Swelling in the absence of recent trauma is a sign that an infection is present. Such infections can quickly become life threatening when they spread outside your mouth and start to include your face and/or neck. Swelling in these areas have the ability to restrict your breathing and ability to swallow, making them a medical emergency. It is strongly recommended that if you are experiencing facial swelling, you seek immediate medical attention to avoid further complications. An endodontist can help when your airway is not obstructed. However, once your airway is compromised, the emergency room is best place to be treated.