Divergent chondro/osteogenic transduction laws of fibrocartilage stem cell drive temporomandibular joint osteoarthritis in growing mice / 国际口腔科学杂志·英文版

The anterior disc displacement (ADD) leads to temporomandibular joint osteoarthritis (TMJOA) and mandibular growth retardation in adolescents. To investigate the potential functional role of fibrocartilage stem cells (FCSCs) during the process, a surgical ADD-TMJOA mouse model was established. From 1 week after model generation, ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis (OA)-like joint cartilage degeneration, manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis. Lineage tracing using Gli1-CreER+; Tmfl/-mice and Sox9-CreER+;Tmfl/-mice showed that ADD interfered with the chondrogenic capacity of Gli1+ FCSCs as well as osteogenic differentiation of Sox9+ lineage, mainly in the middle zone of TMJ cartilage. Then, a surgically induced disc reposition (DR) mouse model was generated. The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice. And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment. In conclusion, ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage, resulting in cartilage degeneration and loss of subchondral bone homeostasis, finally causing TMJ growth retardation. DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.

Application of digital three-dimensional surgical simulation system combined with 3D printing in specialist training of orthognathic surgery / 中华医学教育探索杂志

The teaching of orthognathic surgery is difficult because it is complex and emphasizes the combination of theory and practice. The traditional teaching method focuses on theoretical teaching, but due to the limitation of conditions, it is difficult for students to master the operation. In this paper, we apply the digital three-dimensional surgical simulation system combined with 3D printing in specialist training of orthognathic surgery. Digital software and 3D printing are applied in the theoretical teaching, surgical operation, summary and reflection to combine practical teaching with theoretical teaching, so as to stimulate the subjective initiative of the students. The results showed that the teaching evaluation of the experimental group [(3.89±0.84) points] was better than that of the control group [(2.91±1.21) points]. The application of digital three-dimensional surgical simulation system combined with 3D printing has achieved satisfactory results.