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. Such cyst remains initially completely asymptomatic unless when infected and can be discovered only on routine radiographic examination.Here is a case of dentigerous cyst, present in left mandibular region associated with cortical expansion and facial asymmetry which has been enucleated and tooth extracted surgically is discussed in the present case report.