en Oral medicine Oral medicine Original article Original article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><b><span style="color:#2e74b5">Background and Aim:</span></b> The Graded Chronic Pain Scale version 2.0 (GCPS 2.0) has no Persian version for use on the Iranian population. Thus, this study aimed to validate the Persian version of this scale.<br> <b><span style="color:#2e74b5">Materials and Methods: </span></b>The cross-sectional study was conducted on 160 patients with chronic pain who filled out the GCPS 2.0. The 8-item self-report GCPS 2.0 was first translated to Persian. The validity of its Persian version was examined by a group of 7 expert specialists and calculation of the content validity index. The test-retest method was used to measure the reliability of the Persian version of GCPS 2.0. The Bartlett&#39;s test, KMO index, and exploratory factor analysis were used to confirm its construct validity. The internal consistency of the questions was analyzed by calculation of Cronbach&#39;s alpha coefficient and item-scale correlation coefficient, and retesting. The relationship between the questionnaire score and demographic information of the participants was analyzed (alpha=0.05). &nbsp;&nbsp;<br> <b><span style="color:#2e74b5">Results: </span></b>The content validity coefficient was 0.98. The test-retest coefficient was 0.98, indicating high reliability of the questionnaire. The mean age of the participants was 38 years, and 81 (50.6%) were males. Education was found to have a significant correlation with the total questionnaire score (P<0.05) but age had no such correlation (P>0.05).<span style="font-family:&quot;Verdana&quot;,sans-serif"></span><br> <b><span style="color:#2e74b5">Conclusion:</span></b> The Persian version of the GCPS 2.0 with the omission of questions 1 and 5 may be used for assessment of chronic pain in the temporomandibular joint (TMJ) area in the Iranian population. &nbsp;</span></span></div> Chronic pain, Facial pain, Pain measurement, Temporomandibular joint disorders, Reproducibility of results 117 123 http://jrdms.dentaliau.ac.ir/browse.php?a_code=A-10-255-1&slc_lang=en&sid=1 Sahar Mafi Sahar.mafi86@gmail.com 100319475328460012299 0000000201503641 No Oral Medicine Department, Islamic Azad University, Dental Branch, Tehran Iran. Farhad Ghahremani farhad95gh@gmail.com 100319475328460012301 0009000333397534 No Private Dentistry Practice, Kermanshah, Iran. Mahmood Rahmani n_s_514@yahoo.com 100319475328460012300 0009000076111426 No Oral Medicine Specialist, Kermanshah, Iran. Arezoo Alaee arezoo.alaee@yahoo.com 100319475328460012298 0000000208826232 Yes Oral Medicine Department, Dental Material Research Center, Islamic Azad University, Dental Branch, Tehran Iran.