Intraoral scanner having tomographic imaging function and method for tomographic imaging of oral cavity using the same
An intraoral scanner having a tomography function capable of setting a tomography area using shape information of an oral cavity includes a shape measurement light projector that irradiates shape measurement light for obtaining a shape image of an oral structure; a shape measurement camera that obtains a surface shape image of the oral structure by detecting reflected light; an optical coherence tomography (OCT) body that transmits tomography measurement light to the oral structure and detect reflected light to obtain an internal cross-sectional image of the oral structure; an OCT scan probe that irradiates the tomography measurement light emitted from the OCT body onto a desired position of the oral structure and transfer the reflected light to the OCT body; and a beam splitter that superimposes optical paths of the shape measurement light irradiated from the shape measurement light projector and the tomography measurement light irradiated from the OCT scan probe.
1. An intraoral tomography method comprising:
sequentially irradiating pieces of shape measurement light onto an oral structure, detecting reflected light formed when the shape measurement light is reflected from a surface of the oral structure, and obtaining an entire image (T) of the oral structure;
setting a position of a region of interest (ROI) requiring tomography for the entire image (T) of the oral structure;
transmitting tomography measurement light along the set ROI, detecting reflected light reflected inside the ROI, and
obtaining an internal cross-sectional image of the ROI, wherein the internal cross-sectional image of the ROI is obtained by steps comprising:
irradiating the shape measurement light onto a part of the oral structure(S), detecting reflected light formed when the shape measurement light is reflected from a surface of the part of the oral structure(S), and obtaining a partial image (p) of the oral structure;
comparing the partial image (p) of the oral structure(S) with the entire image (T) of the oral structure(S), detecting a position of the partial image (p) in the entire image (T) of the oral structure(S), and detecting whether the ROI is present in the partial image (p);
transmitting the tomography measurement light to the part of the oral structure(S) onto which the shape measurement light has been irradiated, detecting reflected light reflected inside the oral structure(S), and obtaining an internal cross-sectional image of the oral structure(S); and
when the ROI is present in the partial image (p), registering the internal cross-sectional image, which is obtained from the part of the oral structure(S) onto which the shape measurement light has been irradiated, as the internal cross-sectional image of the ROI of the partial image (p).
2. The intraoral tomography method of claim 1 , wherein the ROI set in a surface shape image of the oral structure guides a path or area in which tomography is performed.
3. The intraoral tomography method of claim 1 , wherein the shape measurement light and the tomography measurement light are not irradiated simultaneously, and the tomography measurement light is irradiated immediately after irradiation of the shape measurement light is completed.
4. The intraoral tomography method of claim 1 , wherein, when the ROI is not present in the partial image (p), the internal cross-sectional image, which is obtained from the part of the oral structure(S) onto which the shape measurement light has been irradiated, is discarded.
5. The intraoral tomography method of claim 1 , wherein, after a cross-sectional image of the position of the partial image (p) is registered, the partial image (p) of the oral structure(S) is discarded without being separately stored.