The purpose of this study was to determine the prevalence of periodontal disease in 690 15-year-old school children, living in Tokyo, Japan. This clinical survey was performed prior to the roentogenografic examination which was intended to study the prevalence of marginal bone loss.
Plaque Index (by Silness and Löe) and Gingival Index (by Löe and Silness) were recorded on maxillary right first molar, left incisor, first premolar, mandibular left first molar, right premolar and right incisor. Pocket depth was measured in mm at the six teeth, maxillary and mandibular first molars, and incisors on the mesial sides. Bleeding Index during probing (by Ainamo) was also recorded.
The means of the Plaque Index were 1.00 and 1.30 in girl and boy students respectively. The girl students were statistically superior (p<0.05) than the boys in oral prophylaxis. About 60 per cent of the children exhibited gingival inflammation as indicated more than 1.00 of Gingival Index. Very severe inflammation more than 2.00 of Gingival Index was observed about 1 per cent among the school children. About 30 per cent of the examined teeth showed pockets deeper than 2mm. About 10 per cent of the examined teeth were bleeded on probing.
These results suggest that periodontal breakdown was occured on more than 10 per cent the 15-year-old school children. Periodontal care and education are necessary to early teen aged children.