Digital Smile Design: Utilizing Novel Technologies for Ultimate Esthetics.

Digital smile design allows dental providers to digitally strategize treatments prior to performing irreversible procedures. Through the integration of various digital records, a comprehensive digital replica of the patient can be produced in which crucial facets of the patient's oral health and smile are captured. This article discusses the benefits of digital smile design and identifies key smile design and facial harmony principles when designing a patient's smile. Such principles as central incisor ratio, recurring esthetic dental (RED) proportions, facial flow, axial angulations, and more are discussed.

Bayesian inference using hierarchical and spatial priors for intravoxel incoherent motion MR imaging in the brain: Analysis of cancer and acute stroke.

The intravoxel incoherent motion (IVIM) model allows to map diffusion (D) and perfusion-related parameters (F and D*). Parameter estimation is, however, error-prone due to the non-linearity of the signal model, the limited signal-to-noise ratio (SNR) and the small volume fraction of perfusion in the in-vivo brain. In the present work, the performance of Bayesian inference was examined in the presence of brain pathologies characterized by hypo- and hyperperfusion. In particular, a hierarchical and a spatial prior were combined. Performance was compared relative to conventional segmented least squares regression, hierarchical prior only (non-segmented and segmented data likelihoods) and a deep learning approach. Realistic numerical brain IVIM simulations were conducted to assess errors relative to ground truth. In-vivo, data of 11 central nervous system cancer patients and 9 patients with acute stroke were acquired. The proposed method yielded reduced error in simulations for both the cancer and acute stroke scenarios compared to other methods across the whole investigated SNR range. The contrast-to-noise ratio of the proposed method was better or on par compared to the other techniques in-vivo. The proposed Bayesian approach hence improves IVIM parameter estimation in brain cancer and acute stroke.

DSDapp use for multidisciplinary esthetic planning.

OBJECTIVES: Digital smile design (DSD) is useful in planning multidisciplinary esthetic treatments. However, DSD requires clinician training and skill to ensure its effective use. The Digital smile design application (DSDapp) was recently developed, to facilitate such planning. The objective of this study was to illustrate the use of the DSDapp for esthetic planning in a clinical case that included periodontal plastic surgery and ceramic laminate veneers. CLINICAL CONSIDERATIONS: An intraoral digital scan was performed, and a photograph was obtained using an iPad (frontal facial full smile). The images were analyzed using the DSDapp. All reference lines were inserted, and dental shapes predetermined by the app were superimposed on the photographs. A digital diagnostic wax-up was performed considering the plan created in the DSDapp. After 3D printing the wax-up, a mock-up transferred the planning to the oral cavity. Following this, the patient was referred to a periodontist for the periodontal plastic surgery. After the healing period, the teeth were prepared for computer-aided design/computer-aided modeling lithium disilicate ceramic laminate veneers. CONCLUSIONS: DSDapp use accelerated the initial planning steps. Smile planning can be performed during the clinical session with the patient's active participation. In addition, the DSDapp facilitated better communication within the multidisciplinary team. CLINICAL SIGNIFICANCE: The DSDapp relies more on intuition than on skill and training to execute the treatment plan. The DSDapp provides immediate feedback to the patient, offering greater predictability and helps monitor the planning through all the clinical stages.

Chairside 3D digital design and trial restoration workflow.

Different digital tools have been used in clinical practice to assist in the planning and rehabilitation of patients. Some applications (apps) and software programs used in esthetic planning allow simulation of the smile design, improving communication between patients and professionals. Nonetheless, they are usually difficult to use, time-consuming, unattractive to present to the patient, and complicated to link with the 3D workflow. This article presents a new 3D digital smile design app for esthetic planning, smile simulation, chairside 3D virtual wax pattern, and trial restoration performed with portable devices. In this technique description, a facial frontal photograph, a facial scan standard tessellation language (STL) file, and a maxillary intraoral scan STL file were uploaded to the app. The files were calibrated to each other to allow a 3D facially driven smile design project. The definitive maxillary 3D digital waxing of facial templates was exported to a 3D printer as an STL file. The printed resin templates were directly placed in the mouth with flowable composite resin for an immediate trial restoration without the need for casts, silicone guides, or autopolymerizing resin. The workflow presented in this article linked the 3Dapp project to a printer and allowed straightforward chairside trial restorations.