Prevalence of radiographic alveolar bone loss in young adults, a multinational study.

In a multinational study of alveolar bone loss, bite-wing radiographs of 8,703, 15-17-year-old adolescents from 18 centres in 16 countries were examined. Of these, 13 per cent were excluded as non-informative because of bad quality radiographs or missing first molars. Bone loss was a common finding globally (mean prevalence rate of subjects with bone loss 10.2 per cent), although there were great geographical variations. The bone loss was mostly horizontal, infrabony lesions were rare. The most frequently affected sites were the mesial aspects of the first maxillary molars followed by the distal aspects of the same teeth. Twenty-three subjects from the Finnish bite-wing study were examined for clinical conditions. When subjects with and without radiographic bone loss were compared, no statistically significant differences in the mean Gingival Index were found. The subjects were re-examined 5 years later. The gingival condition and the oral hygiene tended to be better at the end of the period than they had been at the start, but it was only in males that the differences were statistically significant. Periodontal destruction cannot be predicted from the gingival condition, but bite-wing radiographs of adolescents seem to be a valuable diagnostic tool for early detection of periodontal bone loss.