The common causes of gum lumps are as follows: 1. Gum polyp: children’s gum recession is not completely caused by the formation of polyp because the tooth eruption position is not high enough, and the gum can return to the normal position by itself. If there is a cavity on the adjacent surface of the affected tooth, the polyp formed by the gingiva proliferating to the cavity, it is necessary to see whether the tooth has treatment value, if there is treatment value, root canal treatment can be done to repair the tooth, otherwise it should be extracted and do denture repair; 2, gingival tumor: generally caused by local factors such as dental calculus, food residue, etc., and stimulation or chronic inflammatory stimulation. First of all, food residues, calculus and other stimulating factors should be removed, if the gingival tumor does not recover on its own after removing the stimulus, surgical removal is required.