치과방사선 (Journal of Korean Academy of Oral and Maxillofacial Radiology)
- 제21권1호
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- Pages.137-143
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- 1991
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- 1225-049X(pISSN)
Orthophantomograph에 있어서 상층면적에 관한 연구
A STUDY OF THE FOCAL TROUGH IN ORTHOPANTOMOGRAPH
- Choi Chong-Ho (Department of Maxillofacial Radiology, School of Dentistry, Chosun University) ;
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Khim Jhai-Dhuck
(Department of Maxillofacial Radiology, School of Dentistry, Chosun University)
- 발행 : 1991.06.01
초록
In the study of the focal trough of panoramic radiograph using Panoura Eight-S (the Yoshida company), a series of 63 X-ray films were taken with the 8-19 metal pins placed in the holes of the plastic model plate and evaluated by 4 observers. The author analized the focal trough defined by the sharpness criteria and calculated dimension of focal trough in the horizontal plane. The results were as follows; 1. Focal trough was not continued in the anterior region within a very high degree of sharpness. 2. With optional sharpness, the width of anterior and posterior focal trough was approximately l3㎜ and 60㎜ respectively. 3. The focal trough was narrow in the anterior region and was flared laterally with symmetry in posterior region. 4. Sharp image began to show at the position of 18㎜ posteriorly from the most anterior position of chin rest.
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