A bright white mark on a child’s tooth can be easy to miss until the lighting changes, a photo is taken, or the tooth dries after brushing. Some white spots are harmless differences in how enamel formed. Others are an early signal that a tooth is losing minerals and needs attention before a cavity develops. Because several conditions can look alike, the appearance of a white spot alone cannot tell the whole story. The useful question is not simply whether a spot is present, but when it appeared, where it…