Background: The authors conducted this study to determine the most common location of odontogenic keratocysts, or OKCs, in the maxilla and the implication of this for dental practice.
Methods: The authors reviewed all cases diagnosed as an OKC by the Oral and Maxillofacial Pathology Diagnostic Laboratory at University of Florida College of Dentistry from July 1, 1993, to June 30, 2001. They determined the location for each cyst and recorded relevant clinical information such as age and sex. In addition, the authors noted the practitioners' clinical diagnoses for the cases in the most common location in the maxilla and compared them with the final diagnosis.
Results: A total of 398 OKCs occurred in 393 patients. Of the 398 cysts, 266 (66.8 percent) were in the mandible, and 132 (33.2 percent) were in the maxilla. The most common location for OKCs was the third molar and ramus area of the mandible, with 137 cysts. The canine region of the maxilla, with 54 cysts, was the second most common location. Submitting clinicians mentioned OKC as a diagnostic possibility in only 31.5 percent of the maxillary canine region cases.
Conclusion: The most common maxillary location for OKCs is the canine region where they commonly are mistaken for an apical inflammatory lesion or lateral periodontal cyst. Accurate diagnosis is essential for proper patient therapy and follow-up.
Clinical implication: A diagnosis based solely on clinical information can be problematic. In many cases, histologic examination of surgically removed tissue is necessary to establish a definitive diagnosis. That is particularly true for cases that do not resolve when treated by conservative endodontic therapy.