There are many causes of parotid swelling and pain, such as pulpitis, jaw arthritis and mumps. 1. Pulpitis: The pulpitis can invade through the trigeminal nerve, causing maxillary or submandibular neuralgia, resulting in pain and swelling of the cheeks. 2. Mandibular arthritis: Swelling and pain in the cheeks of children may be related to mandibular arthritis. Children often have symptoms of pain in opening their mouths, and need to be examined by a doctor to confirm the diagnosis of mandibular arthritis and treat the symptoms. 3. Mumps: Children with poor immunity are vulnerable to certain viruses. The mumps virus can cause mumps, a self-limiting respiratory infection, which can be characterized by swelling and pain in both cheeks or in one side of the cheek. The child’s parotid swelling and pain may also be caused by other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to determine the cause of the disease, and then carry out targeted treatment.