Search

Copyright of Journal of Clinical Periodontology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Subtraction of two serially-obtained radiographs is a technique that increases detectability of small temporal changes in supporting bone as compared with conventional radiographic methods. The success of the technique is contingent on the ability to cancel unchanged anatomical structures, Hence, it suffers from artifacts introduced by inexact replication of the projection geometry, uncontrolled variations in film exposure and processing, and tissue changes resulting from normal growth and development.