A radiographic method for assessing changes in alveolar bone height following periodontal therapy

A method is described for obtaining reproducible radiographs of several groups of teeth in the same jaw. The method was applied to assess changes in the alveolar bone height following periodontal treatment. An oral device was designed to permit direction of the central rays of the beam perpendicularly to the alveolar process in different parts of the jaws. The exposures were made at 60 kVp and 10mA, and standardized procedures were used for developing, fixing and rinsing the films. Alterations in the marginal alveolar bone level were determined in a stereocomparator system. The reproducibility of the method was determined. A pilot experiment was performed on 5 patients with periodontal disease. Following conservative treatment, including scaling and root planning, all patients were subjected to periodontal surgery, including alveolar bone denudation. Radiographs of the alveolar bone were obtained before and 2 months after the operation. By measuring in the stereocomparator parallaxes of both control points and points of the alveolar bone crest on paired radiographs, a mean decrease in interproximal alveolar bone height of 0.69 mm was found. Taking into account the small errors which are inherent in the method, this change in bone height could be regarded as a reliable measure of actual loss of bone.