The cracks in the corner of mouth won't heal. what do you recommend?

Angular Chelitis: You probably have angular chelitis though generally there is some itching or burning associated with it but not always. One thing that can cause this is eating a lot of acid containing foods like tomatoes or oranges. You might try using Hydrocortisone cream over the counter 4-5 times a day but will most likely need prescritption strength to clear it up. Your dentist is the best person to see.