When you fall on a tooth and it feels like the tooth is lengthening, the tooth has undergone a partial subluxation. Partial subluxation occurs when the tooth is partially dislocated and elongated along the long axis of the tooth toward the tangential end, and is often associated with pain, looseness, and bleeding in the gingival sulcus. It is recommended to visit the dentist to rule out root loosening by taking X-rays, and consider fixation after repositioning if necessary. If the tooth is painful with hot or cold stimulation, or spontaneous pain, root canal treatment is needed. If there is no obvious pain or discomfort, try not to bite with the tooth in the near future, observe it temporarily and try to keep the affected tooth. If you fall on the tooth, it is recommended to consult a doctor in time, through the examination of a professional doctor, after a clear diagnosis and symptomatic treatment, to avoid delaying the condition.