Osteoblastoma is a very rare disease and in case of the jaw, maxilla infrequently occurs more than mandible. On account of difficulty to discriminate from other benign tumor or sarcoma, we need to pay attention to make differential diagnosis based on clinical, radiographic, pathological findings. A tumor on the maxilla and maxillary sinus could lead to a bad result for aesthetic appreciation and function. Therefore, reconstruction after maxillectomy is one of the most important issues concerning a surgery. The aim of this study is to report a case of osteoblastoma on the left maxilla which was misdiagnosed as ossifying fibroma and was treated with hemimaxillectomy and reconstruction using deep iliac circumflex artery musculo-osseous flap which resulted in satisfactory result.

Ⅰ. Introduction
 Ⅱ. Case report
 Ⅲ. Discussion
 IV. References

• 최유리(Department of Oral and Maxillofacial Surgery, Chosun University Dental Hospital, School of Dentistry, Chosun University) | Yu ri Choi
• 윤정훈(Department of Oral and Maxillofacial Pathology, Daejeon Dental Hospital, College of Dentistry, Wonkwang Bone Regeneration Research Institute, Wonkwang University) | Jung Hoon Yoon
• 문성용(Department of Oral and Maxillofacial Surgery, Chosun University Dental Hospital, School of Dentistry, Chosun University) | Seong Yong Moon correspondence