インプラント画像診断におけるマルチスライスヘリカルCTの有用性

―ダブルオブリーク断面再構築画像について―

抄録

For imaging diagnosis before dental implant treatment,conventional X-ray tomography or computed tomography (CT) has been used. Recently, multislice helical CT has been developed, and detailed two-dimensional (2-D) and three-dimensional (3-D) reconstructed images can be obtained. Double oblique reconstructed images, which are a kind of 2-D image, can be set for free angles of the axial CT plane.
In this investigation, the usefulness of double oblique reconstructed images was assessed for measurement of the mandibular height at the designed implant site.
Subjects included 22 patients with mean age of 56.1 years and the number of designed implant sites in the posterior mandibular region was 73. Mandibular height at the designed sites was measured from the alveolar crest to the superior border of the mandibular canal using multi-planar reconstructed images and double oblique reconstructed images.
As a result, the mean of differences between multi-planar reconstructed images and double oblique reconstructed images was 1.0 mm. This was significantly different from the designed sites over 15 degrees of mesio-distal angle in sites ranging from 0 to 5 degrees (p＜0.01).
It was concluded that the double oblique images were useful for accurate measurement of bone height in the designed implant sites.