Use of 3D Printed Models to Create Molds for Shaping Implants for Surgical Repair of Orbital Fractures

Does a Point-of-Care 3-Dimensional Printer Result in a Decreased Length of Surgery for Orbital Fractures?

BACKGROUND

Utilization of point-of-care 3-dimensional printing (3DP) has decreased length of surgery in facial trauma. Little is known regarding 3DP's impact on length of surgery in orbital fracture.

PURPOSE

The purpose of this study was to compare length of surgery between 3DP/preadapted (3DPPA) orbital plates and intraoperative adapted plates (IOAP) for orbital fracture reconstruction.

STUDY DESIGN, SETTING, SAMPLE

This was a prospective, non-blinded, randomized clinical study of consecutive subjects with orbital fractures presented to Grady Memorial Hospital in Atlanta, Georgia, between January 2018 and June 2021. Subjects ≥ 18 years, unilateral fracture, no previous orbital surgery, and/or congenital craniofacial anomaly were included. We excluded subjects <18 years and bilateral fractures.

PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE

Primary predictor variable was the treatment approach. Randomization software was used, and subjects were randomized to 3DPPA or IOAP groups.

MAIN OUTCOME VARIABLE(S)

Primary outcome variable was length of surgery in minutes. Secondary outcomes were the time required for plate insertion and fixation in minutes, operating room (OR) charges, and orbital volume (OV) calculation.

COVARIATES

Age, sex, race, etiology, laterality, location, dimension, indication for surgery, postoperative enophthalmos, and diplopia.

ANALYSES

Univariate and bivariate analyses were calculated. Statistical significance was P < .05.

RESULTS

Twenty-five subjects met the inclusion criteria. Mean ages in 3DPPA and conventional IOAP groups were 41.5 (±9) and 38.2 (±10, P = .31), respectively. The mean length of surgery was 32.6 (±13.7) in 3DPPA and 53.3 (±12.8, P < .001) in conventional IOAP. The mean time required for plate insertion and fixation was 15.8n (±14.4) in 3DPPA and 41.4 (±9.4, P < .001) in conventional IOAP. The mean OR charges were $1,072.5 (±524.6) in 3DPPA and $1,757.3 (±422.6, P ≤ 0.001) in conventional IOAP. The mean calculated OV of uninjured and reconstructed orbit for the 3DPPA was 23.5 (±3.2)cm3 and 23 (±3.5, P = .37)cm3, respectively. The mean calculated OV of uninjured and reconstructed orbit for conventional IOAP was 28.6 (±3.6)cm3 and 22.8 (±2.6, P < .001)cm3, respectively.

CONCLUSION AND RELEVANCE

Using 3DP to produce a model that enables preoperative plate bending/adaptation reduces the length of surgery, decreases OR charges, and results in predictable OV.

3D printing materials and 3D printed surgical devices in oral and maxillofacial surgery: design, workflow and effectiveness

Oral and maxillofacial surgery is a specialized surgical field devoted to diagnosing and managing conditions affecting the oral cavity, jaws, face and related structures. In recent years, the integration of 3D printing technology has revolutionized this field, offering a range of innovative surgical devices such as patient-specific implants, surgical guides, splints, bone models and regenerative scaffolds. In this comprehensive review, we primarily focus on examining the utility of 3D-printed surgical devices in the context of oral and maxillofacial surgery and evaluating their efficiency. Initially, we provide an insightful overview of commonly utilized 3D-printed surgical devices, discussing their innovations and clinical applications. Recognizing the pivotal role of materials, we give consideration to suitable biomaterials and printing technology of each device, while also introducing the emerging fields of regenerative scaffolds and bioprinting. Furthermore, we delve into the transformative impact of 3D-printed surgical devices within specific subdivisions of oral and maxillofacial surgery, placing particular emphasis on their rejuvenating effects in bone reconstruction, orthognathic surgery, temporomandibular joint treatment and other applications. Additionally, we elucidate how the integration of 3D printing technology has reshaped clinical workflows and influenced treatment outcomes in oral and maxillofacial surgery, providing updates on advancements in ensuring accuracy and cost-effectiveness in 3D printing-based procedures.

The Use of Additive Manufacturing Techniques in the Development of Polymeric Molds: A Review

The continuous growth of additive manufacturing in worldwide industrial and research fields is driven by its main feature which allows the customization of items according to the customers' requirements and limitations. There is an expanding competitiveness in the product development sector as well as applicative research that serves special-use domains. Besides the direct use of additive manufacturing in the production of final products, 3D printing is a viable solution that can help manufacturers and researchers produce their support tooling devices (such as molds and dies) more efficiently, in terms of design complexity and flexibility, timeframe, costs, and material consumption reduction as well as functionality and quality enhancements. The compatibility of the features of 3D printing of molds with the requirements of low-volume production and individual-use customized items development makes this class of techniques extremely attractive to a multitude of areas. This review paper presents a synthesis of the use of 3D-printed polymeric molds in the main applications where molds exhibit a major role, from industrially oriented ones (injection, casting, thermoforming, vacuum forming, composite fabrication) to research or single-use oriented ones (tissue engineering, biomedicine, soft lithography), with an emphasis on the benefits of using 3D-printed polymeric molds, compared to traditional tooling.

Altered brain network centrality in patients with orbital fracture: A resting‑state functional MRI study

The present study aimed to investigate potential functional network brain-activity abnormalities in individuals with orbital fracture (OF) using the voxel-wise degree centrality (DC) technique. The present study included 20 patients with OF (12 males and 8 females) and 20 healthy controls (HC; 12 males and 8 females), who were matched for gender, age and educational attainment. Functional magnetic resonance imaging (fMRI) in the resting state has been widely applied in several fields. Receiver operating characteristic (ROC) curves were calculated to distinguish between patients with OF and HCs. In addition, correlation analyses were performed between behavioral performance and average DC values in various locations. The DC technique was used to assess unprompted brain activity. Right cerebellum 9 region (Cerebelum_9_R) and left cerebellar peduncle 2 area (Cerebelum_Crus2_L) DC values of patients with OF were increased compared with those in HCs. Cerebelum_9_R and Cerebelum_Crus2_L had area under the ROC curve values of 0.983 and 1.000, respectively. Patients with OF appear to have several brain regions that exhibited aberrant brain network characteristics, which raises the possibility of neuropathic causes and offers novel therapeutic options.

Medical 3D Printing Using Desktop Inverted Vat Photopolymerization: Background, Clinical Applications, and Challenges

Medical 3D printing is a complex, highly interdisciplinary, and revolutionary technology that is positively transforming the care of patients. The technology is being increasingly adopted at the Point of Care (PoC) as a consequence of the strong value offered to medical practitioners. One of the key technologies within the medical 3D printing portfolio enabling this transition is desktop inverted Vat Photopolymerization (VP) owing to its accessibility, high quality, and versatility of materials. Several reports in the peer-reviewed literature have detailed the medical impact of 3D printing technologies as a whole. This review focuses on the multitude of clinical applications of desktop inverted VP 3D printing which have grown substantially in the last decade. The principles, advantages, and challenges of this technology are reviewed from a medical standpoint. This review serves as a primer for the continually growing exciting applications of desktop-inverted VP 3D printing in healthcare.

Low-Cost Cranioplasty-A Systematic Review of 3D Printing in Medicine

The high cost of biofabricated titanium mesh plates can make them out of reach for hospitals in low-income countries. To increase the availability of cranioplasty, the authors of this work investigated the production of polymer-based endoprostheses. Recently, cheap, popular desktop 3D printers have generated sufficient opportunities to provide patients with on-demand and on-site help. This study also examines the technologies of 3D printing, including SLM, SLS, FFF, DLP, and SLA. The authors focused their interest on the materials in fabrication, which include PLA, ABS, PET-G, PEEK, and PMMA. Three-dimensional printed prostheses are modeled using widely available CAD software with the help of patient-specific DICOM files. Even though the topic is insufficiently researched, it can be perceived as a relatively safe procedure with a minimal complication rate. There have also been some initial studies on the costs and legal regulations. Early case studies provide information on dozens of patients living with self-made prostheses and who are experiencing significant improvements in their quality of life. Budget 3D-printed endoprostheses are reliable and are reported to be significantly cheaper than the popular counterparts manufactured from polypropylene polyester.

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

Compared to traditional manufacturing methods, additive manufacturing and 3D printing stand out in their ability to rapidly fabricate complex structures and precise geometries. The growing need for products with different designs, purposes and materials led to the development of 3D printing, serving as a driving force for the 4th industrial revolution and digitization of manufacturing. 3D printing has had a global impact on healthcare, with patient-customized implants now replacing generic implantable medical devices. This revolution has had a particularly significant impact on oral and maxillofacial surgery, where surgeons rely on precision medicine in everyday practice. Trauma, orthognathic surgery and total joint replacement therapy represent several examples of treatments improved by 3D technologies. The widespread and rapid implementation of 3D technologies in clinical settings has led to the development of point-of-care treatment facilities with in-house infrastructure, enabling surgical teams to participate in the 3D design and manufacturing of devices. 3D technologies have had a tremendous impact on clinical outcomes and on the way clinicians approach treatment planning. The current review offers our perspective on the implementation of 3D-based technologies in the field of oral and maxillofacial surgery, while indicating major clinical applications. Moreover, the current report outlines the 3D printing point-of-care concept in the field of oral and maxillofacial surgery.

3D Printing in Eye Care

Three-dimensional printing enables precise modeling of anatomical structures and has been employed in a broad range of applications across medicine. Its earliest use in eye care included orbital models for training and surgical planning, which have subsequently enabled the design of custom-fit prostheses in oculoplastic surgery. It has evolved to include the production of surgical instruments, diagnostic tools, spectacles, and devices for delivery of drug and radiation therapy. During the COVID-19 pandemic, increased demand for personal protective equipment and supply chain shortages inspired many institutions to 3D-print their own eye protection. Cataract surgery, the most common procedure performed worldwide, may someday make use of custom-printed intraocular lenses. Perhaps its most alluring potential resides in the possibility of printing tissues at a cellular level to address unmet needs in the world of corneal and retinal diseases. Early models toward this end have shown promise for engineering tissues which, while not quite ready for transplantation, can serve as a useful model for in vitro disease and therapeutic research. As more institutions incorporate in-house or outsourced 3D printing for research models and clinical care, ethical and regulatory concerns will become a greater consideration. This report highlights the uses of 3D printing in eye care by subspecialty and clinical modality, with an aim to provide a useful entry point for anyone seeking to engage with the technology in their area of interest.

3D Printed Models for Teaching Orbital Anatomy, Anomalies and Fractures

PURPOSE

The aim of this study was to determine the efficacy of using 3D printing models in the learning process of orbital anatomy and pathology by ophthalmology residents.

METHODS

A quasi-experimental study was performed with 24 residents of ophthalmology at Mashhad University of Medical Sciences. Each stratum was randomized into two groups. The educational booklets were distributed, and various forms of orbital 3D models were printed from orbital computed tomography (CT) scans. Knowledge enhancement on the topics was measured by comparing pretest and posttest scores.

RESULTS

Thirteen residents who were trained using traditional methods were deemed the control group; while 11 residents who were trained using the 3D printed models were classed as the intervention group. The control group was younger than the intervention group (P = 0.047). The results showed that there was a statistically significant difference in the total posttest scores between the two groups. Based on the repeated measures of the analysis of variance (ANOVA), score variables were significant between the two groups (P = 0.008). Interestingly, the use of the 3D educational model was more effective and statistically significant with the year one residents as compared to the year two residents (P = 0.002).

CONCLUSION

This study is the first one in Iran quantifying the effects of learning using 3D printed models in medical education. In fact, 3D modeling training is seemingly effective in teaching ophthalmic residents. As residents have never encountered such technology before, their experience using 3D models proved to be satisfactory and had a surprising positive effect on the learning process through visual training.

3D Printing Applications for Radiology: An Overview

Three-dimensional (3D) printing technologies are part of additive manufacturing processes and are used to manufacture a 3D physical model from a digital computer-aided design model as per the required shape and size. These technologies are now used for advanced radiology applications by providing all information through 3D physical model. It provides innovation in radiology for clinical applications, treatment planning, procedural simulation, medical and patient education. Radiological advancements have been made in diagnosis and communication through medical digital imaging techniques like computed tomography, magnetic resonance imaging. These images are converted into Digital Imaging and Communications in Medicine in Standard Triangulate Language file format, easily printable in 3D printing technologies. This 3D model provides in-depth information about pathologic and anatomic states. It is useful to create new opportunities related to patient care. This article discusses the potential of 3D printing technology in radiology. The steps involved in 3D printing for radiology are discussed diagrammatically, and finally identified 12 significant applications of 3D printing technology for radiology with a brief description. A radiologist can incorporate this technology to fulfil different challenges such as training, planning, guidelines, and better communications.

Orbital Bony Reconstruction With Presized and Precontoured Porous Polyethylene-Titanium Implants

PURPOSE

Complex bony orbital defects are reconstructively challenging due to loss of intraoperative anatomical landmarks and adjacent support. Presized and precontoured porous polyethylene-titanium implants (Medpor Titan 3D Orbital Floor Implant) are designed to reestablish normal orbital floor and medial wall anatomy and are modeled after anatomically averaged orbits. This is the first study to report clinical outcomes with this implant.

METHODS

This retrospective case series reviewed clinical data and outcomes for patients undergoing orbital reconstruction with a presized and precontoured porous polyethylene-titanium orbital implant from January 2016 to June 2018.

RESULTS

A total of 34 orbits of 33 patients were identified (mean age: 43 ± 16 years, 70% men). Most bony defects were a result of trauma and included large orbital floor deformities (100%), medial wall defects (74%), disrupted inferomedial struts (68%), and broken posterior ledges (82%). Symptomatic diplopia (73%) and enophthalmos (89%, mean: 3.7 ± 2.1 mm) were common preoperatively. Many cases were revisions (44%). Mean follow up was 7.8 ± 6.7 months. All patients had improved globe positioning, enophthalmos, and hypoglobus. Seven patients had persistent postoperative diplopia: 6 responded to prism therapy and 1 required strabismus surgery. One patient required retrobulbar hematoma drainage and 1 patient required implant explantation due to chronic infection.

CONCLUSIONS

Commercially available presized and precon toured porous polyethylene-titanium implants are useful for complex orbital bony defects and can achieve functional improve ments in diplopia, enophthalmos, and extraocular motility with a low incidence of postoperative complications or revisional surgery.

Utilizing 3D-Printed Orbital Floor Stamps to Create Patient-Specific Implants for Orbital Floor Reconstruction

PURPOSE

This study seeks to test a novel technique of custom-printed midface contour models with orbital floor "stamps" to guide reconstruction of orbital floor blowout fractures, with or without concomitant zygomaticomaxillary complex injury.

METHODS

A series of 4 consecutive patients with orbital floor blowout fractures (including 3 with zygomatic maxillary complex fractures) were retrospectively examined for outcomes associated with orbital floor reconstruction using 3-dimensional-printed stamps and midface models. Data collected included demographics, pre- and postoperative visual globe malposition, motility, and visual field disturbances. Three-dimensional printing methodology is reported, as well as associated costs and time required to generate the models and stamps.

RESULTS

The cost of producing a midface-contour model and orbital floor stamps was $131, inclusive of labor and materials. Cases averaged 170 minutes to segment, design, and print. Patients with preoperative diplopia and motility restrictions had resolution of their symptoms. Two patients had resolution of their enophthalmos, while one patient with a concomitant zygomaticomaxillary fracture had persistent mild enophthalmos.

CONCLUSIONS

Midface contour models and orbital floor stamps may be produced in a timely and cost-effective manner. Use of these "homemade" stamps allows for patient-specific custom-contoured orbital floor reconstruction. Further studies are warranted to examine long-term visual and esthetic outcomes for these patients.

Treatment of orbital blowout fracture using a customized rigid carrier

PURPOSE

This study aimed to examine the usefulness of treating orbital blowout fracture using a customized rigid carrier.

MATERIAL AND METHODS

Patients who underwent surgery for orbital blowout fractures in our department from April 2016 to March 2019 were recruited in the study. We molded a rigid thermoplastic material into the same shape as the reconstruction material according to the 3D model and transplanted it into the orbital space along with the reconstruction material. We assessed Hertel exophthalmometry, awareness of diplopia, and the Hess area ratio (HAR%).

RESULTS

We performed this procedure in 15 patients with blowout fractures. Reconstruction materials used were iliac bone, absorbable plates, and titanium mesh in 12, 2, and 1 patient, respectively. None of the patients showed a difference of more than 2 mm on Hertel exophthalmometry. Only one patient had diplopia after surgery. The average preoperative and postoperative HAR% were 83.1 and 90.6, respectively. HAR% was more than 85% in 6 of 7 postoperative cases.

CONCLUSIONS

This method can be applied for surgery using various reconstructive materials and can be a useful method, especially in patients with a wide range of orbital bone defects.

Complications Following Orbital Floor Repair: Impact of Intraoperative Computed Tomography Scan and Implant Material

Importance: Orbital floor fracture repair is complex and postoperative complications are common. A variety of applicable surgical techniques and technologies are available to surgeons, so data about which of these may decrease postoperative complication rates can help better guide clinical decision making. Objectives: To characterize the patient demographics and surgical techniques utilized in orbital floor fracture repairs at San Antonio Military Medical Center and their relationship with rates of postoperative complications. Design, Setting, and Participants: Retrospective chart review of patients who underwent orbital floor fracture repairs from March 2014 to March 2019 with a mean follow-up time of 1.86 months at a tertiary care academic military hospital and level 1 trauma center. Main Outcomes and Measures: Demographic data, indication for surgical repair, fracture severity, orbital floor approach, implant material, and use of intraoperative computed tomography (CT) scan were recorded. Chi-square analysis was performed to determine the relationship between these factors and postoperative diplopia, hypoglobus, enophthalmos, and infection. Results: A total of 124 procedures were performed during the study period: 71.8% of patients were male and 74% were civilian. Mean age was 39 years (range 19-81). Thirty-one patients were lost to follow-up. The most common approach was transconjunctival (83%), which was most frequently used exclusively (68.5%), but was also combined with cantholysis, transcaruncular, or transantral approach. Postoperative diplopia at follow-up was common (53.8%), resolved after an average of 36.3 days, and was significantly associated with surgical indication of entrapment or revision (p = 0.01) and nonutilization of intraoperative CT (p = 0.04). From 2014 to 2016, intraoperative CT was utilized in 21% of cases and revision rate was 10.5%. From 2017 to 2019, 50% of cases utilized intraoperative CT and revision rate was 2% (p = 0.15). Three cases were revisions performed for abnormal plate position noted on postoperative CT scan. Conclusions and Relevance: A statistically significant association was found between postoperative diplopia, surgical indication of entrapment or revision, and nonutilization of intraoperative CT. Revision rates decreased when use of intraoperative CT increased. Three revision cases may have been prevented by use of an intraoperative CT scan. Patients with entrapment should be counseled regarding the increased risk of postoperative diplopia.