en دهان و دندان Oral and Maxillofacial گزارش مورد Case Report <ul> <li style="text-align: justify;">This article presents a case of extensive External Root Resorption (ERR) involving the distal root of the left mandibular second molar due to the pressure of wisdom tooth in its neighborhood in a 32 year‑old female patient. Clinical and radiographic examination revealed no pulp in respond to the vitality test, periapical radiolucency in the apical of the mesial root, and root resorption of the distal root. A definite diagnosis of pulpal necrosis with chronic apical periodontitis and ERR of the distal root was made. The tooth was managed by nonsurgical endodontic treatment. One‑year follow‑up revealed satisfactory results clinically and radiographically.</li> </ul> Tooth Resorption, Therapy, Complications, Cone Beam Computed Tomography 39 44 http://jsurgery.bums.ac.ir/browse.php?a_code=A-10-298-1&slc_lang=en&sid=1 Maryam Dalaei Moghadam maryam.dalaei@yahoo.com 10031947532846008510 10031947532846008510 Yes Assistant Professor of Endodontic, Razi Herbal Medicines Research Center, Department of Endodontic, Faculty of Dentistry, Khorramabad University of Medical Science, Khorramabad, Iran Najmeh Ebadi maryam.dalaei@yahoo.com 10031947532846008511 10031947532846008511 No Post Graduate Endodontic Student, Department of Endodontic, School of Dentistry, Zahedan University of Medical Science, Zahedan, Iran