# US 12,213,856 B2 · Treatment plan generation using collision detection by shape filling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,213,856 B2 - Document ID: US12213856B2 - Status: Granted - Kind: B2 - Application number: 17/410,784 - Filed: 2021-08-24 - Published: 2021-12-09 - Granted: 2025-02-04 - Earliest claimed: 2017-11-01 - Assignees: Align Technology, Inc. - Applicants: Align Technology, Inc. - Inventors: Igor Akopov; Anton Lapshin; Samuel Blanco; Artem Kuanbekov; Eric P. Meyer; Andrey Maximov; Boris Likhtman; Michael Flanagan; Jason Ramos; Mitra Derakhshan; Roman A. Roschin; Alexander Belous; Olga Matusevich; Maria Shirshova; Nikolay Yakovlev - Web page: https://patentgrep.com/patent/US12213856B2 ## CPC - A61C 7/002: {Orthodontic computer assisted systems} - A61C 7/08: Mouthpiece-type retainers {or positioners, e.g. for both the lower and upper arch (arch-shaped medicament applicators for teeth or gums A61C19/063; mouthguards for protecting the teeth of sportsmen A63B71/085)} - A61C 9/0053: {Optical means or methods, e.g. scanning the teeth by a laser or light beam} - G16H 20/30: relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising - G16H 20/40: relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture - G16H 40/67: for remote operation - G16H 50/50: for simulation or modelling of medical disorders - A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00) - G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA ## Abstract Orthodontic and/or dental treatment planning methods and apparatuses. In particular, described herein are methods of generating a plurality of orthodontic treatment plans digitally using a hierarchy of bounding boxes enclosing the plurality of 3D shapes to avoid collisions during treatment. ## Claims ### Claim 1 A method of creating an orthodontic treatment plan of a patient, the method comprising: forming a digital model of a surface for each tooth of a plurality of a patient's teeth by packing a plurality of 3D shapes to model the surface for each tooth, wherein the 3D shapes each have a core that is a line segment or a closed plane figure and an outer surface that is a constant radius from the core; forming, for the surface for each tooth of the plurality of the patient's teeth, a hierarchy of bounding boxes enclosing the plurality of 3D shapes; identifying one or more sets of proposed tooth positions for the plurality of the patient's teeth; determining collision data for one or more collisions between adjacent teeth for each of the one or more sets of proposed tooth position by identifying colliding bounding boxes and determining a spacing or overlap between the 3D shapes bound by the colliding bounding boxes; and identifying one or more orthodontic treatment plans comprising a series of dental appliances for moving the patient's teeth from the collision data and the one or more sets of proposed tooth positions; fabricating one or more dental appliances based on the one or more orthodontic treatment plans. ### Claim 2 (depends on 1) The method of claim 1, wherein forming the digital model of the surface for each tooth comprises determining regions of the surface having a similar curvature and, for each determined region, determining a 3D shape to fit each determined region. ### Claim 3 (depends on 1) The method of claim 1, wherein forming the digital model of the surface for each tooth comprises determining regions of the surface having a similar curvature and, for each determined region, use a quadratic error metric to determine a 3D shape to fit each determined region. ### Claim 4 (depends on 1) The method of claim 1, wherein the 3D shapes are capsules. ### Claim 5 (depends on 1) The method of claim 1, wherein forming the digital model of the surface for each tooth comprises separately forming a left interproximal surface and a right interproximal surface for each tooth. ### Claim 6 (depends on 5) The method of claim 5, wherein determining collision data comprises identifying collisions between adjacent left interproximal surface and right interproximal surface of the adjacent teeth. ### Claim 7 (depends on 1) The method of claim 1, wherein forming the digital model of the surface for each tooth comprises packing the plurality of 3D shapes to approximate the surface. ### Claim 8 (depends on 1) The method of claim 1, wherein forming the hierarchy of bounding boxes comprises, forming a hierarchy in which bounding boxes of a lowest tier of the hierarchy each enclose a single 3D shape, subsequent tiers of the hierarchy each enclose adjacent bounding boxes or groups of bounding boxes, and a highest tier of the hierarchy encloses all of the bounding boxes around the 3D shapes forming the surface. ### Claim 9 (depends on 1) The method of claim 1, wherein determining collision data comprises determining the spacing or overlap between the 3D shapes bound by the colliding bounding boxes to get a magnitude of each collision of the one or more collisions. ### Claim 10 (depends on 1) The method of claim 1, wherein determining collision data comprises going from a top tier of the hierarchy of bounding boxes to a lowest tier of the hierarchy of bounding boxes corresponding to each adjacent tooth to identify colliding bounding boxes at the lowest tier of the hierarchy of bounding boxes. ### Claim 11 (depends on 1) The method of claim 1, wherein determining collision data comprises sequentially adjusting a position of a first tooth of the adjacent teeth by a small predetermined amount in each of a plurality of axes of the first tooth and determining a change in spacing or overlap between the 3D shapes bound by the bounding boxes to get a velocity of the collision for each of the corresponding axes of the plurality of axes. ### Claim 12 (depends on 1) The method of claim 1, wherein determining collision data comprises determining a magnitude and velocity of the one or more collisions between adjacent teeth collision for each of three spatial and three rotational axes. ### Claim 13 A method of creating an orthodontic treatment plan of a patient, the method comprising: collecting a digital representation of a plurality of the patient's teeth, wherein each tooth of the digital representation is segmented; forming a digital model of a surface for each tooth of the digital representation by packing a plurality of 3D shapes to approximate the surface, wherein the 3D shapes each have a core that is a line segment or a closed plane figure and an outer surface that is a constant radius from the core; forming, for the digital model of the surface for each tooth, a hierarchy of bounding boxes enclosing the plurality of 3D shapes, wherein for each digital model of the surface for each tooth, bounding boxes of a lowest tier of the hierarchy each enclose a single 3D shape, subsequent tiers of the hierarchy each enclose adjacent bounding boxes or groups of bounding boxes, and a highest tier of the hierarchy encloses all of the bounding boxes around the 3D shapes forming the digital model of the surface for each tooth; passing a set of tooth positions for the plurality of the patient's teeth from a treatment plan solver to a collision detector; measuring, in the collisions detector, a magnitude and a velocity of a collision between adjacent teeth when the plurality of the patient's teeth are in the set of tooth positions by identifying colliding bounding boxes at the lowest tier of the hierarchy for each of the adjacent teeth, determining a spacing or overlap between the 3D shapes bound by the bounding boxes to get the magnitude of the collision, and sequentially adjusting a position of a first tooth of the adjacent teeth by a small predetermined amount in each of a plurality of axes of the first tooth and determining a change in spacing or overlap between the 3D shapes bound by the bounding boxes to get the velocity of the collision for each corresponding axis; and outputting the magnitude and velocity of the collision between adjacent teeth corresponding to the set of tooth positions to the treatment plan solver; outputting, from the treatment plan solver, one or more orthodontic treatment plans comprising a series of dental appliances for moving the patient's teeth; and fabricating one or more dental appliances based on the one or more orthodontic treatment plans. ### Claim 14 A system for automatically creating an orthodontic treatment plan of a patient, the system comprising: one or more processors; a treatment plan solver operating on the one or more processors; a collision detector operating on the one or more processors; and a memory coupled to the one or more processors, the memory configured to store computer-program instructions, that, when executed by the one or more processors, perform a computer-implemented method comprising: forming a digital model of a surface for each tooth of a plurality of a patient's teeth by packing a plurality of 3D shapes to approximate the surface for each tooth, wherein the 3D shapes each have a core that is a line segment or a closed plane figure and an outer surface that is a constant radius from the core; forming, for the surface for each tooth of the plurality of the patient's teeth, a hierarchy of bounding boxes enclosing the plurality of 3D shapes; passing a set of tooth positions for the plurality of the patient's teeth from the treatment plan solver to the collision detector; determining, with the collisions detector, a magnitude and a velocity of a collision between adjacent teeth when the plurality of the patient's teeth are in the set of tooth positions by identifying colliding bounding boxes and determining a spacing or overlap between the 3D shapes bound by the colliding bounding boxes; and passing the magnitude and velocity of the collision between adjacent teeth corresponding to the set of tooth positions to the treatment plan solver; outputting, from the treatment plan solver, one or more orthodontic treatment plans comprising a series of dental appliances for moving the patient's teeth; and fabricating one or more dental appliances based on the one or more orthodontic treatment plans. ### Claim 15 (depends on 14) The system of claim 14, wherein the 3D shapes are capsules. ### Claim 16 (depends on 14) The system of claim 14, wherein forming the digital model of the surface for each tooth comprises determining regions of the surface having a similar curvature and, for each determined region, determining a 3D shape to fit each determined region. ### Claim 17 (depends on 14) The system of claim 14, wherein forming the digital model of the surface for each tooth comprises determining regions of the surface having a similar curvature and, for each determined region, use a quadratic error metric to determine a 3D shape to fit each determined region. ### Claim 18 (depends on 14) The system of claim 14, wherein forming the digital model of the surface for each tooth comprises separately forming a left interproximal surface and a right interproximal surface for each tooth. ### Claim 19 (depends on 18) The system of claim 18, wherein measuring the magnitude and velocity of the collision between adjacent teeth comprises identifying collisions between adjacent left interproximal surfaces and right interproximal surfaces of the adjacent teeth. ### Claim 20 (depends on 14) The system of claim 14, wherein forming the digital model of the surface for each tooth comprises automatically packing the plurality of 3D shapes to approximate the surface. ### Claim 21 (depends on 14) The system of claim 14, wherein forming the hierarchy of bounding boxes comprises, forming a hierarchy in which bounding boxes of a lowest tier of the hierarchy each enclose a single 3D shape, subsequent tiers of the hierarchy each enclose adjacent bounding boxes or groups of bounding boxes, and a highest tier of the hierarchy encloses all of the bounding boxes around the 3D shapes forming the surface. ### Claim 22 (depends on 14) The system of claim 14, wherein measuring the magnitude of the collision between adjacent teeth comprises determining the spacing or overlap between the 3D shapes bound by the colliding bounding boxes to get the magnitude of the collision. ### Claim 23 (depends on 14) The system of claim 14, wherein measuring the magnitude and velocity of the collision between adjacent teeth comprises going from a top tier of the hierarchy of bounding boxes to a lowest tier of the hierarchy of bounding boxes corresponding to each adjacent tooth to identify colliding bounding boxes at the lowest tier of the hierarchy of bounding boxes. ### Claim 24 (depends on 14) The system of claim 14, wherein measuring the velocity of the collision between adjacent teeth comprises sequentially adjusting a position of a first tooth of the adjacent teeth by a small predetermined amount in each of a plurality of axes of the first tooth and determining a change in spacing or overlap between the 3D shapes bound by the bounding boxes to get the velocity of the collision for each of the plurality of axes. ### Claim 25 (depends on 14) The system of claim 14, wherein passing the magnitude and velocity comprises passing the magnitude and velocity for each of three spatial and three rotational axes. ### Claim 26 (depends on 14) The system of claim 14, wherein, prior to outputting the one or more orthodontic treatment plans, the steps of passing the set of tooth positions for the plurality of the patient's teeth to the collision detector, measuring the magnitude and velocity of collisions between adjacent teeth and passing the magnitude and velocity of collisions are repeated for a plurality of different sets of tooth positions, wherein the treatment plan solver generates the different sets of tooth positions. ### Claim 27 (depends on 26) The system of claim 26, wherein the treatment plan solver generates the different sets of tooth positions while minimizing a numerical function subject to a plurality of numerical limits to get a solution vector including all stages of the one or more orthodontic treatment plans.