Thank you for your query.
I can understand your concern. However, it is very difficult for me to say whether the dent in your daughter's case will be permanent or not without either examining or seeing a photograph. You are doing the right thing by seeing the doctor.
Most likely there might have been a fracture
of the cheek bone which was over looked due to the bruise
. Now that the bruise has disappeared the fracture may be evident. In most of the cases nothing needs to be done as there is no moveable joint on the cheek and it should heal in due course of time.
I hope I have answered your query to your satisfaction.
Wishing your daughter all the best.
Rajiv K Khandelwal