World Health Organization(WHO) revised the classification of neoplasms and other tumours related to odontogenic apparatus in 1992. The aim of this study was to classify the odontogenic tumors of Korean according to the WHO Histologic classification. A total of 271 cases were reviewed for the study which were diagnosed as odontogenic tumors at the department of Oral Pathology, Yonsei University College of Dentistry for the period from Jan. 1997 to March 2003. Clinical and pathology reports were reviewed & radiographic feature were examined. The following results were obtained :
1. Among 271 cases, 269 cases(99.3%) were diagnosed as benign odontogenic tumors, and the remaining 2 cases(0.7%) were malignant tumors, which were diagnosed as odontogenic ghost cell carcinoma and squamous cell carcinoma ex odontogenic cyst.
2. Four cases were not able to classify into the WHO classification. All of them were belonged to mixed odontogenic tumors; two cases of adenomatoid odontogenic tumor with calcifying epithelial odontogenic tumor, one case of adenomatoid odontogenic tumor with odontoma, odotogenic cyst and one case of ameloblastoma with immature odontoma.
3. The most frequent odontogenic tumour was odontoma(45.2%), followed by ameloblastoma (29.2%), odontogenic fibroma(9.2%)
4. One case of atypical amelobalstoma and one case of calcifying odontogenic cyst with ameloblastic fibroma were not able to subclassify histologically.
5. Male to female ratio of odontogenic tumors was 1.2:!. Odontogenic tumors mainly occured in the first and second decade, occurred twice as much as in the mandible than in the maxilla
6. The odontogenic tumors was discovered by routine oral x-ray examination, whereas the chief complaint of ameloblastoma were swelling, pain.
7. Ameloblastoma, adenomatoid odontogenic tumor, calcifying odontogenic cyst and odontoma were related to the impacted teeth and tooth displacement. The root resorption was frequently observed in ameloblastoma and calcifying odontogenic cyst.