The accuracy of virtual surgical planning in segmental Le Fort I surgery: A comparison of planned and actual outcome.

Segmental Le Fort I surgery is an effective technique to correct complicated dentomaxillofacial deformities. This retrospective study evaluated the accuracy of segmental Le Fort I surgery under the guidance of virtual surgical planning (VSP). A total of 129 patients who accepted segmental Le Fort I surgery were investigated in this study. VSP was transferred to segmental surgery with different pieces precisely with the aid of 3D-printed surgical templates and splints. The surgical result was evaluated by postoperative complications, color distance maps, and quantitative accuracy analysis. Outcomes showed that the VSP was successfully transferred to actual surgery with high accuracy. The overall mean linear difference was 1.28 mm, and the overall mean angular difference was 2.4°. Except for one case of root injury, there was no serious complication recorded. The results suggested that VSP was a reliable assistance for segmental Le Fort I surgery.

Loading of erythropoietin on biphasic calcium phosphate bioceramics promotes osteogenesis and angiogenesis by regulating EphB4/EphrinB2 molecules.

Improving osteogenesis and angiogenesis using different cells and drugs is critical in the field of bone tissue engineering. Recent research has found that erythropoietin (EPO) plays an important role in both osteogenesis and angiogenesis. In this study, we grafted polydopamine and EPO onto the surface of biphasic calcium phosphate. The characterization and release property of the modified bioceramics were assessed. Cell proliferation, expression of osteoblastic and endothelial markers, and EphB4/EphrinB2 molecules were investigated while employing co-cultures of two different cells [rat vein endothelial cells (VECs) and rat bone marrow mesenchymal stromal cells (BMSCs)]. The modified bioceramics were finally implanted into the SD rats' femurs and followed by investigating the bone defect repair efficacy and the expression of EphB4/EphrinB2 molecules in vivo. The results indicated that the modified bioceramics could control the release of EPO continuously. The osteogenesis and angiogenesis were improved along with the increased expression of EphB4/EphrinB2 molecules. The expression of EphB4/EphrinB2 molecules was also significantly increased in vivo and the bone defect was repaired effectively. Overall, our findings demonstrated that EPO loading on biphasic calcium phosphate bioceramics could promote both osteogenesis and angiogenesis. The results suggest that EphB4/EphrinB2 may be crucial in the process. Graphical abstract.

Simultaneously constructing nanotopographical and chemical cues in 3D-printed polylactic acid scaffolds to promote bone regeneration.

Topographical structures and bioactive surface coatings are effective in improving the biological function for bone regeneration. However, the simultaneous introduction of these benefits into three-dimensional (3D) porous scaffolds poses a daunting challenge. In this study, we proposed a simple yet effective approach to decorate 3D-printed polylactic acid (PLA) scaffolds with chemically modified nanotopographical patterns. The nanotopography was produced by etching the amorphous phase of PLA in an alcohol/alkali solution to expose dense lamellae. Subsequently, conformal decoration of polydopamine (PDA) was realized via self-assembly of catecholamines without changing the surface nanotopography. In vitro cell experiments including live and dead staining, cell morphology, cell growth, and alkaline phosphatase showed that the combination of nanotopography and PDA-coating led to a favorable enhancement of osteoblasts adhesion, spread and proliferation in 3D-printed scaffolds. The contribution of integrated patterns to bone regeneration was evaluated using a rat femur critical-sized defect model in vivo. Micro-CT evaluation and histological analysis demonstrated that the scaffold decorated with integrated pattens promoted osteogenesis more than the bare scaffolds and the scaffolds decorated with only nanotopography. Our proposed approach offers a promising method for improving bioactivity of 3D polymer scaffolds for bone tissue regeneration.