Annals of 3D printed medicine最新文献

Introduction Middle ear anatomy is difficult for learners because of its intricate and complex anatomy. Historically its anatomy has been taught with dissections and figures. 3D printed models have grown in popularity for their ability to represent complex structures. This study sought to assess the efficacy of a conceptual 3D printed middle ear model in radiology trainee education.

Methods An uncontrolled before-after trial was performed in which radiology trainees participated in small group teaching sessions using a 3D printed conceptual middle ear model. Participant knowledge was assessed with identical pre- and 1-week post-intervention knowledge assessments and surveys.

Results A total of 26 participants completed the study. The mean pre-intervention test score for participants (out of 20) was 6 ± 3.4, which increased to 11.7 ± 3.5 (p-value < 0.02) following interaction with the model. Second year radiology residents had the largest improvement in score, 9.0 ± 4.2, while fourth year radiology residents had the least, 2.8 ± 2.6. The small increase in post-intervention scores for the neuroradiology fellows was not found to be statistically significant (p-value 0.07). Subgroup analysis of post-intervention knowledge found no statistical difference among participants of different years of training. The survey showed increased understanding and desire for incorporation into curriculum.

Discussion: Interaction with the 3D printed model was found to improve anatomical knowledge in radiology residents but not neuroradiology fellows, whose improvement was not statistically significant. All participants, regardless of their years of training, were found to have knowledge equivalent to that of a fellow following their training.

Human and animal anatomy can benefit from the use the life-sized three-dimensional (3D) images of the Anatomage Table which is an intuitive touchscreen that allows virtual dissection, interactions, and control features, including the turning on and off of selected structures categorized on various cadaver models.

This technical note reports the innovative application of the Anatomage Table in a forensic odontology training program, allowing an accurate and high-resolution study and observation of the head, skull, jaws, and teeth, for the purpose of teaching dental autopsy procedures and standardized collection of dental autoptic parameters, as well as to familiarize with radiological images. Moreover, we propose virtual post-mortem dental data collection as an efficient tool in forensic odontology education and training, as an adjunct onsite as well as remote learning resource.

Purpose

Patient understanding of complex surgical procedures and post-intervention consequences is often poor. Little is known about the effectiveness of 3D printed models to improve the comprehension of the medical information provided to patients. The purpose of this study was to determine if 3D printed patient-specific anatomical models could help improve patients’ satisfaction and understanding of complex oncological surgical procedures, their risks, benefits, and alternatives.

Basic procedure

A randomized, controlled crossover experiment was performed, where subjects were randomly assigned to different treatments of the study. This experiment involved teenage patients experts from Kids Barcelona, a Young Person's Advisory Group. The team (n = 14, age range 14–20, 9 females and 5 males) was divided into two groups involved in two simulated pre-surgical outpatient visits for complex oncologic surgical procedures: a high-risk stage 4 abdominal neuroblastoma, and a biliary tract rhabdomyosarcoma. Two senior oncologic surgeons participated in the study by performing the structured outpatient pre-surgical visit. Each participant received information before the study explaining the study methodology and was given a questionnaire.

Main findings

Data analysis of the group using the 3D printed model for the neuroblastoma case showed better results than without the 3D model. On the other hand, conversely, on the data analysis of the rhabdomyosarcoma case with the 3D printed model no better results were observed as compared to the case of not using a 3D model. However, the results of the participants’ knowledge were still better than before the intervention. Satisfaction was significantly better with a 3D model in both cases.

Conclusion

The use of 3D physical models improves the patient's knowledge and shows the effectiveness of 3D printed models to enhance the comprehension of the medical information provided to patients and improve satisfaction.

Additive manufacturing, or 3D printing, has made incredible steps over the last 30 years and is now being widely used for healthcare applications. There has been increasing research into the possibilities of using this technology for creating viable tissues and organs, a field known as 3D bioprinting. This is motivated by the severe mismatch in demand for organ transplantation and the availability of donors. In this review, we examine the technology of 3D bioprinting and focus on extrusion-based technology, giving its relative advantages and disadvantages. We review work on creating tissues and organs, particularly focussing on the examples of skin, liver, heart and blood vessels. We examine the challenges in creating viable tissues and organs and also the associated ethical issues. Given the great progress made already in this field, the prospect of creating fully functional tissues and organs for transplantation by 3D bioprinting is now a real near-future possibility.

The replication of blood vessels for training and research purposes is possible with the help of additively manufactured (AM) models. However, a meaningful evaluation of the quality of the haptics, here concentrating on friction characteristics, of additively manufactured blood vessel models compared to human vessels is difficult and often only based on subjective assessments. To enable an objective comparison of friction of different AM materials, tests were performed in which a braided stent was pulled through straight test tubes. The force required to do so was measured. The same test setup was used to examine animal blood vessels so that these results could be compared with the findings of the AM materials. In addition, physicians were asked for their assessment of the haptics concerning friction of different materials. Summarizing the results, for the tested Formlabs materials Flexible 80A and Elastic 50A, it can be stated that Flexible 80A is strongly recommended for the replication of blood vessels - even though it is comparatively smooth. The Elastic 50A should only be used for training with increased difficulty since the models are stickier and a flipping of instruments is possible. Coating the materials only involve effort that is not reflected in the benefits.

This study aims to evaluate the mechanical performance of a unique, state-of-the-art, patient-specific alloplastic total replacement system for the temporomandibular joint that allows for enthesis reconstruction developed by CADskills BV (Ghent, Belgium), and its influence on the remaining adjacent healthy tissue, by looking into the magnitude and location of the stresses and micromotions. Because the reattachment of the lateral pterygoid muscle is unique, having never before been used in temporomandibular joint prostheses, the loading patterns and performance may be completely different from existing devices and their analyses. Therefore, multiple finite element models were created to compare existing devices, prosthetic models of the CADskills device, and healthy situations. These were used to investigate the influence of such patient-specific prostheses through the evaluation of micromotion, loading on the opposite joint, strain on the healthy bone and condyle, and stress shielding.

The results showed that the temporomandibular joint prostheses were subject to stress considerably below their yield strength, except for the polyethylene of the fossa component, which might undergo abrasion under extreme muscular loads (larger than loads occurring during the activities of daily living). Additionally, the implant was shown to have little influence on stresses in the bone compared to a healthy model. Furthermore, the dynamic model shows how the load upon and stresses in the healthy joint increase when maximum muscle activation takes place with the mouth open.

The ongoing growth of three-dimensional (3D) printing has started to expand into the medical field. To date, the main challenge is a lack of information surrounding the materials which accurately mimic soft tissue, and how they can be reproduced into a surgical phantom for medical use. This study reports on successful materials for simulating soft tissue, and the methods in which they can be printed to create surgical phantoms. Noteworthy materials which have been reported in literature as having good concordance with soft tissue mechanical properties have been identified as silicone, gelatin, polyvinyl alcohol (PVA), and Stratasys-manufactured TangoPlus. Four printing techniques, namely material extrusion, material jetting, photopolymerization, and powder bed fusion, are discussed and reviewed on their suitability for fabricating phantoms, and a summary of their use in literature has been presented in tabular format. This study explores the current uses of 3D-printed phantoms for surgical training, surgical planning and patient understanding and discusses ways in which this could be advanced in the future.

Introduction

The fabrication process of an arch bar used during a corrective jaw surgery is traditionally labour intensive and time consuming when done manually by a dental technician. The objectives of this study are therefore to test the feasibility of using selective laser melting (SLM) to directly print patient-specific stainless steel (SS316L) arch bars from computer-aided-design (CAD) files and investigate the most optimal printing parameters to achieve that.

Material and methods

An initial print-out of 72 SS316L test coupons was done to determine the most optimal print orientation and print bed location based on chemical composition and mechanical test results from 4 different printer settings:

Parameter 1: 200 W, 50 µm

Parameter 2: 150 W, 50 µm

Parameter 3: 200 W, 30 µm

Parameter 4: 150 W, 30 µm

Ten archived digital lower dentition scans were then used to produce 10 CAD files for 3D printing of 280 dental arch bars using the aforementioned parameters. All 3D printed arch bars were then assessed for fit and subjected to physical testing.

Results

Test coupons printed using parameter 4 in the horizontal print bed (0°) location had the best mechanical properties. Similarly, for 3D printed arch bars, those printed using parameter 4 had the highest proportion of arch bars with satisfactory fit. The most common area of distortion is the posterior molar region.

Conclusion

3D printing of SS316L dental arch bars is feasible via a digital workflow using low laser power (150 W) and low layer thickness (30 µm) in a Renishaw AM 400 printer (from Renishaw plc, Gloucestershire).

Mandibular distraction osteogenesis (MDO) is a surgical procedure that can successfully treat the micrognathia in neonates with Pierre Robin Sequence (PRS), avoiding glosoptossis and airway obstruction. While virtual surgical planning (VSP) and three-dimensional (3D) printing is a common technique in Oral & Maxillofacial Surgery, it has not been widely used in neonates with this condition. The objective of this study is to describe how we employ 3D technology on MDO for neonates with mandibular hypoplasia.

The aim of this study was to employ and understand the feasibility of an infrared (IR)/red-diode laser with a wavelength of 808 nm for the selective laser sintering (SLS)-mediated sintering of 3D printlets, altering the dye composition and temperature variations. Kollicoat® IR (KIR) and an infrared (IR) laser-absorbing dye were physically mixed at various concentrations and subjected to SLS-mediated sintering to achieve 3D printlets by varying printing temperature (feed and print beds) at a fixed laser power ratio. Initially, the desired concentration of dye (1.25% w/w) was selected based on its sintering performance, and the same concentration was used to sinter the physical mixtures (PMs) at different feed bed temperatures (between 100 °C and 130 °C) and print bed temperature (120 °C to 150 °C), keeping the laser power ratio constant (1.0). It was found that good sintering performance was associated with a feed bed temperature of 130 °C and a print bed temperature of 150 °C. Printlets obtained from the aforementioned conditions showed highest dimensional accuracy (9.31 ± 0.30 mm diameter and 3.56 ± 0.04 mm thickness) in respect to feeded CAD dimensions (10 mm diameter and 3.60 mm thickness) with an average weight of 77.45 ± 4.56 mg. In addition, no physical/thermal or chemical degradation of the sintered 3D printlets was observed during the thermal and functional group analysis, respectively. Depending on the conditions given, we can conclude that an IR/red diode laser with a wavelength of 808 nm and a laser power ratio of 1.0 is feasible for sintering 3D printlets.