When the child’s tooth root is inflamed and the face is swollen, an oral examination should be conducted as soon as possible and a whole-mouth surface tomogram should be taken, and treatment should be carried out according to the patient’s condition, as follows: 1. If there is a large carious cavity in the crown of the affected tooth, and the bacteria cause a periapical infection through the exposed pulp, resulting in maxillofacial swelling, the pus can be drained out by grinding open the pulp cavity, and then the root canal can be thoroughly rinsed using a 3% hydrogen peroxide solution, and medicinal cotton pads are placed for disinfection,. When the swelling of the face is not easy to subside, the mucosa can be directly incised at the site of pus formation for drainage, and at the same time, the systemic application of antibiotics to promote anti-inflammatory; 2. If the child has only the tooth root left, and periodontal infection occurs around the residual root, antibiotics should be applied to anti-inflammatory first and then extracted the residual root, and then restored at a later date.