Dimensional Printing Technology Research Articles

Influence of preoperative simulation on the reduction quality and clinical outcomes of open reduction and internal fixation for complex proximal humerus fractures

PurposeProximal humerus fractures (PHFs) are common. With the development of locking plates, open reduction and internal fixation (ORIF) of the proximal humerus can provide excellent clinical outcomes. The quality of fracture reduction is crucial in the locking plate fixation of proximal humeral fractures. The purpose of this study was to determine the impact of 3-dimensional (3D) printing technology and computer virtual technology assisted preoperative simulation on the reduction quality and clinical outcomes of 3-part and 4-part proximal humeral fractures.MethodA retrospective comparative analysis of 3-part and 4-part PHFs undergoing open reduction internal fixation was performed. Patients were divided into 2 groups according to whether computer virtual technology and 3D printed technology were used for preoperative simulation: the simulation group and the conventional group. Operative time, intraoperative bleeding, hospital stay, quality of fracture reduction, Constant scores, American Society for Shoulder and Elbow Surgery (ASES) scores, shoulder range of motion, complications, and revision surgeries were assessed.ResultsThis study included 67 patients (58.3%) in the conventional group and 48 patients (41.7%) in the simulation group. The patient demographics and fracture characteristics were comparable in these groups. Compared with the conventional group, the simulation group had shorter operation time and less intraoperative bleeding (P < 0.001, both). Immediate postoperative assessment of fracture reduction showed a higher incidence of greater tuberosity cranialization of < 5 mm, neck-shaft angle of 120° to 150°, and head shaft displacement of < 5 mm in the simulation group. The incidence of good reduction was 2.6 times higher in the simulation group than in the conventional group (95% CI, 1.2–5.8). At the final follow-up, the chance of forward flexion > 120° (OR 5.8, 95% CI 1.8–18.0) and mean constant score of > 65 (OR 3.4, 95% CI 1.5–7.4) was higher in the simulation group than the conventional group, as well as a lower incidence of complications in the simulation group was obtained (OR 0.2, 95% CI 0.1–0.6).ConclusionsThis study identified that preoperative simulation assisted by computer virtual technology and 3D printed technology can improve reduction quality and clinical outcomes in treatment of 3-part and 4-part PHFs.

Individualized medicine using 3D printing technology in gynecology: a scoping review

ObjectiveDevelopments in 3-dimensional (3D) printing technology has made it possible to produce high quality, affordable 3D printed models for use in medicine. As a result, there is a growing assessment of this approach being published in the medical literature. The objective of this study was to outline the clinical applications of individualized 3D printing in gynecology through a scoping review.Data sourcesFour medical databases (Medline, Embase, Cochrane CENTRAL, Scopus) and grey literature were searched for publications meeting eligibility criteria up to 31 May 2021.Study eligibility criteriaPublications were included if they were published in English, had a gynecologic context, and involved production of patient specific 3D printed product(s).Study appraisal and synthesis methodsStudies were manually screened and assessed for eligibility by two independent reviewers and data were extracted using pre-established criteria using Covidence software.ResultsOverall, 32 studies (15 abstracts,17 full text articles) were included in the scoping review. Most studies were either case reports (12/32,38%) or case series (15/32,47%). Gynecologic sub-specialties in which the 3D printed models were intended for use included: gynecologic oncology (21/32,66%), benign gynecology (6/32,19%), pediatrics (2/32,6%), urogynecology (2/32,6%) and reproductive endocrinology and infertility (1/32,3%). Twenty studies (63%) printed 5 or less models, 6/32 studies (19%) printed greater than 5 (up to 50 models). Types of 3D models printed included: anatomical models (11/32,34%), medical devices, (2/32,6%) and template/guide/cylindrical applicators for brachytherapy (19/32,59%).ConclusionsOur scoping review has outlined novel clinical applications for individualized 3D printed models in gynecology. To date, they have mainly been used for production of patient specific 3D printed brachytherapy guides/applicators in patients with gynecologic cancer. However, individualized 3D printing shows great promise for utility in surgical planning, surgical education, and production of patient specific devices, across gynecologic subspecialties. Evidence supporting the clinical value of individualized 3D printing in gynecology is limited by studies with small sample size and non-standardized reporting, which should be the focus of future studies.

Treatment of Comminuted Radial Head Fractures with Personalized Radial Head Prosthesis Produced with 3D Printing Technology.

The radial head is the forearm's pivot point for supination-pronation motions. Although radial head resection can be performed in comminuted radial head fractures, radial head prosthesis has gained popularity in order to prevent possible complications such as progressive valgus instability in the elbow and secondary ulnocarpal impaction that may develop due to proximal displacement of the radius. As for radial head prostheses, standard prosthetic designs do not provide the same results in everyone, and the alignment of the radial head and radial neck angle cannot be fully achieved. We believe that the radial head, considered the pivot point of the elbow joint, must be reconstructed with a complete anatomical implant. We designed and applied personalized prostheses to our patients, and in this study, we wished to share the 2-year results of these patients. In this study, 23 patients who had comminuted radial head fractures were applied personalized radial head prostheses. Preoperative variables such as type of injury, age, side, additional ligament injury, operation time, number of radial head parts, neck angle of individual prosthesis, stem length, and stem diameter were noted. Mean operating time was 26 ± 9 minutes. One month postoperatively, after physical therapy, elbow ROM, loss of strength compared to the opposite joint, Mayo elbow scores, QuickDASH scores, and patient satisfaction were evaluated. Patients were summoned two years postoperatively. QuickDASH and Mayo elbow scores were satisfactorily good (mean QuickDASH score: 9.091, mean Mayo score: 91.08). According to the results of the patient satisfaction questionnaire, 16 of the 23 patients reported excellent satisfaction, 5 patients good satisfaction, and 2 patients moderate satisfaction. None of the patients reported poor results. Since a personalized radial head prosthesis consists of a single monoblock, its surgical application consists of a single step and has a short operating time. As the applications in the literature increase and more studies are conducted, this subject will be better understood. Our study demonstrated that these patients, whose anatomy were individually replicated, achieved good range of motion and patient satisfaction. In fact, none of the patients reported negative results. In comminuted radial head fractures, surgical implantation of personalized radial head prosthesis is a treatment modality with easy application, short operating time, and good functional results due to nearly complete preservation.

Application of and Prospects for 3-Dimensional Printing in Transcatheter Mitral Valve Interventions.

ClinicalTrials.gov Protocol Registration System (NCT02917980).

Real Stiffness and Vividness Reproduction of Anatomic Structures Into the 3-Dimensional Printed Models Contributes to Improved Simulation and Training in Skull Base Surgery.

Despite the advancement of 3-dimensional (3D) printing technology with medical application, its neurosurgical utility value has been limited to understanding the anatomy of bones, lesions, and their surroundings in the neurosurgical field. To develop a 3D printed model simulating the surgical technique applied in skull base surgery (SBS), especially to reproduce visually the surgical field together with the mechanical properties of tissues as perceived by the surgeon through procedures performance on a model. The Young modulus representing the degree of stiffness was measured for the tissues of anesthetized animals and printing materials. The stiffness and vividness of models were adjusted appropriately for each structure. Empty spaces were produced inside the models of brains, venous sinuses, and tumors. The 3D printed models were created in 7 cases of SBS planned patients and were used for surgical simulation. The Young modulus of pig's brain ranged from 5.56 to 11.01 kPa and goat's brain from 4.51 to 13.69 kPa, and the dura of pig and goat values were 14.00 and 24.62 kPa, respectively. Although the softest printing material had about 20 times of Young modulus compared with animal brain, the hollow structure of brain model gave a soft sensation resembling the real organ and was helpful for bridging the gap between Young moduli values. A dura/tentorium-containing model was practical to simulate the real maneuverability at surgery. The stiffness/vividness modulated 3D printed model provides an advanced realistic environment for training and simulation of a wide range of SBS procedures.

Thermal and acoustic performance evaluation of 3D-Printable PLA materials

In this study, additive manufacturing or three dimensional (3D) printing technology was utilized to develop thermal and acoustic insulation materials. A 3D model was carefully designed to obtain thermal and acoustic insulation properties using Autodesk software and print the materials using QIDI X-PLUS 3D printer with precise and controlled shape and structure. Biodegradable PLA filament was used as printing ink. A comprehensive evaluation was conducted to check whether this new branch of technology is suitable for producing insulation materials. Testing results revealed that insulation materials produced from 3D printing technology have excellent thermal and acoustic insulation properties. The lowest obtained thermal conductivity value was 0.037 W/mK, and the maximum obtained sound transmission loss was 48.27 dB at 1600 Hz frequency. In case of physical properties, density of insulation panels ranges from 366.46 to 721.26 kg/m3, and porosity ranges from 43 to 71%. Life cycle cost (LCC) analysis was carried out to obtain the optimum insulation thickness, energy savings, and payback period of developed insulation materials for different locations in the USA. It was found that the optimum insulation thickness varies between 4 and 10 mm, energy savings varies between 45.0% and 67.2%, and payback period varies between 8.5 and 14.8 years. The effect of structural parameters (thickness, density, air permeability, and porosity) on insulation properties was also checked in order to obtain a relationship between structural parameters and insulation properties. It was found that both density and porosity have significant influence on insulation properties. Testing results also revealed that thermal and acoustic insulation properties follow opposite trends with the increase of density and porosity. The increase in density and decrease in porosity causes increase in acoustic insulation property, but decrease in thermal insulation property. A comparison was also made with commercially available acoustic and thermal insulation panels, and it was observed that produced 3D printed samples have better insulation properties. This indicates that developed materials have very good potential to be commercially used as building insulation materials. As produced insulation material has colored and glossy surfaces, it can be used in the interior or exterior of building walls and may also replace plasterboard or tiles of building walls.

Design and Control for WLR-3P: A Hydraulic Wheel-Legged Robot.

The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain. The hybrid wheel-legged robot (WLR-3P, prototype of the third-generation hydraulic wheel-legged robot) has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough terrains. In this paper, 3 design requirements are proposed to improve the mobility and environmental adaptability of the robot. To meet these 3 requirements, 2 design principles for each requirement are put forward. First, for light weight and low inertia with high stiffness, 3-dimensional printing technology and lightweight material are adopted. Second, the integrated hydraulically driven unit is used for high power density and fast response actuation. Third, the micro-hydraulic power unit achieves power autonomy, adopting the hoseless design to strengthen the reliability of the hydraulic system. What is more, the control system including hierarchical distributed electrical system and control strategy is presented. The mobility and adaptability of WLR-3P are demonstrated with a series of experiments. Finally, the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.

3D Printing Technology for Chest Wall Reconstruction With a Sternum-Ribs-Cartilage Titanium Implant: From Ideation to Creation.

We describe the use of 3-dimensional (3D) printing technology to plan and reconstruct the sternum, adjoining cartilages, and ribs with a custom-made, anatomically designed, 3D-printed titanium implant for an isolated sternal metastasis complicated with a pathological fracture. We imported submillimeter slice computed tomography scan data into Mimics Medical 20.0 software and by manual bone threshold segmentation created a 3D virtual model of the patient's chest wall and tumor. For all-around tumor-free margins, we grew the tumor by 2 cm. The replacement implant was designed in 3D using the anatomical features of the sternum, cartilages, and ribs and manufactured using TiMG 1 powder fusion technology. Physiotherapy was provided prior to and following surgery, and the impact of reconstruction on pulmonary functions was assessed. At surgery, the precise resection, clear margins, and a secure fit were achieved. At follow-up, there was no dislocation, paradoxical movement, change in performance status, or dyspnea. There was a decrease in forced expiratory volume in 1 s (FEV1) from 105% prior to surgery to 82% following surgery and in forced vital capacity (FVC) from 108% to 75%, with no difference in the FEV1/FVC ratio, suggesting a restrictive pattern of impairment. With 3D printing technology, reconstructing a large anterior chest wall defect with a custom-made, anatomical, 3D-printed titanium alloy implant is feasible and safe, and it preserves the shape, structure, and function of the chest wall, albeit with a restrictive pattern of pulmonary function, which can be addressed with physiotherapy.

USE OF THREE DIMENSIONAL (3D) PRINTED MODELS OF SHEEP BRAIN IN ONLINE VETERINARY ANATOMY EDUCATION

Three dimensional (3D) printing technology in veterinary anatomy education is an evolving area providing accurately, rapidly, and reproducibly anatomical specimens. In this study, 3D printed sheep brain models were produced using magnetic resonance imaging (MRI) scanning, and their effectiveness was compared with cadaveric materials by creating three groups from undergraduate veterinary students. The study was performed when veterinary anatomy lectures in Erciyes University were carried out via live fully online learning platforms in virtual classes like many other universities in the world due the Covid-19 pandemic. Participants were subjected to an approximately 30 minute online lecture on the external and internal anatomy of the sheep brain using cadaveric materials only (n=21, Group 1), 3D printed models only (n=20, Group 2), or a combination of cadaveric materials and 3D printed models (n=20, Group 3) as teaching aids. Online post-tests carried out following the online lectures showed no statistically significant difference between the scores of the groups. Furthermore, online questionnaires conducted after the post-tests demonstrated that 3D printed models helped students learn about sheep brain anatomy. The finding of this study suggests that 3D printed models can be considered as a supplement teaching resource to cadaveric materials in veterinary anatomy education particularly when students are supposed to learn more in a limited time regardless of whether or not the Covid-19 pandemic might end.

REPLY FROM AUTHORS: Septal myectomy performed along the "septal band".

We appreciate the insightful comments on our paper from Dr Andrushchuk and his colleagues.1 First and foremost, we admire their pioneering work on the introduction of 3-dimensional printing technology in septal myectomy.

Three-dimensional Printing Technologies in Craniofacial Plastic Surgery: An Institutional Experience.

Rapid developments in 3-dimensional(3D) printing technologies in craniofacial plastic surgery have provided a new treatment modality for patients. In this article, we intend to share our institution's experience using 3D printing in 3 modes-namely, 3-dimensional printing for manufacturing contour models, guides, and implants. Fifty-nine patients were enrolled in our study between September 2009 and September 2021. Among the 3D printing-assisted technologies, 41 cases were used for congenital malformations, 82 for trauma repair, and 112 for cosmetic surgery. Preoperative design and postoperative data were compared and analyzed based on imaging data. In craniofacial plastic surgery, all patients had excellent postoperative objective bone measurements close to the preoperative design and improved esthetic appearance. Our survey of postoperative satisfaction showed that patients were quite satisfied with the surgery, especially concerning congenital deformities. Rapid prototyping 3-dimensional printing technology provides a practical and anatomically accurate means to produce patient-specific and disease-specific translational tools. These models can be used for surgical planning, simulation, and clinical evaluation. Expanding this technology in craniofacial plastic surgery will provide adequate assistance to practitioners and patients.

Extrusion 3D printing of minicaplets for evaluating in vitro &in vivo praziquantel delivery capability

This study aimed to explore extrusion three dimensional (3D) printing technology to develop praziquantel (PZQ)-loaded minicaplets and evaluate their in vitro and in vivo delivery capabilities. PZQ-loaded minicaplets were 3D printed using a fused deposition modelling (FDM) principle-based extrusion 3D printer and were further characterized by different in vitro physicochemical and sophisticated analytical techniques. In addition, the % PZQ entrapment and in vitro PZQ release performance were evaluated using chromatographic techniques. It was in vitro observed that PZQ was fully released in the gastric pH medium within the period of gastric emptying, that is, 120 min, from the PZQ-loaded 3D printed minicaplets. Furthermore, in vivo pharmacokinetic (PK) profiles of PZQ-loaded 3D printed minicaplets were systematically evaluated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The PK profile of the PZQ-loaded 3D printed minicaplets was established using different parameters such as Cmax, Tmax, AUC0-t, AUC0-∞, and oral relative bioavailability (RBA). The Cmax value of pristine PZQ was found at 64.79 ± 13.99 ng/ml, while PZQ-loaded 3D printed minicaplets showed a Cmax of 263.16 ± 47.85 ng/ml. Finally, the PZQ-loaded 3D printed minicaplets showed 9.0-fold improved oral RBA compared with that of pristine PZQ (1.0-fold). Together, these observations potentiate the desired in vitro and improved in vivo delivery capabilities of PZQ from the PZQ-loaded 3D printed minicaplets.

Application of 3D printing technology combined with PBL teaching method in clinical teaching of cerebrovascular disease: An observational study

Traditional clinical teaching does not allow medical students to combine theoretical knowledge with practical knowledge. As such, we aimed to determine the effectiveness of three dimensional (3D) printing technology combined with problem-based learning (PBL) in the clinical teaching of cerebrovascular diseases. Medical interns were randomly divided into an experimental group (n = 136) that was taught using 3D printing technology + PBL method and a control group (n = 133) that was taught using traditional methods. We compared assessment results of theoretical and clinical practice skills and the subjective evaluation of teaching methods between the 2 groups. The assessment results of the experimental group were significantly higher than those in the control group (P < .05). The survey assessing the evaluation of teaching methods showed higher satisfaction with teaching methods, increased learning interest, and improvement in the spatial thinking ability of interns in the experimental group compared to the control group (P < .05). There was no significant difference when assessing which teaching method better improved the interns' understanding of cerebrovascular diseases (P < .05). The application of 3D printing technology combined with the PBL teaching method in neurosurgery clinical teaching can stimulate interest in learning and significantly improve academic performance and problem-analysis and solving skills.

Use of 3D anatomical models in mock circulatory loops for cardiac medical device testing.

Mock circulatory loops (MCLs) are mechanical representations of the cardiovascular system largely used to test the hemodynamic performance of cardiovascular medical devices (MD). Thanks to 3 dimensional (3D) printing technologies, MCLs can nowadays also incorporate anatomical models so to offer enhanced testing capabilities. The aim of this review is to provide an overview on MCLs and to discuss the recent developments of 3D anatomical models for cardiovascular MD testing. The review first analyses the different techniques to develop 3D anatomical models, in both rigid and compliant materials. In the second section, the state of the art of MCLs with 3D models is discussed, along with the testing of different MDs: implantable blood pumps, heart valves, and imaging techniques. For each class of MD, the MCL is analyzed in terms of: the cardiovascular model embedded, the 3D model implemented (the anatomy represented, the material used, and the activation method), and the testing applications. MCLs serve the purpose of testing cardiovascular MDs in different (patho-)physiological scenarios. The addition of 3D anatomical models enables more realistic connections of the MD with the implantation site and enhances the testing capabilities of the MCL. Current attempts focus on the development of personalized MCLs to test MDs in patient-specific hemodynamic and anatomical scenarios. The main limitation of MCLs is the impossibility to assess the impact of a MD in the long-term and at a biological level, for which animal experiments are still needed.

Individualized Medicine Using 3D Printing Technology in Gynecology: A Scoping Review

<h3>Study Objective</h3> Developments in 3-dimensional (3D) printing technology has increased production of high quality, affordable 3D printed models, and the investigation of 3D printing in the medical literature. The objective of this study was to outline the clinical applications of individualized 3D printing in gynecology through a scoping review. <h3>Design</h3> Four medical databases (Medline, Embase, Cochrane CENTRAL, Scopus) and grey literature were searched for publications meeting eligibility criteria up to May 2021. Publications were included if they were published in English, had a gynecologic context, and involved production of patient specific 3D printed product(s). Studies were manually screened and assessed for eligibility by two independent reviewers (CC,TF) and data was extracted using pre-established criteria. <h3>Setting</h3> NA. <h3>Patients or Participants</h3> NA. <h3>Interventions</h3> NA. <h3>Measurements and Main Results</h3> Overall, 32 studies (15 abstracts,17 full text articles) were included in the scoping review. Most studies were either case reports (12/32,38%) or case series (15/32,47%). Gynecologic sub-specialties in which the 3D printed models were intended for use included: gynecologic oncology (21/32,66%), benign gynecology (6/32,19%), pediatrics (2/32,6%), urogynecology (2/32,6%) and reproductive endocrinology and infertility (1/32,3%). Twenty studies (63%) printed 5 or less models, 6/32 (19%) printed greater than 5 (up to 50 models), the remainder did not specify. Types of 3D models printed included: anatomical models (11/32,34%), medical devices, (2/32,6%) and template/guide/cylindrical applicators for brachytherapy (19/32,59%). <h3>Conclusion</h3> Our scoping review has outlined novel clinical applications for individualized 3D printed models in gynecology. To date, they have mainly been used for production of patient specific 3D printed brachytherapy guides/applicators in patients with gynecologic cancer. However, individualized 3D printing shows great promise for utility in surgical planning, surgical education, and production of patient specific devices, across gynecologic subspecialties. Data on the topic of individualized 3D printing in gynecology is limited by low quality study design, small sample size and non-standardized reporting, which should be the focus of future studies.

Cranioplasty for Multilobular Osteochondrosarcoma Using 3-Dimensional Printing Technology in Dogs: A Report of Two Cases with a Long-Term Follow-Up

Cranioplasty for Multilobular Osteochondrosarcoma Using 3-Dimensional Printing Technology in Dogs: A Report of Two Cases with a Long-Term Follow-Up

Lightweight 3D-Printed Fractal Gradient-Index Lens Antenna with Stable Gain Performance

This paper proposes a millimeter-wave lens antenna using 3-dimensional (3D) printing technology to reduce weight and provide stable gain performance. The antenna consists of a four-layer cylindrical gradient-index (GRIN) lens fed by a wideband Yagi antenna. We designed a fractal cell geometry to achieve the desired effective permittivity for a GRIN lens. Among different candidates, the honeycomb structure is chosen to provide high mechanical strength with light weight, low dielectric loss, and lens dispersion for a lens antenna. Therefore, the measured peak gain was relatively flat at 16.86 ± 0.5 dBi within 25−31.5 GHz, corresponding to 1 dB gain bandwidth = 23%. The proposed 3D-printed GRIN lens is cost-effective, with rapid and easy manufacturing.

Virtual surgical planning of inferior alveolar nerve microsurgery and benign pathology of the mandible: case reports

: With the aid of virtual surgical planning (VSP) software as well as 3-dimensional printing technology, custom surgical guides can be created utilizing the pre-operative data of patients, including both computed tomography and intraoral scans. VSP technology allows for the customization of surgical guides which can provide an array of benefits that aid in improving patient care. Surgical guides can be designed as occlusal borne, bone borne, or a combination of the two. Though an intraoral scan is beneficial to bolster surgical guide accuracy, it is not necessary, as demonstrated in the following case presentations. This manuscript will demonstrate the use of custom occlusal and bone borne surgical guides that were used for access to the inferior alveolar nerve for exploratory microsurgery as well as two cases necessitating removal of benign pathology within the mandible. Surgical guides aid in improving intraoperative efficiency, in decreasing operating time and in reducing potential surgical trauma. Overall, we expect a decrease in morbidity due to the more predictable nature of guided surgeries. The use of custom surgical guides allows for a more precise and conservative osteotomy, thereby decreasing morbidity. The more efficient and predictive nature of guided surgery aids in patient recovery and surgical outcomes, as well.

Effects of postpolymerization conditions on the physical properties, cytotoxicity, and dimensional accuracy of a 3D printed dental restorative material

Statement of problemAlthough the introduction of high-speed 3-dimensional (3D) printing technology has significantly reduced printing time, the time required for postpolymerization is a speed-determining step because of the long wait time. How postpolymerization conditions affect material properties is unclear. PurposeThe purpose of this in vitro study was to assess the physical properties, accuracy, and biosafety of a 3D printed dental restorative material according to postpolymerization conditions. Material and methodsSpecimens were prepared by 3D printing with a digital light processing 3D printer with 1 interim dental material (C&B MFH). All printed specimens underwent a postpolymerization process with 5 different postpolymerization devices and were designated as groups D1 (D102H), FO (Form Cure), LC (LC-3DPrintBox), ME (Medusa), and MP (MP100). The light intensity and temperature of each device were measured, and the Vickers hardness, flexural strength and modulus, degree of conversion (DC), cytotoxicity, and polymerization shrinkage were analyzed. Statistical analyses were conducted with 1-way analysis of variance, the Tukey post hoc test, and regression testing (α=.05). Scanning electron microscopy was used to assess the fracture surface characteristics of the specimens. ResultsLight intensity was strongest with the ME device, and the temperature inside the device during postpolymerization showed the highest increase with the LC device and the lowest increase with the D1 device. The LC group specimens showed the highest mean Vickers hardness, and the MP group showed the lowest. The flexural strength was ≥100 MPa in all groups, with a flexural modulus ranging from 1.17 to 1.5 GPa. The DC results were similar to the physical properties test results. The D1, FO, LC, and ME groups all showed ≥70% cell viability, indicating no toxicity. The FO group showed the highest shrinkage rate of 0.52%. ConclusionsWhen the light intensity was strong, the surface was sufficiently hard, and toxic substances were not eluted even after a short postpolymerization time, suggesting that light intensity modulation and time management can be used to improve the postpolymerization process.

Chest Wall Reconstruction With 3D Printing: Anatomical and Functional Considerations.

Large chest wall defects, as a result of wide local excision of chest wall pathology, require skeletal and soft-tissue reconstruction to restore the anatomical shape, structure, and respiratory function of the thorax. Reconstruction is challenging and requires the surgical reconstructive team to understand the anatomic and physiologic morbidity related to the defect and the choice of reconstructive techniques available to restore form and function. Rapidly emerging 3-dimensional (3D) printing technology allows the reconstructive surgical team to customize the therapeutic process of skeletal reconstruction by accurately mimicking the shape and structure of the chest wall being replaced. An integrated knowledge of the anatomy, physiology, mechanics of breathing, and respiratory tests is important to restore form and function. The focus of this article is to review the anatomy, physiology, and assessment of respiratory function from the classical textbooks and integrate this knowledge with the precise anatomy of the chest wall created by 3D printing technology. By doing so, this article will demonstrate how 3D printing may help the reconstructive team to understand the anatomic and physiologic morbidity related to the chest wall defect and the importance of taking each of these aspects into consideration when undertaking chest wall reconstruction of the thorax.