The aim of this survey was to study the prevalence of juvenile periodontitis in schoolchildren aged 12-19 yr in Lagos, Nigeria. 1001 children, 565 boys and 436 girls, took part in the study. Initially all the children were screened clinically at school according to the recommendations of CPITN. A mirror and WHO 621 pattern probe were used for this examination. Any child with two or more sextants or teeth with CPITN code 3 or one sextant code 4 was taken for a radiographic and full clinical examination. Only 19 children, 12 boys and seven girls, fulfilled these requirements. Of these 19 children, five boys and three girls showed radiographic evidence of bone loss as well as increased probing depths, and were diagnosed as having juvenile periodontitis. The other children showed no evidence of bone loss radiographically, despite maximum probing depths of 4-5 mm. The results indicate a prevalence of juvenile periodontitis of 0.8% in this Negro population.

The purpose of this study was to monitor clinical attachment levels, using a constant force probe, in patients with untreated periodontal disease, and to use darkfield microscopy to monitor changes in subgingival plaque. 10 patients with untreated disease were studied over 12 weeks. The parameters measured at baseline and every 4 weeks were probing depth, attachment level and bleeding. The subgingival microflora of the deepest site in each quadrant was examined by darkfield microscopy, using a Hellber counting chamber, at baseline and 12 weeks. The subgingival plaque from any site which lost more than 2 mm clinical attachment was also sampled and the microflora examined. Analysis of the results shows that 91% of probing depths and attachment levels remained the same or within +/- 1 mm. 3.5% of probing depths and 3.7% of attachment levels became deeper by 2 mm. 6.9% of probing depths and 4.5% of attachment levels became shallower by 2 mm. Only 6 sites out of 1029 showed loss of clinical attachment greater than 2 mm. Darkfield microscopy showed no differences in the proportion of microorganisms at the 6 sites which lost more than 2 mm of clinical attachment, compared with the baseline value. A surprising result was the tendency for probing depths and attachment levels to decrease, especially in deeper pockets. This study showed that none of the parameters monitored, i.e., probing depth, attachment level, bleeding or subgingival microflora, indicated which sites would lose attachment over a 12-week period.