DOI: 10.11607/jomi.10531Language: EnglishAl-Jarsha, Mohammed Y. / Almezyad, Omar / AlOtaibi, Noura / Naudi, Kurt B. / Robertson, Douglas P. / Ayoub, Ashraf F.
Purpose: Despite the high clinical accuracy of dynamic navigation, inherent sources of error
exist. The purpose of this study was to improve the accuracy of dynamic navigated surgical
procedures in the edentulous maxilla by identifying the optimal configuration of intra-oral
points that results in the lowest possible registration error for direct clinical implementation.
Materials and Methods: Six different 4-area configurations were tested by 3 operators against
positive and negative controls (8-areas and 3-areas, respectively) using a skull model. The
two dynamic navigation systems (X-Guide® and NaviDent®) and the two registration
methods (bone surface tracing and fiducial markers) produced four registration groups. The
accuracy of the registration was checked at the frontal process of the zygoma. Intra- and
inter- operator reliability for each registration group were reported. Multiple comparisons
were conducted to find the best configuration with the minimum registration error. Results:
Ranking revealed one configuration in the tracing groups (Conf.3) and two configurations in
the fiducial groups (Conf.3 and Conf.5) that had the best accuracy. When the inferior surfaces
of the zygomatic buttress were excluded, fiducial registration produced better accuracy with
both systems (p 0.006 and <0.0001). However, tracing 1 cm areas at these surfaces bilaterally
resulted in similar registration accuracy as placing fiducial markers there (p 0.430 and 0.237).
NaviDent® performed generally better (p 0.049, 0.001 and 0.002) albeit having a wider
margin of uncertainty in the obtained values. Changing the distribution of the 4 tracing areas
or fiducial markers had a less pronounced effect with X-Guide® than with the NaviDent®
system. Conclusion: For edentulous maxillary surgeries, 4 fiducial markers placed according
to configuration 3 or 5 result in the lowest registration error. Where implants are being placed
bilaterally, an additional 2 sites may reduce the error further. For bilateral zygomatic implant
placement, it is optimal to place 2 fiducials on the inferior surfaces of the maxillary
tuberosities, other 2 on their buccal surfaces, and 2 on the anterior labial surface of the
alveolar bone. Utilising the inferior zygomatic buttress is recommended over the inferior
maxillary tuberosities in other types of maxillary surgeries.
Keywords: Dynamic Navigation, Fiducial, Implants, Maxilla, Registration, Tracing
