Hello, I can understand your concern. The blow or injury to face in the cheek area can cause swelling due to two possibilities. Sometimes the teeth that are present in the area get the blow and the blood supply in the teeth stops causing the tooth to become non-vital after some time. This tooth develops infection later due to presence of dead tissue within. As you rightly guessed, root canal treatment is needed in such cases to cure the infection and save teeth from extraction. However, a week is a short period of time to develop such problem. If you develop pain in these teeth after a month or so, do keep this possibility in mind. In addition, the zyomatic bone in the cheek area may get cracked or fractured due to the blow. Fractured bones tend to cause lot of swelling and pain. This possibility should be ruled out by visiting an oral surgeon for examination of the area and x-ray to rule out any such bone problem. The tooth xray taken at dentist s office may not show the area concerned here. This consultation should be done sooner than later as delay in treatment of possible crack or fracture can cause complications. If oral surgeon clears you of any bony pathology, then the swelling can be considered as just soft tissue swelling due to trauma and medications should be continued for relief. I hope this information helps you. Thank you for choosing HCM. I wish you feel better soon. Best, Dr. Viraj Shah