Four-Dimensional Superimposition Techniques to Compose Dental Dynamic Virtual Patients: A Systematic Review

A fully digital planning protocol for dynamic computer-assisted zygomatic implant surgery based on virtual surgery simulation: A dental technique

Dynamic navigation-guided zygomatic implant (ZI) surgery has been a preferred option for achieving optimal prosthetic-driven implant placement. However, during the actual surgical procedure, surgical execution may still be hindered by environmental factors such as mouth opening. A fully digital planning protocol is described that integrated the patient's maxillofacial soft tissue information and virtual surgical handpiece with the drills on the implant planning path to ensure the precise, time-saving, and smooth implementation of dynamic navigation-guided ZI surgery.

Recent Advances in Digital Technology in Implant Dentistry

Digital technology has emerged as a transformative tool in dental implantation, profoundly enhancing accuracy and effectiveness across multiple facets, such as diagnosis, preoperative treatment planning, surgical procedures, and restoration delivery. The multiple integration of radiographic data and intraoral data, sometimes with facial scan data or electronic facebow through virtual planning software, enables comprehensive 3-dimensional visualization of the hard and soft tissue and the position of future restoration, resulting in heightened diagnostic precision. In virtual surgery design, the incorporation of both prosthetic arrangement and individual anatomical details enables the virtual execution of critical procedures (e.g., implant placement, extended applications, etc.) through analysis of cross-sectional images and the reconstruction of 3-dimensional surface models. After verification, the utilization of digital technology including templates, navigation, combined techniques, and implant robots achieved seamless transfer of the virtual treatment plan to the actual surgical sites, ultimately leading to enhanced surgical outcomes with highly improved accuracy. In restoration delivery, digital techniques for impression, shade matching, and prosthesis fabrication have advanced, enabling seamless digital data conversion and efficient communication among clinicians and technicians. Compared with clinical medicine, artificial intelligence (AI) technology in dental implantology primarily focuses on diagnosis and prediction. AI-supported preoperative planning and surgery remain in developmental phases, impeded by the complexity of clinical cases and ethical considerations, thereby constraining widespread adoption.

Sagittal condylar guidance angle measurement methods: A systematic review

STATEMENT OF PROBLEM

Precise assessment of the condylar guidance angle can aid successful prosthodontic treatment. However, the reliability and accuracy of current methods remain unclear.

PURPOSE

The purpose of this systematic review was to evaluate the reliability and accuracy of current methods of determining the sagittal condylar guidance angle, including protrusive interocclusal records, axiography, cone beam computed tomography (CBCT), and panoramic and cephalometric radiographs.

MATERIAL AND METHODS

A literature search was conducted using BASE, Embase, PubMed, and Web of Science databases up to June 2022. Inclusion criteria involved studies that compared protrusive interocclusal records against other methods of sagittal condylar guidance angle assessment in adult dentate and edentulous patients. Studies that did not provide the values for the right and left joint separately were excluded. The methodological quality of the included studies was assessed by using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Data were tabulated and analyzed for correlations and their significance.

RESULTS

A total of 24 articles qualified for the analysis. The differences between protrusive interocclusal records and panoramic radiograph sagittal condylar guidance angle values were up to 9 degrees. Lateral cephalometric radiographs revealed greater condylar guidance values than facebow transfers or the Bonwill methods. Correlations between average sagittal condylar guidance angle values obtained from CBCT and protrusive interocclusal records differed depending on the method of registration. For protrusive interocclusal records, axiographic or pantographic measurement variance analysis showed that the condylar inclination values recorded with wax were statistically lower than those recorded with a pantograph (P<.05).

CONCLUSIONS

Although CBCT appears to be the most suitable method of evaluating the sagittal condylar guidance angle, the limitations and discrepancies among methods, including protrusive interocclusal records and panoramic and cephalometric radiographs, should be acknowledged. Digital axiography, with its potential to capture comprehensive functional data, may surpass other techniques. The use of mean values for articulators may be a practical solution for some patients. Further research is needed to refine sagittal condylar guidance angle assessment methods and to develop more reproducible and reliable approaches for the future.

A novel technique for implant-supported fixed complete rehabilitation based on a dynamic virtual patient

BACKGROUND

A digital workflow for implant-supported fixed complete prostheses (ISFCP) using photogrammetry (PG), virtual articulator (VA), and virtual facebow (VF) data remains a challenge.

METHODS

The novel ISFCP technique included four steps: (1) formation of a dynamic virtual patient, (2) integration of PG data, (3) fabrication of a diagnostic ISFCP, and (4) fabrication of a definitive ISFCP and test of the deviation.

RESULTS

Dynamic virtual patients were formed by integrating PG, VA, and VF data. The cumulative root mean square deviation between the designed data and actual definitive prosthesis was 140.4 µm.

CONCLUSIONS

The novel technique for ISFCP fabrication described in this paper can help optimise the clinical efficiency and quality of ISFCP but requires an initial learning curve.

CLINICAL SIGNIFICANCE

This technique provides a direct workflow, using PG, VA, and VF data, to fabricate ISFCP based on the provisional restoration.