Patient: Description of the condition (onset time, main symptoms, hospital visited, etc.): Hello, Dr. Wang! My daughter is 2.5 years old and her incisors have lost 1/3 of their teeth from biting rocks when she was a child, and they are a bit black, and it hurts when you touch them. What is the best way to treat it? Wang Minyong, Department of Pediatric Stomatology, Peking University Stomatological Hospital Second Outpatient Department: This situation should belong to the dental trauma, after the trauma of the tooth becomes black or bite discomfort, may be the performance of dental nerve necrosis inflammation; this age of the child’s permanent incisors are developing, the corresponding long-term chronic inflammation of the milk teeth may affect its normal development. Therefore, it is recommended that you take your child to a specialist for examination and treatment in a timely manner. In case of nerve necrosis, root canal treatment will be required to control the inflammation and avoid spilling over to the permanent teeth.