James R. Glidewell Dental Ceramics, Inc.

Fedor Chelnokov

Sergey Vladimirovich Nikolskiy

Grant Karapetyan

Sergei Azernikov

Andrey Tolstov

Andrey Svistunov

Stanislav Shushkevich

A system and method include performing digital block-out of one or more digital preparation teeth.

Digital block out of digital preparation

A computer-implemented method, system, and instructions can include receiving a reconstructed volume of an object; determining an air density and a material density from the reconstructed volume of the object; subdividing the reconstructed volume into one or more blocks, each block comprising one or more voxels; determining one or more contrast blocks within the reconstructed volume; and determining a reconstruction quality based on the number of contrast blocks in the reconstructed volume.

CT reconstruction quality control

A system and method can determine one or more CT scanner calibration parameters from a plurality of calibration object projections in a plurality of radiographs.

CT scanner calibration

Computer-implemented method and system automatically detects an out-of-view CT scan by receiving a voxel density file, determining a threshold iso-value of density between air density and a material density of one or more scanned objects in the voxel density file, and evaluating, using the threshold iso-value of density, one or more horizontal slices of the voxel density file to determine whether at least a portion of the one or more scanned objects is out of view.

Out-of-view CT scan detection

A computer-implemented method/system of determining a trim-line includes receiving a 3D digital dental model; combining the one or more virtual teeth; determining a distance field; determining a first iso-line; determining a back distance field; determining a second iso-line to generate a trim-line. A computer-implemented method/system of segmenting the 3D digital dental model includes receiving a 3D digital dental model; determining an initial virtual tooth location of one or more virtual teeth; constructing a virtual crown line; determining a long axis of one or more virtual teeth; constructing a virtual root line; determining a virtual tooth virtual bounding box; performing an initial segmentation; performing final segmentation.

Automatic determination of trim-line for aligners

A computer-implemented method and system of digitally segmenting teeth in a digital model comprises generating a panoramic image from a 3D digital model of a patient's dentition, labeling, using a first trained neural network, the panoramic image to provide a labeled panoramic image, mapping the labeled panoramic image to corresponding coarse digital surface triangle labels in the 3D digital model to provide a labeled 3D digital model, and segmenting the labeled 3D digital model to provide a segmented 3D digital model. A computer-implemented method and system of generating a panoramic image comprises determining, using a trained neural network, digital tooth bounding region(s) corresponding to digital teeth from a 2D depth map of a patient's dentition, connecting digital tooth bounding region(s) by a spline, determining sampled digital surface points from the sampled spline points; and determining associated digital surface points corresponding to each sampled digital surface point.

Teeth segmentation using neural networks

A computer-implemented method and system compresses CT reconstruction images and can include: receiving a volumetric density file including one or more voxels; replacing one or more voxel density values below an air density value with the air density value; replacing one or more voxel density values above a material density value with the material density value; determining one or more voxels of interest; replacing one or more non-interesting voxel density values below a material surface density with the air density value; replacing one or more non-interesting voxel density values above the material surface density with the material density value; quantizing all voxels to provide a reduced volume image; and compressing the reduced volume image to provide a compressed volume image.

Compression of CT reconstruction images

A computer-implemented method and system performs segmentation on at least a portion of the digital jaw to provide one or more digital surface segments, determines a digital tooth center for at least one digital tooth in the digital jaw, determines a digital tooth area around the digital tooth center, deletes one or more surface segments not intersecting with the digital tooth area; and smooths a mesh boundary.

Automatic clean up of jaw scans

A computer-implemented method of automatically determining photon-count to penetrated depth function for a CT reconstruction includes performing one or more test CT reconstructions on one or more radiographs, each test CT reconstruction using a test transfer function, to provide one more test reconstructions and determining a final transfer function from the one or more test reconstructions.

Automatic determination of transfer function for CT reconstruction

A computer-implemented method and system of determining a material surface from a volumetric density file includes generating a density frequency distribution of a volumetric density file of a dental impression and determining an iso-value of density between air and a particular material in the density frequency distribution. A computer-implemented method and system of creating a digital model from a CT scan of a physical dental impression includes selecting an iso-value of density for a digital volumetric density file having one or more voxels, generating one or more digital surface points in virtual 3D space for each of one or more voxels, and selecting a subset of digital surface points from the one or more digital surface points. A computer-implemented method and system of optimizing a digital surface includes moving one or more digital surface points to satisfy a criteria of optimum digital surface selection.

Processing CT scan of dental impression

A computer-implemented method of processing a digital dental impression includes determining one or more first digital surface regions visible from a first side of the digital dental impression along an occlusion axis and one or more second digital surface regions visible from a second side of the digital dental impression along the occlusion axis, segmenting the digital dental impression into one or more digital segments and determining the one or more digital segments as a first digital segment or a second digital segment based on the majority of digital surface regions in the one or more digital segments.

Processing digital dental impression

A system and method of processing a CT scan includes receiving a plurality of radiographs and determining an axis of rotation per scan from the plurality of radiographs prior to CT reconstruction.

Determining rotation axis from x-ray radiographs

A method and system provide segmenting a digital tooth in a 3D digital model of dentition.

Growing community of inventors

Khimki, Russia

Fedor Chelnokov