LAUSR

The aims of this systematic review were to identify and synthesize the evidence for an association in DNA methylation/histone modifications between periodontal diseases and systemic diseases/smoking. Electronic database searches using relevant search terms in PubMed, Embase, MEDLINE, CINAHL, Web of Science, Scopus, and SciELO, and manual searches, were independently conducted to identify articles meeting the inclusion criteria. Nine studies of 1482 participants were included. Periodontitis was compared to metabolic disorders, rheumatoid arthritis (RA), cancer, and smokers, as well as healthy controls. Substantial variation regarding the reporting of sample sizes and patient characteristics, statistical analyses, and methodology was found. IL6 and TNF were modified similarly in RA and periodontitis. While TIMP-3 and GSTP-1 were significantly lower in periodontitis patients and controls than in cancer, SOCS-1, RMI2, CDH1, and COX2 were modified similarly in both cancer and periodontitis. While TLR4 in and CXCL8 were affected in periodontitis independent of smoking habit, smoking might change the transcription and methylation states of ECM organization-related genes, which exacerbated the periodontal condition. There was some evidence, albeit inconsistent, for an association between DNA methylation and periodontal diseases and systemic diseases or smokers compared to healthy patients or non-smokers.