Measuring System for Bone Mineral Content by Panoramic Radiography

Research Project

Project/Area Number	11557148
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	展開研究
Research Field	補綴理工系歯学
Research Institution	Tokyo Medical and Dental University
Principal Investigator	KOBAYASHI Kenichi Tokyo Medical and Dental University, Gerodontology, Full Time Lecturer, 歯学部・附属病院, 講師 (00170316)
Co-Investigator(Kenkyū-buntansha)	SEKITA Toshiaki Tokyo Medical and Dental University, Prosthodontics, Assistant Professor, 歯学部・附属病院, 助手 (90236092) MINAKUCHI Shunsuke Tokyo Medical and Dental University, Gerodontology, Full Time Lecturer, 大学院・医歯学総合研究科, 講師 (30219688) TAKAOKA Seiji Tokyo Medical and Dental University, Prosthodontics, Assistant Professor, 大学院・医歯学総合研究科, 助手 (30334444) KATOH Tsuguhisa Tokyo Medical and Dental University, Radiologic Science, Associate Professor, 放射線学科, 助教授 (70095107) HONDA Eiichi Tokyo Medical and Dental University, Radiology, Full Time Lecturer, 大学院・医歯学総合研究科, 講師 (30192321)
Project Period (FY)	1999 – 2001
Project Status	Completed (Fiscal Year 2001)
Budget Amount *help	¥4,700,000 (Direct Cost: ¥4,700,000) Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000) Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000) Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
Keywords	bone mineral density / digital imaging
Research Abstract	The investigation of bone mineral content(BMC) is useful for osteoporosis screening and for accurate prognosis for implant treatment. BMC was measured by special devices, as quantitative computed tomography. In this study, BMC measuring system was improved by using panoramic X-ray system to obtain overall coverage of the dental arches and associated structures at a time. We surveyed the measuring performance of this system. We applied bone phantom to reference and test stepwedges, X500CR(Morita Co.Ltd.) to panoramic X-ray system and Denoptix digital imaging system ( Dentsply Co. Ltd.) to image input device. The exposure condition was 60kV, 10mAs. The reference stepwedge was fixed at left side on image layer, the position of test stepwedge was changed as followings 1)inside or outside of the layer, 2) in premolar or molar region. We verified the measuring accuracy and reproducibility of this system at each condition. Measured value in molar region was higher than that in premolar region. The variation of measured value depended on the measuring position. The accuracy of adjusted RMET value was 1.25%(relative error). The difference in the magnification between in the mesial and the distal region was detected. The conversion corresponding with the position in mandible decreased the distortion. The BMC value from this study showed 1.7 times as large as from previous method, however, the distribution of BMC from this study was similar to one from previous method. The results demonstrated that the measuring system was able to measure BMC in edentulous mandible and that this system may be useful for an accurate prognosis for implant treatment and for osteoporosis screening.