Dental treatments, tooth extractions, and osteonecrosis of the jaw in Japanese patients with rheumatoid arthritis: results from the IORRA cohort study

This study aimed to evaluate dental treatments, tooth extractions, and osteonecrosis of the jaw (ONJ) in Japanese patients with rheumatoid arthritis (RA). Patients with RA enrolled in our cohort completed self-administered questionnaires, which included questions regarding their dental treatments, tooth extractions by dentists during the past 6 months, and past history of ONJ. The history of ONJ was validated with the patients’ medical records. Logistic regression was used to determine the association of variables with dental treatments and tooth extractions during the past 6 months. Among 5695 Japanese patients with RA who responded to the questionnaires (mean age, 61.0 years; 85.6 % female), 2323 patients (40.8 %) and 378 patients (6.6 %) reported having had dental treatments and tooth extractions performed by a dentist within the past 6 months, respectively. In multivariate models, advanced age was significantly (P < 0.0001) associated with both dental treatments and tooth extractions during the prior 6-month period, and ever smoking was significantly (P = 0.023) correlated with tooth extractions during that time. Among patients who reported a history of ONJ, we confirmed five cases of ONJ with patient medical records. The prevalence of ONJ was 0.094 % among all RA patients and 0.26 % among female RA patients ≥65 years of age (n = 1888). Our data suggest that more than a few Japanese patients with RA have dental complications that require care by dentists, and that Japanese rheumatologists and dentists should cooperate to improve dental health in patients with RA.