Intraoral scanner with dental diagnostics capabilities
Methods and apparatuses for generating a model of a subject's teeth. Described herein are intraoral scanning methods and apparatuses for generating a three-dimensional model of a subject's intraoral region (e.g., teeth) including both surface features and internal features. These methods and apparatuses may be used for identifying and evaluating lesions, caries and cracks in the teeth. Any of these methods and apparatuses may use minimum scattering coefficients and/or segmentation to form a volumetric model of the teeth.
1. A method for generating a three-dimensional (3D) volumetric model of a subject's teeth using an intraoral scanner, the method comprising:
taking a plurality of images into the teeth using an infrared (IR) wavelength with the intraoral scanner as the intraoral scanner is moved over the teeth, so that multiple images of a same internal region of the teeth are imaged;
determining, for each of the plurality of images into the teeth, a position of the intraoral scanner relative to the subject's teeth;
using the position of the intraoral scanner to determine a list of intensity values for each point of a plurality of points corresponding to an inner volume of the patient's teeth from corresponding points on each of the plurality of images into the teeth;
determining a minimum scattering coefficient for each point of the plurality of points from the list of intensity values; and
forming the 3D volumetric model of the subject's teeth including internal features using the minimum scattering coefficient for each of the plurality of points corresponding to the inner volume of the patient's teeth.
2. The method of claim 1 , wherein the IR wavelength comprises a near-IR wavelength.
3. The method of claim 1 , wherein forming the 3D volumetric model comprises including a model of the gums relative to the teeth.
4. The method of claim 1 , further comprising capturing a 3D color model of the teeth as the intraoral scanner is moved over the teeth.
5. The method of claim 1 , further comprising switching between taking the plurality of images into the teeth as the intraoral scanner is moved over the teeth and capturing 3D surface image data.
6. The method of claim 1 , wherein taking the plurality of images comprises using a same sensor on the intraoral scanner to capture a 3D surface model data and the plurality of images into the teeth.
7. The method of claim 1 , wherein taking the plurality of images into the teeth comprises taking small-angle penetrative images.
8. The method of claim 1 , wherein forming the 3D volumetric model of the subject's teeth comprises combing a 3D surface model data with a 3D model of the internal structure.
9. A method for generating a three-dimensional (3D) volumetric model of a subject's teeth using an intraoral scanner, the method comprising:
taking a plurality of images into the teeth using a near-infrared (near-IR) wavelength as the intraoral scanner is moved over the teeth by emitting a near-IR light from the intraoral scanner and detecting, in an image sensor in the intraoral scanner, the near-IR light returning to the intraoral scanner;
determining, for each of the plurality of images into the teeth, a position of the intraoral scanner relative to the subject's teeth when each of the plurality of images is captured;
using the position of the intraoral scanner relative to the subject's teeth to determine a list of intensity values for each point of a plurality of points corresponding to an inner volume of the patient's teeth from corresponding points on each of the plurality of images into the teeth;
determining a scattering coefficient for each point of the plurality of points from the list of intensity values; correcting the scattering coefficients according to a volume response, and identifying a minimum scattering coefficient; and
forming the 3D volumetric model of the subject's teeth including internal features using the minimum scattering coefficient for each of the plurality of points corresponding to the inner volume of the patient's teeth.
10. An intraoral scanning system for generating a three-dimensional (3D) volumetric model of a subject's teeth, the system comprising:
a hand-held wand having at least one image sensor and a light source configured to emit light at within a near-infrared (near-IR) range of wavelengths;
one or more processors operably connected to the hand-held wand, the one or more processors configured to:
take a plurality of images into the teeth using an infrared (IR) wavelength with the intraoral scanner as the intraoral scanner is moved over the teeth, so that multiple images of a same internal region of the teeth are imaged;
determine, for each of the plurality of images into the teeth, a position of the intraoral scanner relative to the subject's teeth;
use the position of the intraoral scanner to determine a list of intensity values for each point of a plurality of points corresponding to an inner volume of the patient's teeth from corresponding points on each of the plurality of images into the teeth;
determine a minimum scattering coefficient for each point of the plurality of points from the list of intensity values; and
form the 3D volumetric model of the subject's teeth including internal features using the minimum scattering coefficient for each of the points corresponding to the inner volume of the patient's teeth.
11. The system of claim 10 , wherein the hand-held wand comprises at least one additional secondary image sensor in addition to the image sensors.
12. The system of claim 10 , wherein the one or more processors is configured to determine surface information by using confocal scanning, stereo vision or structured light triangulation.
13. The system of claim 10 , wherein the hand-held wand is configured to cycle between emitting light at the near-IR wavelength to detect internal structures and emitting light at a second spectral range to perform a surface scan, by switching between the near-IR wavelength and the second spectral range so that images taken with the second spectral range share a coordinate system with the near-IR wavelength.
14. The system of claim 13 , wherein the image sensor is configured to capture both 3D surface model data and the internal data of the tooth.
15. The system of claim 10 , wherein the plurality of light sources comprises a white light light source.
16. The system of claim 10 , further wherein the plurality of light sources and the image sensor are arranged so that light emitted in the second spectral range is reflected from a tooth and received by the one or more sensors at an angle of between 0° and 15°.