Abstract: Objective To evaluate the outcome of defect filling with allogenic freezedried bone mixed with bone marrow following conservative enucleation of large intraosseous cystic lesions of the mandible.Methods Fortytwo patients with large intraosseous cystic lesions of the mandible were treated by defect filling with allogenic freezedried bone combined with bone marrow following conservative cyst enucleation.All patients were evaluated postoperatively by repeated clinical examination done by the operating surgeon.Radiographic examination was performed using panoramic radiographs taken before operation,immediately after operation,6 months and 12 months after operation.Results Postoperative hemorrhage occurred in one patient.Wound dehiscence occurred in two patients,and the woundhealing was delayed.All patients showed satisfactory healing.The patients were followedup for 1348 months using panoramic radiographic examination.Recurrence was seen in 2 patients with KCOTs.Clinical and panoramic radiographic examination showed no residual or recurrent cyst in the remaining patients.Conclusions We demonstrate successful clinical application of allogenic freezedried bone mixed with autologous bone marrow as an alternative filling material for intraosseous cystic lesions of the mandible after conservative enucleation.

Key words: intraosseous cystic lesion, odontogenic cystic lesions, enucleation, allogenic freezedried bone, autologous bone marrow