BACKGROUND: Long-term enophthalmos and diplopia resulting from orbital bone loss pose significant challenges in reconstructive surgery. This study evaluated the effectiveness of patient-specific porous titanium implants (PSIs) for addressing these conditions.
METHODS: This retrospective study involved 12 patients treated at Croix-Rousse Hospital, Lyon, from April 2015 to April 2022 who underwent late reconstruction via PSI for unilateral complex orbital bone loss. These implants were customized via 3D mirroring techniques on the basis of high-resolution computed tomography (CT) scans of the patients\' unaffected orbits.
RESULTS: All 12 patients presented with significant preoperative enophthalmos, with an average displacement of 3.24 mm, which was effectively corrected postoperatively to an average of 0.17 mm (p < 0.001). Orbital volume notably improved from a preoperative average of 3.38 mL to 0.37 mL postsurgery (p < 0.001). Functional improvements were evident as both enophthalmos and diplopia resolved completely. The Lancaster test revealed an improvement in the visual field, with 83.3 % of patients achieving normal results postoperatively.
CONCLUSIONS: By ensuring anatomical accuracy, patient-specific porous titanium implants, tailored from patient-specific imaging and fabricated via advanced 3D printing technology, provide a precise, effective, and reliable solution for reconstructing complex orbital defects and performing complicated revision surgeries.

BACKGROUND: Encountering a retained root tip post-extraction and prior to implant placement is a possible clinical complication. There are numerous approaches for removing retained roots that may be traumatic or atraumatic. Regardless of the approach, careful treatment planning is important to minimize complications, reduce morbidity, and preserve bony structures. The aim of the current case study is to introduce a technique and digitally generated device used for identifying and atraumatically removing a retained root tip and simultaneously placing a stable dental implant.
METHODS: A 63-year-old female with a history of myocardial infarction, hypertension, and acute pancreatitis presented for implant placement at site #5. Clinical examination revealed adequate interocclusal, mesiodistal, and buccolingual dimensions for implant placement. Radiographic examination using cone beam computed tomography revealed that retained root #5 interfered with implant placement. Digital planning was used to extract the root tip with minimal trauma to maintain adequate bone for simultaneous implant placement with good primary stability.
RESULTS: The follow-ups at 1, 3, and 6 weeks and 4, 8, and 10 months revealed good bone preservation with an osseointegrated implant.
CONCLUSIONS: Employment of digital planning to create a palatal window allowed excellent accuracy in removing the retained root while maintaining the bony foundation for a well osseointegrated dental implant.
CONCLUSIONS: Pre-planning using cone beam computed tomography scan merged with an intraoral digital scan is necessary for precise location of a retained root and correct implant placement with excellent primary stability. A digitally planned 3D surgical guide is a useful method for extracting retained roots during implant placement to minimize bone damage. Digital planning provides a precise and minimally invasive implant surgery.

BACKGROUND: Supra aortic obstruction in children is uncommon and is seen in certain unique conditions. While intraluminal obstruction due to heavy calcification is seen in older populations, it is not described in pediatric populations. The coral reef aorta is a rare and distinct calcifying disease causing luminal obstruction of the suprarenal aorta in adults. The definition of this diagnosis relies entirely on the unique aspects and consistency of the lesions, which are rock-hard, irregular, gritty plaques with a white luminal surface resembling a coral reef. However, no such case has been described in children.
METHODS: We present an adolescent boy who presented with a heavily calcified ascending aortic lesion associated with aortopathy and hypertension, 12 years after an aortic coarctation repair. The investigations included echocardiography, magnetic resonance and computer-tomographic imaging. A 3-D model was printed in order to visualize and plan surgical steps in advance for safe placement of clamps and defining the extent of resection. In addition, it provided an idea about tissue quality, thickness, spatial relationship, and orientation in relation to surrounding structures. Successful resection and replacement of the diseased segment of the aorta were achieved on cardiopulmonary bypass support. Post-operative recovery was uneventful, and at 6-month follow-up, the patient is doing well. In this report, various aspects of such lesions have been discussed, including clinical presentations, complications, planning and conduct of a safe cardiopulmonary bypass, and precautions during surgery for a successful outcome.
CONCLUSIONS: Complicated obstructive aortic lesions in children require careful assessment, appropriate advanced imaging, and the use of 3-D printing technology in order to plan and perform safe and effective surgical management. The etiology of severe calcified aorta in children may be related to metabolic factors, previous surgery, use of a homograft, or an inflammatory process. However, it has yet to be proven.

The global trend in additive manufacturing is the technology of three-dimensional (3D) printing with a high potential to avoid some of the weaknesses of conventional fabrication techniques. This new technology has been used to manufacture small tidal and wind turbines. In isolated areas, small turbines can be manufactured and assembled on-site for green energy production. The purpose of this document is to evaluate the thermomechanical behavior of a printed tidal turbine using Digimat-AM (Additive Manufacturing) with fused filament fabrication method. The finite element computes the mechanical deflection, temperature, residual stresses, and warpage fields of the printed part. The composites used during printing are thermoplastic polymers (acrylonitrile butadiene styrene, polyamide 6 [PA6], polyamide 12 [PA12], and polyetherimide [PEI]) reinforced with carbon and glass fillers in the form of fibers and beads (CF/GF and CB/GB). Through the simulation, one could show that the blade printed with PEI-CB/CF has excellent mechanical performance of low mechanical deflection and warpage, compared to PA6-CB/CF. In addition, the fiber-shaped fillers are better than the bead-shaped ones for the 3D printing process. In general, this study has shown the potential and feasibility of 3D printing as an excellent opportunity in the fabrication of small blades in the future, but more studies are required to understand this potential.

Printers can release numerous particles to contaminate indoor environments and pose health risks. Clarifying the exposure level and physicochemical properties of printer-emitted particles (PEPs) will help to evaluate the health risks of printer operator. In our study, the particles concentration in the printing shop was monitored in real time for a long time (12 h/day, total 6 days), and the PEPs were collected to characterize their physicochemical properties including shape, size and compositions. The result showed that the concentration of PEPs is closely related to the printing workload and the highest particle mass concentration of PM10 and PM2.5 was 212.73 μg m-3 and 91.48 μg m-3, respectively. The concentration of PM1 in the printing shop was in the range of 11.88-80.59 μg m-3 for mass value, and 174.83-1348.84 P cm-3 for count value which changed with the printing volume. The particle sizes of PEPs were less than 900 nm, 47.99% of PEPs was less than 200 nm, and 14.21% of the particles were at the nanoscale. PEPs contained 68.92% organic carbon (OC), 5.31% elemental carbon (EC), 3.17% metal elements, and 22.60% other inorganic additives, which contained more OC and metal elements than toners. Total polycyclic aromatic hydrocarbons (PAHs) levels were 18.95 ng/mg in toner and 120.70 ng/mg in PEPs. The carcinogenic risk of PAHs in PEPs was 1.40 × 10-7. These findings suggested future studies should pay more attention to the health effects of printing workers exposed to nanoparticles.

The management of missing teeth as a result of dental trauma or associated with hypodontia in children and adolescents presents as a clinical challenge for the dental team. One of the options that is regaining popularity is dental autotransplantation. To improve autotransplantation outcomes, careful interdisciplinary planning, surgical simulation using cone beam computed tomography images and three-dimensional-printed teeth replicas should be undertaken for presurgical preparation. This case report showcases two applications of autotransplantation, with emphasis on interdisciplinary management, presurgical preparation and postsurgical orthodontic and aesthetic management to deliver a good long-term, sustainable, biological outcome, as a part of a comprehensive rehabilitation treatment plan in children.

Replacement of missing teeth is becoming more prevalent, currently with more than 700,000 dental implants being placed every year. Patients seek out dental treatment with the expectations of having procedures performed in the least number of time/visits, for as inexpensive as possible, and at the highest quality. As this continues, clinicians can adapt with changing times and adopt the newer advancements in digital dentistry. This case letter aims to provide readers with insight to integration of digital workflows to optimize patient and clinician outcomes with single tooth implant therapy.

OBJECTIVE: To address the anatomical challenges facing complex and revision spinal surgery, patient-specific 3D-printed models (3D-PMs) have received growing attention worldwide, primarily in adults. We report the use of a 3D-PM in the treatment of a case of wound breakdown over a component of a VEPTR (Vertical Expandable Prosthetic Titanium Rib; DePuy-Synthes) system, requiring replacement of Dunn-McCarthy hook and sleeve with components contoured to a patient-specific 3D-PM of the spine.
METHODS: A two-year-old born with myelomeningocele (MMC), repaired at birth, developed progressive MMC-associated kyphoscoliosis. Elective insertion of a rib-to-pelvis \'Eiffel Tower\' bilateral VEPTR growing rods construct was performed without initial complication. Prominence of the right VEPTR sleeve and Dunn-McCarthy hook side-to-side connector resulted in breakdown of overlying poor-quality soft tissues, necessitating washout, partial implant removal, intravenous antibiotic therapy and delayed primary wound closure. A patient-specific 3D-PM, utilising pre-operative CT spine and pelvis 3D-reconstructions, allowed pre-operative formation of a contoured implant, which was inserted without need for further revision.
RESULTS: The patient underwent further VEPTR lengthening without recurrent infection, wound breakdown or implant failure at 24-month follow-up. Satisfactory control of the deformity has been achieved with continued improvement in sitting height and radiographic indices.
CONCLUSIONS: This case illustrates the possibility, in certain cases, of using 3D-PM to develop complex components of spinal implant systems pre-operatively, removing the time and difficulty of intra-operative contouring. Consequently, custom-contoured implants may be produced, sterilised and implanted. This technique may be an option, in infants, including MMC-associated kyphoscoliosis, where midline fixation is not possible.

UNASSIGNED: Hand orthoses are often prescribed for persons with chronic hand and wrist impairments. This study assessed the feasibility, in terms of production time and user satisfaction, of 3-dimensional printed hand orthoses compared with conventional hand orthoses for this population.
UNASSIGNED: In this prospective case series, both a conventional hand orthosis and a 3-dimensional printed hand orthosis were manufactured for 10 participants. Production time (in minutes) of each orthosis was recorded. Each orthosis was worn for one week, after which participants completed a self-designed questionnaire on satisfaction, scored on a 5-point Likert scale. Functionality and orthosis preference were also assessed.
UNASSIGNED: The mean (standard deviation (SD)) production time for the 3-dimensional printed orthoses, of 112 (11.0) min, was significantly shorter compared with 239 (29.2) min for the conventional orthoses (95% confidence interval (95% CI) 71-182 min, p = 0.001). Satisfaction scores were similar for both orthoses, except for comfort item \"fitting method\", which was rated significantly higher for scanning compared with casting (median [IQR] score: 5 [0.0]; 4 [2.0], p = 0.034). Functionality and orthosis preference were rated similar for both orthoses.
CONCLUSIONS: As the production time was halved, user satisfaction similar, and scanning experienced as slightly more comfortable than casting, 3-dimensional printed hand orthoses seem feasible and potentially beneficial for use in people with chronic hand and wrist impairments.

OBJECTIVE: To compare the clinical efficacy and safety of a personalized three-dimensional (3D) printed dynamic anterior plate-screw system for the quadrilateral area (DAPSQ) titanium plate and a traditional DAPSQ reconstruction plate in the treatment of double-column acetabular fractures.
METHODS: This was a retrospective case-control study. From May 2014 to January 2018, 43 patients with double-column acetabular fractures underwent open reduction and internal fixation. Among these, 20 cases were fixed with a 3D printed DAPSQ plate (3D printed group) and 23 cases were fixed with a DAPSQ reconstruction plate (control group). The 3D printed group comprised 15 men and 5 women, with an average age of 50.1 ± 8.2 years. The control group comprised 16 men and 7 women, with an average age of 51.0 ± 8.6 years. The evaluation index included the surgical data (i.e. blood loss, operating time, duration of hospital stay, and intraoperative and postoperative complications), position and length of implants, reduction quality, hip function, and related complications. The reduction quality was evaluated using the Matta scoring standard and hip function was evaluated using the modified Merle d\'Aubigné score.
RESULTS: A total of 43 patients met the inclusion criteria. The mean postoperative follow up was 35.2 months in the 3D printed group and 36.9 months in the control group. There were no significant group differences in demographic data between the two groups. The position and length of the 3D printed implants were generally in accord with preoperative planning using a 3D pelvic model. Patients in the 3D printed group had significantly shorter operation time (223.2 vs 260.5 min, P < 0.05) and less intraoperative blood loss (930.4 vs 1426.1 mL, P < 0.05) compared to the control group. Anatomic, imperfect, and poor reduction was obtained in 13, 5, and 2 cases in the 3D printed group, respectively, and was obtained in 12, 8, and 3 cases in the control group. The modified Merle d\'Aubigné scores were excellent in 11 cases, good in seven cases, and fair in two cases in the 3D printed group. They were excellent in 11 cases, good in eight cases, fair in three cases, and poor in one case in the control group. The reduction quality and hip function did not differ within the groups (P > 0.05). The general complication rate in the 3D printed group and the control group was 15% and 26.1%, respectively, but the difference between the two groups was not statistically significant.
CONCLUSIONS: Use of a personalized 3D printed DAPSQ plate has potential advantages in reducing the operation time and blood loss during the treatment of double-column acetabular fractures.