3D Slicer as an image computing platform for the Quantitative Imaging Network.

While the study of psychology has offered little in the way of explaining the creative process, Koestler examines the idea that we are at our most creative when rational thought is suspended--for example, in dreams and trancelike states. All who read The Act of Creation will find it a compelling and illuminating book.

The Act of Creation

Creativity: Flow and the Psychology of Discovery and Invention

Anthropometry of the head and face

Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given

A review on stereolithography and its applications in biomedical engineering

In the last decades, research in the orthodontic field has focused on the development of more comfortable and aesthetic appliances such as thermoformed aligners. Aligners have been used in orthodontics since the mid 20-century. Nonetheless, there is still not enough knowledge about how they interact with teeth. This paper is focused on the development of a Finite Element Method (FEM) model to be used in the optimization process of geometrical attributes of removable aligners. The presented method integrates Cone Beam Computed Tomography (CBCT) data and optical data in order to obtain a customized model of the dental structures, which include both crown and root shapes. The digital simulation has been focused on analyzing the behavior of three upper frontal teeth. Moreover, the analyses have been carried out by using different aligners’ thicknesses with the support of composite structures polymerized on teeth surfaces while simulating a 2 degrees rotation of an upper central incisor.Copyright © 2014 by ASME

FEM Analysis of Bone-Ligaments-Tooth Models for Biomechanical Simulation of Individual Orthodontic Devices

Studio delle tensioni di contatto e della ripartizione del carico fra denti in ingranaggi face gear

In the present work, the effect of Eruption Guidance Appliances (EGAs) on TemporoMandibular Joint (TMJ) disks stress level is studied. EGAs are orthodontic appliances used for early orthodontic treatments in order to prevent malocclusion problems. Commercially available EGAs are usually produced by using standard sizes. For this reason, they are not able to meet all the specific needs of each patient. In particular, EGAs are symmetric devices, while patient arches generally present asymmetric conditions. Thus, uneven stress levels may occur in TMJ disks, causing comfort reduction and potential damage to the most solicited disk. On the other hand, a customized EGA could overcome these issues, improving the treatment effectiveness. In this preliminary study, a Finite Element (FE) model was developed to investigate the effects of a symmetric EGA when applied to an asymmetric mouth. Different misalignment conditions were studied to compare the TMJ disks stress levels and to analyze the limitations of a symmetric EGA. The developed FE model can be used to design patient-specific EGAs, which could be manufactured by exploiting non-conventional techniques such as 3D printing.

Finite Element Analysis of TMJ Disks Stress Level due to Orthodontic Eruption Guidance Appliances

Recent advances in 3D imaging techniques have provided flexible tools for clinical assessments within many medical fields. In the field of orthodontic and orthognathic surgery, the reliable creation of 3D anatomical models can assist clinicians for both diagnosis and treatment planning. In particular, the accurate integration between facial soft tissue, facial skeleton and dentition (maxillofacial triad) provides clinicians with a complete model for virtual 3D treatment planning. However, none of the existing imaging technologies is able to simultaneously capture the complete triad with the optimal resolution and accuracy. For this reason, a “model fusion” process must be carried out in order to integrate 3D models obtained using different imaging techniques. This paper aims at introducing a procedure to create accurate maxillofacial triad models by guiding the fusion of multi-modal 3D imaging techniques. The methodology is based on integrating a structured light optical scanner with Cone-Beam Computed Tomography (CBCT) data processing in order to capture the different tissue groups composing the maxillofacial triad. The generated models represent an all-embracing virtual workbench for orthodontists in the treatment planning of malocclusion problems and for surgeons in the preoperative prediction of surgical outcomes.

3D maxillofacial model creation for computer-guided treatments in oral rehabilitation

The reconstruction of tooth anatomies is of utmost importance when dental implant surgeries and/or orthodontic corrections must be planned. In the last few years, cone beam CT (CBCT) has gained popularity in dentistry for 3D imaging of jawbones and teeth. However, within CBCT data sets, each tooth is defined by a region, which cannot be easily separated from surrounding tissues (i.e., bone tissue) by only considering pixel’s grey-intensity values. For this reason, some enhancement is usually necessary in order to properly segment tooth geometries.In this paper, a semi-automatic approach to reconstruct individual 3D tooth anatomies by processing CBCT-scan data is presented. The methodology is based on the creation of a minimal number of 2D “local ray-sum” images by adding the absorption values of adjacent voxels along the most significant views for each tooth. The knowledge of the specific anatomical patient morphology drives the selection of these significant projection directions. The reconstructed “ray-sum” images greatly enhance the clearness of the root contours, which can then be interactively traced by dentists. A set of meaningful 2D tooth contours is consequently obtained and used to automatically extract a cubic spline curve for each transverse slice, thus approximating the overall 3D tooth profile.The effectiveness of the methodology has been evaluated by comparing the results obtained for the reconstruction of anterior teeth with those obtained by using classical segmentation tools provided within commercial software.Copyright © 2015 by ASME

Sandro Barone

Papers

FEM Analysis of Bone-Ligaments-Tooth Models for Biomechanical Simulation of Individual Orthodontic Devices

Studio delle tensioni di contatto e della ripartizione del carico fra denti in ingranaggi face gear

Finite Element Analysis of TMJ Disks Stress Level due to Orthodontic Eruption Guidance Appliances

3D maxillofacial model creation for computer-guided treatments in oral rehabilitation

Three-Dimensional Tooth Segmentation by Integrating Multiple Ray-Sum Images From CBCT Data