Assessment of Dental Root Reconstruction for Implant Planning Using SSM

Overview

This retrospective study evaluated the correlation between statistically shape model (SSM)-based reconstructed tooth axes (RTA) and clinically determined implant axes (CIA) in single-tooth implant cases. Results suggest a meaningful relationship, indicating that SSM can provide valuable information for virtual implant planning.

Background

Preoperative planning is critical for the long-term success of dental implants, traditionally relying on two-dimensional imaging and physical models. Advances such as Cone-Beam Computed Tomography (CBCT), intraoral scanners, and computer-aided design have enabled fully digital backward-planning workflows. Despite digitalization, implant axis determination remains manual and time-consuming, motivating the exploration of automated methods like statistical shape models (SSM) for reconstructing missing dental anatomy to aid implant planning.

Data Highlights

The study retrospectively analyzed single-tooth implant cases planned with coDiagnostiX software between 2018 and 2021 at a university medical center. Inclusion criteria required availability of CBCT scans, intraoral scans, digital wax-ups, and virtually placed implants. Implant planning was performed by residents and reviewed by senior surgeons, ensuring dual control. Anatomical landmarks were annotated on remaining teeth, and SSM was applied to reconstruct missing tooth axes for comparison with clinical implant axes.

Key Findings

• SSM-based reconstructed tooth axes (RTA) showed a statistically significant correlation with clinically determined implant axes (CIA).
• The anatomical SSM could accurately estimate tooth root axes based on remaining crown morphology.
• The study included only single-tooth gaps without adjacent missing teeth to ensure precise reconstruction.
• Implant planning was restoratively driven using diagnostic wax-ups and dual surgeon review to ensure clinical relevance.
• The SSM approach offers an objective, potentially time-saving alternative to manual implant axis determination.

Clinical Implications

Incorporating SSM-based reconstruction into implant planning workflows may enhance objectivity and efficiency by providing automated estimations of implant axes. This approach could reduce the manual workload for clinicians and improve predictability in implant placement, especially in cases with single-tooth gaps. Further integration of SSM tools into planning software may facilitate wider adoption.

Conclusion

The study supports the clinical utility of anatomical SSM for reconstructing tooth axes that correlate with implant axes used in practice, suggesting that SSM can be a valuable adjunct in virtual implant planning. This method holds promise for streamlining and improving the accuracy of implant axis determination.

References

1. Original Study Authors/University of Freiburg/2024 -- Assessment of Dental Root Reconstruction for Implant Planning