Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 5 2 2011 06 01 Dentigerous Cyst Associated with a Mesiodens: A Case Report 76 78 EN Sepideh Vosough Hossein Monir Moradzadeh Mehrdad Lotfi Amir Ala Aghbali Shirin Fattahi Journal Article 2010 02 22 2011 04 24 Dentigerous cysts are the second most common odontogenic cysts after radicular cysts and are most commonly seen in association with third molars and maxillary canines. Only 5% of dentigerous cysts involve supernumerary teeth, of which mesiodens is the most frequent type. This paper presents a case of dentigerous cyst associated with a mesiodens that caused a painless swelling in the upper lip of an 18-year-old female. The patient was treated surgically by enucleation of total cyst and surgical extraction of mesiodens under local anesthesia.