Hyalinization and Molecular Pathways Involved in Orthodontic Tooth Movement: A Systematic Review and Meta-Analysis

ABSTRACT

Abstract Objective: To systematically review the hyalinization of experimental tooth movement in humans and animals. Material and Methods: The electronic databases of MEDLINE, PubMed, Cochrane Library, Embase, Institute for Scientific Information, and Google Scholar were searched for performing a systematic review of the related literature published until 2019. Moreover, Endnote X9 software was utilized to manage electronic titles. The searches were fulfilled using keywords of "hyalinization," "orthodontic tooth movement" OR "OTM" AND "periodontal ligament" OR "PDL," "molecular pathways," AND "mechanical cell." Therefore, this systematic review was conducted based on the key consideration of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: Forces ranged between 2.3 and 50 CN had been applied. According to the research design, incisors had been included in two experiments, whereas maxillary molars had been displaced by tipping forces in another rat examination. However, a majority of investigations had stated that hyalinization had firstly appeared within the first 24 hours. Moreover, the amount of prostaglandin-end peroxide synthase 2 (PTGS2) had been positively related to force term and size utilizing Western blotching. As PTGS2 had been included in the prostaglandin E2 (PGE2) metabolism, the up-regulation of PTGS2 gene expression could be connected with that of PGE2 emission. Conclusion: Gene expression in connection with force term and size and also the first signalling pathways were recognized utilizing protein-protein interactions (PPIs).