How is your cat doing now? Is he still in pain from the tooth extraction?
Oh bless him, I expect he is a bit sore after the tooth extraction. Ring up vet if you are very concerned that he is still not eating, as that is a worry.
I had a cat the same age as yours, and I think, like humans (I am 71) it takes longer to get over things.
He is obviously unhappy at the moment. See how he goes, but if he continues like that, you will have to see vet again I should think. Oh such a worry.
Do hope he feels better soon. Let me know how he gets on.