Radiographic alveolar bone loss from posterior teeth in young adults over a 4-year period

The objective of this study was to determine alveolar bone loss from premolar and molar teeth in young adults over a 4-year period between the ages of 15-16 years and 19-20 years. Pairs of posterior bitewing radiographs from 382 subjects aged 15-16 years were examined and the height of the alveolar bone adjacent to mesial and distal tooth surfaces recorded. Repeat radiographs of the same individuals taken 4 years later were then examined and the height of the alveolar bone remeasured. Change in bone height over the study period was computed for individual sites. Clinical data for the cohort were also obtained at both examinations and included plaque score, bleeding on probing and probing depth. Of the 3314 sites, 16.7% exhibited bone gain, 4.5% exhibited no change whilst 78.8% demonstrated bone loss. The overall mean bone loss for all sites combined was 0.407 mm. Bone loss than 0.5 mm was found in 36% of sites, bone loss between 0.5 and 0.99 mm in 33% of sites whilst only 0.5% of sites had bone loss greater than 2 mm. Only one site had bone loss greater than 3 mm. Bone loss was affected significantly by subject (p < 0.001) and by site (p < 0.05) but there was no significant effect for tooth type, whether the surface was mesial or distal or between quadrants. There was significantly more bone loss from around maxillary teeth than mandibular (p < 0.05). There were no significant associations between bone loss and plaque score, bleeding on probing, pocket depth, gender or social class.