eng Science and Education Publishing International Journal of Dental Sciences and Research 2333-1259 2020-07-05 8 5 123 126 10.12691/ijdsr-8-5-2 IJDSR2020852 article Basser Ali Abdullah basserali30@yahoo.com 1 Gassan Yassin Hamed 1 Oral and Maxillofacial surgery, Oral Medicine, College of Dentistry, Mosul, Iraq This study consist of 450 patients with TMDs, 271 females and 179 males, 13-65 years were age range of the sample. Helkimo index was used to assess the TMDs by scores, grinding and clenching were recorded, the most relevant age group was 21-30 years, they signify (59.3%) from the whole sample, female patients signify 60.4% from the total participtant.130 (28.8%) patients were reported grinding where as 122 (24.8%) were complained from clenching. Significant relations (p ¡Ü 0.001) of grinding and clenching with age, sex, symptoms and signs of TMDs were found in this study. In conclusion grinding and clenching implicated in etiology and severity of TMDs and their incidence decrease with age. http://pubs.sciepub.com/ijdsr/8/5/2/ijdsr-8-5-2.pdf grinding clenching Helkimo TMDs