ABSTRACT
Aggressive periodontitis characterized by a rapid rate of periodontal disease progression in the absence of large quantity of bacterial plaque and or calculus present, affects otherwise healthy individuals less than 30 years old. The purpose of this study was to determine the prevalence of aggressive periodontitis among high school students in Qazvin, Iran. 780 students attending high school in Qazvin, Iran during 2004-2005 were randomly selected. Probing depths on 6 sites of permanent incisors and first molars were measured in each individual. Those presenting with pocket depths >4.5 mm in more than one tooth were asked to participate in the next phase of the study, in which bitewing and pen apical radiographs were taken. Individuals with radiographic evidence of bone loss received full clinical and radiographic examinations. The prevalence of aggressive periodontitis was determined. Fisher's exact test was used to determine significant 4 differences between gender groups. Data analysis was done utilizing SPSS Version 13. Of the 780 patients examined initially, 39 individuals had probing depths >4.5mm. Thirty four of these individuals presented for further examination which led to the diagnosis of localized aggressive periodontitis in 6 individuals [0.77%], 4 girls [0.86%] and 2 boys [0.63%]. No significant difference between boys and girls were found. We found no cases of generalized aggressive periodontitis. The results of this study revealed that 0.77% of the population studied was diagnosed with localized aggressive periodontitis. This figure is similar to those reported for European and North American populations