Feeling hard on the edge of the gums after wisdom teeth extraction may be due to local inflammation, or slight alveolar bone protrusion or displacement during the extraction process, or tooth fragments left behind during extraction, or it may be due to the growth of harder fibrous tissues in the gum area while the wound is healing. 1. Local inflammation: after wisdom teeth extraction, there is a wound in the gum area, which is prone to local inflammation, resulting in gum lumps, which can be treated with medication and other means, and can usually be eliminated in a week or so. 2. Alveolar bone protrusion or displacement: If the growth of wisdom teeth is not in a good position, oblique or lateral obstruction, it will affect the growth of the surrounding alveolar bone, and it may be necessary to remove part of the alveolar bone during extraction. This process may cause the surrounding alveolar bone to protrude or shift, resulting in hardened gums after extraction. Therefore, the alveolar bone needs to be reset or trimmed after wisdom tooth extraction. 3. Remaining tooth fragments: When wisdom teeth are extracted, improper operation may cause the teeth to break down and small tooth fragments may remain, which may lead to hardening of the gums. Therefore, after wisdom teeth extraction, you can check whether there are tooth fragments remaining through filming and other methods, so as to remove them in time. 4. Hard fibrous tissue growth: after wisdom teeth removal, the gum wound healing process may grow out of the harder tissue, resulting in hard packs, but this hard packs generally do not cause discomfort in the gums. After wisdom teeth removal, you should do a good job of oral care, regular medication, pay attention to cleaning, so as not to cause infection, resulting in other oral problems.