In a system (10) configured to localize gingival inflammation within a user's mouth, one or more light emitters (42) emit light at a plurality of locations within the user's mouth, one or more light detectors (40) generate reflectance data from a surface at each of the plurality of locations, a controller (30) determines, for each of the plurality of locations, whether the gingiva at that location is inflamed, and a user interface (46) provides information to the user regarding the inflamed location or locations.