The relationship between alveolar bone height and age in the primary dentition. A retrospective longitudinal radiographic study.

The natural history of changes in attachment level in the primary dentition should be determined before considering diagnostic criteria for periodontal diseases in children. The present study was designed to describe longitudinal changes in the distance between the alveolar bone crest and the cementoenamel junction (ABC-CEJ) determined radiographically. Bite-wing radiographs were obtained from 33 children as part of a routine annual dental examination in a rural community. The ABC-CEJ distance of 1500 sites located at the mesial and distal aspects of primary molars and distal aspect of primary cuspids were measured. An analysis of variance model was used to assess the effect of age, sex, tooth, side of the mouth, jaw, site and patient on the ABC-CEJ measurements. The side of the mouth (left, right) and the site (mesial, distal) had no significant effect on the ABC-CEJ distance. ABC-CEJ distances in the upper jaw were greater than in the lower jaw, and different teeth exhibited different ABC-CEJ distances. Canines had the greatest distance and second molars the smallest. The most interesting relationship was between alveolar bone height and age. The overall ABC-CEJ distance seemed to increase with age; however, this was not a linear relationship but followed the pattern of facial growth, with two spurts separated by a period of minimal increase. The results indicate that different levels of ABC-CEJ distance might be considered as a cut-off value for radiographic diagnosis of alveolar bone loss at different ages, for different primary teeth and for different jaws.