Page 32 - Craniomaxillofacial Implant Surgery - Jeroen P.J. Dings
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Chapter 2
three-dimensional measurements compared to physical gold standards.15,16,18-20,22,26,35,36
Some authors conclude that accuracy of linear measurements does not statistically
differ from multiplanar images of the craniofacial complex obtained by MDCT or
CBCT and both yield submillimeter accuracy.15,18,19,21,24,26,37-39 Other studies show MDCT
providing the most accurate images with least mean deviation in measurement errors,
although these differences may not be of clinical significance for diagnostic purposes
and pre-surgical planning.3,16,21,36,40 In contrast, studies have also been published, which
describe the opposite, namely that clinically and statistically significant differences in
measurement errors were observed in favor of CBCT.6,41-43 These different findings in
literature can be explained by methodical differences, protocols for image acquisition,
spatial resolution selection , and operator skill in interpretation of the composite image.12,18,28,30,44
To our knowledge, no literature exists on the accuracy of linear measurements for planning of craniofacial implants on cross-sectional image derived from MDCT and CBCT data. The purpose of this study was to evaluate the accuracy of these image- based linear measurements. Furthermore, the effect of different brightness and contrast settings was evaluated.
MATERIALS AND METHODS
Specimen
Five human dry skulls of similar size were obtained from the department of Anatomy of the Radboud University Medical Centre Nijmegen, the Netherlands. Seven anatomical sites were identified, of which 5 were bilateral (Figure 1). These sites represent potential locations of craniofacial implants45. Cuts were made at these anatomical locations with a surgical circular bone saw. Two millimetre aside of each cut two reference holes were prepared with a 1.0 mm drill (high-speed turbine) and a 0.8-mm-diameter tungsten carbide surgical bur (Zekry, Dentsply, York, Pennsylvania) parallel to the cut surface (Figure 2).
