CT scan standard reconstruction technique for reliable jaw bone volume determination.

Computed tomography can assist the surgeon in planning the exact three-dimensional positioning of endosseous implants in the jaw bone. This study examined the reliability of three CT techniques: direct imaging (normal coronal and sagittal slices), standard reconstruction (based on axial slices), and multiplanar reconstruction and display (also based on axial slices). The three imaging techniques were used to estimate the bone height, bone width, and maximal implant length in six dissected human jaw bones. These jaws were then sawed perpendicular to their axis to enable measurement of real values for comparison. The sagittal and coronal slices frequently were overestimated, especially in the canine and premolar regions. The mean absolute deviation was 1.4 mm. Standard reconstruction offered the most reliable cross-sectional images, with a mean absolute deviation of 0.5 mm. The multiplanar reconstruction and display technique frequently demonstrated underestimations (mean absolute deviation was 2.3 mm). The standard reconstruction technique seems to be the method of choice in preoperative radiographic examination of patients before implant placement.