Submit Manuscript | http://medcraveonline.com Abbreviations: OC, osteochondroma; CBCT, cone beam com- puted tomography; 3D, three-dimensional; CT, computed tomography Introduction Osteochondroma (OC) is the most common benign tumor in the axial and appendicular skeleton. It accounts for %35-50 of all benign bone tumors and %8-15 of all primary bone tumors. The World Health Organization describes the OC as a cartilage-capped bony protrusion on the external surface of bone. 1 Although Von Langenbeck defned coronoid process hyperplasia in 1853, Jacob frst described OC of the coronoid process forming pseudojoint between the coronoid process and the zygoma in 1899, now it was known as Jacob disease. 2 This benign skeletal tumor is frequently located at the level of the metaphysis of long bones and occurs rarely in the oral and maxillofacial region. OC is commonly seen coronoid and condylar processes of the mandible within the facial bones. 3 The tumour grows slowly and it causes progressive limitation of mouth opening and facial asymmetry when it is sited in the coronoid process. 4 Another symptoms are remodeling, devastation or expansion at the zygoma and/or zygomatic arch or pain with mouth opening. 5 Clinical examination, radiography and cone beam computed tomography (CBCT) is useful diagnostic tools for OC. In the radiologic diagnosis, panoramic radiography and Water’ sprojection are useful that can show an expanded coronoid process. 6 CBCT is the gold standard for exact diagnosis because it provides anatomical details. The facial asymmetry and limitation of mouth opening are determinative of the need for surgical removal of the lesion. The excision of the coronoid process with the tumor is the precise treatment. 7 After excision, the recurrence rate is very low (%2). 8 In this case report, we present details of the patient with OC of coronoid process attendance by limited mouth opening. Case presentation A 69-year-old male patient referred to the radiology clinic of the Atatürk University with complaint limitation of mouth opening, with no evidence of pain or joint sound. There was no history of facial trauma and medical history was not signifcant. In clinical examination, limitation of mouth opening and deviation to the left side during the mouth openning was found in patient. Figure 1 Panoramic radiography showed expanded irregularly shaped radiopaque lesion on the left coronoid process. Figure 2 CBCT scan was performed. Three-dimensional (3D) reconstruction of the CBCT images showed a mushroomshaped hyperplastic enlargement of the coronoid process which causesresorption under the bones of the skull base. Figure 3 The size of the lesion was measured 33,1x25,5x30,2mm. Patient was referrred to the surgery clinic with the prediagnosis of osteochondroma. Figure 1 showes A) limitation of mouth opening B) deviation to the left side during the mouth opening. MOJ Clin Med Case Rep. 2017;7(2):190‒192. 190 © 2017 Yesiltepe et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Large osteochondroma of the coronoid process of left mandible: clinical and imaging fndings of a rare case Volume 7 Issue 2 - 2017 Selin Yesiltepe, 1 Ibrahim Sevki Bayrakdar, 2 Hayati Murat Akgül, 1 Ahmet Berhan Yilmaz, 1 Suayip Burak Duman 3 1 Department of Dentomaxillofacial Radiology, Ataturk University, Turkey 2 Department of Dentomaxillofacial Radiology, Osmangazi University, Turkey 3 Department of Oral and Maxillofacial Radiology, Inonü University, Turkey Correspondence: Ibrahim Sevki Bayrakdar, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Osmangazi University, Turkey, Tel 0090 222 2391303, Fax 0090 222 2391273, Email ibrahimsevkibayrakdar@gmail.com Received: July 05, 2017 | Published: August 01, 2017 Abstract Osteochondroma (OC) is the most common benign tumor of the skeleton which having both chondroma and osteoma. This tumor generally found on the metaphysis of long bones and occurs very rarely in the maxillofacial region. In maxillofacial region, condyle and coronoid process of the mandible are the most commonly affected areas. When it is sited in the coronoid process, it causes progressive facial asymmetry and limitation of mouth opening. In this case report we present a rare case of osteochondroma of left condyle region in a 69-year-old male patient attendance by limited mouth opening. Keywords: osteochondroma, coronoid process, CBCT MOJ Clinical & Medical Case Reports Case Report Open Access