Association Between the Combined Herbal Medicines and Risk of Dental Diseases in Patients with Rheumatoid Arthritis: Insight from a Nationwide Database.

Background and Objectives: Patients with rheumatoid arthritis (RA) are found to have a higher risk of dental diseases. Although herbal medicines (HMs) have long been used to treat various conditions, few studies focus on its impact on dental diseases. In this longitudinal cohort study, we assessed the correlation between HM use and risk of dental diseases in RA groups. Materials and Methods: A total of 2359 persons with RA aged 20-80 who were free of dental diseases between 2001 and 2010 were retrospectively enrolled from nationwide register-based data. They were then classified into HMs and non-HMs groups based on whether they ever used combined HMs after RA onset. Incidence rate and hazard ratios (HRs) of dental diseases were estimated for both groups by the end of 2013 via fitting Cox proportional hazards model. Results: Incidence rate of dental disease was reported to be lower in the HMs group than in the non-HMs group (90.21 per 1000 person-years versus 106.94 per 1000 person-years, respectively). RA individuals treated with HMs showed a significantly lower risk of dental diseases, especially dental caries, pulpitis, periodontitis, and stomatitis. Among commonly prescribed formulas, eleven herbal products significantly associated with a lower risk of dental diseases, such as Hai-Piao-Xiao, Yan-Hu-Suo, Chuan-Niu-Xi, Mo-Yao, Olibanum, Bei-Mu, Mu-Gua, Gui-Zhi-Shao-Yao-Zhi-Mu-Tang, Shao-Yao-Gan-Cao-Tang, Xue-Fu-Zhu-Yu-Tang, and Ping-Wei-San. Conclusions: The addition of HMs treatment may have advantages to proactively prevent sequent risk of dental disorders for persons with rheumatic diseases. A deeper exploration focusing on pharmacological action is needed to provide more reliable evidence for the improvement of susceptible individuals' oral hygiene.