Abstract: A comparative orthodontic treatment planning tool that can provide multiple treatment plan options based on a single initial tooth data set. A user can use the treatment planning tool to select a treatment plan based on factors, including cost, treatment duration, treatment complexity, and material or feature selection. Tooth arrangements at different treatment stages can be compared. In some cases, a tooth arrangement at one treatment stage can be superimposed over a tooth arrangement at a different treatment stage or over a tooth arrangement from a different treatment plan.

Abstract: This disclosure provides low-viscosity resins for producing polymers with properties suitable for use in various mechanical appliances, such as orthodontic appliances (e.g., aligners). The low-viscosity resins may be photo-curable and can be used with direct fabrication methods and equipment. In various embodiments, the polymeric materials produced from the low-viscosity resins described herein have high toughness while remaining resistant to stress relaxation. Low-viscosity, photo-curable resins described herein have reduced hydrogen bonding in comparison to traditional materials (e.g., materials having high urethane content) used in orthodontic appliances.

Abstract: Laser cutting systems and methods are described herein. One or more systems include a laser, an optical component, a fixture for holding a support with a part positioned on the support, and a controller. The controller is configured to identify a cut path for trimming excess material from a dental appliance, determine adjustment instructions for adjusting a focal length of the laser to cut along the cut path, and trim the excess material from the dental appliance along the cut path with the laser. The focal length is adjusted by adjusting at least one of: the laser, the optical component, and the fixture, and while moving the fixture at a constant speed relative to the laser to avoid increasing a brittleness of a polymer material of the dental appliance along the cut path.

Abstract: This disclosure provides polymeric materials comprising weak crosslinking covalent bonds and/or weak crosslinking units comprising a weak covalent bond. Weak covalent bonds can be used in place of hydrogen bonds present in traditional polymeric materials (e.g., polyurethanes). Advantageously, the toughness can be controlled by varying the strength of weak covalent bonds and/or by varying the number of weak covalent crosslinks. Crosslinked materials applying the weak covalent crosslinking bonds can be used to create tough materials able to resist stress relaxation. Further, the present disclosure provides polymer chains and polymeric materials comprising inchain loops (also referred to herein as rings). The inchain loops comprise weak bonds and/or weak bridges comprising at least one weak bond.

Abstract: An intraoral scanning device comprises housing comprising a head configured for insertion into a patient oral cavity, the head comprising a sloped surface and an aperture for transmission of optical signals, a transparent element positioned within the aperture, wherein the transparent element is at an acute angle with respect to the sloped surface, and a defogging unit comprising a heating unit. The intraoral scanning device further comprises a protective sleeve configured to cover at least a part of the head when the protective sleeve is coupled to the housing. The protective sleeve comprises an additional aperture that aligns with the aperture and an additional transparent element in the additional aperture.

Abstract: In embodiments, a system for scanning an intraoral cavity comprises an intraoral scanner to generate intraoral scan data of the intraoral cavity and viewfinder images of the intraoral cavity, a display, and a processing unit operatively connected to the intraoral scanner and to the display. The processing unit is to: receive the intraoral scan data and the viewfinder images from the intraoral scanner; generate a three-dimensional (3D) digital model of the intraoral cavity using the intraoral scan data; output the 3D digital model to the display; output the viewfinder images to the display; determine which portions of the intraoral cavity have been scanned; determine a current field of view of the intraoral scanner; determine a visual indicator that provides guidance for positioning and orienting the field of view of the intraoral scanner; and output the visual indicator to the display.

Abstract: A medical image might be generated for a patient image using a convolutional neural network trained on prior patient pre-procedure and post-procedure 2D images. A method might generate 3D models from pre-procedure 2D images and from post-procedure 2 images, and train the convolutional neural network with training images being the 3D models, to generate at least one 3D model of the present patient from the 2D image of the present patient, apply the 3D model of the present patient to the convolutional neural network in an inference stage, and apply patient-specific parameters derived from the proposed surgical procedure as a second input to the convolutional neural network in the inference stage to generate an inferred post-surgery 3D model of the present patient given the patient-specific parameters.

Abstract: An apparatus for intraoral scanning comprises an elongate handheld wand comprising a probe at a distal end, one or more light projectors, and two or more cameras. Each light projector comprises at least one light source configured to generate light and a pattern generating optical element configured to generate a pattern of light when the light is transmitted through the pattern generating optical element. Each camera comprises a camera sensor and one or more lenses and is configured to capture a plurality of images that depict at least a portion of the projected pattern of light on an intraoral surface, wherein each camera is configured to focus at an object focal plane that is located between about 1 mm and about 30 mm from a lens of the one or more lenses that is farthest from the camera sensor.

Abstract: A dual aligner assembly including a plurality of aligners, including a first aligner and a second aligner. The first aligner has a first shape corresponding to a set of target tooth positions and applies an orthodontic force against a set of target teeth. The first orthodontic force generates movement of the set of target teeth to the set of target tooth positions. The second aligner has a second shape corresponding to a combination of current tooth positions of the set of target teeth, the set of target tooth positions, and a thickness of the first aligner. The second aligner partially encloses the first aligner and provides an anchor for at least a portion of the first aligner. Via the anchor, a combination of the first aligner and the second aligner provides an orthodontic force that prevents the set of target teeth from moving to unwanted tooth positions during orthodontic treatment.

Abstract: A series of a palatal expanders increasing width can be used to gradually expand a patient's palate. Each palatal expander may have a palatal region flanked by teeth regions. The palatal region can have a plurality of anchor-receiving features (e.g., anchor interfaces) that allow the palatal expander to be attached to temporary anchorage device anchors that have been implanted into the patient's maxilla.

Abstract: Methods for obtaining an adjusted 3D model of patient's teeth based on a 2D image of the patient's teeth. In some examples, the method includes: obtaining a 3D digital model based on a scan of the patient's teeth; obtaining a 2D image based on a camera picture; iteratively comparing a distance between corresponding points on one or more teeth of the 3D digital model and of the 2D image, and generating an adjusted 3D model in which the one or more teeth of the 3D digital model are moved to reduce said distance, wherein iteratively comparing and generating comprises iterating until one or more deviations between the teeth of the 3D digital model and the 2D image are below a threshold.

Abstract: Described herein are methods and apparatuses to obtain an image, or a set of images, of a patient's teeth from one or more predetermined viewing angles. These methods and apparatuses may include the use an overlay comprising an outline of teeth for each predetermined viewing angle. The overlay may be used for automatically capturing, focusing and/or illuminating the teeth. Also described herein are methods and apparatuses for using a series of images of the patient's teeth including a set of predetermined views to determine if a patient is a candidate for an orthopedic procedure.

Abstract: The present disclosure provides computing device implemented methods, computing device readable media, and systems for motion compensation in a three dimensional scan. Motion compensation can include receiving three-dimensional (3D) scans of a dentition, estimating a motion trajectory from one scan to another, and calculating a corrected scan by compensating for the motion trajectory. Estimating the motion trajectory can include one or more of: registering a scan to another scan and determining whether an amount of movement between the scans is within a registration threshold; determining an optical flow based on local motion between consecutive two-dimensional (2D) images taken during the scan, estimating and improving a motion trajectory of a point in the scan using the optical flow; and estimating an amount of motion of a 3D scanner during the scan as a rigid body transformation based on input from a position tracking device.

Abstract: Methods for fabricating orthodontic appliances are described herein. In some embodiments, a method includes fabricating a shell including a plurality of cavities shaped to receive teeth, fabricating a discontinuity in the shell, and fabricating an elastic member positioned to interact with the discontinuity. At least one of the shell, the discontinuity, or the elastic member can be fabricated using a direct fabrication technique.

Abstract: Methods for designing orthodontic appliances for repositioning a patient's teeth are provided. In some embodiments, a method includes determining a movement path to move one or more teeth from an initial arrangement to a target arrangement, determining a force system to produce movement of the one or more teeth along the movement path, and determining an appliance geometry for an orthodontic appliance configured to produce the force system. The orthodontic appliance can include an outer shell comprising a plurality of teeth-receiving cavities and an inner structure positioned on an inner surface of the outer shell. The inner structure can have an elastic modulus different than an elastic modulus of the outer shell. The method can also include generating instructions for directly fabricating the orthodontic appliance using a layer-by-layer additive manufacturing technique.

Abstract: Systems for volume manufacturing of items are provided. In some embodiments, a fabrication system is configured to retrieve a fabrication data package including manufacturing data. The system can verify the manufacturing data of the fabrication data package, and transmit the fabrication data package to at least one fabrication terminal configured to perform at least one fabrication process in accordance with the manufacturing data of the fabrication data package. If a predefined fabrication processing time period has not expired, the system can determine a process load associated with at least one additional fabrication data package, and repeating the above processes for the at least one additional fabrication data package, if the process load of the at least one additional fabrication data package is less than a predetermined process load of the fabrication system. If the predefined fabrication processing time period has expired, the system can generate a status report.

Abstract: Orthodontic appliances and associated methods are provided. In some embodiments, an orthodontic appliance includes an appliance shell configured to reposition a patient's teeth from a first arrangement toward a second arrangement. The appliance shell can include a plurality of shell segments, each shell segment including a first material having a first elastic modulus. The appliance shell can also include a plurality of elastic segments, each elastic segment including a second material having a second elastic modulus less than the first elastic modulus. Each elastic segment can be coupled to a respective adjacent pair of shell segments.

Abstract: The present disclosure provides systems that utilize a cheek retractor and/or a mobile device holder. The cheek retractor includes a first and a second lip holder to hold a cheek away from a mouth of a user to expose teeth of the user. A mobile device holder can receive a mobile device to capture images of the patient's teeth. These systems may be useful for case assessment and/or dental treatments.

Abstract: The present disclosure provides methods, devices, and systems for adjusting a tooth position. A system for adjusting a tooth position can include an attachment configured to be attached to a tooth to be moved, a dental appliance including a guide slot configured to receive the attachment and to define an adjustment trajectory of the tooth, and an adjustment band to generate force on the tooth to move the tooth along the adjustment trajectory.

Abstract: In a technique to assess the blurriness of an image, an image of a face is received, the image including a depiction of lips. A processing device determines a region of interest in the image, wherein the region of interest comprises an area inside of the lips. The processing device applies a focus operator to the pixels within the region of interest, and calculates a sharpness metric for the region of interest using an output of the focus operator. The processing device determines whether the sharpness metric satisfies a sharpness criterion, and one or more additional operations are performed responsive to determining that the sharpness metric satisfies the sharpness criterion.