en Oral pathology Oral pathology Original article Original article <strong>Background and Aim:</strong> Patients affected by thalassemia major show great skeletal changes in the head and neck area in addition to malocclusion. It seems that examination of malocclusion in these patients and evaluation of the frequency of temporomandibular disorders (TMD) can help identify people with a high risk of illness in the society. The current study aimed to compare the frequency of TMD between &beta;-thalassemia major patients and high school and guidance school students.<br> <strong>Materials and</strong> <strong>Methods:</strong> In this descriptive-analytical study, 51 patients affected by thalassemia major (23 girls and 28 boys) and 78 normal (43 girls and 35 boys) guidance and high school students between 12 and 18 years old were evaluated. The presence of TMD and malocclusion and their relationship were determined. After examination and completion of the related questionnaire, data were analyzed by chi-square test and t-test using SPSS software.<br> <strong>Results:</strong> According to the data, there was no significant difference in spacing, occlusion, crowding, open bite, headache, bruxism, crepitation, clicking, TMD, subluxation, locking, cleaning, deviation, deep bite, and crossbite between the control and thalassemia students (P>0.05). However, significant differences were observed regarding overjet and pain (P<0.05).<br> <strong>Conclusion:</strong> These results suggest that TMD and occlusion type have no significant correlation <span dir="RTL">with</span> thalassemia. Thalassemia, Temporomandibular Joint Disorders, Malocclusion 21 29 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-671-1&slc_lang=en&sid=1 S Salimzadeh dr.ssalimzade@gmail.com 10031947532846009019 10031947532846009019 Yes Periodontal Dept, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran H SHeykhNezhad 10031947532846009020 10031947532846009020 No Assistant Professor, Department of Prothesis, Guilan University of Medical Sciences, Rasht, Iran Z Zohri 10031947532846009021 10031947532846009021 No Periodontist, department of periodontology,school of dentistry, Guilan University of Medical Sciences, P Salimzadeh 10031947532846009022 10031947532846009022 No Dentist