Abstract: Orthodontic systems and related methods are disclosed for designing and providing improved or more effective tooth moving systems for eliciting a desired tooth movement and/or repositioning teeth into a desired arrangement. Methods and orthodontic systems include the generation of an overcorrection in the tooth-receiving cavities of an appliance worn in the dentition. The overcorrection may provide an improved and more accurately applied force or moment applied to a tooth. The overcorrected force or moment can move a tooth closer to a desired position than if not overcorrected as sufficient force can still applied to the tooth as it gets closer to the desired position. The overcorrected force or moment may also better target the root of the tooth where the biological response to tooth movement occurs. The overcorrection may be calculated in various ways as described herein.

Abstract: A three-dimensional (3D) model representing at least one tooth of a patient is received. A two-dimensional (2D) contour of the 3D model representing the at least one tooth of the patient is generated. The 2D contour with a 2D x-ray image of the at least one tooth of the patient to generate alignment data is aligned. The 3D model is updated based on the alignment data.

Abstract: A scan model that is a mathematical model to simulate an imaging process performed by an x-ray imaging device that created a two-dimensional x-ray image of at least one tooth is generated. The scan model uses an initial estimate of one or more parameters of the x-ray imaging device. The one or more parameters include a scan angle parameter indicative of a scan angle of the x-ray imaging device. A two-dimensional contour of a three-dimensional model is adjusted to cause a first component of the two-dimensional contour to approximately align with a second component of the two-dimensional x-ray image. The scan model is calibrated based on data obtained from adjusting the two-dimensional contour.

Abstract: Methods and systems for generating and modifying three-dimensional occlusograms. One method includes calculating a height map and/or a distance field of a tooth of an upper jaw or a lower jaw. An occlusogram for the tooth may be generated based on a space and/or a collision depth between the tooth and a tooth on an opposite jaw. The occlusogram may be displayed over a three-dimensional (3D) model of the tooth. The occlusogram may be dynamically changed in response to a change in one or more input parameters associated with one or more dental treatments on the tooth.

Abstract: Methods and systems for generating a three-dimensional occlusogram are disclosed. One method includes determining a virtual three dimensional (3D) mesh model object of at least one tooth of a patient and displaying the determined virtual 3D mesh model object of at least one tooth of a patient wherein the 3D mesh model object includes a plurality of data sets associated with a set of occlusal information for the at least one tooth of the patient. In some examples, a 3D occlusogram is updated in response to a change of position of a 3D model of a tooth.

Abstract: A method may include obtaining a plan model of a patient's teeth, obtaining a tracking model of the patient's teeth representing an arrangement at an intermediate stage of a treatment plan, generating a comparison of the plan model with the tracking model using a coarse to fine volume 3D array to represent one or both of the plan model and the tracking model, detecting one or more positional differences between anatomical reference shapes and surface features of the plan model and corresponding anatomical reference shapes and surface features of the tracking model based on the comparison and using the coarse to fine volume 3D array, generating a modified treatment plan based on the one or more detected positional differences, and fabricating a dental appliance based on the modified treatment plan.

Abstract: A method may include generating a comparison of one or more anatomical reference shapes and one or more surface features on a planned dentition model with a corresponding one or more anatomical reference shapes and one or more surface features on a tracking dentition model using a coarse to fine volume 3D array to represent one or both of the plan model and the tracking model to minimize distances between teeth represented in the plan model and corresponding teeth represented in the tracking model. The method may also include detecting one or more positional differences between the anatomical reference shapes and surface features of the plan model and the corresponding anatomical reference shapes and surface features of the tracking model based on the comparison and generating a modified treatment plan based on the one or more detected positional differences.

Abstract: Embodiments are provided for using an individualized orthodontic treatment index. One method embodiment includes receiving an initial virtual dental model from a first scan of a patient's dentition, modifying the initial virtual dental model to create a target virtual dental model according to a treatment goal, assigning a number of dental references to the target virtual dental model, receiving a treatment outcome virtual dental model from a second scan of the patient's dentition, mapping the number of dental references from the target virtual dental model to a treatment outcome virtual dental model, and calculating an individualized treatment index score for the treatment outcome virtual dental model according to one or more differences between the target virtual dental model and the treatment outcome virtual dental model based on the number of dental references.

Abstract: Methods for designing and fabrication of a series of apparatuses for expanding a patient's palate (“palatal expanders”). In particular, described herein are methods and apparatuses for forming palatal expanders, including rapid palatal expanders, as well as series of palatal expanders formed as described herein and apparatuses for designing and fabricating them.

Abstract: Palatal expander apparatuses for expanding a patient's palate (“palatal expanders”) and methods of using and making them. These palatal expanders may be configured to have a variable surface smoothness on one side (e.g., the lingual-facing surface) compared to the opposite side (e.g., the palatal-facing surface). These palatal expanders may be configured to have a varying thickness in the palatal region. These palatal expanders may be adapted for ease in removal by the patient or caregiver (e.g., including a hinged region and/or detachment region, and/or including a thinner buccal side then occlusal side, etc.).

Abstract: Methods and systems for dental treatment are provided. In some embodiments, a method includes receiving a plurality of treatment stages for repositioning a patient's teeth from an initial tooth arrangement toward a target tooth arrangement, where each treatment stage is associated with a target position for a tooth of the patient. The method can include determining, for one or more treatment stages, an overcorrected movement corresponding to an overcorrected position for the tooth that is different from the target position, where at least some of the one or more treatment stages include different magnitudes of overcorrected movements. The method can further include outputting fabrication instructions for one or more dental appliances corresponding to the one or more treatment stages, each dental appliance including an overcorrected tooth receiving cavity corresponding to the overcorrected position for the respective treatment stage.

Abstract: Series of apparatuses for expanding a patient's palate (“palatal expanders”), including rapid palatal expanders, wherein a left tooth engagement region and a right tooth engagement region are configured to add anti-tipping torque to at least one tooth. Left and right tooth engagement regions may include lingual surfaces with at least one lingual protrusion. Left and right tooth engagement regions may have buccally rotated cavities.

Abstract: Systems, methods, and non-transitory computing device readable media for determining an individualized orthodontic treatment index. One embodiment includes generating a target dental model by modifying an initial dental model, graphically marking dental references on the target dental model including assigning contact points between adjacent first and second teeth of the target dental model, generating a treatment outcome dental model representing the patient's dentition after at least a portion of the orthodontic treatment has been completed, mapping the dental references marked on the target dental model to the treatment outcome dental model, and calculating an individualized treatment index score for the treatment outcome dental model according to one or more differences between the target dental model and the treatment outcome dental model.

Abstract: A series of palatal expanders and methods of designing palatal expanders, including rapid palatal expanders, where outer occlusal surfaces of a palatal expander are shaped to conform to a geometry of corresponding teeth surfaces of the patient's lower jaw to provide occlusion between occlusal surfaces and the corresponding teeth surfaces.

Abstract: Orthodontic systems and related methods are disclosed for designing and providing improved or more effective tooth moving systems for eliciting a desired tooth movement and/or repositioning teeth into a desired arrangement. Methods and orthodontic systems include the generation of an overcorrection in the tooth-receiving cavities of an appliance worn in the dentition. The overcorrection may provide an improved and more accurately applied force or moment applied to a tooth. The overcorrected force or moment can move a tooth closer to a desired position than if not overcorrected as sufficient force can still applied to the tooth as it gets closer to the desired position. The overcorrected force or moment may also better target the root of the tooth where the biological response to tooth movement occurs. The overcorrection may be calculated in various ways as described herein.

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: Palatal expander apparatuses for expanding a patient's palate (“palatal expanders”) and methods of making them. The apparatuses may include a pair of tooth engagement regions connected by a palatal region. A detachment region on at least one of the tooth engagement regions may be defined by one or more first vertical cut-out regions extending from a bottom of a buccal side toward an occlusal side of the tooth engagement region. The buccal side may be more flexible than the occlusal side so that the detachment region flexes when a removal force to release the palatal expander apparatus from the patient's palate is applied to the detachment region.

Abstract: Palatal expander apparatuses for expanding a patient's palate (“palatal expanders”) and methods of using and making them. The palatal expanders may include tooth engagement regions connected by a palatal region that is configured to apply force between the tooth engagement regions. At least a portion of the palatal region may be configured to have a clearance from the patient's mid-palatal region when the palatal expander is worn by the patient. The clearance between the palatal region and the patient's palate may decrease from the patient's mid-palatal region laterally toward the tooth engagement regions.

Abstract: A system and method for determining a center of resistance of a tooth may include receiving a 3D digital representation of an initial arrangement and a final arrangement of a patient's teeth and determining a 3D treatment plan. The 3D treatment plan may include a plurality of 3D stages for rearranging the teeth from the initial arrangement toward the final arrangement. The method may also include determining, in accordance with the 3D treatment plan, an intended movement of the teeth for each of the stages and deriving, using a 3D resistance model, an applied force system for achieving the intended movement of the teeth for each of the stages. The method may also include deriving 3D geometries of oral appliances for the stages in response to the applied force system. Various other systems and methods are also disclosed.