MARGINAL BONE LOSS IN THE PRIMARY DENTITION - A SURVEY OF 7-9-YEAR-OLD CHILDREN IN SWEDEN

The present study was designed to determine the prevalence of bone los s in the primary dentition of children. Radiographs from children aged 7-9 were collected from 25 out of a total of 26 Public Dental Clinics in the County of Orebro, Sweden. These radiographs, representing 36.0 %, 50.3% and 48.7% of all 7-, 8- and 9-year-old children (n = 8666) li ving in the districts of the participating clinics, constituted a prim ary sample. In addition, the 9-year-olds were subjected to a more comp rehensive sampling procedure to obtain a more complete sample (sample of 9-year-olds), resulting in a group of 2017 children (71.9%). The ra diographs were evaluated with respect to presence of marginal bone los s (CEJ-MBL: distance between the cemento-enamel junction and the margi nal bone level > 2 mm), proximal calculus and number of decayed and fi lled proximal surfaces (dfs(p)) in the posterior areas of the primary dentition. In the primary sample, the prevalence of bone loss for grea ter-than-or-equal-to 1 proximal surfaces of the primary dentition in t he 7-, 8- and 9-year-old children was 2.0%, 3.1% and 4.5%, respectivel y. The corresponding figures for proximal calculus were 2.5%, 3.1% and 4.2%. Mean number of dfs(p) amounted to 2.3, 2.5 and 3.0. The prevale nces of bone loss and proximal calculus as well as the mean number of dfs(p) in the sample of 9-year-olds corresponded to the findings for t he 9-year-old children in the primary sample. The analyses of the samp le of 9-year-olds showed that most of the children with bone loss had 1 affected surface only. The largest CEJ-MBL distance for each individ ual with bone loss ranged from 2.5 to 6.0 mm. Children with bone loss displayed calculus more often than children without bone loss. The chi ldren with bone loss also showed higher mean dfs(p) compared to childr en without bone loss.