Computerized tomography findings and recurrence of keratocystic odontogenic tumor of the mandible and maxillofacial region in a series of 46 patients.

OBJECTIVES: The aim of this study was to evaluate the computerized tomography (CT) features of keratocystic odontogenic tumors (KCOTs). Another aim was to determine the recurrence rate of KCOTs during a mean follow-up of 4.7 years.

STUDY DESIGN: The CT features of histopathologically verified KCOTs in 46 patients were reviewed. The features examined included the shape of the lesion, the lesion's influence on surrounding structures, such as cortical bone and teeth, and the behavior of contrast medium. The recurrence rate and the time to recurrence were determined in the series.

RESULTS: In the body of the mandible, KCOTs demonstrated only minimal cortical expansion. The vast majority of the lesions caused border scalloping in both jaws. In the maxilla, this could be demonstrated only by CT. Increased attenuation within the tumor cavity that did not show enhancement was evident in 30% of cases. Recurrences occurred in 39% of the patients, with a mean time to a recurrence of 2.2 years.

CONCLUSIONS: The CT features that should arouse suspicion of a KCOT include high attenuation areas in the inner part of the lesion, minimal expansion in the body of the mandible, and border scalloping. The high recurrence rate of KCOT makes periodic and long-term follow-up important. The importance of CT imaging in the follow-up is stressed, especially in the maxilla because of its complex 3-dimensional anatomy.