There are several reasons why the tooth extraction is still painful for a week: 1. Bacterial infection: The residual tooth fragments, bone fragments and granulation tissue in the alveolar sockets can cause continuous bacterial infection, causing swelling and pain, and it is not easy to subside. 2. Large scope of trauma: Repeatedly pulling the soft tissues, separating the periosteum and grinding away part of the alveolar bone during tooth extraction, forming a large scope of trauma, triggering continuous swelling of the jaw and face. 3. Bone plate fracture: The alveolar When the bone plate on the buccal or lingual side of the socket is fractured, accompanied by capillary fracture, more blood will be leaked and the pain will last longer. 4. Dry socket: When brushing or rinsing too early or exercising vigorously, the blood clot on the extraction wound will be loosened and dislodged, causing dry socket, and the wall of the alveolar bone will be exposed in the oral cavity and become seriously infected, emitting putrid odor and unbearable pain and radiating to the head and face, which will take about 2-3 weeks to heal.