原著
SCANORA®によるパノラマ像と顎骨横断面像の下顎臼歯部での拡大率とその関係
キーワード:
implant installation,
panoramic radiograph,
cross-section tomograph,
Scanora® multimodal radiography system
2000 年 13 巻 1 号 p. 52-58
詳細
2000 年 13 巻 1 号 p. 52-58
Purpose: For pre-operative planning of implant installation to the posterior mandible, radiographic diagnosis using both mesio-distal images by panoramic radiograph and the bucco-lingual images by cross section tomograph is very useful to under stand the position of the mandibular canal and the shape of the mandible. Therefore, informations of precise magnification on each position of a radiograph are required to decide the length of fixtures during planning. The purpose of this study is to evaluate the accuracy of magnification on both images by means of Scanora® multimodal radiography system.
Materials and methods: Ninety seven ITI Bonefit solid screw implant fixtures that were installed in the posterior edentulous mandible of fifty patients who underwent measured the length of their fixtures on panoramic radiographs and crosssection tomographs immediately after surgery and caluculated its' magnificationo. Measurement points were the first premolar (PM1), second premolar (PM2), first molar (M1), and second molar (M2) parts of the mandible. The PM2 located at the center of the mental foramen was determined as the standard point, PM1 was at distances of 7 mm anterior to its center, M l and M2 were at distances of 8 mm and 16 mm posterior to its center.
Results: In panoramic radiograph magnification (1.3 standard magnification), each magnification of PM1, PM2, M1 and M2 indicated 1.30±0.02,1.30±0.03,1.29±0.02 and 1.29±0.02, and the whole magnification of the posterior edentulous mandible indicated 1.29±0.02. In cross section magnification (1.7 standard magnification), each magnification of PM1, PM2, M1 and M2 indicated 1.70±0.04,1.70±0.03,1.70±0.03 and 1.70±0.02, and the whole magnification of the posterior edentulous mandible indicated 1.70±0.03.Correlation analysis of the magnification between panoramic radiograph and cross section tomograph by means of Spearman's correlation coefficient by rank best indicated that at M1(p=0.0006), magnification of panoramic radiograph and cross-section radiograph correlated, but at PM1 (p=0.546), PM2 (p=0.605) and M2 (0.676), it did not correlated.
Conclusion: Radiographic diagnosis using both panoramic radiograph and cross section tomograph is fairly precise and clillically useful when perforlning implant surgery,because both ilnages have very small standard deeiation.
