AUTHOR=Behm Christian , Zhao Zhongqi , Andrukhov Oleh TITLE=Immunomodulatory Activities of Periodontal Ligament Stem Cells in Orthodontic Forces-Induced Inflammatory Processes: Current Views and Future Perspectives JOURNAL=Frontiers in Oral Health VOLUME=Volume 3 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2022.877348 DOI=10.3389/froh.2022.877348 ISSN=2673-4842 ABSTRACT=Orthodontic tooth movement (OTM) is induced by applying active mechanical forces, causing a local non-infectious inflammatory response in the periodontal ligament (PDL). As a prerequisite for OTM, the inflammation status is associated with increased levels of various cytokines and involves the interaction between immune cells and periodontal ligament stem cells (hPDLSCs). It is well established that hPDLSCs respond to orthodontic forces in several ways, such as by secreting multiple inflammatory factors. Another essential feature of hPDLSCs is their immunomodulatory activities, which are executed through cytokine-induced production of various soluble immunomediators and direct cell-to-cell contact. It is well known that these immunomodulatory abilities are essential for local periodontal tissue homeostasis and regeneration. So far, only a handful of studies provides first hints that hPDLSCs change immunological processes during OTM via their immunomodulatory activities. In this perspective article, we will discuss the potential role of the immunomodulatory potential of hPDLSCs in establishing and resolving the OTM-associated non-infectious inflammation and hence its potential impact on periodontal tissue homeostasis during OTM.