Facial swelling (cellulitis) is a true dental/medical emergency.
If you notice swelling from your child's cheek extending towards the chin or up towards the eye, you should seek emergency attention immediately. Untreated dental infection can lead to negative health consequences, even if taking oral antibiotics to control infection until definitive treatment is completed.
If facial swelling or trouble breathing occurs (particularly in young children), then emergency medical treatment needs to be delivered as soon as possible - call for emergency medical services (9-1-1).
Often, emergency management will include intravenous (IV) management of the disease in a hospital environment before proceeding to the operating room or returning to the office for treatment. The dentist will be in contact with the admitting hospitalist to determine a plan once the immediate threats have been mitigated.