Prevalence of Juvenile Periodontitis in 15-18-year-old Students in Japan

Part I. Findings of First and Second Screening

Abstract

The purpose of this study was to determine the prevalence of juvenile periodontitis and periodontal disease in high school students. The survey was conducted on 12, 723 students aged from 15 to 18 years, living in Sapporo, Japan.
The examination was carried out in three stages. The first stage, probing depth was measured at six teeth, maxillary and mandibular first molars and mandibular central incisors on mesial surface. The second stage, bite-wing radiographs were taken on the individuals who had one or more periodontal pockets (probing depth≥4mm). The third stage, all individuals who had clear signs of marginal bone destruction on bite-wing radiographs, were invited to our hospital for thorough clinical and radiographic examinations.
The results of the first and second stage were as follows;
1) Periodontal pocket (probing depth≥4mm) was detected in 2.1% of the teeth examined. Probing depth≥5mm was detected in 0.3%. About 7.3% of the individuals had periodontal pocket on at least one teeth.
2) The mean of probing depth and prevalence of deepend periodontal pocket was higher in following order, mandibular central incisor<mandibular first molar<maxillary first molar.
3) There was no significant difference between sexes or ages from 15 to 18, with regard to probing depth.
4) The mean of probing depth was significantly high on the teeth with proximal restorations.
5) About 0.4% of the individuals had bone loss≥3mm from cemento-enamel junction, on at least one first molar. About 0.1% had bone loss≥4mm.