Dentigerous cyst is the most common odontogenic cyst. It is characterized by a unilocular radiolucent lesion that encloses permanent tooth buds or, under certain circumstances, displaced tooth buds. Buccal bony expansion is the most common clinical feature. Several treatment modalities have been mentioned in the literature for management of dentigerous cysts. The purpose of this article was to report an extensive right mandibular dentigerous cyst on a 10-year-old boy. Marsupialization was chosen to preserve the permanent tooth bud and a denturelike obturator was then provided for space maintenance and masticatory function. Long-term follow-up revealed good healing of the bony lesion with converted tooth eruption.