Trueness of One Stationary and Two Mobile Systems for Three-Dimensional Facial Scanning.

PURPOSE: To evaluate the trueness of one stationary and two mobile systems for 3D facial scanning. MATERIALS AND METHODS: Twenty participants were included in this study. After marking facial soft tissue landmarks, their faces were scanned using three facial scanning systems: the Bellus3D Dental Pro app on an iPad Pro 2020 (Apple; IP); the ARC-7 Face Scanning System (Bellus3D; BA); and the EinScan Pro 2X Plus (Shining 3D Tech; EP) following the manufacturers' operating instructions. Three-dimensional images were reconstructed with corresponding software and saved in object (OBJ) file format. The interlandmark distances were measured and compared to direct caliper measurements, and absolute error (AE) was chosen as the measurement to determine the trueness of the three scanners. The normal distribution and variance of homogeneity were measured, and then the data were analyzed using one-way ANOVA or Kruskal-Wallis H test. The significance level was set at P = .05. RESULTS: For the measurement of interlandmark distances, no significant differences were found among the four measuring techniques, and the mean AEs of the IP, BA, and EP systems were 1.17 ± 0.80 mm, 0.76 ± 0.61 mm, and 0.69 ± 0.65 mm. CONCLUSION: The three facial scanning systems tested provided a reliable 3D facial reconstruction. The portable IP system could meet the clinical requirements for facial scanning, but it is suggested to select the EP and BA systems when a higher trueness is required.

Accuracy of digital complete dentures: A systematic review of in vitro studies.

STATEMENT OF PROBLEM: Reports on digital complete dentures (CDs) are increasing. However, systematic reviews on their accuracy and influencing factors are lacking. PURPOSE: The purpose of this systematic review was to evaluate the accuracy of digital CDs and to summarize influencing factors. MATERIAL AND METHODS: An electronic search of the English language literature from January 2009 to October 2019 was performed in the database PubMed/MEDLINE, with the results enriched by manual searches and citation mining. Factors investigated in the selected articles included the fabrication technique, type of computer-aided design and computer-aided manufacturing (CAD-CAM) system, shape of reference model, long-term service, analytical method, and statistical indicators. RESULTS: A total of 522 articles were identified, of which 14 in vitro articles met the inclusion criteria. Eight articles compared the adaptation of the denture base between digital and conventional methods, 4 studies evaluated the occlusal discrepancies, 4 compared the trueness or adaptation of the denture fabricated with CAD-CAM milling and 3D printing, 1 compared the denture adaptation with 4 different CAD-CAM systems, and 2 evaluated the adaptation of the denture base before and after incubation in artificial saliva. CONCLUSIONS: Most of the studies reported clinically acceptable values for the occlusal trueness and adaptation of digital CDs. The digital CDs showed similar or better adaptation than conventionally fabricated CDs, and the greatest misfit of the intaglio surface was reported in the posterior palatal seal area and border seal area. The fabrication technique, CAD-CAM system, and long-term service were statistically significant in relation to denture accuracy. Clarification is needed concerning the accuracy of digital CDs according to the shape of the cast, the parameters related to the CAD-CAM process, the analytical method, and the statistical indicators. No clear conclusions can be drawn about the superiority of CAD-CAM milling and 3D printing regarding denture accuracy.

The transducible TAT-RIZ1-PR protein exerts histone methyltransferase activity and tumor-suppressive functions in human malignant meningiomas.

Malignant meningiomas are a rare meningioma subtype and tend to have post-surgical recurrence. Significant endeavors have been taken to identify functional therapeutic targets to halt the growth of this aggressive cancer. We have recently discovered that RIZ1 is downregulated in high-grade meningiomas, and RIZ1 overexpression inhibits proliferation while promoting cell apoptosis of the IOMM-Lee malignant meningioma cell line. In this report, we show that the N-terminal PR domain of RIZ1 alone possessed growth-inhibitory activity and anticancer activity in primary human meningioma cells. Interestingly, the effects seem to be dependent on differential RIZ1 protein levels. Transducible TAT-RIZ1-PR protein could also inhibit meningioma tumor growth in nude mice models. We further demonstrate that PR protein exerts histone methyltransferase activity. A microarray analysis of TAT-RIZ1-PR-treated human malignant meningioma cells reveals 969 differentially expressed genes and 848 alternative splicing exons. Moreover, c-Myc and TXNIP, two putative downstream targets of H3K9 methylation, may be involved in regulating RIZ1 tumor-suppressive effects. The reciprocal relationship between RIZ1 and c-Myc was then validated in primary meningioma cells and human tumor samples. These findings provide insights into RIZ1 tumor suppression mechanisms and suggest that TAT-RIZ1-PR protein is a potential new epigenetic therapeutic agent for advanced meningiomas.