Volume 85 • Number 3
Letters to the Editor To the Editor:
Narayana Dental College and Hospital, Nellore-3, India.
Re: Periodontal Condition of Patients With Autoimmune Diseases and the Effect of Anti-Tumor Necrosis Factor-a Therapy. Mayer Y, Elimelech R, Balbir-Gurman A, Braun-Moscovici Y, Machtei EE. (J Periodontol 2013;84:136-142.)
The authors report no conflicts of interest related to this letter.
We read with great interest the article by Mayer et al.1 published in February 2013. We wish to make a few comments on the data reported. The functional disability in patients with rheumatoid arthritis (RA) and psoriatic arthritis (PA) might limit their ability in brushing teeth,2 which increases their risk of developing gingivitis and periodontitis. The confounding effect of this functional disability on periodontal parameters is an issue of particular significance, and it has not been addressed in the article. It was reported in the article that joint status of patients with RA and PA was assessed using composite disease activity scores (DAS 28). In addition, in the Results section, it was reported that DAS 28 scores were shown in Table 1. However, they were reported neither in Table 1 nor anywhere else in the article. One study published in January 2013 showed no correlation between rheumatoid disease activity and severity of clinical periodontal disease,3 while another study reported a correlation.4 In the wake of contradictory evidence, reporting disease activity of autoimmune patients involved in the study adds significance, especially when there is a discrepancy in duration of disease between study groups. It was also reported: ‘‘The null hypothesis was that patients with AI have worse periodontal conditions and anti-TNF-a therapy has a beneficial effect on periodontal parameters.’’ However, by definition, null hypothesis in hypothesis testing is ‘‘the hypothesis that an intervention has no effect, i.e., there is no true difference in outcomes between a treatment group and a control group.’’5 Hence, to prevent misunderstanding, the terminology used in the article needs reevaluation.
Vijay Kumar Chava, Department of Periodontics & Implantology, Narayana Dental College and Hospital, Chinthareddy Palem Nellore, Nellore-2, India; and Pramod Samudrala, Department of Periodontics, 372
REFERENCES 1. Mayer Y, Elimelech R, Balbir-Gurman A, BraunMoscovici Y, Machtei EE. Periodontal condition of patients with autoimmune diseases and the effect of anti-tumor necrosis factor-a therapy. J Periodontol 2013;84:136-142. 2. Torkzaban P, Hjiabadi T, Basiri Z, Poorolajal J. Effect of rheumatoid arthritis on periodontitis: A historical cohort study. J Periodontal Implant Sci 2012;42(3):6772. 3. Joseph R, Rajappan S, Nath SG, Paul BJ. Association between chronic periodontitis and rheumatoid arthritis: A hospital-based case-control study. Rheumatol Int 2013;33:103-109. 4. Ranade SB, Doiphode S. Is there a relationship between periodontitis and rheumatoid arthritis? J Indian Soc Periodontol 2012;16:22-27. 5. National Information Center on Health Services Research and Health Care Technology. HTA 101: Glossary. http:// www.nlm.nih.gov/nichsr/hta101/ta101014.html. Updated August 16, 2012. Accessed May 31, 2013. Submitted May 31, 2013; accepted for publication May 31, 2013. doi: 10.1902/jop.2014.130345
Authors’ Response: We would like to thank Drs. Chava and Samudrala for their interest in our paper published in the Journal of Periodontology.1 Rheumatoid or psoriatic arthritis affects the cells that lubricate and line joints. Therefore, when the synovium becomes inflamed and swollen, the tissues stretch the ligaments and tendons, and the joints become deformed and unstable. These deformities may lead to functional disability. Nonetheless, other studies have failed to show an effect on plaque control.2,3 However, the significant findings in the present study are the differences in the probing depth and bleeding index between subjects with rheumatoid arthritis (RA+ group) taking anti-TNF-a therapy and subjects with autoimmune diseases (AI group) not taking anti-TNF-a (Table 3 in our paper). These findings occurred despite very similar plaque score.
Letters to the Editor
J Periodontol • March 2014
The data of DAS 28, as well as C-reactive protein, erythrocyte sedimentation rate, and amount of disease-modifying anti-rheumatic drugs were not included because there were no significant differences between the groups. The reference to Table 1 was a typographical error. The correct term we should have used in the Introduction is ‘‘hypothesis’’ and not ‘‘null hypothesis’’ as was written mistakenly. Yaniv Mayer, Rina Elimelech, and Eli E. Machtei, Department of Periodontology, School of Graduate Dentistry, Rambam Health Care Campus, Haifa, Israel. The authors report no conflicts of interest related to this letter.
REFERENCES 1. Mayer Y, Elimelech R, Balbir-Gurman A, Braun-Moscovici Y, Machtei EE. Periodontal condition of patients with autoimmune diseases and the effect of anti-tumor necrosis factor-a therapy. J Periodontol 2013;84:136-142. 2. Esen C, Alkan BA, Kırnap M, Akgu glu S, Erel O. ¨ l O, Isxıko The effects of chronic periodontitis and rheumatoid arthritis on serum and gingival crevicular fluid total antioxidant/oxidant status and oxidative stress index. J Periodontol 2012;83:773-779. 3. Mayer Y, Balbir-Gurman A, Machtei EE. Anti-tumor necrosis factor-a therapy and periodontal parameters in patients with rheumatoid arthritis. J Periodontol 2009;80:1414-1420. Submitted June 18, 2013; accepted for publication June 18, 2013. doi: 10.1902/jop.2014.130394
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