[Dental radiographic survey of rapidly progressive periodontitis]

The purpose of this study was to determine the prevalence of rapidly progressive periodontitis (RPP) by radiographic evaluation in patient at the department of conservative dentistry, Ohu University hospital during two years from 1987 to 1988. The survey was conducted on 370 patients. The radiographic evaluation was done by the method of Schei. The results obtained were as follows. 1. The number of RPP patient was eight. The prevalence of RPP in all patients and periodontitis patients were 2.1%, 6.0%, respectively. RPP patients consisted of 4 females and 4 males. 2. The age of RPP patients ranged from 34 to 41 (mean age 37.5) years old. 3. The number of affected and missed teeth ranged from 4 to 19 (mean 12.1), 0 to 23 (mean 8.0), respectively in RPP patients. 4. Severe alveolar bone loss (more than 50%) was observed in the teeth except canine.