Journal of Korean Academy of Oral and Maxillofacial Radiology (치과방사선)

Korean Academy of Oral and Maxillofacial Radiology (대한영상치의학회)
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A STUDY OF THE FOCAL TROUGH IN ORTHOPANTOMOGRAPH

Orthophantomograph에 있어서 상층면적에 관한 연구

  • Choi Chong-Ho (Department of Maxillofacial Radiology, School of Dentistry, Chosun University) ;
  • Khim Jhai-Dhuck (Department of Maxillofacial Radiology, School of Dentistry, Chosun University)
  • 최종호 (조선대학교 치과대학 치과방사선학교실) ;
  • 김재덕 (조선대학교 치과대학 치과방사선학교실)
  • Published : 1991.06.01
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Abstract

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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