A positioning device for computed tomography: a clinical report.

This clinical report describes a device (Centrascan) used to assist in the correct alignment of the patient's head during computed tomography (CT) assessment of a proposed implant site. To obtain the desired anatomic detail, CT requires precise alignment of the axial images at right angles to the long axis of the proposed implant. This clinical report compared the anatomic morphology of a projected implant site derived from axial images provided by DentaScan software analysis of the CT scan acquisition. Images from a conventional scan, with the patient's head aligned along the frontal plane (perpendicular to the Frankfort plane) and along the sagittal plane (coinciding with either the cortical bone of the hard palate or the inferior border of the mandible), were compared with images acquired by use of the Centrascan device. The two scans differed substantially. In particular, the cross-sectional images obtained by the conventional procedure showed a distorted anatomy; conversely, the images obtained by the Centrascan procedure showed a better reproduction of the examined area. The Centrascan device seemed to help the radiologist achieve a more correct alignment of the patient's head during CT scan acquisition. Further studies are necessary to fully explore the relative technical merits of the Centrascan device.