Objective: Aggressive resection of a large mandibular cystic ameloblastoma may cause severe deformity and dysfunction, while simple enucleation may carry a high risk of recurrence.The purpose of this study was to evaluate, in terms of recurrence as well as the preservation of contour and function, the effectiveness of the enucleation combined with peripheral ostectomy (Enu/PO) method in managing large mandibular cystic ameloblastomas.Methods: The Enu/PO method was applied to manage fourteen patients who suffered from large mandibular cystic ameloblastoma (11 unicystic, 3 multicystic) between 2002 and 2012.The age ranged from 17 years to 85 years (5 teenagers, 4 patients between 20y and 30y, 4 patients between 30y and 50y and 1 patient at 85y).In these patients, once the large cystic lesion was enucleated, a small amount of bone was trimmed offthe bone walls.The inferior alveolar nerve, if exposed, should be carefully preserved during enucleation and peripheral ostectomy.The residual cavity was then packed with Bismuth iodoform paraffin paste (BIPP)-impregnated gauze which was regularly changed until the bone cavity healed completely.The patients were followed up regularly, and radiography or CT scanning was performed periodically to monitor bone regeneration as well as potential recurrence.