A palatal dentigerous cyst arising from a mesiodente.

Dentigerous cysts can develop from unerupted primary, permanent, or rarely supernumerary teeth. When a supernumerary tooth is in the maxilla, near the midline, it is called a mesiodente. Such a mesiodente lies in the palate and a cyst developing about this tooth can extend directly up into the nasal fossae. More commonly a dentigerous cyst arising from unerupted maxillary teeth occurs about the molar, premolar, or canine teeth and the cyst extends up into the maxillary sinus. The CT and MR findings in a rare case of a dentigerous cyst of a mesiodente are presented.