Radiographic measurements of alveolar bone loss in the rat

A new method to evaluate alveolar bone loss in rodents is described. The palatal and lingual halves of maxillae and mandibles were radiographed. On enlarged positive prints, 5 vertical distances were drawn at defined sites from the cemento-enamel junction to points revealing fully intact bone structure. These were either located on the alveolar crest or at the depth of intrabony defects. These distances were recorded with a trace-reading pen coupled to a computer. Results were expressed in mm for each site separately and totals (left plus right values) for either maxillae or mandibles were calculated. This technique was compared to other methods for evaluating alveolar bone loss, using the jaws of rats subjected to a gnotobiotic regime in which the degree of bone loss was low. It was demonstrated that the measurement of vertical distances based on radiography by which also intrabony defects were defined was accurate, reproducible and more sensitive than other means of evaluating bone loss.