Background: This study investigated whether patient-specific condylar positioning devices (CPDs) are beneficial compared to the conventional manual positioning of the condyles. Methods: In this prospective, randomized trial, patients undergoing orthognathic surgery with a bilateral sagittal split osteotomy of the mandible were included. The ascending ramus was positioned with computer-aided designed and computer-aided manufactured (CAD/CAM) patient-specific devices in the CPD group and manually in the control group. Postoperatively, cone-beam computed tomography (CBCT) was performed to align the virtually planned position with the postoperative result. Results: Thirty patients were enrolled in the study, with 14 randomized to the CPD group and 16 to the control group. In the CPD group, the ascending ramus differed in the postoperative CBCT scan from the virtually planned position by 0.8 mm in the left/right, 0.8 mm in the front/back, and 1.3 mm in the cranial/caudal direction. The corresponding control-group values were 1.1 mm, 1.3 mm, and 1.6 mm. CPD and controls differed significantly for the left/right movement of the rami (p = 0.04) but not for the other directions or rotations (p > 0.05). Conclusions: The results demonstrate that both methods are accurate, and postoperative results matched the virtually planned position precisely. It can be assumed that the described CPDs are beneficial when a condylar position different from the preoperative is desired.

Bone defects resulting from trauma, diseases, or surgical procedures pose significant challenges in the field of oral and maxillofacial surgery. The development of effective bone substitute materials that promote bone healing and regeneration is crucial for successful clinical outcomes. Calcium phosphate cements (CPCs) have emerged as promising candidates for bone replacement due to their biocompatibility, bioactivity, and ability to integrate with host tissues. However, there is a continuous demand for further improvements in the mechanical properties, biodegradability, and bioactivity of these materials. Dual setting of cements is one way to improve the performance of CPCs. Therefore, silicate matrices can be incorporated in these cements. Silicate-based materials have shown great potential in various biomedical applications, including tissue engineering and drug delivery systems. In the context of bone regeneration, silicate matrices offer unique advantages such as improved mechanical stability, controlled release of bioactive ions, and enhanced cellular responses. Comprehensive assessments of both the material properties and biological responses of our samples were conducted. Cytocompatibility was assessed through in vitro testing using osteoblastic (MG-63) and osteoclastic (RAW 264.7) cell lines. Cell activity on the surfaces was quantified, and scanning electron microscopy (SEM) was employed to capture images of the RAW cells. In our study, incorporation of tetraethyl orthosilicate (TEOS) in dual-curing cements significantly enhanced physical properties, attributed to increased crosslinking density and reduced pore size. Higher alkoxysilyl group concentration improved biocompatibility by facilitating greater crosslinking. Additionally, our findings suggest citrate’s potential as an alternative retarder due to its positive interaction with the silicate matrix, offering insights for future dental material research. This paper aims to provide an overview of the importance of silicate matrices as modifiers for calcium phosphate cements, focusing on their impact on the mechanical properties, setting behaviour, and biocompatibility of the resulting composites.

Background: Patient-specific splints have become an integral component of virtual surgical planning in orthognathic surgery. However, transferring the virtually planned condylar position into the intraoperative setting remains technically challenging and typically requires labor-intensive manual modification of splint geometries. The aim of this study was to develop and describe an open-source Blender add-on that automates the generation of patient-specific splint extensions for condyle positioning and to evaluate its technical feasibility in a proof-of-concept clinical setting. Methods: A Python-based add-on for the open-source 3D modelling software Blender was developed to automate the generation of condyle-positioning splint extensions from stereolithography (STL) models exported by a commercial virtual surgical planning system. The software architecture and processing pipeline comprise facilitated data import, coordinate normalization, extension generation, Boolean processing, optional manual refinement, and STL export for additive manufacturing. The workflow was applied in three patients undergoing bilateral sagittal split osteotomy. Postoperative correspondence between the planned and achieved mandibular positions was assessed using translational and rotational transformation parameters together with qualitative surface distance heatmaps provided by the planning software. Results: The proposed add-on successfully generated patient-specific splint extensions in all three proof-of-concept cases while automating manual modelling steps. All splints were successfully manufactured and applied intraoperatively without redesign. Postoperative evaluation demonstrated good agreement between the virtually planned and achieved mandibular positions, with only small translational and rotational deviations. Descriptive statistical analysis supported the technical feasibility and reproducibility of the proposed workflow. Conclusions: The presented open-source Blender add-on provides a reproducible and extensible workflow for automated generation of patient-specific condyle-positioning splint extensions. The proposed approach successfully integrates virtual surgical planning with additive manufacturing and demonstrates technical feasibility in a proof-of-concept clinical setting. The software establishes a foundation for future validation studies in larger patient cohorts and illustrates the potential of open-source tools to improve transparency, reproducibility, and accessibility in digital orthognathic surgery workflows.