Older dog with swelling under eye

Question
We have a 12 year old female dog whom we came home today to find with swelling under her eye on one side of her face.  I suspect it is caused by an infected tooth.  She has really bad teeth, despite brushing, etc.  Anyway, since it is Saturday afternoon where we are, is it reasonable to wait to take her to the vet, or should we be taking her to the emergency vet now?  Thanks in advance for you advice!

Answer
I am sorry for the delay but my husband is in the hospital, Has he been able to eat hard dog food, or has there been signs of trouble that he is in pain and cannot chew, If he is suspected to have problems with his teeth then he would need a dental cleaning to get rid of the germs and plaque and so the doc can see his teeth and gums clearer, the doc and staff would probably give him medication in one of his legs to knock him completely out the nurse or vet tech would do the cleaning then the doc would go through each tooth and see how secure it is in the gum any loose teeth would be pulled and stitch the gums, he would also pull any tooth that he thought looked bad and then medicate him again, many dogs loose half the teeth in their mouths also the eye would also have to be  examined for any possible eye infections, You probably took your dog to the vet already, since it has been 2 days already but if you haven't been able to you should call a good vet and inform him of what is going on he might want you to give your dog antibiotics for a while until the infection clears up before doing a dental. I hope this helped, Sincerely Concerned, Angela