When an infant drops a tooth, a full-mouth surface tomogram should be taken and then treated. If the baby tooth is intact and completely dislodged, it can be immediately rinsed and disinfected with saline, reset under local anesthesia according to the occlusal relationship, ligated and fixed with a resin splint, and removed after the tooth is stabilized for about 3 months. If the x-ray shows that the crown of the baby tooth is fractured, the root of the remaining tooth can be closed after a one-time root canal treatment under local anesthesia and waiting for the eruption of the permanent tooth. If the crown of the baby tooth is fractured or the remaining root is short, the root can be extracted under local anesthesia, and a gap retainer can be made and worn to maintain the gap of the missing tooth and wait for the eruption of the succeeding permanent tooth.