Page 123 - Craniomaxillofacial Implant Surgery - Jeroen P.J. Dings

General discussion and future perspectives
Reliability and accuracy of cone-beam computed tomography versus conventional multidetector computed tomography for image-guided craniomaxillofacial (CMF) implant planning – an in vitro study (Chapter 2).
Accurate estimation of the actual bony dimensions using an appropriate radiographic examination is fundamental for implant planning and subsequent placement to achieve good function and esthetics.
The two most common CT technologies used to date for CMF implant treatment planning are multi-detector row computed tomography (MDCT) and cone-beam computed tomography (CBCT). These images provide useful datasets towards generating both two-dimensional (2D-) planar projection and three-dimensional (3D- ) surface or volume rendered images for use in implant treatment planning1,2.
The primary objective was to assess the reliability and accuracy of linear measurements of bone dimensions on multiplanar reconstructions from MDCT and CBCT data.
Results of this study, which used 10 cadaver heads, showed a consistent submillimeter overestimation of the anatomical truth in potential implant locations in the orbital-,
nasal- and temporal region for both CBCT and MDCT images. Most studies in literature
corroborate the sub-millimeter differences between CBCT and gold standard measurements2,3. However, contrary to our findings, most of these differences were not
statistically significant. With regard to CMF locations, no clear trend can be established
with studies both describing over- and underestimation between CBCT and gold
standard measurements3. 7
To our knowledge, no similar cadaver studies exist addressing accuracy of linear measurements on potential locations for CMF implants and comparing these values to physical measurements using a digital caliper. Within the limitations of this study, linear measurements on CBCT images proved to be more accurate compared to MDCT images. This is in accordance with the results of the study by Al-Ekrish and Ekram (2011), but in contrasts with the study of Matta et al. (2016) who described MDCT to be slightly more accurate in comparison to CBCT scans1,4. There aside, several studies showed no significant difference at all in accuracy and submillimeter error range between CBCT imaging and MDCT5-7. However, variation in methodological approaches, CT devices and standard settings contribute to the difficulty in comparing results.
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