Ann Anat 190 (2008) 258—263 RESEARCH ARTICLE Modifications of interdental papilla microcirculation: A possible cause of periodontal disease in Hashimoto’s thyroiditis? Scardina Giuseppe Alessandro à , Messina Pietro Department of Oral Sciences ‘‘G. Messina’’, University of Palermo, Dr. Scardina Giuseppe Alessandro via Del Vespro, 129-90127 Palermo, Italy Received 21 August 2007; accepted 23 December 2007 KEYWORDS Hashimoto thyroiditis; Gingival; Microcirculation Summary Background: Hypothyroidism is defined by a decrease in thyroid hormone production and thyroid gland function. The aim of the present research has been to evaluate the morphologic interdental papilla microcirculation of patients suffering from Hashimoto thyroiditis (HT) and to evaluate a possible correlation with the associated periodontal disease. Methods: Fifteen healthy subjects and 15 patients suffering from HT were examined. The patients who showed conditions known to compromise microcircula- tion, such as diabetes, hypertension and pharmacological treatments, were not included in the group of healthy patients. All patients were non-smokers. Gingival capillaroscopy was used to investigate the characteristics of microcirculation. Visibility, course, tortuosity, the average caliber of the capillary loops and the number of visible capillary loops per square millimeter were evaluated for each patient. Results: An interdental papilla vascular modification results in HT. In patients suffering from HT, it was possible to observe a reduced caliber of capillaries, as well as a greater number and tortuosity of capillary loops. Conclusions: This study shows that capillary alterations in patients suffering from HT occur in gingival microcirculation. & 2008 Published by Elsevier GmbH. Introduction Hypothyroidism is defined by a decrease in thyroid hormone production and thyroid glandular function. It is caused by severe iron deficiency, chronic thyroiditis, lack of stimulation, radioactive ARTICLE IN PRESS www.elsevier.de/aanat 0940-9602/$ - see front matter & 2008 Published by Elsevier GmbH. doi:10.1016/j.aanat.2007.12.004 à Corresponding author. E-mail address: scardina@odonto.unipa.it (G.A. Scardina).