PURPOSE: Creating wax-ups of missing teeth for backward-planning in implant surgery is a complex and time-consuming process. To facilitate implant-planning procedures, the automatic generation of a virtual wax-up would be useful. In this study, the reconstruction of missing teeth in partially edentulous patients was performed automatically using a newly developed software. The accuracy was investigated in order to test its clinical applicability. MATERIAL AND METHODS: This study presents a new method for creating an automatic virtual wax-up, which could serve as a basic tool in modern implant planning procedures. First, a statistical shape model (SSM) based on 76 lower and upper arch scans from dentally healthy individuals was generated. Then artificially generated tooth gaps were reconstructed. The accuracy of the workflow was calculated using a Leave-One Out cross validation (LOOCV) and was given as median deviation (mm). Scans of three clinical cases with partial edentulism were equally reconstructed using the SSM and compared to the final prosthodontic work. RESULTS: The reconstruction of the artificial tooth gaps could be performed with the following median reconstruction accuracy: gap 21 with 0.15mm; gap 27 with 0.20mm; gap 34 with 0.22mm: gap 36 with 0.22mm; gap 12-22 with 0.22mm; gap 34-36 with 0.22mm. A scenario for a close to edentulous lower jaw with all teeth missing except teeth 33 and 43 could be reconstructed with a median reconstruction accuracy of 0.37mm. The median tooth gap deviation of the SSM-based reconstruction in clinical cases differed from the final inserted prosthodontic teeth by 0.49mm-0.86mm in median. CONCLUSION: A first feasibility of creating virtual wax-26 ups using a SSM could be shown. Artificially generated tooth gaps could be reconstructed close to original with the proposed workflow. In the clinical cases the SSM proposes an anatomical reconstruction, which does not yet consider prosthodontic aspects. To obtain clinical use contact to antagonist teeth must be considered and more training data must be implemented. However, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined.
PURPOSE: Creating wax-ups of missing teeth for backward-planning in implant surgery is a complex and time-consuming process. To facilitate implant-planning procedures, the automatic generation of a virtual wax-up would be useful. In this study, the reconstruction of missing teeth in partially edentulous patients was performed automatically using a newly developed software. The accuracy was investigated in order to test its clinical applicability. MATERIAL AND METHODS: This study presents a new method for creating an automatic virtual wax-up, which could serve as a basic tool in modern implant planning procedures. First, a statistical shape model (SSM) based on 76 lower and upper arch scans from dentally healthy individuals was generated. Then artificially generated tooth gaps were reconstructed. The accuracy of the workflow was calculated using a Leave-One Out cross validation (LOOCV) and was given as median deviation (mm). Scans of three clinical cases with partial edentulism were equally reconstructed using the SSM and compared to the final prosthodontic work. RESULTS: The reconstruction of the artificial tooth gaps could be performed with the following median reconstruction accuracy: gap 21 with 0.15mm; gap 27 with 0.20mm; gap 34 with 0.22mm: gap 36 with 0.22mm; gap 12-22 with 0.22mm; gap 34-36 with 0.22mm. A scenario for a close to edentulous lower jaw with all teeth missing except teeth 33 and 43 could be reconstructed with a median reconstruction accuracy of 0.37mm. The median tooth gap deviation of the SSM-based reconstruction in clinical cases differed from the final inserted prosthodontic teeth by 0.49mm-0.86mm in median. CONCLUSION: A first feasibility of creating virtual wax-26 ups using a SSM could be shown. Artificially generated tooth gaps could be reconstructed close to original with the proposed workflow. In the clinical cases the SSM proposes an anatomical reconstruction, which does not yet consider prosthodontic aspects. To obtain clinical use contact to antagonist teeth must be considered and more training data must be implemented. However, the presented method offers a fast and viable way for the approximate placement of missing crowns. This could be used in a digital planning workflow when implant position must be determined.
Authors: Leonard Simon Brandenburg; Stefan Schlager; Lara Sophie Harzig; David Steybe; René Marcel Rothweiler; Felix Burkhardt; Benedikt Christopher Spies; Joachim Georgii; Marc Christian Metzger Journal: J Clin Med Date: 2022-04-24 Impact factor: 4.964
Authors: Leonard Simon Brandenburg; Lukas Berger; Steffen Jochen Schwarz; Hans Meine; Julia Vera Weingart; David Steybe; Benedikt Christopher Spies; Felix Burkhardt; Stefan Schlager; Marc Christian Metzger Journal: Int J Comput Assist Radiol Surg Date: 2022-07-29 Impact factor: 3.421