Measurement of senescence in fibroblast subjected to predetermined compressive forces and duration using in vitro model: an orthodontic perspective

Orthodontic treatment aims to align teeth by remodelling the periodontium, induced by orthodontic force. To ensure effective and safe treatment, understanding the underlying biomechanical and biological causes of tooth movement is crucial. The compression- tension theory, which proposes that chemical messengers regulate cellular responses to mechanical stress on the periodontal ligament and alveolar bone, has been widely accepted (Meikle, 2005). However, the optimal forces on fibroblasts remain unknown. In recent years, new findings about cellular senescence and biological changes to the periodontium have been published (Mohanakumar et al., 2021). High compressive forces may lead to hypoxia, causing irreversible cell cycle arrest, apoptosis, and loss of surrounding tissue cells, particularly in the compression zone. Excessive hypoxia may cause significant and detrimental destruction of tooth-supporting tissues (Younis et al., 2019). To minimize the detrimental effects of these forces, assessing senescence levels in response to different compressive forces may help control orthodontic forces and preserve the periodontal structure and root surface. This study examined the cellular senescence activity in human periodontal ligament fibroblasts using an in vitro compressive model. The cells were exposed to different force magnitudes and observed over time to assess their senescence. However, the research is limited as it only used a two-dimensional model, which may not fully capture the cellular response seen in the mouth. This is a fundamental investigation intended to inspire further research on the mechanisms of cellular senescence and its relevance for orthodontic treatment. Future studies could explore cellular senescence ex vivo and develop or use targeted senolytics to enhance orthodontic outcomes