChiCTR2300072209). Titanium grid scaffolds were manufactured using selective laser melting and implanted in 20 beagle dogs with mandibular segmental defects. Half of the animals were treated with autologous bone chips and bone substances incorporated into the scaffolds; no additional filling was used for the rest of the animals. After 18 months of observation, radiological scanning and histological analysis in canine models revealed that the pores of regenerated bone were filled with titanium grid scaffolds and bone broken ends were integrated. Furthermore, three patients were treated with similar titanium grid scaffold implants in mandibular segmental defects; no mechanical complications were observed, and similar bone regeneration was observed in the reconstructed patients' mandibles in the clinic. These results demonstrated that 3D-printing titanium grid scaffolds with sufficient pores and basic biomechanical strength could facilitate bone regeneration in large-segment mandibular bone defects.

Trueness of cone-beam computed tomography-derived skull models fabricated by different technology-based three-dimensional printers

BACKGROUND

Three-dimensional (3D) printing is a novel innovation in the field of craniomaxillofacial surgery, however, a lack of evidence exists related to the comparison of the trueness of skull models fabricated using different technology-based printers belonging to different cost segments.

METHODS

A study was performed to investigate the trueness of cone-beam computed tomography-derived skull models fabricated using different technology based on low-, medium-, and high-cost 3D printers. Following the segmentation of a patient's skull, the model was printed by: (i) a low-cost fused filament fabrication printer; (ii) a medium-cost stereolithography printer; and (iii) a high-cost material jetting printer. The fabricated models were later scanned by industrial computed tomography and superimposed onto the original reference virtual model by applying surface-based registration. A part comparison color-coded analysis was conducted for assessing the difference between the reference and scanned models. A one-way analysis of variance (ANOVA) with Bonferroni correction was applied for statistical analysis.

RESULTS

The model printed with the low-cost fused filament fabrication printer showed the highest mean absolute error ([Formula: see text]), whereas both medium-cost stereolithography-based and the high-cost material jetting models had an overall similar dimensional error of [Formula: see text] and [Formula: see text], respectively. Overall, the models printed with medium- and high-cost printers showed a significantly ([Formula: see text]) lower error compared to the low-cost printer.

CONCLUSIONS

Both stereolithography and material jetting based printers, belonging to the medium- and high-cost market segment, were able to replicate the skeletal anatomy with optimal trueness, which might be suitable for patient-specific treatment planning tasks in craniomaxillofacial surgery. In contrast, the low-cost fused filament fabrication printer could serve as a cost-effective alternative for anatomical education, and/or patient communication.

Development of a maturity model for additive manufacturing: A conceptual model proposal

Additive manufacturing (AM) is an emerging area with the potential to modify present business models in the near future. In contrast with conventional manufacturing (CM), AM allows the development of a product from a smaller amount of raw material, while allowing an improvement in properties in terms of weight and functionality. Its production flexibility and creativity in terms of materials have enabled not only the industry to use this technology, but also has been used in healthcare (e.g., in the production of human tissue) and by the final consumer. Despite the invaluable opportunities that this technology could provide, the uncertainties concerning its future developments and impacts on business models remain. New business models in AM will convey the need to: specialize the workforce in the design of new parts produced locally or remotely; regulation in the use and sharing of intellectual property rights by partner companies or between users; regulate the possibility of reverse engineering of highly customized products; etc. The present research proposes a conceptual maturity model to support the phases of evolution of AM in the industry, in supply chains, and in terms of open business models.

Managing Predicted Post-Orthognathic Surgical Defects Using Combined Digital Software: A Case Report

For facial abnormalities, recent developments in virtual surgical planning (VSP) and the virtual design of surgical splints are accessible. Software companies have worked closely with surgical teams for accurate outcomes, but they are only as reliable as the data provided to them. The current case's aim was to show a fully digitized workflow using a combination of three digital software to correct predicted post-upward sliding genioplasty defects. To reach our goal, we presented a 28-year-old man with long-face syndrome for orthodontic treatment. Before orthognathic surgery, a clinical and paraclinical examination was performed. For a virtual surgical plan, we used the dedicated surgical planning software NemoFab (Nemotec, Madrid, Spain) and Autodesk MeshMixer (Autodesk Inc., San Rafael, CA, USA). To create the design of the digital guides, DentalCAD 3.0 Galway (exocad GmbH, Darmstadt, Germany) and Autodesk MeshMixer (Autodesk Inc., San Rafael, CA, USA) were used. The patient had undergone bilateral sagittal split osteotomy in addition to Le Fort 1 osteotomy and genioplasty, followed by mandible base recontouring ostectomy. Stable fixation was used for each osteotomy. Based on our case, the current orthognathic surgery planning software was not able to perform all the necessary operations autonomously; therefore, future updates are eagerly awaited.

Can Steam Sterilization Affect the Accuracy of Point-of-Care 3D Printed Polyetheretherketone (PEEK) Customized Cranial Implants? An Investigative Analysis

Polyetheretherketone (PEEK) has become the biomaterial of choice for repairing craniofacial defects over time. Prospects for the point-of-care (POC) fabrication of PEEK customized implants have surfaced thanks to the developments in three-dimensional (3D) printing systems. Consequently, it has become essential to investigate the characteristics of these in-house fabricated implants so that they meet the necessary standards and eventually provide the intended clinical benefits. This study aimed to investigate the effects of the steam sterilization method on the dimensional accuracy of POC 3D-printed PEEK customized cranial implants. The objective was to assess the influence of standard sterilization procedures on material extrusion-based 3D-printed PEEK customized implants with non-destructive material testing. Fifteen PEEK customized cranial implants were fabricated using an in-house material extrusion-based 3D printer. After fabrication, the cranial implants were digitalized with a professional-grade optical scanner before and after sterilization. The dimensional changes for the 3D-printed PEEK cranial implants were analyzed using medically certified 3D image-based engineering software. The material extrusion 3D-printed PEEK customized cranial implants displayed no statistically significant dimensional difference with steam sterilization (p > 0.05). Evaluation of the cranial implants’ accuracy revealed that the dimensions were within the clinically acceptable accuracy level with deviations under 1.00 mm. Steam sterilization does not significantly alter the dimensional accuracy of the in-house 3D-printed PEEK customized cranial implants.

Application of 3D Printing in Bone Grafts

The application of 3D printing in bone grafts is gaining in importance and is becoming more and more popular. The choice of the method has a direct impact on the preparation of the patient for surgery, the probability of rejection of the transplant, and many other complications. The aim of the article is to discuss methods of bone grafting and to compare these methods. This review of literature is based on a selective literature search of the PubMed and Web of Science databases from 2001 to 2022 using the search terms “bone graft”, “bone transplant”, and “3D printing”. In addition, we also reviewed non-medical literature related to materials used for 3D printing. There are several methods of bone grafting, such as a demineralized bone matrix, cancellous allograft, nonvascular cortical allograft, osteoarticular allograft, osteochondral allograft, vascularized allograft, and an autogenic transplant using a bone substitute. Currently, autogenous grafting, which involves removing the patient’s bone from an area of low aesthetic importance, is referred to as the gold standard. 3D printing enables using a variety of materials. 3D technology is being applied to bone tissue engineering much more often. It allows for the treatment of bone defects thanks to the creation of a porous scaffold with adequate mechanical strength and favorable macro- and microstructures. Bone tissue engineering is an innovative approach that can be used to repair multiple bone defects in the process of transplantation. In this process, biomaterials are a very important factor in supporting regenerative cells and the regeneration of tissue. We have years of research ahead of us; however, it is certain that 3D printing is the future of transplant medicine.

Three-Dimensional Accuracy and Stability of Personalized Implants in Orthognathic Surgery: A Systematic Review and a Meta-Analysis

This systematic review aimed to determine the accuracy/stability of patient-specific osteosynthesis (PSI) in orthognathic surgery according to three-dimensional (3D) outcome analysis and in comparison to conventional osteosynthesis and computer-aided designed and manufactured (CAD/CAM) splints or wafers. The PRISMA guidelines were followed and six academic databases and Google Scholar were searched. Records reporting 3D accuracy/stability measurements of bony segments fixated with PSI were included. Of 485 initial records, 21 met the eligibility (566 subjects), nine of which also qualified for a meta-analysis (164 subjects). Six studies had a high risk of bias (29%), and the rest were of low or moderate risk. Procedures comprised either single-piece or segmental Le Fort I and/or mandibular osteotomy and/or genioplasty. A stratified meta-analysis including 115 subjects with single-piece Le Fort I PSI showed that the largest absolute mean deviations were 0.5 mm antero-posteriorly and 0.65° in pitch. PSIs were up to 0.85 mm and 2.35° more accurate than conventional osteosynthesis with CAD/CAM splint or wafer (p < 0.0001). However, the clinical relevance of the improved accuracy has not been shown. The literature on PSI for multi-piece Le Fort I, mandibular osteotomies and genioplasty procedure is characterized by high methodological heterogeneity and a lack of randomized controlled trials. The literature is lacking on the 3D stability of bony segments fixated with PSI.

Implementation of an In-House 3D Manufacturing Unit in a Public Hospital’s Radiology Department

Objective: Three-dimensional printing has become a leading manufacturing technique in healthcare in recent years. Doubts in published studies regarding the methodological rigor and cost-effectiveness and stricter regulations have stopped the transfer of this technology in many healthcare organizations. The aim of this study was the evaluation and implementation of a 3D printing technology service in a radiology department. Methods: This work describes a methodology to implement a 3D printing service in a radiology department of a Spanish public hospital, considering leadership, training, workflow, clinical integration, quality processes and usability. Results: The results correspond to a 6-year period, during which we performed up to 352 cases, requested by 85 different clinicians. The training, quality control and processes required for the scaled implementation of an in-house 3D printing service are also reported. Conclusions: Despite the maturity of the technology and its impact on the clinic, it is necessary to establish new workflows to correctly implement them into the strategy of the health organization, adjusting it to the needs of clinicians and to their specific resources. Significance: This work allows hospitals to bridge the gap between research and 3D printing, setting up its transfer to clinical practice and using implementation methodology for decision support.