An entire human head obtained at autopsy was micro-CT scanned in a nano/micro-CT scanner in a 6-hour long session.
Despite the size of the head, it could still be scanned with a pixel size of 70 μm. The aim of this study was to obtain an
optimal quality 3D data-set to be used as baseline control in a larger study comparing the image quality of various cone
beam CT systems currently used in dentistry.
The image quality of the micro-CT scans was indeed better than the ones of the clinical imaging modalities, both with
regard to noise and streak artifacts due to metal dental implants. Bony features in the jaws, like the trabecular
architecture and the thin wall of the alveolar bone were clearly visible. Therefore, the 3D micro-CT data-set can be used
as the gold standard for linear, angular, and volumetric measurements of anatomical features in and around the oral
cavity when comparing clinical imaging modalities.
Cone-beam computed tomography, also termed digital volume tomography, has become a standard technique in
dentistry, allowing for fast 3D jaw imaging including denture at moderate spatial resolution. More detailed X-ray images
of restricted volumes for post-mortem studies in dental anthropology are obtained by means of micro computed
tomography. The present study evaluates the impact of the pipe smoking wear on teeth morphology comparing the
abraded tooth with its contra-lateral counterpart. A set of 60 teeth, loose or anchored in the jaw, from 12 dentitions have
been analyzed. After the two contra-lateral teeth were scanned, one dataset has been mirrored before the two datasets
were registered using affine and rigid registration algorithms. Rigid registration provides three translational and three
rotational parameters to maximize the overlap of two rigid bodies. For the affine registration, three scaling factors are
incorporated. Within the present investigation, affine and rigid registrations yield comparable values. The restriction to
the six parameters of the rigid registration is not a limitation. The differences in size and shape between the tooth and its
contra-lateral counterpart generally exhibit only a few percent in the non-abraded volume, validating that the contralateral
tooth is a reasonable approximation to quantify, for example, the volume loss as the result of long-term clay pipe
smoking. Therefore, this approach allows quantifying the impact of the pipe abrasion on the internal tooth morphology
including root canal, dentin, and enamel volumes.
Three-dimensional images are vital for the diagnosis in dentistry and cranio-maxillofacial surgery. Artifacts caused by highly absorbing components such as metallic implants, however, limit the value of the tomograms. The dominant artifacts observed are blowout and streaks. Investigating the artifacts generated by metallic implants in a pig jaw, the data acquisition for the patients in dentistry should be optimized in a quantitative manner. A freshly explanted pig jaw
including related soft-tissues served as a model system. Images were recorded varying the accelerating voltage and the beam current. The comparison with multi-slice and micro computed tomography (CT) helps to validate the approach with the dental CT system (3D-Accuitomo, Morita, Japan). The data are rigidly registered to comparatively quantify their quality. The micro CT data provide a reasonable standard for quantitative data assessment of clinical CT.