Displaced premolars in panoramic radiography - Fact or fallacy?

Abstract

Objective: To test the null hypothesis that there is no difference between premolar position visualized on panoramic radiographs (PRs) and lateral headfilms (LHs). Materials and Methods: The prevalence of differences in the direction of crown angulation between PR and LH was assessed. Furthermore, brass wire markers with different sagittal and transverse angulations were placed in a dry skull. With the markers in place, LHs and PRs were taken. Results: A difference in the direction of crown angulation of unerupted second premolars between PR and LH occurred in 19.5% of patients. The reason for the angulation differences is a buccolingual orientation of the tooth, which appears as a mesiodistal angulation on the PR. Conclusion: The null hypothesis was rejected since in one-fifth of the patients premolar projection differs between the panoramic radiograph and the lateral headfilm. © 2008 by The EH Angle Education and Research Foundation, Inc.