Effects of Periodontal Ligament Cells on Alveolar Bone Metabolism under the Action of Force and Inflammatory Factors and Its Molecular Mechanisms.

Periodontal ligament may have independent response to orthodontic stimulation and thus initiate alveolar bone osteogenesis and osteoclasts. Orthodontic-induced alveolar bone remodeling has no bone loss,while inflammation can lead to alveolar bone loss,suggesting that force signal and inflammatory factors may induce the differentiation of undifferentiated cells in the periodontal ligament via different pathways. The strength of the force and the nature of the force (basal tension and fluid shear force) may affect the differentiation of periodontal ligament cells,and may produce antagonistic or synergistic effect with the inflammatory factors through complex autocrine and paracrine regulation,resulting in local bone reconstruction,which is manifested as bone deposition and bone absorption. Studies have shown that Wnt signaling is an important regulatory pathway for osteoblast differentiation. Inflammatory factors can block the differentiation of stem cells into osteoblasts. The Wnt pathway is closely related to the effects of force and inflammatory factors on the differentiation of periodontal ligament cells.