OBJECTIVE: The aim of this randomized clinical trial was to compare the qualitative (linear alveolar ridge changes) and quantitative (healing complications) outcomes after guided bone regeneration (GBR) using a custom-made 3D printed titanium mesh versus titanium reinforced dense PTFE membrane for vertical and horizontal augmentation of deficient alveolar ridges.

BACKGROUND: Case-based learning (CBL) utilizing three-dimensional (3D) printed hip joint models is a problem-solving teaching method that combines the tactile and visual advantages of 3D-printed models with CBL. This study aims to investigate the impact of integrating 3D printing with CBL on learning developmental dysplasia of the hip (DDH).
METHODS: We conducted a prospective study from 2022 to 2023, including 120 fourth-year clinical medical students at Xuzhou Medical University. Students were randomly allocated into two groups of 60 participants each. The CBL group received conventional CBL teaching methods, while the 3D + CBL group utilized 3D-printed models in conjunction with CBL. Post-teaching, we analyzed and compared the theoretical and practical achievements of both groups. A questionnaire was designed to assess the impact of the educational approach on orthopedic surgery learning.
RESULTS: The theory scores of the CBL group (62.88 ± 7.98) and 3D + CBL group (66.35 ± 8.85) were significantly different (t = 2.254, P = 0.026); the practical skills scores of the CBL group (57.40 ± 8.80) and 3D + CBL group (63.42 ± 11.14) were significantly different (t = 3.283, P = 0.001). The questionnaire results showed that the 3D + CBL group was greater than the CBL group in terms of hip fundamentals, ability to diagnose cases and plan treatments, interesting teaching content, willingness to communicate with the instructor and satisfaction.
CONCLUSIONS: The integration of 3D printing with case-based learning has yielded positive outcomes in teaching DDH, providing valuable insights into the use of 3D-printed orthopedic models in clinical education.

Polymer composite scaffolds hold promise in bone tissue engineering due to their biocompatibility, mechanical properties, and reproducibility. Among these materials, polylactic acid (PLA), a biodegradable plastics has gained attention for its processability characteristics. However, a deeper understanding of how PLA scaffold surface properties influence cell behavior is enssential for advancing its applications. In this study, 3D-printed PLA scaffolds containing hydroxyapatite (HA) were analyzed using atomic force microscopy and nanomechanical mapping. The addition of HA significantly increased key surface properties compared to unmodified PLA scaffols. Notably, the HA-modified scaffold demonstrated Gaussian distribution of stiffness and adhesive forces, in contrast to the bimodal properties observed in the unmodified PLA scaffolds. Human adipose-derived mesenchymal stem cell (hADMSC) seeded on the 3D-printed PLA scaffolds blended with 10% HA (P10) exhibited strong attachment. After four weeks, osteogenic differentiation of hADMSCs was detected, with calcium deposition reaching 6.76% ± 0.12. These results suggest that specific ranges of stiffness and adhesive forces of the composite scaffold can support cell attachement, and mineralization. The study highlights that tailoring suface properties of composite scaffolds is crucial for modulating cellular interactions, thus advancing the development of effective bone replacement materials.

OBJECTIVE: This technical note introduces a novel concept of a alveolar inferior nerve protector guide during orthognathic surgery based on a free-software creation and printing.
METHODS: Orthognathic surgery using Virtual Surgical Planning software like Dolphin Imaging ® v 11.9 facilitated a bimaxillary procedure with mandible advancement and occlusal plane correction, later followed by 3D printing of splints. The process involved importing a composite skull with osteotomies into Blender ® software, where solids were added and edited to match Dolphin\'s osteotomies, ensuring bone contact without distortion. The guide creation was performed adhering to bilateral sagittal split osteotomy principles, maintaining precision, resulting in preserved inferior alveolar nerve and faster operation times compared to non-guided procedures, as demonstrated by postoperative CT scans.
CONCLUSIONS: Integrating advanced tools like Blender software into maxillofacial surgery represents a significant advancement. Despite challenges like the absence of specific manuals for this purpose in Blender, using such software offers innovative and cost-effective solutions. Developing user-friendly resources tailored to surgical applications such as a protector guide within Blender can enhance its usability and improve surgical outcomes and patient care, leading to groundbreaking advancements in maxillofacial surgery.

Although dental patterns are unique, the use of bitemark analysis in personal identification remains controversial. To accurately reproduce and compare three-dimensional models of bitemarks and dental arches, intraoral three-dimensional scans, commonly utilized in clinical dental practice for precise and stable digital impressions, are recommended. This study aims to compare two different techniques for bitemark analysis: a digital method based on the superimposition of digital scans of dental patterns and lesions, and a visual method based on the physical superimposition of impressions and resin casts produced by 3D printing. A sample of 12 volunteers (6 males and 6 females) with a mean age of 26 years was collected as biters. Each subject was asked to bite on custom supports made from semi-rigid water bottles covered with imprintable dental wax. The dental arches and bitemarks were then recorded using an intraoral scanner and dental impressions. Scan superimposition analysis was conducted using CloudCompare software, while resin casts were printed using a 3D printer and physically superimposed on the bitemark impressions by a blind operator, who was not involved in sample collection, bite test execution, prior cast acquisition, or CloudCompare analysis. Both superimposition techniques relied on the selection of 10 corresponding landmarks (on canines and central and lateral incisors of the upper and lower arches) between the dental arches and impressions. The digital superimposition showed an average concordance of 92.5% for the upper arch landmarks and 85% for the lower arch landmarks, with an overall average concordance of 88.8% for both arches combined. In contrast, the visual analysis of resin casts showed an average concordance of 77.5% for the upper arch and 76.7% for the lower arch, with an overall average of 77.1% for both arches combined. In the analysis performed using CloudCompare, the maxillary arch demonstrated the best superimposition, with 4 landmarks (R0, R1, R2, R5) consistently overlapping. The digital analysis outperformed the visual analysis in all four quadrants, particularly in the upper right arch compared to the lower left arch, thereby supporting the integration of digital techniques in forensic applications. Further studies are necessary to validate the digital technique on a larger sample, including subjects with different dental characteristics, bite dynamics, and varying types of supports and substrates.

The development of synthetic bone substitutes that equal or exceed the efficacy of autologous graft remains challenging. In this study, a rat calvarial defect model was used as a reference to investigate the influence of composition and architecture of 3D-printed cement, with or without bioactives, on tissue regeneration. Printable cement pastes were formulated by combining hyaluronic acid and cement precursors. Cementitious scaffolds were printed with 3 different patterns. After 7 weeks of implantation with or without bone marrow, multiparametric qualitative and quantitative assessments were performed using µCT, SEM, and histology. None of the set-up strategies was as efficient as autologous cancellous bone graft to repair calvarial defects. Nonetheless, the presence of scaffold improved the skull vault closure, particularly when the scaffold was soaked in total bone marrow before implantation. No significant effect of scaffold macro-architecture was observed on tissue mineralization. Magnesium phosphate-based scaffolds (MgP) seemed to induce higher bone formation than their calcium-phosphate-based counterparts. They also displayed a quicker biodegradation and sparse remaining material was found after 7 weeks of implantation. Although further improvements are required to reach clinical settings, this study demonstrated the potential of organo-mineral cements for bone regeneration and highlighted the peculiar properties of MgP-based cements.

The current primary treatment approach for malignant pelvic tumors involves hemipelvic prosthesis reconstruction following tumor resection. In cases of Enneking type II + III pelvic tumors, the prosthesis necessitates fixation to the remaining iliac bone. Prevailing methods for prosthesis fixation include the saddle prosthesis, ice cream prosthesis, modular hemipelvic prosthesis, and personalized prosthetics using three-dimensional printing. To prevent failure of hemipelvic arthroplasty protheses, a novel fixation method was designed and finite element analysis was conducted. In clinical cases, the third and fourth sacral screws broke, a phenomenon also observed in the results of finite element analysis. Based on the original surgical model, designs were created for auxiliary dorsal iliac, auxiliary iliac bottom, auxiliary sacral screw, and auxiliary pubic ramus fixation. A nonlinear quasi-static finite element analysis was then performed under the maximum load of the gait cycle, and the results indicated that assisted sacral dorsal fixation significantly reduces stress on the sacral screws and relative micromotion exceeding 28 μm. The fixation of the pubic ramus further increased the initial stability of the prosthesis and its interface osseointegration ability. Therefore, for hemipelvic prostheses, incorporating pubic ramus support and iliac back fixation is advisable, as it provides new options for the application of hemipelvic tumor prostheses.

BACKGROUND: Nowadays, stabilization splints for the management of bruxism and temporomandibular disorders (TMD) can be produced utilizing a digital workflow comprising a digital impression of the teeth, digital splint design, and computer-aided manufacturing of the splints. The latter is usually a milling process, however, more recently 3D printing gained popularity due to its better cost and time efficiency. It remains unknown whether 3D printed stabilization splints are inferior to milled splints regarding clinical outcomes.
METHODS: This clinical trial assesses the non-inferiority of 3D printed occlusal splints compared to milled occlusal splints in a monocentric prospective randomized single-blinded crossover trial with two cohorts. One cohort includes 20 participants with bruxism, the other 20 participants with pain-related TMD, i.e., myalgia, myofascial pain, or arthralgia of the jaw muscles/the temporomandibular joint(s) diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Michigan-type stabilization splints are fabricated in a digital workflow by milling or 3D printing using CE-marked materials within their intended purpose. The participants wear a milled and a 3D printed splint in a randomized order for 3 months each, with follow-up visits after 2 weeks and 3 months. Investigated outcome parameters are oral health-related quality of life (OHRQoL) evaluated by the Oral Health Impact Profile (OHIP-G14), participant satisfaction as rated on a visual analog scale, therapeutic efficacy, and technical result of the splints. In this context, therapeutic efficacy means antagonist wear and-in the TMD group-reduction of pain/disability assessed by the Graded Chronic Pain Scale (GCPS v2.0) and clinical assessment following the DC/TMD standard, while technical outcome measures splint fit, wear and fracture rate.
CONCLUSIONS: The trial will provide important information on the clinical outcome of 3D printed stabilization splints in comparison to milled splints and will, therefore, enable an evidence-based decision in favor of or against a manufacturing process. This, in turn, will guarantee for a maximum of the patient\'s OHRQoL during splint therapy, therapeutic efficacy, and longevity of the splints.
BACKGROUND: German Clinical Trials Register (DRKS) DRKS00033904. Registered on March 15, 2024.

Orbital fractures, constituting 10-25% of facial traumas, result from diverse mechanisms such as traffic accidents and assaults. These fractures present with characteristic symptoms like edema, diplopia, and infraorbital paraesthesia. Timely diagnosis and surgical intervention are paramount to mitigate long-term complications. Recent advancements in materials science and surgical methodologies have ushered in innovative approaches including 3D printing and computer-aided design implants. This article details a case study of successful reconstructive orbital surgery in a patient following a traumatic incident where a car accident caused extensive facial fractures. Leveraging 3D printing technology, a precisely tailored titanium mesh aided in the meticulous restoration of the orbital floor. During surgery, entrapped soft tissues were released, and the zygomatic-maxillary complex was carefully repositioned. Postoperative evaluation revealed promising outcomes, affirming the efficacy of contemporary surgical strategies. This case highlights the evolving role of 3D printing in enhancing the accuracy, cost-effectiveness, and accessibility of orbital reconstruction procedures, demonstrating its potential for broader clinical applications.

OBJECTIVE: To verify the accuracy of soy-based resins for dental three-dimensional (3D) printing.
METHODS: After conducting a power analysis, models of 10 consecutively treated patients were produced from four different resins using a dental 3D printer. Two of these resins were soy based and therefore biodegradable. These 20 models were measured manually with a caliper as well as digitally by software and compared based on measurement parameters in all three spatial axes.
RESULTS: No statistically significant differences were found between the four different resins or between the manual and digital measurements.
CONCLUSIONS: Soy-based resin seems to be a suitable material for orthodontic 3D printing and is a more environmentally friendly alternative to conventional dental resins. Digital model analysis seems to produce comparable results to manual measurement.