Plans are generally not necessary to get a permit to do mechanical work on a dwelling. You will be expected to briefly describe the work proposed. For example, describe the appliance you intend to install and whether you will be installing a new vent, new ductwork, etc.
It depends on what kind of stitches the dentist used in your mouth. There are two types: stitches that resorb on their own and you don't need to do anything, and the other are stitches for which you see the dentist in about two weeks and he/she removes them. Ask your dentist which type he/she placed in your mouth.
After your tooth has been extracted, healing will take some time. Within 3 to 14 days, your sutures should fall out or dissolve. For sutures that are non-resorbable, your doctor will schedule a follow-up appointment to remove the stitches for you.