fa Oral & maxillofacial surgery Oral & maxillofacial surgery Original article Original article <p dir="RTL" style="margin: 0in 0in 10pt; text-align: justify; line-height: 150%;"></p> <strong><span dir="LTR">Background and Aim:</span></strong><span dir="LTR"> Given the relatively high prevalence of systemic diseases, the importance of these diseases in patient management, treatment planning, and treatment outcomes, the controversy in the reported incidence rates, and changes in the frequency of diseases over time, we aimed to determine the prevalence of systemic diseases among the patients referring to the Dental Branch of Islamic Azad University of Tehran in 2016-17.</span><br> <strong><span dir="LTR">Materials and Methods: </span></strong><span dir="LTR">The present research was carried out by studying the existing data. All records of patients who referred to the Oral and Maxillofacial Medicine Department during 2016-17 were extracted from the archives and evaluated for systemic diseases. The prevalence of systemic diseases in the subjects was estimated with 95% confidence interval. The role of related factors (age, gender, etc.) was statistically determined by Chi-square test.</span><br> <strong><span dir="LTR">Results:</span></strong><span dir="LTR"> Out of 6270 records, 2595 patients (41.4%) had systemic diseases and conditions; hypertensive diseases (8.42%), thyroid diseases (7.05%), and digestive diseases (6.5%) had the highest prevalence rates. 50.7% of the patients were women and 49.3% were men; the prevalence of systemic diseases was 41.5% below 45 years of age and 48.5% over 45 years of age. Medical consultation was requested for 702 patients, and drug intake was observed in 2029 patients. Request for medical advice and drug intake</span> <span dir="LTR">were more frequent in women and at over 45 years of age.</span><br> <strong><span dir="LTR">Conclusion: </span></strong><span dir="LTR">The results showed that the prevalence of systemic diseases (41.4%) is high. Hypertension showed the highest prevalence. The incidence of systemic diseases increases with age and is higher in women.</span> Prevalence, Disease, Epidemiology, Drug Therapy 9 18 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-557-2&slc_lang=fa&sid=1 M Taghibakhsh mehrdad.taghibakhsh@yahoo.com 10031947532846009826 10031947532846009826 No Assistant professor, Oral Medicine Dept, Faculty of Dentistry, Tehran Medical Sciences, N Moezzi ghadim dr.nahid.moezzi@gmail.com 10031947532846009827 10031947532846009827 Yes , Oral Medicine Dept, Faculty of Dentistry, Tehran Medical Sciences, M Rayat zadeh 10031947532846009828 10031947532846009828 No Dentist