| Objective To compare the results between panoramic radiography(OP), spiral CT(SCT) and direct measurement of the alveoli to provide preoperative guidance for insertion of the dental implant.Materials and Methods 3 human edentulous skulls were examined with OP and SCT(axial and coronal),each marked with 12 radiopaque markers. Then the j aws were sawed at markers' sites in coronal plane. Height and/or width of the alveoli in images and specimens were measured respectively.3D reconstruction was made with computer.Results Both OP and Spiral CT somewhat distorted images,OP(22.39%)> SCT(5.28%) ,P<0.0001.Differences between images and real measurement were statistically significant. The Wilcoxon-test of between alveolar height' s and marker' s magnification in OP showed non-significant difference (P>0.5) , and correlation coefficient(r)=0.8335,demonstrating good positive correlation.Conclusion OP unit' s inherent magnification can' t but marker' s can be used to evaluate height of the alveoli.SCT can showcross-sectional images (buccal-lingual) and is more accurate than OP. It may be most valuable imaging modality for preoperative evaluation of height of the alveoli. |
