Metrical differential diagnosis based on location. Differential diagnosis among various cysts.

An attempt was made to quantify the location of oral lesions. Panoramic radiographs of non-odontogenic cysts (13 globulomaxillary cysts, 8 median maxillary cysts, 8 nasopalatine cysts, 5 nasoalveolar cysts and 11 simple bone cysts) and odontogenic cysts (37 radicular cysts, 13 radicular granulomas, 68 dentigerous cysts and 40 odontogenic keratocysts) were examined. Metrical data (integers) were obtained from a conversion table and the abscissa values (to the first decimal place) were obtained from the centroid of the cysts. Differential diagnosis among these lesions revealed the following: 1. In the maxilla, it was possible to differentiate median maxillary cysts and nasopalatine cysts from globulomaxillary cysts, nasoalveolar cysts, radicular cysts, radicular granulomas, dentigerous cysts and odontogenic keratocysts. 2. In the mandible, it was difficult to differentiate simple bone cysts, radicular cysts, radicular granulomas, dentigerous cysts and odontogenic keratocysts from one another. The present findings revealed that data on lesion location can be changed into metrical data for differential diagnosis of cysts.