Abstract: A spectrum analyzing method and a gingivitis evaluating device are provided. The spectrum analyzing method includes steps as follows. A diffuse reflection signal of a gingiva is calculated, and a gingiva spectrum is generated. The gingiva spectrum and a plurality of reference gingiva spectra are respectively applied with a time-series similarity calculation, and a plurality of similarity values are generated. The plurality of reference gingiva spectra correspond to various gingival indexes (GI). A minimum similarity value of the plurality of similarity values is obtained. A GI result is output according to the minimum similarity value.

Abstract: A mobile device for detecting an oral pathology includes a casing, a probing unit, and a processor. The probing unit includes a fiber bundle set and a contact part configured to contact a gum portion of a tooth of an examinate. The fiber bundle set includes a light source fiber bundle and a light-receiving fiber bundle. The light source fiber bundle has a light-exiting end within the contact part, and can project a probing light onto the gum portion. The light-receiving fiber bundle has a light-receiving end within the contact part. The light-receiving fiber bundle can receive diffuse reflection lights generated after the probing light is diffuse reflected by the gum portion. The processor is in signal connection with the light-receiving fiber bundle, and can receive the diffuse reflection lights, to build an optical spectrum, and to determine a state of the gum portion according to the optical spectrum.