| Autor: |
Mckee, Ian W., Glover, Kenneth E., Williamson, Philip C., Lam, Ernest W., Giseon Heo, Major, Paul W. |
| Předmět: |
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| Zdroj: |
Angle Orthodontist; Dec2001, Vol. 71 Issue 6, p442-451, 10p, 8 Charts, 7 Graphs |
| Abstrakt: |
The purposes of this study were to examine the effect of potentially common patient positioning errors in panoramic radiography on imaged mesiodistal tooth angulations and to compare these results with the imaged mesiodistal tooth angulations present at an idealized head position. A human skull served as the matrix into which a constructed typodont testing device was fixed according to anteroposterior and vertical cephalometric normals. The skull was then repeatedly imaged and repositioned five times at each of the following five head positions: ideal head position, 5° right, 5° left, 5° up, and 5° down. The images were scanned and digitized with custom software to determine the image mesiodistal tooth angulations. Results revealed that the majority of image angles from the five head positions were statistically significantly different than image angles from the idealized head position. Maxillary teeth were more sensitive to 5° up/down head rotation, with 5° up causing mesial projection and 5° down causing distal projection of maxillary roots. Mandibular anterior teeth were more sensitive to 5° right/left head rotation, with the projected mesiodistal angular difference between 5° right and 5° left rotation ranging from 4.0° to 22.3°. Maxillary teeth were relatively unaffected by 5° right/left head rotation, and mandibular teeth were relatively unaffected by 5° up/down head rotation. It was concluded that the clinical assessment of mesiodistal tooth angulation with panoramic radiography should be approached with extreme caution with an understanding of the inherent image distortions that can be further complicated by the potential for aberrant head positioning. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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