Page 59 - Craniomaxillofacial Implant Surgery - Jeroen P.J. Dings

Reliability and accuracy of surgical templates for craniofacial implant placement
implants in this study can possibly be explained by local anatomical characteristics. The narrow, cortical ridge of the lateral nasal floor may have led to deviation of the drill frustrating the optimal implant position21. When bony contours or anatomic situations are unfavorable for craniofacial implant placement subperiosteally anchored titanium plates are a viable alternative treatment option and reported to show good overall success rates46,47.
Verhamme et al10 and Van Assche et al48 showed that deviations at the implant tip are 3 expected to be higher as compared to the implant shoulder with the latter being in
a closer position to the surgical template. No such relation was shown in our study. Furthermore, no statistically significant differences were found between implants with
different lengths10,48.
Recommendations for future research include the added value of the installation of osteosynthesis screws prior to pre-operative imaging49. These can be used as guide for the pre-operative implant planning, as also for the support for the surgical template during implant surgery. Navigation surgery using optical tracking systems avoids positional errors of surgical templates and may prove an alternative for transferring virtual planned positions to the surgical area21,50.
CONCLUSION
The potential of guided flapless implant placement depends on the maximal deviations that will occur in clinical practice. The linear and angular deviations found in the current study, when comparing actual CMF implant positions versus the preoperatively planned implant positions, underline that the inaccuracies, introduced by digitally designed skin-supported surgical templates, are clinically unacceptable. Surprisingly, the use of bone-fixated pins even worsened this inaccuracy.
Considering the potential benefits and implications of achieving an acceptable level of accuracy, further clinical research and technical improvements are indicated for development of surgical templates with optimal fit and stability.
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