Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 9 2 2022 11 19 100 105 Abbas Haghighat Craniofacial and Cleft Research Center, Department of Oral and Maxillofacial Surgery, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. Sayed Mohammad Razavi Dental Implant Research Center, Department of Oral and Maxillofacial Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. Saeedeh Khalesi Dental Materials Research Center, Department of Oral and Maxillofacial Pathology, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran. 2022 09 29 2022 10 22 Objectives: Ameloblastoma is a benign neoplasm with origin from odontogenic epithelium. Unicystic ameloblastoma has clinical and radiographically features resemble to other odontogenic cysts but it has a typical ameloblastomatous epithelium lining the cyst cavity. Case: In this case report study, we presented a 9-year-old girl who was referred to Oral and Maxillofacial Surgery of Isfahan Dental School for the management of a large swelling on the right posterior mandiblular region. The histopathologic examination of the specimen showed mural type of unicystic ameloblastoma. In the first step, the patient was treated by decompression of the lesion. Five month after it, shrinkage of the lesion was observed and in the second stage of surgery, curettage of the remaining lesion and extraction of tooth buds in the areas of lesion was performed. After two years, radiographic image showed new bone formation and complete healing of the lesion. Conclusion: Choosing the best treatment for children with unicystic ameloblastoma requires more attention and all clinical and histopathological parameters should be considered. Conservative treatment for ameloblastoma leads to reduce complications after treatment and affect the patient’s quality of life. https://jcr.tums.ac.ir/index.php/jcr/article/view/417 https://jcr.tums.ac.ir/index.php/jcr/article/download/417/355