A radiologic analysis of dentigerous cysts and odontogenic keratocysts associated with a mandibular third molar

Objective. The purpose of this study was to discriminate radiographically b etween dentigerous cysts (DCs) and odontogenic keratocysts (OKCs) associate d with a mandibular third molar. Study design. The material consisted of panoramic radiographs of dentigerou s cysts (44 patients, 45 cysts) and odontogenic keratocysts (15 patients, 1 6 cysts), all of which were related to a mandibular third molar. The radiog raphic images were analyzed with reference to the patients' ages and sympto ms. Results. The mean age of patients in the OKC group was less than that of pa tients in the DC group. The mean area of the cysts in the OKC group was lar ger than that of those in the DC group. The mean distance from the second t o the third molar in the DC group was greater than that in the OKC group. A lthough there was a significant correlation between the area and distance i n the DC and OKC groups, the patients' ages did not significantly correlate to the area and distance of either cyst. Conclusions. The OKCs had a tendency toward rapid growth in the patient's y outh but short movement of a third molar compared with the DCs. The DCs and OKCs do not appear to develop gradually from the period when follicles or dental lamina were formed but arise at various periods randomly.