Gingivitis in children is mainly concentrated in the free gingiva and gingival papillae, and in severe cases, it can spread to the attached gingiva, and its main symptoms are as follows: 1. The gingival papillae are filled with blood in the interdental space, and the attached gingiva can be dotted with color; in severe cases, the gingival margin becomes thicker and no longer clings to the tooth surface, the gingival papillae are rounded and hypertrophied in the form of spherical hyperplasia, and can even cover part of the tooth surface, and the attached gingiva can disappear with a bright surface; 4. Gingival texture: the texture of normal gingiva is dense and tough, and in severe cases, the gingiva becomes flabby, fragile, and inelastic; when the gingiva is dominated by a proliferative reaction, it is tough When the gingiva is mainly proliferative reaction, it is tough, parenchymal hypertrophy, hard and elastic texture; 5, depth of the gingival sulcus: healthy gingival sulcus probing depth generally does not exceed 3mm, gingivitis can be up to 3mm or less in severe cases, but no attachment loss; 6, gingival sulcus probing bleeding: healthy gingiva does not cause bleeding when gingival sulcus is lightly probed, gingivitis can cause bleeding when severe; 7, gingival sulcus fluid amount: healthy teeth have a very small amount of gingival sulcus fluid, gingivitis serious gingival sulcus The amount of fluid increases, and sometimes there can be gingival sulcus overflow pus phenomenon.