Photograph-based assessment of dental treatments and procedures

A method carried out within a dental-treatment monitoring system having one or more processors, one or more electronic memories that store instructions and data, one or more mass-storage devices that store encoded images and patient information, and a communications subsystem through which the dental-treatment monitoring system receives images and information from remote computer systems, the method comprising:

• storing, in one or more data-storage devices selected from among the one or more electronic memories and one or more mass-storage devices, a three-dimensional model of a patient's teeth;
• receiving, through the communications subsystem, one or more two-dimensional digital photographs of the patient's teeth taken at a time t during the course of a dental treatment, projecting, in time, the three-dimensional model of the patient's teeth to the time t to generate and store a time-projected three-dimensional model of the patient's teeth representing an expected configuration of the patient's teeth;
• comparing one or more of the one or more two-dimensional digital photographs to corresponding two-dimensional digital images generated from the time-projected three-dimensional model of the patient's teeth to generate one or more comparison values;
• generating, from the received one or more two-dimensional digital photographs, a set of one or more processed images with associated metadata for analysis, determining, for each image in the set of one or more processed images, a set of virtual-camera parameters that describe the position and orientation for a virtual camera that produces a generated image from the time-projected three-dimensional model of the patient's teeth equivalent to the image in the set of one or more processed images, using, for each image in the set of one or more processed images, the standard type of view and additional metadata to generate an initial set of virtual-camera parameters for the image, using the standard type of view and additional metadata to determine a value for an iteration variable;
• carrying out a number of optimization iterations equal to the value of the iteration variable;
• and finally refining the virtual-camera parameters for the image, generating, for each image in the set of one or more processed images, a generated image corresponding to the image from the time-projected three-dimensional model of the patient's teeth and the virtual-camera parameters determined for the image, and comparing each image in the set of one or more processed images with the corresponding generated image to generate a comparison value for the image;
• determining, using the one or more comparison values, whether or not a configuration of the patient's teeth is within a threshold level of correspondence to the expected configuration of the patient's teeth;
• and storing an indication of the determination in one of the one or more electronic memories.

A dental-treatment monitoring system comprising:

• one or more processors;
• one or more electronic memories that store instructions and data;
• one or more mass-storage devices that store encoded images and patient information;
• a communications subsystem through which the dental-treatment monitoring system receives images and information from remote computer systems;
• and
• computer instructions, encoded in one or more of the one or more electronic memories, that control the dental-treatment monitoring system to store, in one or more data-storage devices selected from among the one or more electronic memories and one or more mass-storage devices, a three-dimensional model of a patient's teeth, receive, through the communications subsystem, one or more two-dimensional digital photographs of the patient's teeth taken at a time t during the course of a dental treatment, project, in time, the three-dimensional model of the patients teeth to the time t to generate and store a time-projected three-dimensional model of the patient's teeth representing an expected configuration of the patients teeth, compare one or more of the one or more two-dimensional digital photographs to corresponding two-dimensional digital images generated from the time-projected three-dimensional model of the patients teeth to generate one or more comparison values and generate, from the received one or more two-dimensional digital photographs, a set of one or more processed images with associated metadata for analysis, determine, for each image in the set of one or more processed images, a set of virtual-camera parameters that describe the position and orientation for a virtual camera that produces a generated image from the time-projected three-dimensional model of the patient's teeth equivalent to the image in the set of one or more processed images, generate, for each image in the set of one or more processed images, a generated image corresponding to the image from the time-projected three-dimensional model of the patients teeth and the virtual-camera parameters determined for the image, and compare each image in the set of one or more processed images with the corresponding generated image to generate a comparison value for the image and preparing, for each image, a teeth contour from the corresponding generated image;
• overlaying the teeth contour onto the image, generating a fitness metric for the image, corresponding image, and overlaid contour, wherein the fitness metric is based on a per-pixel cost equal to the normalized dot product of gradient vectors for the image and corresponding image computed for each pixel, determine, from the one or more comparison values, whether or not a configuration of the patient's teeth is within a threshold level of correspondence to the expected configuration of the patients teeth, and store an indication of the determination in one of the one or more electronic memories.